Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 
  Home Print this page Email this page Small font sizeDefault font sizeIncrease font size Users Online: 549  

 
   Table of Contents      
POSTER PRESENTATIONS
Year : 2018  |  Volume : 17  |  Issue : 5  |  Page : 49-342

Posterpresentations


Date of Web Publication21-Sep-2018

Correspondence Address:
Login to access the Email id


Rights and Permissions

How to cite this article:
. Posterpresentations. World J Nucl Med 2018;17, Suppl S1:49-342

How to cite this URL:
. Posterpresentations. World J Nucl Med [serial online] 2018 [cited 2019 Sep 19];17, Suppl S1:49-342. Available from: http://www.wjnm.org/text.asp?2018/17/5/49/241904




   Poster Presentations - Saturday Top



   Endocrinology Top



   P001: Discordant Thyroglobulin and Diagnostic 131I Whole-Body Scan in Differentiated Thyroid Carcinoma: The Clinical Value of Nuclear Medicine Top


Emily Mia C Acayan*1, R Ogbac1

1St. Luke’s Medical Center, Quezon City, Philippines

Background/Aims: The overall 10-year survival rate for middle-age adults with differentiated thyroid cancer declines to 40% in the presence of distant metastasis. A 34 year old female patient, diagnosed with follicular thyroid cancer, having had completion thyroidectomy and multiple radioiodine therapies, and appearing to be disease-free for six years, presented with elevated thyroglobulin but negative diagnostic 131I whole body scan. Methods: 18F-FDG positron emission tomography showed probable locoregional nodal metastases. Empiric therapy with 5550 MBq 131I was given for ablation. Results: Post-radioiodine therapy whole body scan with single-photon emission computed tomography/computed tomography done two days after oral administration revealed multiple osseous metastases with no lesions in locoregional nodes. Conclusion: This case discusses the most common tools used in monitoring thyroid cancer recurrence and metastasis. Emphasis is given on the clinical utility of thyroglobulin, the advantage of optimal thyroid stimulating hormone level prior to diagnostic tests, the role of empiric 131I therapy, and the value of post-radioiodine therapy whole body scan with single-photon emission computed tomography/computed tomography.


   P002: 13-Year Outcomes after Low versus High Activity of Radioiodine to Ablate the Thyroid after Thyroidectomy for Cancer: A Prospective Randomized Study Top


Veera Ahtiainen*1, L Vaalavirta1, M Tenhunen1, H Mäenpää1

1Cancer Center, Helsinki University Hospital, Helsinki, Finland

Background/Aims: The optimal activity of radioiodine (131I) in papillary and follicular thyroid cancer following thyroidectomy remains unknown in long term follow-up. Some, shorter follow-up studies suggest that activities 1.1 GBq and 3.7 GBq are considered equally effective. We evaluated the long term outcomes of primary ablation to extend current knowledge about the optimal ablative dose of I-131. Methods: In our cohort, 160 adult patients (129 females, 31 males; mean age 46±14 years, range 18-89 years) diagnosed with histologically confirmed papillary or follicular thyroid cancer, were randomized in prospective, phase III, open-label, single-center study, during 2000-2004, to receive either 1.1 GBq or 3.7 GBq of I-131 after thyroidectomy. At randomization, patients were stratified according to the histologically verified cervical lymph node status, and were prepared for ablation using thyroid hormone withdrawal. No uptake in the whole body scan with I-131 and thyroglobulin concentration <1 ng/mL at 4-8 months after treatment was considered successful ablation. Results: Median follow-up time was 13.02 years (mean 11.03±4.80 years; range 0.33-17.13 years). Altogether 81 patients received 1.1GBq, ablation was successful in 45 (56%) after one administration of I-131 and 36 (44%) needed one or more administrations to replete the ablation. Of these, 4 (8.9%) and 5 (14%) patients were later relapsing respectively. Of the 79 patients treated with 3.7 GBq 45 (57%) had successful ablation after one administration and 34 (43%) needed several treatments. Of these, 2 (4.4%) and 9 (26.5%) patients were relapsing respectively. Of these 79 participants, three died from thyroid cancer during the median follow-up of 13 years. Activity groups did not differ in the proportion of patients relapsing (p=0.951). Conclusion: During follow-up of median 13 years 1.1 GBq is as effective as 3.7 GBq for ablation of the thyroid remnant.


   P003: The Evaluation of Protective and Mitigating Effects of Vitamin C against Side Effects Induced by Radioiodine Therapy Top


Mehrosadat Alavi*1, E Jafari2, M Haghani1

1Ionizing and Non-Ionizing Radiation Protection Research Center, Shiraz University of Medical Sciences, Shiraz, 2Department of Medical Physics, Islamic Republic of Iran

Background/Aims: The goal of this study, in addition to confirming that ionizing radiation in differentiated thyroid cancer (DTC) patients ablated with radioiodine causes stress oxidative, was to evaluate protective and mitigative effect of vitamin C on this phenomenon. Methods: 58 DTC patients for radioactive iodine therapy (RAIT) by 5550 Mbq Iodine-131 were divided into four groups. Group one (control group) were 16 patients who underwent RAIT, routinely. Groups 2, 3 and 4 received 1500 mg vitamin C daily 2 days after, 2 days before to 2 days after and 2 days before RAIT, respectively. Serum oxidative stress markers including malondialdehyde (MDA), glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) were measured immediately before and 2 days after RAIT. Results: A significant increase in MDA after RAIT was observed in all groups (p<0.05). The concentrations of MDA were significantly higher in the control group compared to the intervention groups (p<0.05). A significant decrease in the control group (p=0.049) and increase in group 4 (p=0.026) were observed in GSH level after RAIT (p<0.05). Mean variation of GSH was significant between control group with groups 3 (p=0.008) and 4 (p=0.003). The results indicate that activity of SOD remained unchanged in all groups (p>0.05). A significant increase was observed in CAT activity after RAIT in all groups (p<0.05), which was higher in control group than intervention groups. In groups 3 (p=0.043) and 4 (p=0.05), this increase in CAT activity was significantly lower than the control group. Conclusion: RAIT causes serum oxidative stress, which can be ameliorated by using vitamin C as an antioxidant. These results indicate that radioprotective effect of vitamin C is preferable to its mitigative effect.


   P004: Prevalence of Genetic Duet and its Influence on the Prognosis of Differentiated Papillary Thyroid Carcinoma Patients Top


C S Bal*1, S Ballal1, S Shakya1, S Mathur2

Departments of 1Nuclear Medicine and 2Pathology, AIIMS, New Delhi, India

Background/Aims: The primary objective of the study was to investigate the prevalence of BRAFV600E and TERT promoter mutations in papillary thyroid cancer and secondary objective was their correlation with various clinicopathologic features in the Indian population. Methods: A retrospective study of 160 pathologically proven papillary thyroid cancer patients including 105 women and 55 men with a median age of 35 years (range 13–77 years) was conducted in the Department of Nuclear Medicine, AIIMS, New Delhi, India. The study period was from the year 2008 to 2016 with a mean follow-up of 32.7 months (12-101 months). Univariate and multivariate analysis was performed to determine the association of BRAFV600E and TERT promoter with clinicopathologic features. Prognostic factors affecting the event-free survival were analysed by Kaplan-Meier curves. Results: The prevalence of BRAFV600E mutation was in 33% (53/160) and TERT mutation in 17.5% (28/160) of patients. Both mutations (genetic duet) were co-existent in 19 (11.8%) of patients. No mutation (wild type) was detected in 98/160 (61.3%) PTC patients. Interestingly, no mutation was detected in follicular variant of PTC (0/28) compared to 40% in classic PTC. Prognosis: compared to wild type, BRAFV600E alone or TERT alone showed significant associated with extrathyroidal extension (p=0.030), radioiodine (RAI) refractory persistent disease (p=0.0393) until end of follow-up (p=0.017). Patients with co-existing mutations were significantly associated with poorer outcome. Kaplan-Meier graph depicts the association of wild-type versus various mutations with event-free-survival. Conclusion: Patients with co-existing BRAFV600E and TERT mutations showed the worst clinicopathologic outcomes. The detection of these mutations paves path for the early treatment of RAI refractory disease patients with alternate therapeutic options.


   P005: Evaluation of Recurrent Thyroid Carcinoma by High-Resolution Ultrasonography Where 131I Whole-Body Scan Is Negative and Normal Thyroglobulin Level Top


Shankar Biswas*1, F Haque1, F Rahman1, M Islam1, S Hossain1

1Department of Nuclear Medicine and Ultrasound, Institute of Nuclear Medicine and Allied Sciences, Bangladesh Atomic Energy Commission, Dhaka, Bangladesh

Background/Aims: Total thyroidectomy followed by radioiodine therapy (RIT) and life long hormone replacement is the routine protocol of differentiated thyroid cancer management. During follow up usually we consider serum thyroglobulin (Tg) and whole body scan (WBS) with 131I. This study was designed to unravel the impact of ultrasonography in patients with recurrent thyroid cancer where WBS was negative and normal Tg level. Methods: We enrolled ten patients (age 36±13 years; 9 female) who were attended to Institute of Nuclear Medicine & Allied Sciences (INMAS), Dhaka for routine follow up. All patients were sent for further management after total thyroidectomy. Thyroid scan with 99mTc and other relevant laboratory tests were performed initially. RIT was given according to our institutional protocol. During follow up at certain intervals WBS with 4 mCi 131I and Tg level were evaluated. Along with these, neck palpation and high resolution ultrasound were done routinely for specific features of metastasis (i.e loss of hilar fat, rounded shape & micro calcification). Results: All of them had differentiated papillary thyroid carcinoma. Two patients needed revision surgery for removing residual tissue. Lymphovascular invasion was present in 4 patients and substantially they needed radical neck dissection. Four patients needed nodal dissection for the 2nd time. Six patients took 150mCi radioiodine, one patient 75mCi, one patient 50mCi, and remaining patient underwent operation abroad and had 30mCi. Six patients needed radioiodine ablation twice. Tg level at the time of recurrent disease was 6.5±3.85ng/ml (Normal range 6.45-20.27ng/ml) and all of them showed normal findings in WBS. Conclusion: During routine check up not only Tg & WBS, neck palpation and high resolution ultrasound played pivotal role for evaluating nodal metastasis where WBS and Tg level were unfavourable. This work may open new research window.


   P006: Risk Stratification with Various Prognostic Scoring Systems in Follicular Thyroid Cancer Top


Shazia Fatima*1, S Butt1, A Ammar1, K Mir1, M Faheem1

1Nuclear Medicine, Oncology and Radiotherapy Institute, Islamabad, Pakistan

Background/Aims: Risk stratification in well-differentiated thyroid cancer is based on various available prognostic scoring system which help in differentiated thyroid cancer management. Most of the prognostication data available in literature comprises of papillary thyroid cancer but very few have addressed this issue in patients with follicular thyroid cancer (FTC) alone. Moreover, there are several limitations in existing prognostic scoring systems. These systems only address survival rates and not recurrence, and as the number of deaths from thyroid cancer is small, this poses a restriction in the use of the current risk stratification systems. The aim of this study was to establish the accuracy of the various scoring systems in risk stratification disease specific survival of FTC patients in Pakistan. Methods: Retrospective review was undertaken of 76 patients with FTC treated at a Nuclear Medicine, Oncology & Radiotherapy Institute (NORI) Islamabad, between January 2006 to December 2016. Demographic, clinical, pathological and treatment outcomes were analysed. Prognostic scoring systems evaluated for the cohort included TNM, AGES, MACIS, AMES, NTCTCS, clinical scoring system, Ankara Scoring System and EORTC (European Organisation for Research and Treatment of Cancer). Statistical analysis was performed by plotting Kaplan–Meier survival curves and using the Cox proportional hazards model. Results: There were 17 male and 59 female patients with a mean age of 45 years. The mean follow-up duration was 56 months and there were 7 deaths (9.21%). The ten-year overall survival rate was > 76%. Factors predictive of survival on univariate analysis were age, size of tumour, invasiveness, completeness of resection, metastasis, and risk scores using the TNM, Clinical Scoring and MACIS scoring systems (p<0.05). On multivariate analysis, AGES and MACIS provided the best prognostic information. Conclusion: MACIS is the best prognostic scoring system currently available for FTC and it is superior to other scoring systems in term of guiding management. TNM, NTCTCS and clinical scoring also provided useful information in guiding the clinical management. The scoring systems require alterations to address the variations in regional clinical practice and to improve the prognostic power.


   P007: The Role of Air Pollution in the Incidence and Mortality of Thyroid Cancer in 27 Countries of the European Union for the Years 1992, 2002, 2012 Top


E Giannoula1, S Frangos2, I Katsikavelas3, G Giannoula4, Ioannis Iakovou*1

1Department of Academic Nuclear Medicine, Papageorgiou Hospital, Aristotle University, 2Aristotle University of Thessaloniki, Thessaloniki, Greece, 3Bank of Cyprus Oncology Center, Nicosia, Cyprus, 4Faculty of General Medicine, Comenius University, Bratislava, Slovakia

Background/Aims: During past decades, an increasing incidence of TC has been reported, while its mortality is almost constant and comparatively low. It is currently unclear whether the observed increases are real or due to increased diagnosis, as there exist many analyses stating a real increase in the incidence and mortality of TC of all sizes and stages, with different distribution depending on gender, race, age and environmental conditions. Recent studies are examining risk factors such as diet and exercise, benign thyroid diseases as well as genetic factors. There are only few epidemiological studies examining the effects of exposure to chemical agents. Therefore, the study of environmental factors, potentially influencing the onset and prognosis of TC, such as air pollution is a research field of great interest. The aim of this study is to investigate the role of air pollution in the incidence and mortality from TC in 27 countries of the EU for the years 1992, 2002, 2012. Methods: This is an analytical, ecological, observational study. There were conducted a thorough literature review, data collection from online databases, statistical processing and analysis. This ecological study used age-adjusted incidence and mortality rates of thyroid cancer for the year 2012 with respect to 23 air pollutants as well as 179 socioeconomic confounding factors in the EU for the above years. Results: Data analysis revealed a positive correlation between male incidence of 2012 and male mortality of 1992 of TC and levels of benzo(k)2fluoranthene (BKK) (p=0,04, r2=0,21) and mercury (Hg) (p=0,04, r2=0,17) respectively. Socioeconomic factors examined as confounders, presenting a positive correlation between male incidence of 2012 and Gross-National-Income-per-capita (NIPC), purchasing-power-parity as well as between male mortality of 1992 and adjusted-net-NIPC, adjusted-net-NIPC, hospital-beds-per-1,000-people, Gross-Domestic-Product, Gross-NIPC and purchasing-power-parity. Multiple linear regression did not reveal any statistically significant correlation between the above epidemiological and confounding factors. Conclusion: A positive correlation between the incidence and mortality of TC and BKK & Hg levels was revealed. Although higher socioeconomic status was associated with increased incidence and mortality, no apparent confounding effect was detected in TC’s correlation to air pollution.


   P008: The 131I Radiotherapy Effect and Prognosis of Differentiated Thyroid Carcinoma Complicated by Abnormal Thyroid Autoimmunity Top


Ge Hua*1, W Chen1

1Department of Nuclear Medicine, Fujian Provincial Hospital, Fuzhou, China

Background/Aims: To explore the patients’ recurrence or metastasis status and prognosis of the coexistence of autoimmune thyroid disease (AITD) with differentiated thyroid carcinoma (DTC), explain the association between DTC and the abnormal thyroid autoimmunity. Methods: 132 patients with DTC who had undergone thyroidectomy with positive TgAb were divided into two groups as A1 (n=84) and A0 (n=48) according to whether the patient present with concurrent AITD or not. Evaluation of the patients’ recurrence or metastasis status according to 131I whole body scan (131I-WBS), SPECT/CT and ultrasound examination. Compared TgAb levels, the incidence of recurrence or metastasis, and the median time for disappearance of TgAb between the two groups. Results: Of the 132 DTC patients with positive TgAb, 84 (63.3%) were concurrent with AITD. There was no significant difference between the two groups (t=-1.613, p=0.110) in TgAb levels. The incidence of recurrence or metastasis between group A1 and group A0 were 42.9% (36/84) and 22.9% (11/48) respectively, the difference was statistically significant (x2=5.297, p=0.021). The median time for disappearance of TgAb of the patients who had followed-up regularly in 6-27 months (n=85) were 12.75 months in group A1, and 20.74 months in group A0, the difference was statistically significant (p=0.040). Conclusion: The existence of elevated levels of TgAb in DTC patients may indicates the coexistence of AITD. DTC patients concurrent with AITD probably have a greater incidence of recurrence or metastasis, while the enhanced thyroid autoimmune reactions may also produce a protective effect on the prognosis of DTC patients.


   P009: False-Positive Thymus Uptake on 131I Posttherapeutic Scan of Differentiated Thyroid Carcinoma Patients in Two Therapeutic Nuclear Medicine Departments Top


Ionnis Iakovou*1, E Giannoula1, P Exadaktylou2, N Papadopoulos2, V Chatzipaulidou2, S Frangos3

1Department of Academic Nuclear Medicine, Papageorgiou Hospital, Aristotle University, 2Department of Nuclear Medicine, Theagenio Hospital, Thessaloniki, Greece, 3Bank of Cyprus Oncology Center, Nicosia, Cyprus

Background/Aims: To identify clinical conditions closely associated with thymic uptake on 131I post-therapeutic scan in patients with differentiated thyroid carcinoma (DTC). Methods: Post-therapeutic 131I whole body and SPECT or SPECT/CT scans of 599 consecutive patients were retrospectively reviewed. Radioiodine thymus gland uptake (RTU%), was observed in 16 (3.1%) patients (3 male). Although, without histological confirmation, all patients had a CT scan suggestive of residual thymus. A possible relation with age, sex, type and TNM stage of DTC, total administered 131I dose, number of therapies, type of TSH stimulation (withdrawal or rhTSH), TSH, Tg, TgAb levels was assessed. Results: Mean age of patients with thymic uptake was significantly lower (p<0.001). LT4 withdrawal and repeated 131I therapies also proved to be significant indicators for RTU% (p=0.03). Logistic regression analysis revealed that only the repeat radioiodine therapies and young age were correlated with RTU% (p<0.001). Conclusion: Especially in young patients with repeated 131I therapies, physiological radioiodine concentration by the thymus gland is a potential cause of false positive post-therapy 131I scans.


   P010: Clinical and Image Parameters Associated with the Total Absorbed Dose Assessed by Iodine Scan-Based Dosimetry in Differentiated Thyroid Cancer Patients Top


Zeenat Jabin*1, S Y Kwon1, S W Yoo2, Henry H S Bom1

1Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, 2Department of Nuclear Medicine, Chonnam National University Hospital, Gwangju, Republic of Korea

Background/Aims: To assess clinical and image parameters associated with the total absorbed dose assessed by iodine scan based dosimetry in differentiated thyroid cancer (DTC) patients. We performed I-131 whole body scan (WBS) based dosimetry in postoperative radio-active iodine (RAI) ablated DTC patients of Chonnam National University Hwasun Hospital (CNUHH). Methods: Ongoing research work with 38 thyroidectomized DTC patients till now. Study subjects had first RAI therapy after TSH stimulation with recombinant human thyrotropin (rhTSH). Patients with high serum anti-Tg antibody (TgAb, ≥ 100 U/mL), TSH stimulation with thyroid hormone withdrawal and extensive metastases were excluded. Three sequential WBSs on post ablation days 2 and 7 (2 scans on D2 and 1 on D7) and corresponding serum Thyroglobulin (Tg), TgAb and TSH were measured on therapy day (D0), D2 and D7. Residence times of remnant thyroid tissues were calculated using a dosimetric toolkit and total absorbed doses with OLINDA/EXM software. Patients were classified in Group 1 (total absorbed dose ≤145) and group 2 (>145) for further analysis and comparison with D7Tg. Results: Thirty patients (M=10, F=20) were eligible for preliminary analysis; 15 in group 1 and 15 in group 2. Total absorbed doses in thyroid bed remnants calculated in this study fall into a wide range (36-1347 mSv/MBq) with a mean (± SD) of 242.33±28. Based on univariate analysis, D7Tg (4.27±9.81 vs. 33.81±65.81; p<0.000) and thyroid count (1.78±0.74 vs. 5.59±2.45; p<0.000) were significantly higher in group 2. On the other hand, gender, tumour (T) stage, lymph node (N) stage, primary lesion size, multiplicity or bilaterality of primary tumour, positive BRAF mutations were not significantly different in the two groups. Conclusion: Higher Tg level and neck activities on post-therapy I-131 scans were associated with the total absorbed dose. Survival analysis will be done in the patient groups.


   P011: The Value of Thyroglobulin Antibody in the Treatment of Differentiated Thyroid Carcinoma Top


Liting Jia*1, J Zhang2, Q Ruan2, K Sun2, X Ma1, X Meng1

1Clinical Laboratory, Third Affiliated Hospital of Zhengzhou University, 2Department of Nuclear Medicine, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China

Background/Aims: The aims of the study were: 1) to investigate the relationship between the level of TgAb and its recurrence or metastasis in patients with differentiated thyroid carcinoma (DTC) after surgery and 131-iodine (131I) treatment; and 2) to evaluate the diagnostic value of TgAb in the post-operation of DTC and 131I treatment. Methods: A total of 253 post-surgical patients with DTC were divided into two groups, respectively the metastasis group and non-metastasis group, according to pathology, imaging diagnosis (including 131I-SPECT/CT tomography, CT, MRI, ultrasonography, etc.) and clinical follow-up. The level of TgAb in the stimulated serum of the abovementioned two groups were measured and analysed with independent t test. Out of all patients studied, 46 patients with positive level of TgAb and undertook repeated 131I treatments were selected and divided into cured or improved group (i.e. effective group) and no change or aggravated group (i.e. ineffective group). The level of TgAb in these two groups were continuously monitored and analysed with chi-square test. Results: Overall, 18.9% of all patients studied were identified as TgAb positive. The percentage of TgAb positive patients in the metastasis group and non-metastasis group were 11.7% and 21.6%, respectively. The level of TgAb in the metastasis group were 153.96±550.52 IU/mL, and that in the non-metastasis group were 190.01±515.67 IU/mL. There was no statistical significance in the difference between the level of TgAb in the metastasis group and non-metastasis group (t=-0.514, p=0.608). Continuous monitoring found that the level of TgAb in the effective group increased in 3 cases and decreased in 24 cases, while the level of TgAb in the ineffective group increased in 15 cases and decreased in 4 cases. The changes in the level of TgAb in these two groups was statistically significant (x2 =21.546, p<0.001). Conclusion: TgAb positive is of little value in the diagnosis of the recurrence or metastasis of DTC. However, the continuous decrease of TgAb can indicate the decrease in the size or number of lesions, while the continuous increase may signal the increase in the size or number of lesions.


   P012: Radioactive Iodine Therapy in Papillary Thyroid Carcinoma with Moyamoya Disease: A Case Report Top


Andrew Kalaw*1

1Cardinal Santos Medical Center, San Juan, Philippines

Background/Aims: Papillary thyroid carcinoma is the most common histological subtype of thyroid carcinoma. Management primarily is surgical with post-operative radioiodine therapy to ablate thyroid tissue remnants. Although the management of uncomplicated papillary thyroid carcinoma is well established, treatment of patients affected with Moyamoya disease as a co-morbidity is limitedly described. There are concerns with regards to doing radioactive iodine radiation which might affect the diseased arteries in Moyamoya disease. We present a patient with a known case of Moyamoya disease who developed papillary thyroid carcinoma and was subjected to radioactive iodine therapy post-operatively. Methods: We report a case of a 36-year old male, previously diagnosed with Moyamoya disease, who noticed an enlarging anterior neck mass. Biopsy revealed papillary thyroid carcinoma and subsequent total thyroidectomy was performed. The patient underwent radioactive iodine therapy with a dose of 5.7 GBq (155.0 mCi). There were no complications encountered in relation with the patient’s Moyamoya disease. Post-ablation scan was done showing functional thyroid tissue remnants in the lower anterior neck with suspicious distant tracer-avid focus. He was then maintained on levothyroxine 50 mcg daily and was advised short interval scintigraphic monitoring. Results: Surgery with post-operative radioiodine therapy is still the treatment of choice for the patient given his risk assessment. The Moyamoya disease co-morbidity of the patient was considered and did not resulted in radiation induced arteritis or any other complications during high dose post-operative radioiodine ablation therapy. Conclusion: Our patient with Moyamoya disease who developed papillary thyroid carcinoma reports no complications almost one year after he had undergone surgery and radioactive iodine therapy.


   P013: The Midline Uptake on Postablation Whole-Body Scans Is Related to the Enhanced Ability to Accumulate 131I in Patients with Differentiated Thyroid Carcinoma Top


Ying Kou*1, A Kuang1

1Department of Nuclear Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China

Background/Aims: To evaluate the clinical characteristics and implications of midline uptake on post-ablation whole body scans (Rx-WBS) after initial 131I ablation. Methods: Differentiated thyroid cancer patients, underwent initial 131I ablation after total thyroidectomy, without metastasis on Rx-WBS or other imaging studies, followed up 6 months after remnant ablation, were enrolled in our study. Two groups were classified according to midline uptake above the thyroid bed on Rx-WBS: group 1 was negative (only thyroid remnants on the thyroid bed); group 2 was positive (midline uptake above thyroid bed). Patients with star artifact or any other ambiguous Rx-WBS findings and positive thyroglobulin antibody were excluded. The baseline characteristics and follow-up results after initial remnant ablation between two groups were analysed. Response-to-therapy system was based on 2015 ATA guidelines. Results: A total of 160 patients were studied, and female patients were more than male patients (140 vs. 20). 81 patients were in group 1 and 79 patients were in group 2. Based on univariate analysis, baseline characteristics, such as age, sex, stimulated thyroglobulin before 131I ablation, risk stage and recurrence risk stage were not significantly different. But the positive rate of thyroid scintigraphy (χ2=17.587, p=0.001) and thyroid radioiodine uptake rate (2.69±1.59 vs. 4.25±4.01, t=-4.208, p=0.001) were significantly higher in group 2. The success rate of 131I remnant ablation (χ2=1.011, p=0.315) and response-to-therapy (χ2=1.05, p=0.592) were not significantly different, too. Conclusion: The midline uptake on post-ablation whole body scans is related to enhance ability to accumulate 131I, but which is not related to success rate and response assessment of initial 131I ablation.


   P014: Clinical Impact of 68Ga-DOTATATE Positron Emission Tomography/Computed Tomography Imaging in Medullary Thyroid Carcinoma Top


Jolanta Kunikowska*1, D Pawlak2, K Ziemnicka3, M Ruchała1, L Królicki1

1Department of Nuclear Medicine, Medical University of Warsaw, Warsaw, 2Radioisotope Centre POLATOM, National Centre for Nuclear Research, Otwock, 3Department of Endocrinology, Metabolism and Internal Diseases, Poznan University of Medical Sciences, Poznan, Poland

Background/Aims: Medullary thyroid carcinoma (MTC) is a rare thyroid carcinoma developing from parafollicular C-cells secreting calcitonin and carcinoembryonic antigen (CEA). Imaging techniques in the diagnosis of MTC is still problematic. Seventy-five percent of MTCs reveal overexpression of somatostatin receptors (SSTR), so it is promising nuclear medicine imaging techniques. The aim of the study was to determine the usefulness of PET/CT imaging of somatostatine receptors with 68Ga-DOTATATE in patients with medullary thyroid carcinoma. Methods: This was a prospective study approved by the Ethical Committee of Medical University of Warsaw. 12 patients (6 males and 6 females, age 54.7 ± 16.1) with histologically proven MTC were enrolled in the study. The clinical indication for imaging was the preoperative staging in three of them and the suspicion of recurrence after surgery in the remaining group. All patients underwent somatostatin receptor imaging (SRI) with 68Ga-DOTATATE PET/CT (60 minutes post 120-160MBq injection). PET/CT findings were compared with histopathological examination or clinical follow-up. Results: All patients had rising calcitonin levels with the median calcitonin level of 202.7 pg/ml (N<10 pg/ml). The CEA level was normal in 5 patients and elevated with median 10.4 ng/ml (N<5.0) in the rest. 68Ga-DOTATATE PET/CT was positive in 11 patients, negative in one patient. All patients with primary tumours had positive examinations. The patients with the recurrence of the disease had a positive uptake in the lymph node. 68Ga-DOTATATE PET/CT was true positive in 9 patients, true negative in one patient and false positive in 2 patients. The sensitivity, specificity, positive and negative predictive values were 90%, 33.3%, 81% and 100% respectively. There was no correlation between the calcitonin and CEA level and the result of 68Ga-DOTATATE PET/CT. Conclusion: Results of our report indicate that 68Ga-DOTATATE PET/CT is a promising tool for the imaging of MTC.


   P016: The Effect of Retinoid Acid in the Ability of Cold Thyroid Solid Nodule to Take Up Radioactive Iodine: A Preliminary Study Top


Andreas Lim*1, H Budiawan1, B Darmawan1, B Hidayat1, H Sukandar2, A H S Kartamihardja1

1Dr. Hasan Sadikin General Hospital, 2Universitas Padjadjaran, Bandung, Indonesia

Background/Aims: Most of thyroid nodules are benign nodules that require no surgery. One of the treatment options for benign thyroid nodules is radioactive iodine (RAI). However, this treatment is more effective for hot/warm thyroid solid nodules. Cold thyroid solid nodules are characterized by the lack of iodine uptake compared to normal thyroid tissue. Oral retinoid acid (RA) is a synthetic derivatives of vitamin A. The effect of RA to the uptake of radioactive iodine is still controversial. The aim of this study was to evaluate the effect of RA in the ability of cold thyroid solid nodule to take up RAI. Methods: Subjects with solid thyroid nodule and less iodine uptake based on ultrasonography and thyroid scintigraphy were included. Subjects with liver dysfunction, smoking, and pregnant were excluded. Each subject underwent thyroid uptake scintigraphy twice (pre- and post- RA consumption) using 35 – 37 MBq NaI-131. Subjects consumed RA with dose of 1 mg/kg BW for 2 weeks followed with 1.5 mg/kg BW for the next 4 weeks. This study was approved by Dr. Hasan Sadikin General Hospital Ethic Committee. Results: There were 12 subjects included in this study, 2 subjects were dropped off. A total of 12 cold thyroid solid nodules were evaluated from 10 subjects. The mean percentage of the nodules uptake value pre- and post-intervention were 1.11% and 0.62% respectively (p=0.004), while normal thyroid tissue uptake value pre- and post-intervention were 27.57% and 13.40% respectively (p=0.002). The percentage alteration of nodules and normal thyroid tissue uptake value were 42.4% and 51.5% lower respectively (p=0.354). Conclusion: This study showed that RA reduce the ability of cold thyroid solid nodule to take up RAI as well as normal thyroid tissue.


   P017: Revisiting the Value of Postablation 131I Whole-Body Scintigraphy in Children with Thyroid Cancer Top


Bin Liu*1

1Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China

Background/Aims: The value of post-ablation 131I whole body scintigraphy (PAS) is less described in staging and initial risk-stratification of children with thyroid cancer. The current study was designed to determine the diagnostic value of PAS during initial staging and risk-stratification in children with thyroid cancer. In addition, the relation between the pre-ablation stimulated Tg levels and PAS findings was examined. Methods: From August 2009 to December 2015, consecutive children with thyroid cancer undergoing remnant ablation was retrospectively recruited. A lung computed tomography was performed for each child within 2 weeks of the initial diagnosis of thyroid cancer for examination of metastatic lesions. PAS was obtained 5 days after administration of ablation activity of 131I. ROC curve analysis was employed to find a cutoff level of pre-ablation stimulated Tg as a predictor of distant metastases at the time of ablation. Results: Fifty-seven children were eligible for the analysis. Initial lung CT showed that pulmonary metastases in 15 (26%) children. Metastases were noticed on PAS in 20 (35%) children: 5 post-operative residual neck lymph node metastases, 4 post-operative residual neck lymph node and lung metastases, 3 mediastinal lymph node and lung metastases, 8 lung metastases. None of the children staged pN0 or M0 was found to have unexpected regional and distant metastasis. Neither staging nor initial risk-stratification was altered after completing PAS in study cohort. A significant difference in pre-ablation stimulated Tg levels was found in children with distant metastases compared with those without distant metastases, 5.7 vs. 603.5 ng/mL, respectively. A pre-ablation s-Tg level of 156 ng/mL was established as the optimal cutoff point to predict distant metastases. Conclusion: The role of PAS in improving staging or initial risk-stratification was minimal in children with thyroid cancer. A relationship was observed between pre-ablation stimulated Tg levels and PAS findings, indicating that pre-ablation stimulated Tg could potentially act as a predictor of distant metastases at the time of ablation in children with thyroid cancer.


   P018: Distribution and Association of Preablation Stimulated Thyroglobulin and Clinical-Pathological Characteristics Top


Bin Liu*1

1Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China

Background/Aims: The prognostic role of pre-ablation stimulated thyroglobulin (s-Tg) in thyroid cancer has attracted increasing attention. The current study was designed to investigate the distribution and association of post-operative pre-ablation s-Tg and clinical-pathological characteristics. Methods: From January 2013 to July 2015, consecutive thyroid cancer patients undergoing remnant ablation was retrospectively recruited. All patients have had to undergo total thyroidectomy and in all cases, no grossly visible thyroid remnants remained. Pre-ablation s-Tg and TgAb levels were measured during hypothyroidism just before the ablative 131I administration. Patients with positive TgAb (>40 IU/mL) and distant metastases noticed on post-ablation whole body scintigraphy and other imaging modalities were excluded. Results: The study cohort consisted of 664 patients. The initial risk-stratifications according to the ATA 3-level risk category were low-, intermediate- and high-risk for 174 (26%), 436 (66%) and 54 (8%) patients, respectively. The mean time interval between surgery and pre-ablation s-Tg measurements was 3.2 months. The mean values of pre-ablation s-Tg were 1.55 ng/mL, 8.97 ng/mL, and 25.01 ng/mL (normal range: 0.04–244 ng/mL), respectively, for low-, intermediate- and high-risk patients (p<0.05). Notably, only 1% of low-risk patients had pre-ablation s-Tg higher than 10 ng/mL, 42% of intermediate-risk patients and 13% of high risk patients had pre-ablation s-Tg <1 ng/mL. None of the criteria characterising the population (age at diagnosis, sex) or the disease (TNM stage, tumour size, the presence of extra-thyroidal extension, the presence of aggressive histology, location and number of lymph node metastases) was statistically significant association with pre-ablation s-Tg levels. Conclusion: There is an overlap in pre-ablation s-Tg levels across different initial risk-stratification groups.


   P020: Thyroid Cancer Clinic: Should Serum Calcium Monitoring Become a Routine Part of Follow-Up of Patients Receiving 131I Ablation/Treatment? Top


Nico Malan*1, M Di-Tamba Vangu1

1University of the Witwatersrand, Johannesburg, South Africa

Background/Aims: Thyroidectomy is a procedure with well-known potential risks and complications, amongst others, hypocalcemia following surgery. Patients routinely undergo post-operative testing to exclude hypocalcemia following thyroidectomy as patients may initially be asymptomatic. Once patients are treated in our thyroid cancer clinic, there is no further routine investigation of serum-calcium levels, except if the patient becomes symptomatic. There have been reports in literature to suggest that some patients may become hypocalcemic following the administration of radioactive iodine, whether transient or permanent. This prompted us to investigate the incidence of possible hypocalcemia in our patient population to identify asymptomatic patients requiring calcium supplementation timeously. This may indicate whether routine testing of serum-calcium should be performed in our institution. Methods: This is a prospective, ethics approved, study of patients referred to the Thyroid Cancer Clinic at Charlotte Maxeke Johannesburg Academic Hospital. The patients consented to be enrolled in the study. Serum calcium was measured and compared to the initial calcium levels following surgery. We aimed to enrol 50 patients for an audit of the incidence of patients that may have been hypocalcaemic or became hypocalcaemic. Results: 52 patients (5 males; 47 females) entered the study (mean age 49.7±13.7 years). Seven were found to be hypocalcaemic (s-Ca <2.15mmol/l) [Normal 2.15-2.50mmol/l]. They had s-Ca levels ranging from 1.73 mmol/l to 2.11 mmol/l (mean 1.99 mmol/l). Six patients were already hypocalcaemic following surgery and 1 patient had a normal calcium of 2.29 mmol/l post-surgery. This patient received 5550MBq I-131 and now presented with a s-Ca of 1.75mmol/l and PTH = 1.2pmol/l [normal 1.60 – 6mmol/l]. There were no obvious other causes that could account for the patient’ current hypocalcaemia other than 131I therapy. Conclusion: Routine measuring of s-Ca may assist in detecting patients that are not on optimal calcium replacement or may have become hypocalcaemic following treatment with radioactive iodine.


   P022: The Optimum Level of Serum Thyroid Stimulating Hormone Necessary for Complete Ablation in Patients with Low- to Intermediate-Risk Differentiated Thyroid Carcinoma Top


Neo Mokgoro*1, I Lawal1, N Nyakale2, L Harry2, T Lengana1, M Kgomotso1, M Vorster1, M Sathekge1

1Department of Nuclear Medicine, University of Pretoria and Steve Biko Academic Hospital, Pretoria, 2Department of Nuclear Medicine, Inkosi Albert Luthuli Central Hospital, Durban, South Africa.

Background/Aims: Elevated serum thyroid stimulating hormone (TSH) level is necessary to achieve uptake of radioactive iodine in remnant thyroid tissue during ablation. A cut-off value of 30 mIU/L is commonly use; a decision without a strong support from the literature. We aimed to determine the optimum TSH level necessary for complete ablation of well differentiated thyroid carcinoma using I-131 following initial thyroidectomy in patients with low- to intermediate risk thyroid carcinoma. Methods: A total of 108 patients (female=76, male=32; mean age=45 years) with low- to intermediate-risk differentiated thyroid cancer treated with 370GBq of I-131 were divided into three groups based on pre-ablation serum TSH levels (30 - <60 (n=38); 60 - <90 (n=24) and ≥90 (n=46)). They were followed-up for 12-24 months post treatment with stimulated serum thyroglobulin level, anti-thyroglobulin antibodies, clinical examination and diagnostic whole-body scan with radioactive iodine I-123. Treatment outcome was classified according to the four response-to-therapy categories recommended by the American Thyroid Association. Approval for the study was obtained from the institution’s review board. Results: Sixty-two patients had papillary thyroid carcinoma while 46 had follicular carcinoma. Complete ablation was seen in 67.4% of patients with TSH level ≥90, in 70.8% of the 60 to <90 group and 44.7% in the 30 to <60 group (p=0.017). In a multivariate analysis done to determine the predictors of complete ablation, only pre-ablative TSH level was found to be an independent predictor of successful ablation, Odds Ratio=1.754 (95% CI 1.190-2.586, p=0.005). The effect of other factors such as age, gender, histological sub-type and pre-treatment thyroglobulin level did not reach statistical significance. Conclusion: In patients with low- to intermediate-risk differentiated thyroid carcinoma treated with 370 GBq of I-131 post-thyroidectomy, the highest rate of complete ablation is obtainable at TSH levels between 60 and 89 mIU/L.


   P023: Comparison between Preablative 99mTc-Pertechnetate Scintigraphy and Postablative 131I Whole-Body Scan for Evaluation of Remnant Thyroid Tissue in Differentiated Thyroid Cancer Top


G Mutevelizade1, Y Parlak1, F Gumuser1, Elvan Bilgin*1

1Celal Bayar University, Manisa, Turkey

Background/Aims: Total thyroidectomy and radioiodine (I-131) ablation have been used for patients with differentiated thyroid cancer (DTC). Before radioiodine ablation theraphy, thyroid scintigraphy with 99mTc-pertechnetate is performed to evaluate the remnant thyroid tissue existence and to investigate possible metastatic regions in the neck. Methods: Twenty-eight patients who received radioiodine ablation for DTC were examined retrospectively. Every patient had 99mTc-pertechnetate scintigraphy 3-6 weeks after the surgery and postablative (RxWBS) 131I whole body scan 7-10 days after the radioiodine ablation therapy. Remnant tissue localisations and number of foci were compared. Results: Thirteen (46.4%) of 28 patients have exactly the same number of foci at the same localisations at both images. 99mTc-pertechnetate scintigraphy showed no uptake of remnant thyroid tissue at 2/28 (7.1%) patients, while RxWBS exposed radioiodine avid remnant tissues. 7/28 (25%) patients had more number of remnant foci at 99mTc-pertechnetate scintigraphy, and 6/28 (21.4%) patients had more at RxWBS. Conclusion: Eight patients had more number of foci at RxWBS than 99mTc-pertechnetate scintigraphy due to different uptake mechanisms of these two agents. 7 (25%) patients had more number of foci at 99mTc-pertechnetate scintigraphy due to star artifact. As a result, while evaluating the remnant thyroid tissue existence there was no prominent difference between these two scanning procedures. 99mTc-pertechnetate scintigraphy is easy to perform and cost-effective; it is appropriate to evaluate the remnant thyroid tissue before radioiodine ablation of differentiated thyroid cancer.

Disclosure of interest: Y Parlak conflict with Celal Bayar University.


   P024: Rare Presentation of a Thyroid Cancer Patient with Radioiodine Uptake in Aspergilloma Top


Damayanthi K K Nanayakkara*1, S I Nawaz1

1Department of Nuclear Medicine, Faculty of Medicine, Peradeniya, Kandy, Sri Lanka

Background/Aims: Radioiodine (131I) ablation and post therapy whole body scan (PTWBS) are standard procedures for thyroid cancer management. Administration of 131I has advantages of having therapeutic effects and visualising residual/metastases in thyroid cancer patients. Unusual pathologies may be visualised as false positive scan findings. Methods: 54 year old male was treated for papillary carcinoma of the thyroid in 2014. Histology revealed capsular and vascular invasion, no positive lymph nodes. Initially, total thyroidectomy and post-surgical residual ablation dose of 1110mBq was given 6 weeks post-surgery. Pre-therapy serum thyroglobulin (sTg) was 56.1 ng/dl at TSH >56miu/L. First PTWBS showed significant residual thyroid tissues. Hence second ablation dose of RAI 1110mBq was given after 6 months. The second PTWBS shows no functioning residual thyroid tissue or metastases and sTg has reduced to 0.2 ng/dl at TSH maximum stimulation. Findings were concluded as successful ablation. He is a diabetic with mild renal impairment due to renal stones. He is a farmer, non-smoker. Results: He has been on thyroxine since 2014, and recently presented with right side chest discomfort with intermittent blood-stained sputum. No fever or cough. Chest X ray showed well defined opacity in the right apical lung feild which was not seen in previous chest X-rays. It was suspected as lung metastases inspite of low serum Tg level (<1ng/dl) and negative PTWBS. 3rd RAI ablation dose and PTWBS was suggested. Bronchoscopy examination showed no abnormality. Mantoux test and sputum for acid fast bacillus were negative. 3rd PTWBS showed focal intense radioiodine uptake in the right apical region where the large opacity was seen in the chest X ray. Rest of the scan showed physiological radioiodine uptake. A contrast enhanced CT scan showed a well circumscribed lesion typical of fungus ball which was diagnosed as an aspergiloma. Due to renal impairment and limited pulmonary function surgical resection was not done. Literature survey too showed aspergillosis can lead to radioiodine lung uptake mimicking pulmonary metastases. This is the first case we came across. He was put back on Thyroxine replacement and is being followed up. Conclusion: Pulmonary aspergilloma is a known cause of a false positive radioiodine uptake which mimic pulmonary metastases.


   P025: Low-Dose Thyroid Remnant Ablation: A Follow-Up Study Top


Damayanthi Nanayakkara*1, S Nawaz1, G Samarakoon1, N Jayasooriya1

1University of Peradeniya, Peradeniya, Kandy, Sri Lanka

Background/Aims: Radioactive iodine thyroid remnant ablation improves the quality of life in patients with differentiated thyroid carcinoma (DTC). Low dose (1110 mBq) ablation is cost effective and widely practiced on an outpatient basis reducing the radiation burden to the patient. Lack of in-ward facilities and inadequate radioiodine supply led us to practice low dose ablation. This study was done to assess the clinical effectiveness of low dose thyroid remnant ablation as on outpatient basis. Methods: Cross sectional retrospective study done using the thyroid cancer database at the Nuclear Medicine Unit, University of Peradeniya. All patients were explained the procedure and informed written consent was obtained for necessary multiple therapy administration. DTC patients who were treated with radioiodine and had post-therapy whole body scans from January 2006 – October 2017 were selected for data analysis. Negative whole-body scan with serum thyroglobulin level of less than 2.0 ng/ml was considered as successful treatment. Results: A total of 838 DTC patients were treated and followed up during this period (116 males and 722 females) with a mean age of 42.7 years (range 15-81 y). Common histology type was follicular or follicular variant of papillary carcinoma. Successful ablation with 1110 mBq of Iodine was achieved in 74.9% of the patients (n=404/539) after single administration, in 98.7% (n=69/70) with two doses, in 93.75% (n=15/16) with three doses. Out of 10 patients 9 had to receive (90%) more than 3330mBq (three doses) to achieve successful ablation. Overall success rate was 77.9% (n=482/618) with several 1110 mBq of iodine administration on an outpatient basis. 21.7% of the patients had persistent residual thyroid tissues while 8.4% had nodal or bone metastases which required inward high dose treatment. Conclusion: Over 3/4th of DTC patients were successfully treated with low dose radioactive iodine on an outpatient basis.


   P027: Comparative Efficacy of Short- and Long-Term Administration of 13 Cis-retinoic Acid as Redifferentiation Drug in Refractory Thyroid Cancer Top


Prasanta Kumar Pradhan*1, A Elias1, A Arya1, M Ravina, G Shankar1

1SGPGIMS, Lucknow, Uttar Pradesh, India

Background/Aims: Differentiated thyroid cancer accounts for 95% of all thyroid cancers worldwide. Management is mostly by surgery, radioiodine and suppressive dose of levothyroxine. Metastasis occur in about 7-23% of these patients and among them 2/3rd become refractory to radioiodine. To assess comparative efficacy of radioiodine positivity following 6 and 12 weeks administration of 13 Cis-retinoic acid (RA). Methods: Twenty-eight patients of refractory thyroid cancer with persistence of disease were administered RA at a dose of 1.5 mg/kg body weight. 15 patients were given for 12 weeks and 13 were given for 6 weeks of RA. Then, radioiodine scan of whole body was done following 4 weeks stoppage of levothyroxine or with recombinant human TSH. Patients who showed positive radioiodine scan was considered as redifferentiation and radioiodine therapy was continued at timed interval. Results: Out of 28 patients 13 were male and 15 were female. 23 were papillary carcinoma of thyroid (recurrence, pulmonary or cervical lymph node metastasis), 1 follicular carcinoma, 1 poorly differentiated thyroid cancer, and 3 were Hurthle cell variants. 4/28 (15%) of patients showed positivity following 6 weeks oral administration of RA. These patients were treated with 100-150 mCi of radioiodine depending on disease burden. Long term administration i.e 12 weeks of RA did not add to positivity on radioiodine scan. Following radioiodine therapy, there was decrease in serum thyroglobulin level and increase in radioiodine uptake and clinical improvement. Conclusion: Our findings suggest that 13 Cis-retinoic acid redifferentiation therapy for 6 weeks seems to be optimal duration of administration for inducing redifferentiation in refractory thyroid cancer rather than 12 weeks as it did not offer any additional value with respect to radioiodine positivity. This is an alternative therapeutic approach to otherwise untreatable thyroid cancers as RA has mild side effects like mucositis.


   P028: Calcium Stimulation Test is a Reliable Test Instead of the Pentagastrin Test for the Diagnosis and Follow-Up of Medullary Thyroid Cancer Top


E Rainer1, A Gessl1, K Micheal1, B Niederle1, C Scheuba1, A Haug1, M Hacker1, Shuren Li*1

1Medical University of Vienna, Vienna, Austria

Background/Aims: Calcitonin (CT) is an important tumour marker for the diagnosis and follow-up of medullary thyroid cancer (MTC). The aim of this study was to evaluate the reliability of calcium stimulation test (CST) for MTC diagnosis and follow-up as compared with pentagastrin test. Methods: A total of 256 patients (123 females and 133 males, mean age of 56±27 years, range 21-83 years) had both pentagastrin (0.5 µg/kg body weight) and calcium (2.5 mg/kg body weight calcium gluconate) stimulation tests. Among them, 28 patients with thyroid goiter had thyroidectomy after both CST and pentagastrin test. Results: Stimulated CT levels after administration of pentagastrin or calcium were significantly correlated in all groups. The cut-off values with best sensitivity and specificity to differentiate between MTC and C-cell hyperplasia (CCH) plus healthy individuals were above 727 pg/ml for men and above 395 pg/ml for women. The cut-off values for differentiation between MTC plus CCH and healthy individuals were above 590 pg/ml in men and above 160 pg/ml in women. Conclusion: CST seems to be a reliable, safe and effective test and may replace the pentagastrin test for the diagnosis and follow-up of MTC.


   P029: The Value of 11C-Acetate Positron Emission Tomography and 18F-Flourodeoxyglucose Positron Emission Tomography in the Detection of Metastatic Thyroid Cancer Top


E Rainer1, M Wibbe1, E Kretschmer-Chott1, C Scheuba1, A Haug1, M Hacker1, Shuren Li*1

1Medical University of Vienna, Vienna, Austria

Background/Aims: This prospective study was to investigate the value of 11C-acetate PET and 18F-FDG PET in the detection of differentiated thyroid cancer (DTC). Methods: Eight patients (5 female, 3 male; age range 61–82 years, mean 68 years; 3 papillary and 5 follicular carcinoma) with metastatic DTC underwent 11C-acetate PET and 18F-FDG PET. 131I-whole body scan (WBS) was performed 3–5 days after oral administration of the therapeutic dose. Results: A total of 29 lesions [14 lung, 7 bone, 4 mediastinum, 3 lymph node (LN), 1 brain] were diagnosed as metastases by histopathology and/or other imaging modalities (US, CT, MRI, bone scan and 131I-WBS). The lesion-related sensitivity of 11C-acetate PET, 18F-FDG PET and 131I-WBS was 31% (n=9), 86% (n=25) and 45% (n=13), respectively. 18F-FDG PET, 11C-acetate PET and post-therapeutic 131I-WBS revealed eleven (79%), three (21%) and seven (50%) lung metastases, respectively. Four (100%), one (25%) and one (25%) mediastinum metastases demonstrated by 18F-FDG PET, 11C-acetate PET and post-therapeutic 131I-WBS, respectively. 18F-FDG PET, 11C-acetate PET and post-therapeutic 131I-WBS showed five (71%), three (43%) and three (43%) bone metastases as well as three (100%), two (67%) and one (33%) lymph node metastases, respectively. 18F-FDG PET and 11C-acetate PET were positive in 11 (85%) and only 2 (15%) of the thirteen 131I-WBS positive lesions, respectively, and also in sixteen (100%) and seven (44%) of the sixteen 131I-WBS negative lesions, respectively. Comparison of 18F-FDG PET with 11C-acetate PET revealed concordant results in 12 lesions, and discordant results in 17 lesions (sixteen with positive 18F-FDG PET alone and one with positive 11C-acetate PET alone). Conclusion: 18F-FDG PET is much superior to 11C-acetate PET in terms of ability to detect metastases of DTC.


   P030: The Influence on Low-Iodine Diet by Continuation of Levothyroxine with Recombinant Human Thyroid Stimulating Hormone Stimulated Thyroglobulin Levels at Radioactive Iodine Ablation Top


Kunihito Suzuki*1, M Yoshimura1, T Sanada1, M Kawasaki1, H Tsutsui2, K Koizumi1

Departments of 1Radiology and 2Surgery, Tokyo Medical University, Tokyo, Japan

Background/Aims: Radioactive iodine (RAI) ablation is a beneficial, adjuvant therapy for the management of differentiated thyroid cancer (DTC) after thyroidectomy. Radioactive iodine uptake is enhanced by stimulating TSH levels prior to ablation. One method of stimulating TSH is the use of recombinant human TSH (rhTSH), and rhTSH can continue medication of levothyroxine. But the influence on low-iodine diet (LID) due to continuation of medication of levothyroxine has not been known. This time, we investigated whether continuation of levothyroxine affects LID at RAI ablation by using urinary iodine concentration. Methods: We targeted 60 patients who needed RAI ablation with 1110 MBq after thyroidectomy of high-risk DTC. We divided the patients into two groups, A group (49 patients, ablation therapy using rhTSH only) and B group (11 patients, discontinued levothyroxine for the last 3 days including the day of the ablation therapy, in addition to the protocol of A group). They were taught of the protocol and meal of LID for 2 weeks by nuclear medicine specialists and nutritionists. Each urinary iodine concentration was measured and the success rate of LID was calculated. The success of LID was defined as a pre-ablation spot urinary iodine concentration of <100 mcg/l and/or a urinary iodine to creatinine ratio of <100 mcg/gCr. Results: Success rates of Group A and Group B were 76% (37/49) and 82% (9/11), which were nearly equal. Conclusion: When TSH stimulation with rhTSH was performed, it was presumed that continuation of medication of levothyroxine was considered to have no effect on LID and it was considered that withdrawal of levothyroxine was not necessary.


   P031: Incident of Thyroglobulin Elevated and Negative Iodine Scan Syndrome on Differentiated Thyroid Carcinoma Patient with Radioiodine Ablation in 2016 Top


Zulhendri Syauki*1, B Hidayat1, H Budiawan1, B Darmawan1, E Affandi Soeriadi1, A R Dewi1, A H S Kartamihardja1, J S Masjhur1

1Department of Nuclear Medicine and Molecular Imaging, Faculty of Medicine, RS Hasan Sadikin/Universitas Padjadjaran, Bandung, Indonesia

Background/Aims: In differentiated thyroid carcinoma (DTC) cases, elevated stimulated thyroglobulin level with negative whole body iodine scan (WBS), which known as thyroglobulin elevated and negative iodine scan (TENIS) syndrome, is a challenge both in therapy and diagnostic. This study aimed to determine the incidence of TENIS syndrome during 2016 in Dr. Hasan Sadikin General Hospital (RSHS), Bandung and the characteristics of patients with TENIS syndrome. Methods: TENIS syndrome cases was collected by tracking the medical records of DTC patients having 131I therapy in RSHS during 2016. Data on sex, age, DTC type, TSH levels, thyroglobulin levels, antithyroglobulin antibody levels prior to therapy, and post therapy WBS (rxWBS) results were analysed. Thyroglobulin level were divided into 3 groups (group A: 10-30 ng/mL, group B: >30-50 ng/mL and Group C: >50 ng/mL). Results: TENIS syndrome cases were observed in 37/372 (9.9%) DTC cases. TENIS syndrome was found in 9 (24.3%) male patients (all of them >40 years old) and 28 (75.6%) female patients with 15 of them >40 years old. There were 28 papillary thyroid carcinoma (PTC), 4 PTC follicular variant, 4 follicular thyroid carcinoma (FTC), and 1 FTC oncotic variant. Pre-131I thyroglobulin levels were in range of 13.1-3107ng/mL (group A: B: C = 12:3:22 cases,), TSH level in range 8.7-209.7 μIU/mL and antithyroglobulin antibody level in range 0->3000 IU/mL. 21/37 cases (56.7%) underwent SPECT/CT imaging. Non-iodine avid lymphadenopathy was found in 14 cases. Conclusion: TENIS syndrome is not an uncommon finding. Most patients were more than 40 years old with thyroglobulin levels >50 ng/mL and PTC as the subtype of DTC.


   P032: The Ability of BRAF Therapy to Convert an Iodine Negative to Iodine Positive Thyroid Cancer Patient Top


Belinda K Vaughan*1, M A Rossleigh1, A D Parasyn1, M T Chin1

1The Prince of Wales Hospital, Randwick, Australia

Background/Aims: A 77 year old man presented with a cerebral metastasis from papillary carcinoma of the thyroid. Investigations revealed a left thyroid lobe primary with extensive locoregional lymph involvement and pulmonary metastases. He was treated with a total thyroidectomy, central and left lateral lymph node resection and a 5.8GBq dose of I-131. Unfortunately, the post treatment scan revealed uptake in the thyroid bed but no uptake in the pulmonary metastases. Methods: The tumour was found to be BRAF positive. The patient was commenced on 2 BRAF inhibitors - cobimetinib and vemurafenib, for treatment of his metastatic disease. It was also hoped that these agents may result in redifferentiation of his tumour. Results: After 3 months of BRAF inhibitor therapy, an I-123 scan confirmed uptake in right cervical lymph nodes and multiple pulmonary metastases, a further therapeutic dose of 5.8GBq of I-131 was then administered. Following this second treatment, the post therapy scan confirmed excellent uptake in right cervical lymph nodes and pulmonary metastases. This result mimics the findings reported previously when the MEK inhibitor, selumetinib, was shown to be able to reverse radioiodine refractory disease.[1] Conclusion: This case illustrates the ability of BRAF inhibitor therapy to convert radioiodine refractory disease into iodine positive disease, enabling I-131 therapy to be administered more effectively in a patient with a BRAF positive tumour.

References

  1. Ho AL, Grewal RK, Leboeuf R, Sherman EJ, Pfister DG, Deandreis D, et al. Selumetinib-enhanced radioiodine uptake in advanced thyroid cancer. N Engl J Med 2013;368:623-32.



   P033: Prognostic Value of First Thyroglobulin in Low- and Intermediate-Risk Patients with Differentiated Thyroid Cancer Top


Seyed Rasoul Zakavi*1, N Ayati1, S Zare1, A Ayati1, K Sadri1, N Fekri1, S Shafiei1

1Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Islamic Republic of Iran

Background/Aims: To define prognostic value of the first Tg (fTg) measured after thyroidectomy and just before radioiodine therapy (RIT), in low/intermediate risk patients and to find optimal threshold of fTg for prediction of incomplete response. Methods: This is a retrospective study in 383 patients with low/intermediate risk DTC who were treated with surgery followed by risk based administration of 1110-5550MBq of I-131. Response to treatment was assessed 1 and 2 years after RIT. Odds ratio of different risk factors like age, sex, TNM stage, fTg and Anti-Tg Ab were compared between patients with and without incomplete response 1 and 2 years after treatment. Receiver operating curve (ROC) analysis was used for definition of optimal fTg cut off for prognostic purpose. Results: 273 patients (218 female:55 male) with DTC including 252 PTC and 21 FTC with mean age of 37.5±14.5 years had negative anti-Tg antibody. 86 patients (31.5%) received 1100 MBq of I-131, 70 patients (25.6%): 3700MBq and 117 patients (42.9%): 3700-5550MBq. Using ROC analysis, fTg≥33.5 ng/ml and fTg/TSH ratio of ≥0.36 had the optimal sensitivity and specificity for detection of incomplete response 1 and 2 years after treatment. Multivariate analysis showed that fTg was the most potent risk factor for prediction of treatment failure 1 and 2 years after RIT. Conclusion: fTg was the most important risk factor for prediction of treatment failure after RIT and should be included in decision algorithm regarding RIT or optimal iodine dose determination in low/intermediate risk patients with DTC.


   P034: Can Dynamic Monitoring of Thyroglobulin Doubling Time Predict Disease Progression in Differentiated Thyroid Cancer? Top


Xieyi Zhang*1, T Higuchi1, H Tomonaga1, A Bhattarai1, O Lamid-Ochir1, H Nguyen-Thu1, A Yamaguchi2, H Hirasawa1, A Taketomi-Takahashi1, Y Tsushima1,3

1Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, 2Department of Bioimaging Information Analysis, Gunma University Graduate School of Medicine, 3Gunma University Initiative for Advanced Research, Maebashi, Gunma, Japan

Background/Aims: Thyroglobulin-doubling time (TgDT) with suppressed serum thyrotropin levels and undetectable anti-Tg antibody is a very strong prognostic predictor in the patients with differentiated thyroid carcinoma (DTC). However, the value of dynamic monitoring of TgDT has not been extensively studied. The purpose of our study is to evaluate the value of dynamic TgDT for monitoring the progression in the patients of DTC. Methods: We retrospectively reviewed 22 DTC patients, who had at least 4 serum Tg measurements at a time when serum thyrotropin concentrations were <0.1mIU/L and with undetectable anti-Tg antibody. Patients were differentiated as progression disease (PD) and stable disease (SD) according to Response Evaluation Criteria in Solid Tumours (RECIST) 1.1. TgDT was computed using Tg values measured during routine follow-up and was calculated by Excel based doubling time and progression calculator. Whole data (WDT), initial 4 data (IDT) and recent 4 data (RDT) of TgDT after total thyroidectomy were calculated and compared by chi-square test. Correlation between the date when dynamic RDT was less than one year and when cancer progressed were compared. Results: Among 22 patients, 11 patients were classified into PD and 11 were into SD. The increase rate of Tg between total thyroidectomy and recent data did not show significant difference between PD and SD patients (p=0.3). However, short WDT, IDT and RDT (less than one year) showed correlation with PD (p<0.05). RDT showed the highest predictive value, with the sensitivity of 90.9%, the specificity of 100% and the accuracy of 95.5%. Among 11 PD patients, 10 patients showed RDT less than one year before progression of disease (median duration, 153 days; range, 88-252). Conclusion: Dynamic monitoring of RDT may be a strong PD predictor in patients with DTC.


   P035: Analysis of 179 BRAFV600E Mutation in Papillary Thyroid Carcinoma Patients Top


Shu Zong*1, M Zhang1, J Wang1

1Xijing Hospital, Xi’an, China

Background/Aims: To analyse the relations between BRAFV600E mutation and some pathological parameters in Papillary Thyroid Carcinoma (PTC), and to investigate BRAFV600E mutation in PTC coexisting with Hashimoto’s thyroiditis or nodular goiter. Methods: To retrospectively analyse data of 179 cases of post-operation PTC patients. Clinical data were reviewed and evaluated using SPSS 21.0 statistical software package. Results: Among the 179 Chinese PTC patients, the presence of BRAFV600E mutation was 61.5%. There is a correlation between BRAFV600E mutation rate and age or numbers of lymph node metastasis (p<0.05 respectively). The BRAFV600E mutation rate is higher in PTC patients coexisting with nodular goiter (p=0.024, OR=2,349). Conclusion: The BRAFV600E mutation rates have correlation with age, numbers of lymph node metastasis and whether coexisting with nodular goiter.


   P036: Thyroid Scintigraphy in Congenital Hypothyroidism at Dr. Hasan Sadikin General Hospital 2014–2015 Top


Wulan Apriliani*1, B HIdayat1, E Affandi1, H Budiawan1, B Darmawan1, D A Rosemeilia1, A H S Kartamihardja1, J S Masjhur1

1Hasan Sadikin General Hospital, Bandung, Indonesia

Background/Aims: Congenital Hypothyroidism (CH) is a condition that causes intellectual disability that can be prevented by thyroid hormone intervention as early as possible. Data from Dr. Hasan Sadikin General Hospital and Dr. Cipto Mangunkusumo General Hospital during 2000 to 2005 found incidence was 1:3528 births. The functional morphological features of the thyroid gland of CH are varies, also affect the management of CH. The aim of this research is to describe the profile of functional morphology of thyroid gland from CH cases which perform thyroid scintigraphy (TS) at Dr. Hasan Sadikin General Hospital in 2014-2015. Methods: Retrospective descriptive based on CH medical records data 2014-2015. The functional morphological features of the thyroid gland are obtained from TS examination using 99mTc-pertechnetate. The imaging results may be agenesis, hypoplasia, ectopic and dishormogenesis. Results: The number of TS studies on CH for the period 2014-2015 is 66 cases: 21 (31.8%) male and 45 (68.2%) women. Age at examination ≤1 month: 12 cases (18.2%), >1 month: 54 cases (81.8%). Functional morphological features showed agenesis in 31 cases (46.9%), dyshormogenesis in 24 cases (36.4%), and hypoplasia in 11 cases (16.7%). Case of ectopic thyroid gland were not found. Conclusion: The most common functional morphological feature of the HK case at Dr. Hasan Sadikin General Hospital in 2014-2015 is agenesis. Ectopic thyroid gland case not found.


   P037: The Value of 99mTc-Pertechnetate Thyroid Scintigraphy in the Diagnosis of Hyperthyroidism: 131I Uptake Test Is Indispensable to Determine the Aetiology of Hyperthyroidism Top


A Ergülen1, Ü Korkmaz1, Funda Ustun*1, G D Altun1

1Department of Nuclear Medicine, Faculty of Medicine, Trakya University, Edirne, Turkey

Background/Aims: The primary usefulness of the radioiodine uptake measurement (RIU) is to differentiate Graves’ hyperthyroidism from that caused by subacute or painless thyroiditis or factitious hyperthyroidism. 99mTc pertechnetate scintigraphy is another option to measurement of thyroid function. The aim of this retrospective study was to assess the feasibility of 99mTc-uptake ratio determination via gamma camera in comparison with established 131I RIU in diagnosis of benign thyroid diseases (BTD). Methods: Between 2012 and 2016, a total of 159 patients with BTD were screened, 78 of whom met the inclusion criteria a retrospective analysis was performed of 78 patients (age range 20-81 years, mean age 52 years, 58 women and 20 men) with BTD. All patient files were scanned for the necessary examinations within the scope of current guidelines (anamnesis, TSH, free T3 and free T4, neck ultrasound and planar 99mTc-pertechnetate scintigraphy (TS)) and those with recent RIU test were included in the study group. Two and 24 hr RIU values recorded, and TS quantifications parameter were repeated after then accepting of study group. Thyroid–to-background ratio (TBRmax, TBRmean), thyroid–to-salivary gland ratio (TSgRmax, TSgRmean) were observed. Results: The 2 hour RDR was the best correlated with TBRmax, TBRmean, TSgRmax, TSgRmean (r:0,86, r: 0.86, r: 0.88, and 0.88 respectively, p<0.0001). 24 hr RIU values was correlated with TBRmax (r:0.67, p<0.0001). 2 hour and 24 hour RIU was correlated (r: 0.64, p<0.001). Conclusion: In the literature, the normal range of values is usually given as between 10% and 35% for a 24 hour uptake, and between 6% and 18% for 4 hour uptake. Alternatively, thyroid uptake can be determined, less accurately, using intravenously administered 99mTc-pertechnetate and a gamma camera. The thyroid uptake of 99mTc pertechnetate ranged from 0.15-2.14%. The effective dose generated by the test with 131I RIU is 41 rem/mCi. On scintigraphy with 99mTc, this dose is 0.048 rem/mCi. Since radiation exposure to the patient is approximately a thousand times higher, if there is no other obstacle, TcO4-thyroid scintigraphy in hyperthyroid patients is sufficient for diagnosis and differential diagnosis.


   P038: The Clinical Application Value of Multiple Treatments of Iodine-131 Therapy for Hyperthyroidism with Goiters in the Past 14 Years Top


Liang Guan*1, G Chen1

1Department of Nuclear Medicine, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China

Background/Aims: To retrospectively analyse the clinical application value of multiple treatment of iodine-131 for hyperthyroidism with goiters in the past 14 years. Methods: From 2003 to 2016, 12658 cases of hyperthyroidism iodine treatment in our department were retrospectively analysed, and 6279 cases of 5217 patients were selected after the follow-up more than a year. Results: In 5217 patients, 3790 (72.6%) were female, whereas 1427 (27.4%) were male. Patients of single iodine dosage were 4343 (83.3%), and patients of multiple treatments were 874 (16.7%), whereas 3 times of treatments were 146 cases (2.8%), 4, 5 and 6 times were 32, 8 and 2 cases retrospectively. The dosages of 131 iodine (mCi) for first, second, third, fourth and fifth of treatment were 6.7±1.8, 6.8±2.3, 7.8±3.9, 10±6.8 and 10±7 retrospectively. In the single dosage, the minimum was 3 mCi, the maximum was 15mCi. In the multiple treatments: the single minimum is 2 mCi, the single maximum was 30 mCi, whereas the minimum cumulative dosage was 4 mCi (2 times), the maximum cumulative dosage was 102.5 mCi (5 times) retrospectively. Conclusion: In a small portion of hyperthyroidism with goiters of more than 2 years, multiple iodine treatments were necessary. The iodine dosage was needed more in 3rd, 4th and 5th than that of in the 1st and 2nd treatment. Due to the different personal sensitivity of iodine, the therapeutic effect of low iodine dosage as well as high iodine dosage has also been observed.


   P039: Determination of Diagnostic Accuracy by Risk Stratification Model of American College of Radiology (Thyroid Imaging Reporting and Data System) in Solid Thyroid Nodules and Correlation with 99mTc-Thyroid Scan, Keeping Fine Needle Aspiration Cytology as Gold Standard Top


Ghazal Jameel*1

1Pakistan Atomic Energy Commission General Hospital, Islamabad, Pakistan

Background/Aims: TIRADS is a risk stratification system for classifying thyroid lesions and was recently recognized in an American College of Radiology (ACR). TIRADS classification is now being used in daily routine categorization of sonographically visualized thyroid nodules, followed by thyroid scan done with 99mTc. FNAC is done only when the TIRADs scores are 4 or greater than 4, as increasing scores indicate higher suspicion of malignancy. All nodules categorized as suspicious i.e TIRADS 4-5 need to be evaluated by thyroid scan categorized as hot, warm or cold. The aim of this study was to evaluate the diagnostic accuracy of the TIRADS score by correlating it with thyroid scan and fine needle aspiration cytology. Methods: Ultrasound of thyroid was carried out on GE logic with linear transducer of 7.5–12 MHz frequency. 210 patients referred for sonography of thyroid nodules were included in the study from 1st January 2016 to 31st July 2017. Thyroid scan was performed after ultrasound and before FNAC to avoid misleading increase post intervention and to assess the uptake of radiotracer in the sonographically detected nodule. Fine needle aspiration was carried out under ultrasound guidance and cytology was done of all nodules categorised as TIRADS 4 and above. Results: A total of 210 patients with 253 nodules of mean size 2.5 ± 1.5 cm were included. PPV for malignancy was 38%, 56%, 78%, and 91% for TIRADS 2, 3, 4a, 4b, 4c, and 5 categories, respectively. Conclusion: TIRADS (Thyroid Imaging Reporting and Data System) is a useful diagnostic classification in predicting malignancy and with the help of thyroid scan and FNAC unnecessary surgical procedures and associated risks can be everted.


   P040: A Fixed I-131 Dose in Therapy of Patients with Autonomously Functioning Thyroid Nodules and Normal Thyroid Stimulating Hormone Level Top


Miodrag Lacic*1

1Department of Thyroid, Polyclinic Lacic, Zagreb, Croatia

Background/Aims: The purpose of this study was to evaluate the results of radioactive iodine-131 (131I) therapy in patients with autonomously functioning thyroid nodules (AFTN) and a normal thyroid stimulating hormone (TSH). Up to our knowledge, this is the first study which has scintigraphically evaluated the effect of 131I therapy in patients with AFTN and normal TSH level. Methods: In this study 58 cytological benign AFTN in 51 patients (45 female and 6 male) with normal TSH level have been treated with a fixed 131I doses (370 MBq). Clinical exam, ultrasonography with color Doppler (US), fine needle aspiration biopsy (FNAB), TSH, fT4, fT3, anti-TPO, anti-Tg and thyroid scan (scintigraphy) have been performed in all patients before and 6 months after 131I therapy. Results: The median age of the patients was 57 (range 37-83) years. AFTN were located more frequently in the right thyroid lobe (33 nodules) than in the left lobe (25 nodules). In 11 patients, a solitary AFTN has been found on ultrasonography and the other 40 patients had AFTNs in multinodular goiter. Seven patients had two AFTNs. On post-131I therapy thyroid scan in 41 AFTN, complete therapy effect has been observed, but in 17 AFTN a scintigraphycally partial effect has been noted. Statistical analysis showed a significant reduction in the thyroid (p=4.7515E-15) and AFTN (p=0.0018) volume after 131I therapy. TSH value significantly increased (p=0.0048) and FT4 value significantly decreased (p=0.0012) after 131I therapy. FT3 (p=0.3508), anti-TPO (p=0.8701) and anti-Tg (p=0.6805) values did not change significantly. Conclusion: In conclusion, we wish to stress that fixed 131I doses in therapy of patients with AFTN and normal TSH level is a simple, cheap and very effective modality. The effect of the 131I therapy on AFTN can be exactly evaluated with a post 131I therapy thyroid scan.


   P041: The Use of 99mTc-Sestamibi Thyroid Scintigraphy in the Differentiation and Management of a Patient with Amiodarone-Induced Thyrotoxicosis Top


Sophie Liddicoat*1, K Walsh1, R Gauci1,2

Departments of 1Nuclear Medicine and PET and 2Endocrinology, Fiona Stanley Hospital, Murdoch, Australia

Background/Aims: Thyrotoxicosis is a potential side effect of amiodarone treatment, an iodine-rich drug used to treat serious tachyarrhythmias refractory to other treatments. Amiodarone-induced thyrotoxicosis (AIT) is classified into two types each with a different therapeutic approach. Excessive hormone synthesis and release causes AIT I which is treated with carbimazole (thionamides). AIT II is a result of destructive thyroiditis and responds to prednisolone (glucocorticoids). Some patients may have mixed forms, and differentiating the two clinically is challenging. Methods: A 36 year old male with AIT was referred to Nuclear Medicine so that the type of AIT could be determined. He was an outpatient found to be thyrotoxic on routine pathology and a two year history of amiodarone treatment. The patient was referred for 99mTc-sestamibi thyroid scintigraphy (99mTc-STS) and colour flow Doppler sonography (CFDS). 99mTc-STS was performed where planar images were acquired at 2, 10, 15 and 60 minutes post-injection. Thyroid-to-background ratios (TBRs) were calculated using the Pattison et al.[1] method and displayed on a time activity curve. The observed result showed no significant uptake. Results: The early TBRs fell within the range determined to be suggestive of Type II, aside from the final ratio at 60 minutes which was indefinite. Overall the scintigraphic images and TBRs were interpreted to be in keeping with AIT II. The ultrasound performed on the same day found normal thyroid vascularity and appearance; suggesting AIT II. Scintigraphic and ultrasound imaging were congruent. This led to the patient being treated with Prednisolone 40mg daily for four weeks which resolved his thyroxicosis. Conclusion: 99mTc-STS played a vital role in confirming the diagnosis of AIT II for this patient and guided his treatment. The justified use of prednisolone was important due to his medical co-morbidities of type II diabetes mellitus and obesity, both of which prednisolone may exacerbate.

References

  1. Pattison DA, et al. Nucl Med Commun 2015.



   P042: Radioactive Iodine Therapy in Hyperthyroid Patients with Cold Nodules on Thyroid Scintigraphy but without Prior Fine Needle Aspiration Top


Dickson Ma*1, R Sohawon2, G Ramaseshan1

1Department of Nuclear Medicine and PET, Geelong Hospital, Barwon Health, 2Department of Medical Imaging, Geelong Hospital, Geelong, Melbourne, Victoria, Australia

Background/Aims: The 2015 American Thyroid Association Guidelines stipulate that thyroid scintigraphy should be performed in a patient with biochemical hyperthyroidism as evidenced by a suppressed TSH. It is implicit that the subsequent management of a cold nodule demonstrated in such a patient should be in accordance with the guidelines. Our aim was to review the patterns of management of cold nodules in a cohort of hyperthyroid patients and factors that influenced the clinician’s decision to proceed to radioactive iodine therapy (131I). Methods: Retrospective study of consecutive patients who presented to an Australian tertiary teaching hospital and were shown to have cold nodules on thyroid scintigraphy from 2/2015 to 8/2017 in relation to thyroid function test results, correlative ultrasound & fine needle aspiration findings as well as subsequent radioactive iodine therapy. Results: Of the 70 patients whose case records were reviewed, 101 cold nodules were demonstrated all of which had ultrasound correlates. The vast majority of these nodules (n=93, 92% of all cold nodules) were associated with multinodular goitres. Of the 47 patients (67% of all patients) who were hyperthyroid, 12 patients subsequently received 131I therapy, 8 of whom had not undergone any fine needle aspiration procedure prior to therapy. Of these 8 patients, all were referred direct by endocrinologists or under the direction of endocrinologists, all were above the age of 55 with 4 patients above 70, and 3 had toxic nodules. None of these 8 patients developed cancer within the study period. Conclusion: Age, endocrinologist assessment of risk profile and demonstration of toxic nodules appeared to influence the decision to proceed with 131I therapy without prior fine needle aspiration of concomitant cold nodules uncovered on thyroid scintigraphy.


   P043: Long-Term Thyroid Function after 131I Treatment of Toxic Thyroid Adenoma Top


Zlatko Petrovski*1, O Lozanovska1

1Department of Nuclear Medicine, Clinical Hospital, Bitola, The Former Yugoslav Republic of Macedonia

Background/Aims: The aim of the study was to analyse the outcome of 131I therapy for autonomous thyroid adenomas in long period of follow up. Methods: We had 68 patients with Plummer’s disease (50 females, 18 males, mean age 54,7 yrs, range 21-79 yrs) for period 1997-2016. 92.6%(63/68) patients had a unifocal nodule, while 7.4% (5/68) patients had multifocal toxic autonomous nodules. Patients stopped antithyroid drugs for at least one month prior to the radioiodine treatment and than we administered a 131I activity of 740+/-200 MBq (range 550-1100 MBq), based of size and weight of “hot” nodules and the value of radioiodine uptake. Volumetry was done by ultrasound. The mean duration of follow up was 5,84 years. Results: 65/68 (95%) patients were administered a single dose, while 3/68 (5%) patients needed two doses. 55/68 (80.9%) patients who were treated with radioiodine were euthyroid with scintigraphic normalization. The percentage of euthyroidism did not significantly change in long term of 20 years observation. The recurrent hyperthyroidism was 2.9% (2/68) patients. The cumulative incidence of hypothyroidism was 16.2% (11/68) patients within 1-6.2 years. Hypothyroidism developed earlier in patients who were euthyroid before 131I therapy (3.5-7.7 months) than in the subclinically hyperthyroid patients, who became hypothyroid within 7.2-13.6 months (p=0.001). The development of hypothyroidism was higher in pts who showed extranodular uptake and after TSH suppression. The nodular volume was statistically higher in pts who had recurrent hyperthyroidism over hypothyroidism (p<0.01) and euthyroidism (p<0.02). No differences were observed in the results between unifocal and multifocal nodules. Conclusion: 131I therapy is a simple, safe and effective treatment of autonomous functioning thyroid adenoma with a low rate of recurrent hyperthyroidism (3%) and development of hypothyroidism (16%).


   P044: Incidentaloma in the Posterior Thyroid on 18F-Flourodeoxyglucose Positron Emission Tomography/Computed Tomography Scan: A Case Study Top


Nicole Smolcic*1, J Bradley1, P Bowen1, S Ramdave1

1Monash Health, Melbourne, Victoria, Australia

Background/Aims: To demonstrate the importance of considering a potential parathyroid adenoma in avid nodules posterior to the thyroid are found on 18F-Flurodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) scans. 18F-FDG PET/CT scans are predominantly utilised for oncology indications but it is essential to contemplate that there is a plethora of benign and inflammatory conditions which may exhibit 18F-FDG metabolism. Methods: A case report of a scan that contains an incidental finding of a potential parathyroid adenoma on a 18F-FDG PET/CT scan presented in poster format. Results: A case study of a 18F FDG PET scan in a 61 year old female with a suspicious malignant 15mm right lower lung nodule shows an incidental finding of an intensely avid 2.4 cm nodule posterior to the left thyroid gland. Given that the 15mm lung nodule is not 18F-FDG avid, the incidentaloma is reported as a likely parathyroid adenoma. The consequential biochemistry suggests the patient has primary hyperparathyroidism with elevated parathyroid hormone (PTH) level of 14.0 mmol/L and a serum calcium level of 3.04 mmol/L. The pathogenesis of primary hyperparathyroidism is most commonly due to the presence of a parathyroid adenoma therefore a parathyroid scan, ultrasound and fine needle aspiration were successively performed. Conclusion: The patient was subsequently diagnosed with a parathyroid adenoma posterior to the left thyroid gland and underwent a parathyroidectomy. The patient was also found to be suffering with osteopenia and was managed appropriately. The consideration of a parathyroid adenoma in this case considerably altered this patient’s management. This case study is an excellent example of the sensitivity of 18F-FDG PET/CT scans and the importance of exploring all likely causes of unusual avidity.


   P047: Forearm Dual-Energy X-Ray Absorptiometry for Primary Hyperparathyroidism Top


Matt Daley*1, J Lee2

1Mater Hospital, 2Department of Nuclear Medicine, The Prince Charles Hospital, Brisbane, Australia

Background/Aims: Primary hyperparathyroidism (PHPT) is a disease whose natural history leads to symptomatic hypercalcaemia, renal calculi, premature osteoporosis, and increased risk of fracture. Operative management remains the only cure, and is indicated if a patient is osteoporotic. Our aims were to: 1) evaluate how often the (distal) radius findings changed the overall bone mineral density (BMD) assessment, and 2) evaluate whether considering other sites other than hip, spine or distal-third radius in dual-energy x-ray absorptiometry (DXA) scans increased the incidence of osteoporosis diagnosis. Methods: 2277 consecutive DXA scans at a tertiary hospital were retrospectively reviewed from the years 2012 to 2016 inclusive. The cohort for this study was identified by selecting patients who had a forearm DXA performed, and diagnosis of PHPT noted on their DXA request. Individuals had their T- and Z-scores at the hip, spine, distal third radius, ultra-distal (UD) radius and total radius tabulated. T- and Z-scores for the UD radius and total radius were obtained from a standardised reference population (combined NHANES/Lunar). Results: 65 instances of a patient who had a DXA scan for PHPT were identified, corresponding to 56 unique individuals. These individuals were predominantly female (42:14) and had a mean age of 62.8 years. Of the 56 individuals identified, 6 (10.7%) had a diagnosis of osteoporosis made on distal third radius when they otherwise had osteopenia based on hip and spine DXA only. Interestingly, an additional 5 patients (8.9%) would have a diagnosis of osteoporosis if the UD radius was included in addition to the three sites above. Conclusion: This study identified a significant cohort of patients who, if radial BMD sites are considered, would have a diagnosis of osteoporosis and an indication for parathyroidectomy. While the UD radius is not currently advocated as a location for diagnosis in osteoporosis, the findings of this study supports emerging literature advocating for inclusion of this data.


   P048: Usefulness of the Portable Gamma-Camera in Radioguided Parathyroidectomy in Patients with Oncologic Disease: A Single-Centre Experience in Mexico Top


Sevastian Medina-Ornelas*1, F García-Pérez1, A Gómez-Pedraza2

Departments of 1Nuclear Medicine and 2Head and Neck Surgery, Instituto Nacional de Cancerologia, Mexico City, Mexico

Background/Aims: Evaluate the utility of portable gamma-camera (pGMC) at real time intraoperative imaging for assessing localization of parathyroid adenoma in patients with oncologic disease. Methods: This was a retrospective analysis of patients with parathyroid adenoma and oncologic underlying condition, such as breast cancer, renal, prostate, cervix, ovarian, and melanoma; who underwent radioguided surgery at Instituto Nacional de Cancerología (INCan, México). Planar scintigraphy was performed 15 minutes after intravenous injection of 99mTc-MIBI, 60-120 minutes before intervention. pGMC was used to identify the adenoma during surgery, as well as to verify if it was removed completely. All surgical specimens were taken for intraoperative histopathological evaluation. Results: 20 patients were diagnosed with parathyroid adenoma (17 with usual location and 3 with ectopic location). Parathyroid adenoma was localized intraoperatively with a portable gamma-camera in all patients, reducing the time of surgery. After removing the adenoma, the activity it was verified in vivo and ex vivo. All surgical specimens were confirmed as parathyroid adenoma in the intraoperative and definitive histopathological evaluation. In all cases the radioactivity measured intraoperatively with pGMC, identified the affected gland, which coincided with the scintigraphy findings previous. pGMC showed sensitivity, specificity, diagnostic accuracy, PPV, and NPV values of 100%. No patient was identified disease multiglandular. All patients had normal levels of calcium postoperative serum with mean 9.5 mg/dl (CI 95%: 7.65-10.33 mg/dl), and PTH values with mean 47 pg/ml (CI 95%: 10-55 pg/ml). Conclusion: pGMC in intraoperative identification of parathyroid adenoma has contributed to the development of minimally invasive parathyroidectomy. Therefore, in our opinion, in addition to the realization of preoperative scintigraphy, radioguided surgery with pGMC should always be performed, thus reducing complications, hospital stay, surgical and recovery time, with the same therapeutic effectiveness as classical treatment.


   P049: Feasibility and Safety of Minimally Invasive Radioguided Parathyroidectomy using Very Low Intraoperative Dose of 99mTc-Sestamibi Top


M Mehrabibahar1, Ramin Sadeghi*2, Z Mousavi3, P Layesh3, M Noori1, M Asadi1

1Surgical Oncology Research Center, Mashhad University of Medical Sciences, 2Nuclear Medicine Research Center, Mashhad University of Medical Sciences, 3Endocrine Research Center, Mashhad University of Medical Sciences, Mashhad, Islamic Republic of Iran

Background/Aims: Surgical resection of the abnormal parathyroid glands is the only curative treatment for primary hyperparathyroidism (PHPT). Radioguided parathyroidectomy with 99mTc-sestamibi has been successfully used in patients with PHPT. This study was designed to evaluate the results of a series of patients with PHPT who underwent minimally invasive radioguided parathyroidectomy (MIRP) using very low dose (1 mCi) of 99mTc-sestamibi (MIBI) without application of intraoperative parathyroid hormone (PTH) assay or frozen section analysis. Methods: Eighty-seven patients with PHPT were prospectively studied from November 2012 to January 2015. Following neck ultrasound and MIBI scan concordant for single gland disease, patients underwent MIRP using a handheld gamma probe. The technique involved injecting of 1 mCi MIBI in the operative room before the beginning of the intervention. All patients were followed up for a minimum of 6 months postoperatively. Results: MIRP was successfully performed in 86 out of 87 patients (98.85%). The gamma probe was particularly useful in detection of ectopic parathyroid adenomas in upper mediastinum. Mean operative time was 23.95±7.982 min and mean hospital stay was 1.44±0.604 days. No major surgical complications were recorded. Conclusion: The MIRP technique using very low dose (1 mCi) of 99mTc-sestamibi without intraoperative PTH assay and frozen section analysis resulted in excellent cure rate for PHPT. This technique involves a radiation exposure to patients and surgical staffs 20 times lower than conventional MIRP using 20 mCi 99mTc-sestamibi. Besides, patients with PHPT due to ectopic parathyroid adenoma may especially benefit from MIRP.


   P052: The Clinical Value of 99mTc-Sestamibi Single Photon Emission Computed Tomography/Computed Tomography versus Four-Dimensional Computed Tomography or Ultrasound in Management of Patients with Hyperparathyroidism Top


Karthika Ramakrishnan*1, C Fundakowski2, S Dadparvar1

Departments of 1Radiology and 2Otolaryngology, Temple University Hospital, Philadelphia, Pennsylvania, United States

Background/Aims: Parathyroid adenomas result in primary hyperparathyroidism and surgery is the mainstay of therapy. Localisation, however, can be challenging. Although 99mTc-MIBI SPECT/CT is the gold standard for detection, recently 4DCT and ultrasound (US) are being utilized. This retrospective study compared SPECT/CT, 4DCT and US studies in detection of adenomas prior to surgery. Additionally, feasibility of intraoperative localisation with preop injection of Tc-MIBI was evaluated. Methods: Of 102 patients who underwent parathyroid imaging, 41 patients (31 female, 10 male) underwent surgery. Patients’ age ranged 28-77 (mean 57.9 years) with PTH levels ranging 44-2400 pg/mL (mean 326). All patients underwent SPECT/CT with 20 mCi Tc99m-MIBI. Thirty-five patients had additional US imaging and 14 patients had 4DCT scans. Additionally, 15 patients had injection of 10mCi Tc99m-MIBI on the day of surgery. Pathological correlation was performed. Results: There were 37 adenomas, 3 normal tissues and 1 parathyroid carcinoma. Comparing SPECT/CT vs 4DCT resulted in sensitivity (0.84 vs 0.35, p=0.03), specificity (0.33 vs 1.0, p=0.002) and accuracy (0.80 vs 0.38, p=0.02). Comparing SPECT/CT vs US resulted in sensitivity (0.84 vs 0.42, p=0.03), specificity (0.33 vs 0.67, p=0.02) and accuracy (0.80 vs 0.46, p=0.02). Combination of SPECT/CT and 4DCT increased sensitivity to 0.91, specificity to 0.33 and accuracy to 0.72. Combining SPECT/CT with US resulted in sensitivity of 0.92, specificity of 0.78 and accuracy of 0.78. Intraoperative localisation improved in patients who received preop injections. Conclusion: SPECT/CT remains the best imaging modality for preoperative localisation of parathyroid adenomas with high sensitivity. Combining SPECT/CT with either 4DCT or US in challenging cases resulted in increased sensitivity and accuracy. We recommend utilizing SPECT/CT as the primary modality in detection of parathyroid adenomas, and for challenging cases addition of 4DCT or US. Intraoperative localisation and adjunctive imaging may improve surgical management of patients with hyperparathyroidism.


   P053: Diabetes Testing in Positron Emission Tomography: Is There a Sweet Spot? Top


Jean Elamrousy*1, R Quinn1

1Department of Nuclear Medicine, St. George Hospital, Sydney, Australia

Background/Aims: Diabetes is an increasing problem in the Australian population. Only 50% of people with diabetes are tested and diagnosed. Therefore, a significant portion of the population have undiagnosed diabetes. For a PET scan, patients routinely fast overnight. Before the test a blood glucose level is taken using a blood glucose monitor (BGM). The Australian standard for the diagnosis of diabetes is: fasting glucose (serum) > 7 mmol/L, HbA1c > 6.5% (48 mmol/L), random glucose > 11.1 mmol/L and oral glucose tolerance test. In asymptomatic patients, the standard for diagnosis is an abnormal result on two different diagnostic tests. A BGM measurement that is greater than 6mmol/L, in a fasting patient not known to be diabetic, requires further assessment. This work assesses the incidence of previously undiagnosed diabetes, the accuracy of blood glucose monitors and the efficacy of this approach in a PET scan setting. Methods: In patients with a BGM of >6mmol/L with no history of diabetes, blood was collected along with a patient history and a fasting blood glucose level and a HbA1c were performed. If the results indicated diabetes then a letter including the results was sent to the patient’s doctor. Results: The BGM was found to overestimate a patient’s BSL with a mean difference of 0.871 (paired t-test, p<0.0001). Of 728 PET scan patients, 101 had known diabetes. Of the remainder, 103 had a BGM above 6 mmol/L. Of these, 43 patients had a fasting glucose blood test and a HbA1c; 3 were found to have diabetes and 11 had results indicating pre-diabetes. Conclusion: Patients that have a BGM over 6 mmol/L should be tested for diabetes and follow up and management should continue with the patient’s doctor.


   P054: 25-Hydroxyvitamin-D Serum Levels in Patients with Type 2 Diabetes Mellitus: Correlation with Disease Severity Top


M Katsibri1, C Tsigalou2, M Lambropoulou3, A Pistola1, Z Orestia1, T Lianou4, S Darousi1, V Aristotelidou4, N Papanas5, Athanasios Zissimopoulos*1

1Department of Nuclear Medicine, 2Laboratory of Biopathology-Immunology, 3Laboratory of Histology-Embryology, 4Department of Molecular Biology and Genetics, 5B’Pathological Clinic, Democritus University of Thrace, Alexandroupolis, Greece

Background/Aims: Diabetes Mellitus (DM) is a condition of increasing prevalence worldwide. In recent studies, there is an association with vitamin D deficiency and the risk of developing diabetes and diabetes complications. The aim of this study is to evaluate the 25-hydroxyvitamin-D (25-ΟΗ-D) serum levels in patients with type 2 diabetes mellitus in correlation with the disease severity. Methods: We studied 108 patients (66 male and 42 female) aged between 43 and 70 years old (median age 58±12 years) with type 2 diabetes mellitus, with or without diabetes complications. All were followed up at the University Hospital of Evros. The vitamin D levels were measured by radioimmunoassay (RIA) method with Diasorin kits at in-vitro laboratory of Nuclear Medicine Department of the University Hospital of Evros, Democritus University of Thrace. We also studied 40 healthy individuals (blood donors) as the control group. Statistical analysis was performed by the x2-test (student test) and statistical significance was considered for p<0.005. Results: Diabetes mellitus patients had lower levels of (25-ΟΗ-D) than controls (p<0.005). In 62 patients with severe complications of the disease the levels of (25-ΟΗ-D) were significantly low, at 0-20ng/mL (p<0.005) (deficiency). In 28 patients with mild complications of the disease the levels of (25-ΟΗ-D) were 20-29ng/mL (insufficiency), and the rest 18 with no complications had sufficient levels of (25-ΟΗ-D) >40 ng/mL (p<0.005). Conclusion: Diabetes mellitus patients had lower levels of (25-ΟΗ-D) than controls. Patients with severe complications of the disease had significantly lower levels than the others. Vitamin D deficiency may be a risk factor for DM. Clinical trials with vitamin D supplementation are needed.


   Infection/Inflammation Top



   P055: 68Ga-citrate and 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Management of Patients with Known or Suspected Tuberculosis: A Prospective Comparative Study Top


A Ankrah*1,2, T Ebenhan1, T Boshomane1, I Lawal1, H Klein2,3, A Glaudemans2, M Sathekge1

1University of Pretoria, Pretoria, South Africa, Departments of 2Nuclear Medicine and Molecular Imaging and 3Psychiatry, University Medical Center Groningen, Groningen, Netherlands

Background/Aims: 68Ga-citrate is, like 18F-FDG, a PET tracer that images infection and inflammation. In this study, we compared these 2 tracers in patients with known or suspected tuberculosis (TB). Methods: Approval for the study was granted by the institutional ethics committee. Every participant had at least one pair of PET/CT scans (68Ga-citrate and 18F-FDG). The scans were acquired within two weeks of each other. All lesions detected by the tracers were counted and maximum standard uptake values (SUVmax) were recorded. Results: 21 patients were prospectively recruited (age±mean was 37.95±10.25 years; Male=9, Female=12). A total of 54 PET/CT scans were acquired. One pair of scans was acquired in 15 patients while six patients had two pairs (five at baseline and two months after therapy, and one at baseline and at the end of therapy). 12 patients had microbiologic confirmation, six had clinical confirmed diagnosis and three had suspected TB. 15 of the patients were HIV-positive. 68Ga-citrate detected significantly less lesions (718 vs. 601, p<0.001) and had lower mean SUVmax (2.27 vs. 5.56, p<0.0001) compared to 18F-FDG. The extra lesions detected by 18F-FDG were mostly additional lymph nodes around the vasculature that did not change management. In one patient, TB of the pericardium detected by 18F-FDG was not detected by 68Ga-citrate. In another patient, 68Ga-citrate detected more intracranial abscesses than 18F-FDG. Inflammatory lesions were detected in three patients on 18F-FDG when 68Ga-citrate showed no uptake. 68Ga-citrate correctly diagnosed no residual vertebral TB when findings on 18F-FDG were equivocal. Both tracers detected good response in all five patients with confirmed TB that correlated with their good clinical outcome. Conclusion: Despite finding less lesions, 68Ga-citrate performed as well as 18F-FDG PET in the management of TB. 68Ga-citrate can be particularly useful in the detection of intracranial lesions.


   P056: 18F-Fluorodeoxyglucose Positron Emission Tomography in the Management of Patients with Invasive Fungal Infections Top


A Ankrah*1,2, E de Vries1, R Slart1,3, R Dierckx1, H Klein1,4, M Sathekge2, A Glaudemans1

Departments of 1Nuclear Medicine and Molecular Imaging and 4Psychiatry,, University Medical Center Groningen, Groningen, 3University of Twente, Enschede, Netherlands, 2Department of Nuclear Medicine, University of Pretoria, Pretoria, South Africa

Background/Aims: 18F-FDG PET has proven added value in many malignant diseases, and its role in infectious diseases is increasing but for many indications it still has to be defined. Here, we evaluated the added value of 18F-FDG PET compared with conventional imaging in the management of patients with invasive fungal infections (IFIs). Methods: Patients with proven IFIs (by histology or cultures) who underwent a 18F-FDG-PET/CT were included. All patient dossiers were checked for infection parameters, clinical history, and imaging procedures. 18F-FDG-PET/CT findings were compared to the findings on other imaging modalities to determine if 18F-FDG–PET/CT could provide more information. The 18F-FDG-PET findings were also correlated to the infection markers. The local institution review board approved this retrospective study and waived the requirement for informed consent. Results: A total of 80 scans were acquired in 46 patients (mean age±SD = 43.75±23.68 years, M:F = 29:17). 18F-FDG-PET detected significantly more lesions (533 vs. 343, p<0.001) compared to conventional imaging. In 19 patients, more lesions were detected. The majority (17) of these patients had extra-thoracic disease. In 6 patients, 18F-FDG-PET/CT noted disease activity where findings on other modalities were equivocal. In 4 patients, 18F-FDG-PET/CT excluded infection allowing immunosuppressive therapy to be undertaken. In 3 patients, follow-up 18F-FDG-PET/CT resulted in a change in antifungal therapy. In 3 patients, there was no evidence of metabolic uptake when lesions persisted on conventional imaging allowing antifungal therapy to be stopped. In total, 18F-FDG-PET/CT showed added value in 35 (83.3%%) patients, potentially influencing clinical decision making. No correlation was found between the infection parameters and 18F-FDG-PET/CT findings. Conclusion: 18F-FDG PET/CT has significant added value over conventional imaging in both the initial staging of IFIs and follow-up of disease, leading to changes in therapy decision making.


   P057: Positron Emission Tomography/Computed Tomography in Evaluation of Extrapulmonary Tuberculosis and Treatment Monitoring in Multidrug-Resistant Tuberculosis Top


Shamim Momtaz Ferdousi Begum*1, M A S Khan2, F Begum1, K K Nath1, F T Zohra1, N Nahar1

1National Institute of Nuclear Medicine and Allied Sciences, Bangladesh Atomic Energy Commission, 2National Institute of Diseases of the Chest and Hospital, Dhaka, Bangladesh

Background/Aims: FDG PET/CT has the ability to quantify 18F-FDG uptake in infection and can localize the active tuberculosis (TB) with extension. This study observed the ability of FDG PET/CT in evaluation of extra-pulmonary tuberculosis (EPTB) and monitoring treatment response in multidrug resistance (MDR) TB. Methods: This prospective study was approved by the Medical Research Ethics Committee and conducted at National Institute of Nuclear Medicine and Allied Sciences, Dhaka, Bangladesh, under an IAEA CRP 15021. Twenty-five EPTB patients, among them thirteen were culture positive for MDR TB enrolled from November 2015 to November 2017. All patients underwent baseline whole-body 18F FDG PET-CT scan before starting anti-tubercular drugs. In MDR TB patients first and second follow up scans were performed after two and eight months of initiation of therapy. Standardised uptake values (SUVmax) and size of the lesions were measured in follow up respectively and then compared. Results: All 25 patients (15 male, 10 female, age range 18-65 years, average age 26.5±12.3years) showed increased FDG uptake in extra-pulmonary lesions in baseline PET/CT scan. The mean SUVmax values of pleural, pulmonary lesions and lymph nodes in MDR TB patients were 4.56±5.35, 7.0±5.35 and 6.17±4.97 respectively with average size of involved lymph node 15.74±9.12mm. Follow-up scans showed reduced FDG uptake with decreased mean SUVmax values comparing to the baseline, which was not significant in first follow up but significant in second follow up. Follow-up scans also showed morphological change with significant reduction of size of lymph nodes at second follow up. Conclusion: 18F-FDG PET/CT plays a potential role in localising EPTB and treatment monitoring of both pulmonary and extra-pulmonary MDR TB. Reduction of SUVmax value and size of lesions after anti MDR TB treatment suggests response.


   P058: A Prospective Comparison of Disease Burden, Pattern and Response Assessment between HIV-Positive and HIV-Negative Patients with Extrapulmonary Tuberculosis using 18F-Flurodeoxyglucose Positron Emission Tomography/Computed Tomography Top


G Boshomane*1, A Ankrah2, I Lawal1, T Lengana1, K Ololade1, F Reynecke1, A Kaoma1, M Vorster1, M Sathekge1

1University of Pretoria, Pretoria, South Africa, 2University Hospital Groningen, Groningen, Netherlands

Background/Aims: Extrapulmonary tuberculosis (EPTB) patients require swift and accurate stratification prior management, but the disease remains difficult to diagnose and treat. Imaging with 18F-FDG PET/CT may emarge as one of the significant steps in the managemnet of tuberculosis. We aim to evaluate the value of 18F-FDG PET/CT in the assessement of tuberculosis actvity, pattern and response to therapy in comparison with CT in HIV negative and positive patients with EPTB. Methods: Ehical approval was granted, and consented patients with EPTB undewent imaging with 18F-FDG PET/CT prior to therapy, after 2-months on anti-tuberculosis treatment and post-therapy. Findings were evaluated qualitatively and semi-qualitatively (SUVmax) and compared to CT results. Results: Thirty-two patients with EPTB (mean age 38 years, range 18-58 years) underwent a total of 53 18F-FDG PET/CTs. Twenty-two (68%) patients were retroviral disease positive, of whom 13 (59%) had absolute CD4 counts <200 cells/uL. 18F-FDG PET/CT was positive in 31 of 32 baseline scans (96%). HIV positive patients (57%) demonstrated a more extensive extranodal burden compared to the HIV negative patients. PET was superior to CT in discriminating responders to non-responders. Furthermore, PET outperformed CT in 10 (31%) patients, with more extensive disease detected. Conclusion: 18F-FDG PET/CT is useful in the assessment of EPTB activity, pattern and response to therapy comparison with CT in HIV naive and positive patients with extrapulmanary tuberculosis.


   P059: Iliopsoas Abscess-Hidden Pathology Revealed by Three-Phase Bone Scan Top


G Cehic1, Debra Huddleston*1, D Topham1

1Flinders Medical Centre, Adelaide, Australia

Background/Aims: A 75 year old woman with a history of stage III C undifferentiated ovarian cancer presented with right hip pain. Previous plain films were normal. The patient did not have any musculoskeletal tenderness. A bone scan was requested to exclude bony metastases. Methods: The patient was injected with 725 MBq 99mTc-HDP. Early images included anterior blood flow of the pelvis followed by anterior/posterior blood pool images of the lumbar spine and pelvis on a Symbia S system. Delayed images included anterior and posterior whole body, lateral skulls and oblique rib views with SPECT/CT of the pelvis acquired on a Phillips Brightview XCT. Results: Blood flow of the pelvis was normal. Blood pool images of the pelvis and lumbar spine showed a region of hyperaemia in the right iliac fossa. Delayed images showed a focus of mild increased activity in the distal left femur which was later confirmed on x-ray as enchondroma. Delayed images showed the right kidney and proximal ureter were obstructed. SPECT/CT images of the pelvis demonstrated an abnormal soft tissue density in the right retroperitoneum adjacent the right psoas muscle which correlated with the hyperaemia on early blood pool imaging. Appearances were consistent with retroperitoneal lymphadenopathy or haematoma with associated ureteric obstruction. No osteoblastic metastases were demonstrated. A subsequent diagnostic CT abdomen and pelvis confirmed a right iliopsoas abscess with associated inflammatory changes. Cytology performed on the abscess fluid was negative for malignant cells. Conclusion: Although SPECT/CT is often credited for improved bone scan sensitivity, this case clearly demonstrates that early imaging is still an integral component of whole body scintigraphy. The diagnosis of a soft tissue mass, in this case an iliopsoas abscess, was made possible by performing a full three phase bone scan.


   P060: Evaluation of Proteinuria in Lupus Nephritis with Semiquantitative 67Ga-Single Photon Emission Computed Tomography/Computed Tomography Top


Yu-Hung Chen*1, S H Liu2,3, S T Tsai4

1Nuclear Medicine, 2Department of Nuclear Medicine, Tzu-Chi General Hospital, 4Division of Allergy, Immunology, and Rheumatology, Tzu-Chi General Hospital, 3Department of Medical Imaging and Radiological Sciences, Tzu Chi College of Technology, Hualien, Taiwan

Background/Aims: Proteinuria is common for lupus nephritis and it can reflect the severity. The semiquantitative planar 67Ga image has been used as a surrogate to assess severity. However, bowel preparation is required. We therefore use SPECT/CT to obviate this problem. Methods: A retrospective review of 18 cases with lupus nephritis was conducted from May 2016 to June 2017. The study has been approved by the local Institutional Review Board and Ethics Committee. A waiver of consent has also been obtained. The urinalysis and 67Ga images from the subjects were recorded for analysis. The proteinuria was measured by test strip methods (0 to +4). The regions-of-interests of 67Ga SPECT/CT were placed on the liver, left kidney and spines. The kidney/liver (LK/L) and kidney/spine (LK/S) were calculated. Spearman’s correlation coefficients (ρ) were calculated for the image measures and the test strip results. Results: Correlation analysis of the image measures with the test strip results showed that the ρ for LK/L and LK/S were 0.124 and 0.412, respectively. In order to realise the inter-subject variability of liver uptake, we also calculated the liver to spine ratio (L/S). The maximum and minimum of L/S were 2.696 and 0.774, respectively. The average of L/S was 1.622, with a standard deviation of 0.488. Conclusion: The LK/S better correlates with proteinuria, although the correlation is only moderate. The LK/L shows poor correlation with proteinuria, probably related to a high intersubject variability of liver uptake. Thus, liver is not a good reference organ for semiquantitative analysis. Further larger study number and correlation with pathologic finding are needed.


   P061: Simultaneous Positron Emission Tomography/Magnetic Resonance Imaging in the Evaluation of Diabetic Foot Infections Top


Dinko Franceschi*1, K Yaddanapudi2, R Matthews1, N Relan1

1Radiology, 2SUNY, Stony Brook, Stony Brook, New York, United States

Background/Aims: A new hybrid technology combining positron emission tomography (PET) with magnetic resonance imaging (MRI) has been increasingly used in cancer and brain imaging. We evaluated its utility in patients with diabetic foot infections. Infected wounds in the foot are common problem in patients with diabetes. Diagnosis of osteomyelitis in the setting of chronic foot infections is very challenging. Methods: We performed 17 PET/MRI scans in 14 patients with diabetic foot infections in order to determine involvement of the bones. Well delineated focal increased FDG uptake in the bone within the region of soft tissue infection suspected for the bone involvement was considered as osteomyelitis. Signal abnormalities on MRI imaging were graded and classified as normal (grade 0), edema (grade 1), and confluent T1 hypointense signal (grade 2). Grade 2 signal in bone was considered as indicative of osteomyelitis. In 14 cases surgery was performed and histopathological correlation was obtained. Results: In 13 cases, abnormal PET/MRI findings indicated bone involvement in diabetic patients with foot infections. Sites of osteomyelitis included phalanges (8), metatarsals (4), tarsal bones (2) and calcaneus (1). In 10 of these positive cases histopathology was available and confirmed osteomyelitis (sensitivity 100%). Also in 4 patients without PET/MRI findings for bone involvement pathology results were negative. There was discrepancy between PET and MRI findings in three patients with false negative results on MRI images (MRI sensitivity 70%). Conclusion: FDG PET/MRI proved to be highly accurate modality for diagnosis of osteomyelitis in diabetic patients with chronic foot infections. While PET appears to be more sensitive modality, simultaneous MRI acquisition and its superior tissue contrast resolution is essential to localize abnormal FDG uptake in the bones and achieve high specificity.


   P062: Role of 18F-Flurodeoxyglucose Positron Emission Tomography/Computed Tomography in Documenting the Disease Burden in Pott’s Spine Top


Sanjay Gambhir*1, K Rangan1, N Kakani2, S Kumar2, A Singh1, M Ravina1, M Dixit1

1Sanjay Gandhi Postgraduate Institute of Medical Sciences, 2KGMU, Lucknow, Uttar Pradesh, India

Background/Aims: Study aims at demonstrating the potential use of 18F-FDG-PET/CT in evaluating the disease burden in Pott’s spine, and to assess its complementary role with MRI spine. Finally, to explore its impact in planning duration of treatment, change in management and establishing therapeutic end point. Methods: 36 Pott’s spine patients were recruited and subjected to standard 18F-FDG PET/CT imaging. At baseline, scan results were independently assessed and region specific comparison was done with MRI spine. In follow up, only 18F-FDG PET/CT was done and results were compared with its previous scan results. Based on the metabolic response in the follow up scans, subjects were categorised as progressive disease (PD), stable disease (SD), partial response (PR) or complete metabolic response (CMR). Results: Among 36 patients, median age was 47 (range, 18-75) years, and men representing 57% of the total study subjects. 18F-FDG PET/CT confirmed MRI findings in all the subjects, and also revealed additional findings in these subjects, such as extensive lymph-node involvement in 9 subjects, lung lesions in 10 subjects, bilateral psoas abscess in 3 subjects, a right sternoclavicular joint uptake and 12 subjects with extensive bone marrow activation. In the follow-up study, 15 subjects underwent a 2nd scan, of which 3 had CMR, 10 had PR and 2 with PD. Third follow-up scan was done in 6 subjects, of which 2 had CMR, 2 had PR and 2 with PD. Progressive disease patients had MDR disease status. Conclusion: 18F-FDG PET/CT has an admirable role in delineation of actual disease burden in tuberculosis and a complementary association with MRI. Thus, it can be a one shop stop modality in assessing the disease burden at the start of the treatment, can play a pivitol role in individualizing management, monitoring disease status and help in guiding the physicians to reach the therapeutic end point.

Acknowledgement

IAEA, Coordinated Research Project E 15021.


   P063: Diagnostic Value of 99mTc-Ethambutol in the Management of Pulmonary Tuberculosis Top


Yulia Kurniawati*1, A Kartamihardja2, A Yuwono2

1Universitas Andalas, Padang, 2Universitas Padjadjaran, Bandung, Indonesia

Background/Aims: Ethambutol labelled 99mTc-pertechnetate (99mTc-Ethambutol) will be specifically taken up by Mycobacterium tuberculosis (M. tuberculosis) and it can be used to detect tuberculosis. The aim of this study was to know the diagnostic ability of 99m Tc-Ethambutol scintigraphy in identifying M. tuberculosis infection of pulmonary tuberculosis (pulmonary TB). Methods: A case control study was conducted on 43 Subjects suspected of pulmonary tuberculosis who came to Pulmunology Policlinic of Dr. Hasan Sadikin General Hospital consecutively. Subjects were divided into two groups (25 subjects of pulmonary TB as cases and 18 subjects of non-pulmonary TB as control group).99mTc-Ethambutol scintigraphy was performed in all subjects and then qualitatively analysed by observing pathological uptakes by 1, 4 and 24 hours. Results: The data were analysed by 2x2 table. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 99mTc-Ethambutol scintigraphy were 92%, 72%, 82%, 87% and 84% respectively. False negative and false positive were observed due to 99mTc-Ethambutol uptakes based on characteristic of tuberculosis lesions. Conclusion: 99mTc-Ethambutol scintigraphy is a promising diagnostic modality which showed good performance in detecting of pulmonary tuberculosis lesions.


   P064: Incidental Treatment of Mycobacterium avium Complex Infection with 131-Iodine Top


T Langton1, V Agarawol2, R Shretha3, Nat Lenzo*1,4,5

Departments of 1Nuclear Medicine, 2Oncology and 3Respiratory Medicine, Fiona Stanley Hospital, 5University of Western Australia, Perth, 4Theranostics Australia, East Fremantle, Australia

Background/Aims: Mycobacterium avium complex (MAC) is a non-tuberculous mycobacterial infection more commorn in women, in those with underlying structural lung damage, the elderly and in immunocompromised patients. Treatment regimens are complex and often poorly tolerated. Multi-resistance is becoming an increasing problem limiting treatment options. This is a case of incidental treatment of MAC using 131I as adjuvant therapy for papillary thyroid carcinoma. Methods: 72 year old female with history of MAC infection presented with symptoms of weight loss, persistent cough and breathlessness. Past history: NIDDM; 40 pack year cigarette exposure. Patient was undergoing CT surveillance and was not on any treatment for MAC infection. Progression of nodules were noted therefore an FDG PET scan was ordered. PET scan revealed a “hot” thyroid nodule. Biopsy confirmed a thyroid malignancy. Total thyroidectomy pathology revealed a 15mm papillary carcinoma with involved margins and extrathyroidal extension. 2/8 central lymph nodes were involved. After counselling she was treated with 4.5 GBq of 131I following ThyrogenTM stimulation. Results: Post-Thyrogen TSH: 160 mU/L; thyroglobulin 0.4 ug/L. Post 131I therapy scan: remnant activity in the thyroid bed. 131I uptake in lungs correlated on SPECT/CT to the known granulomatous lung disease. Post-therapy monitoring at 3 months revealed significant clinical improvement with resolution of cough, weight gain and improved well-being. Thyroglobulin 0.1 ug/L. There was objective radiological improvement in the form of a contraction in the lung lesions and clearance of prior inflammatory changes. This clinical and radiological benefit has persisted over time. Conclusion: This patient presented with an incidental thyroid cancer detected by FDG PET. In our published data this occurs in approx 1% of FDG PET scans and approx. 40% of FDG-avid nodules are due to thyroid malignancy.[1] 131I accumulation in granulomas has been described.[2] The mechanism is not well understood. Ionizing radiation has bacteriocidal,[3] and sterilisation effects and is used in a number of industries.[4],[5] To our knowledge this is the first reported case of mycobacteriocidal effect of 131I administered for adjuvant treatment of thyroid cancer. This has potential implications for the growing problem of multi-resistant mycobacterial infection.

References

  1. Flukes S, Lenzo N, Moschilla G, Sader C. Positron emission tomography-positive thyroid nodules: Rate of malignancy and histological features. ANZ J Surg 2016;86:487-91.
  2. Garger YB, Winfeld M, Friedman K, Blum M. J Investig Med High Impact Case Rep 2016;4:???.
  3. Trampuz A, Piper KE, Steckelberg JM, Patel R. Effect of gamma irradiation on viability and DNA of Staphylococcus epidermidis and Escherichia coli. J Med Microbiol 2006;55:1271-5.
  4. Hasanain F, Guenther K, Mullett WM, Craven E. Gamma sterilization of pharmaceuticals – a review of the irradiation of excipients, active pharmaceutical ingredients, and final drug product formulations. PDA J Pharm Sci Technol 2014;68:113-37.
  5. Arvanitoyannis IS, Stratakos ACh, Tsarouhas P. Irradiation applications in vegetables and fruits: A review. Crit Rev Food Sci Nutr 2009;49:427-62.



   P065: Russell Body Gastritis Masquerading as Gastric Lymphoma Top


Sidney Levy*1, S Ramdave1, M Atarod2, G Soo1, I Jong1

1Department of Diagnostic Imaging, Monash Health, 2Melbourne Pathology, Melbourne, Victoria, Australia

Background/Aims: Russell body gastritis is a rare reactive mucosal infiltration of plasma cells filled with cytoplasmic Russell bodies, thought to be related to Helicobacter pylori infection. This case presentation illustrates its importance as a potential mimic of gastric lymphoma on 18F-FDG-PET CT imaging. Methods: Serial surveillance 18F-FDG-PET/CT imaging over an 18-month period from October 2014 to May 2016 was performed on a patient undergoing treatment for Stage IV follicular non-Hodgkin’s lymphoma. The distribution and intensity of gastric FDG avidity was correlated with histopathological analysis of gastric biopsy specimens obtained during gastroscopy in April 2016. Results: Diffuse intense gastric FDG avidity, initially attributed to extra-nodal gastric involvement of follicular non-Hodgkin’s lymphoma, was subsequently found to be caused by Russell body gastritis after analysis of histopathological specimens obtained during gastroscopy. Gastric FDG avidity completely resolved following completion of Helicobacter pylori eradication therapy. Conclusion: Russell body gastritis is an under-recognised mimic of gastric lymphoma on 18F-FDG-PET/CT imaging performed during lymphoma surveillance. It should be considered in cases of isolated diffuse gastric FDG avidity which is discordant with overall lymphoma treatment response.


   P066: Clinical Value of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Rheumatologic Diseases Top


Andrew Nguyen*1,2,3, I Swainson1,2

1Department of Nuclear Medicine, Wollongong Hospital, 3University of Wollongong, 2Illawarra PET Centre, Wollongong, New South Wales, Australia

Background/Aims: FDG PET/CT, integrating functional and anatomical images, has been used worldwide as a powerful imaging modality in oncology. FDG, being a glucose analogue, can also be taken up by inflammatory lesions due to increased glucose metabolism in activated inflammatory cells, such as activated macrophages and proliferating fibroblasts. In the last two decades, there is evolving evidence of the clinical value of FDG-PET/CT in the evaluation of rheumatologic diseases. Several authors have demonstrated the usefulness of FDG PET/CT imaging in the diagnosis and/or the assessment of the severity of inflammatory diseases, including rheumatoid arthritis, spondyloarthritis, polymyalgia rheumatica, adult-onset Still’s disease, relapsing polychondritis, large vessel vasculitis, granulomatosis with polyangiitis, polymyosistis and dermatomyositis. In addition, FDG-PET/CT imaging appears to be useful in the therapy response assessment of some of these inflammatory conditions. FDG-PET/CT has also been shown to have a role in sarcoidosis, a multisystem granulomatous disease that can coexist or mimic rheumatologic diseases such as systemic lupus erythematosis, rheumatoid arthritis and ankylosing spondylitis. In this study, we retrospectively evaluate the clinical value of FDG PET/CT in rheumatologic diseases using our data from the Illawarra PET Centre. Methods: Retrospective study to determine the clinical value of FDG PET/CT in a cohort of rheumatologic patients who had scans at the Illawarra PET Centre over a three and a half year period. These PET/CT scans, reports and relevant clinical data will be reviewed by two experienced PET/CT specialists. Results: During the period from 11.02.2014 to 11.08.2017, there were 139 FDG PET/CT scans performed at the Illawarra PET Centre for the evaluation of rheumatologic disease or presentations. These will be reviewed and discussed. Conclusion: A conclusion will be drawn based on our research findings.


   P067: Whole-Body Bone Scan and 18F-Flourodeoxyglucose Positron Emission Tomography/Computed Tomography in a Case of Voriconazole-Induced Periostitis Top


Renee Praehofer*1, C Chew1

1Department of Nuclear Medicine PET and Bone Mineral Densitometry, Royal Adelaide Hospital, Adelaide, Australia

Background/Aims: Voriconazole is an antifungal that can cause periostitis. We present the bone scan and FDG PET findings in such a case. Methods: A 20 year old male with treated B-cell acute lymphoblastic leukemia presented with severe generalised joint pain, deconditioning and weight loss. He was on voriconazole for presumed fungal infection for 7 months and periostitis was diagnosed. A bone scan and FDG PET scan were ordered for hypercalcemia. The whole body bone scan with 800 MBq 99mTc MDP performed with SPECT/CT covered neck to pelvis. PET/CT with 285 MBq 18F FDG covered vertex to thighs. This case report was approved by the ethics committee of our hospital. Results: The bone scan showed diffuse arthropathy in upper and lower limbs and the axial skeleton. The CT showed osteophytes in the long bones adjacent to joints, vertebral interspaces, manubrium and scapulae which were radiotracer avid compatible with voriconazole induced periostitis. The PET showed marked FDG marrow avidity in the axial and appendicular skeleton compatible with leukemia recurrence which was confirmed on marrow biopsy. In addition, some of the MDP avid osteophytes were also FDG avid indicative of active inflammation. Conclusion: Voriconazole induced periostitis can result in florid bone scan abnormalities which resemble a paraneoplastic process. FDG PET will also demonstrate active bone inflammation and should be a diagnostic consideration in patients on voriconazole. Voriconazole causes debilitating diffuse periostitis possibly from fluoride toxicity that induced bone formation with bone scan appearance resembling paraneoplastic hypertrophic osteoarthropathy in the long bones. The distinguishing feature was the florid bony involvement that included the axial skeleton. The FDG PET showed leukemia recurrence. FDG avidity was demonstrated in sites of active periosteal reaction as it can detect active inflammation. This case highlights the importance of knowing the clinical history when interpreting scans.


   P068: The Role of Flourodeoxyglucose Positron Emission Tomography/Computed Tomography in Determining the Foci of Infection Postvascular Grafts Top


Christian Testa*1, K Pathmaraj1, S T Lee1,2,3, A M Scott1,2,3,4

1Department of Molecular Imaging and Therapy, Austin Health, 2Olivia Newton-John Cancer Research Institute, Austin Health, Heidelberg, 3School of Cancer Medicine, La Trobe University, 4Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia

Background/Aims: A 87 year old female, with a recent history of thoracic endovascular aortic repair (TEVAR) for a penetrating aortic ulcer, presented with fevers and gram negative bacteraemia with no identifiable source. A 18F-Fluoro-deoxyglucose (FDG) PET/CT study was requested for investigation of the infective focus. Methods: A total body FDG PET/CT study was undertaken according to standard departmental protocol, with the patient scanned from skull vertex to toes following intravenous administration of 222MBq of 18F-FDG and an uptake period of 69 minutes. Images were acquired on the Philips Ingenuity TF 128 scanner. Results: Moderately intense FDG uptake was demonstrated along the length of the descending thoracic aortic graft, along with associated FDG uptake in the peri-aortic soft tissues, which was consistent with infection of the thoracic aortic graft. Additionally, mild FDG uptake was identified within small hilar and mediastinal lymph nodes, as well as within bilateral pleural effusions, which were considered reactive. The patient subsequently underwent appropriate antibiotic therapy resulting in resolution of the infection. Conclusion: Infection of prosthetic vascular grafts is a rare but potentially severe complication in reconstructive vascular surgery, although early diagnosis can substantially reduce morbidity and mortality.[1] The sensitivity of FDG PET/CT in the detection of such infections is well established. This case highlights the value of FDG PET/CT in infectious disease identification and localisation, as well as its concurrent benefits such as non-requirement of ex-vivo blood handling and decreased patient radiation burden compared with traditional procedures for infection imaging.

References

  1. Karaca S, Rager O, Albrecht S, et al. Vasc Dis Manag 2012;9:113-2.



   P069: Tracking Zika Virus Disease Pathology with Flourodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging Top


Carla Bianca Victorio*1, J Y Tham1, S Watanabe2, A Sekula1, E Koumarianou1, J Ong1, M J Reolo1, J Low3, S Vasudevan2, A M Chacko1

1Laboratory for Translational and Molecular Imaging, 2Duke-NUS Medical School, 3Department of Infectious Diseases, Singapore General Hospital, Singapore

Background/Aims: Apart from the brain and testes, the primary organ sites of Zika virus (ZIKV)-induced pathology during the course of infection are still largely unknown. 18F-fluorodeoxyglucose (FDG)-PET/CT is clinically validated for tracking metabolic changes in tumours, and is increasingly explored for tracking inflammation and infection. With our recent success in using FDG as a PET imaging biomarker in dengue virus infection, we extended our study to include ZIKV. We hypothesized that FDG-PET/CT imaging of ZIKV-infected mice will facilitate non-invasive monitoring of metabolic changes during infection and reveal inflammation-mediated disease pathology in organs affected by ZIKV replication. Methods: All animal studies were approved by the Institutional Animal Care and Use Committee (IACUC) of Duke-NUS Medical School. We infected AG129 mice (deficient in IFNα/β and γ receptors) with ZIKV and performed serial FDG-PET/CT imaging over the one-week course of acute lethal infection. FDG uptake was confirmed by ex vivo biodistribution and digital autoradiography. Imaging data was validated against detailed gross and histopathological examination of the infected animals, and tissue viral load was measured. Results: Serial in vivo PET/CT imaging revealed markedly increased FDG uptake in the heart and brown fat, as well as slight increase in the brain, compared to pre-infection baseline levels. The increased uptake occurred as early as 1 day post-infection; brown fat uptake peaked at day 5, while heart uptake remained high until the last day of imaging at day 9 post-infection. Autoradiography and histopathological analysis of brain tissues revealed widespread inflammation throughout the brain, corroborating our FDG-PET/CT results. Conclusion: FDG-PET/CT imaging in our preclinical ZIKV infection model has the potential to identify sites of virus-induced inflammation-mediated disease pathology.


   Technologist Top



   P071: Can You Replace Two-Dimensional Whole-Body Planar with a Three-Dimensional Whole-Body Single Photon Emission Computed Tomography/Computed Tomography? A Technical Guide for Implementing and Evaluating Three-Dimensional Imaging Protocols Top


Andrew Cluff*1, E Bailey1

1Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, Sydney, Australia

Background/Aims: Advances in gamma camera technology and software algorithms have allowed faster scans. SPECT/CT has facilitated the development of advanced quantitative reconstruction allowing SPECT to generate SUV equivalent information similar to PET with the clinical applications still to be determined. In this research we have investigated if 3 bed whole body SPECT/CT could replace the traditional 2D whole body planar for Gallium, Bone and 123I-mIBG patient studies. Methods: A retrospective review of gallium, bone and 123I-mIBG studies acquired over a 6 month period was undertaken to determine the incidence of clinically significant lower limb abnormalities on the 2D whole body planar scan. Only gallium and bone studies with an indication of Pyrexia of Unknown Origin (PUO) or an infective process such as bacteremia or endocarditis were included, excluding studies with known or suspected lower limb pathology. Workflow improvements and scan time efficiency including analysis of ideal acquisition parameters for a multi-bed SPECT/CT for Bone and Gallium scans were assessed based on image quality, patient compliance and impact on clinical workflow. Results: A total of 50 patients having a Gallium scan were reviewed with 36 having a bone scan with 2D planar whole body imaging. The patients had a mean age of 69 years (range: 16-92), 36 of 50 were imaged 48 hours post injection. 33 (66%) an indication of PUO, 5 MSSA bacteraemia, 5 osteomyelitis and 6 infective endocarditis. Of the 50 Gallium scans, 7 patients (14%) had abnormal uptake in the lower legs with 5 of 7 being degenerative, 1 with known gout and 1 a recent fracture. There were 24 of 50 patients that had 2 or more SPECT/CT studies acquired with the remaining 26 having a single SPECT/CT study. The total time taken to acquire a bone and gallium using the standard clinical protocol is 45 minutes and 70 minutes respectively, compared with 25 to 30 and 45 minutes using multi-bed SPECT/CT. Conclusion: Based on these results, the acquisition of 3 bed SPECT/CT could replace 2D planar whole body for bone and gallium studies. Improvements in workflow efficiency, time saving and image quality along with the known gains in sensitivity, specificity and accuracy of SPECT/CT would support replacing 2D with 3D multi-bed SPECT/CT. Generating reprojected 2D data from multi-bed SPECT/CT is currently being developed.


   P072: Dose Reduction in Renal 99mTc-Diethylene-Triamine-Pentaacetate Scintigraphy with Glomerular Filtration Rate Top


Katrina Devitt*1, M Johnson1, A Evans1, E Bailey1

1Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, Sydney, Australia

Background/Aims: The administered dose used for renal scintigraphy with Glomerular Filtration Rate (GFR) measurement at our institution is 600 MBq 99mTc-Diethylene-triamine-pentaacetate (DTPA) and 100 MBq is GFR measurement only. The dose is higher than used for MAG3 due to the lower first pass extraction and glomerular filtration of the tracer. The aim of this study was to review the dose required to accurately assess renal function using DTPA scintigraphy. Methods: A retrospective review of patients on 177Lu-DOTATATE (Lutate) therapy having renal DTPA GFR assessment at baseline, mid-cycle and follow-up was performed. The studies were acquired using a dynamic 2-phase protocol following oral hydration with 300-600mL of water and voiding prior to commencing imaging. Studies were analysed using a standard clinical protocol generating whole kidney time activity curves as well as differential perfusion and function. Data was collected on administered dose, height, weight, creatinine, eGFR, absolute and normalized DTPA GFR for each study. A visual assessment was done by 2 expert reviewers comparing the whole kidney curve noise characteristics using a 3 point score at each time point per patient to determine the impact of injected dose on image quality and accuracy of semi-quantitative analysis. This was correlated with DTPA GFR measurements, creatinine and eGFR to look at the significance of changes in kidney function. Results: A total of 10 patients, each having 3 renal studies performed were analysed, with 30 studies reviewed. All patients had normal renal function with a mean eGFR 84 ml/min (range 58-90 ml/min), creatinine 73 umol/L (range 70-95 umol/L), absolute DTPA GFR of 94ml/min (range 91-129 ml/min) and normalized DTPA GFR 84 ml/min/1.73 m2 (range 92-122 ml/min/1.73 m2). The administered dose range was 423-637MBq with an average of 535MBq. Expert review showed no correlation between the curve noise and administered dose and no impact on semi-quantitative analysis of kidney function. Conclusion: A change in administered dose to the patient did not affect the noise characteristics of the time activity curve or impact the semi quantitative calculation of kidney function. Therefore, a dose reduction of 25% could be implemented resulting in a lower dose to the patient and compliance with the 50th percentile diagnostic reference level (DRL) recommended by ARPANSA.


   P073: To Gate, Or Not to Gate? That Was the Question Top


My Linh Diep*1

1Monash Health, Melbourne, Victoria, Australia

Background/Aims: It is well known that respiratory motion degrades image quality and can lead to reduced diagnostic accuracy in reporting avidity and metabolic activity of lower lung nodules on 18F-FDG PET scans. There are various imaging strategies utilised to minimise respiratory motion artefact. One such strategy is quiescent period respiratory gated PET imaging. Results: Patient administered 197MBq 18F-FDG following a 6 hour fast period. Uptake time 87 minutes. Imaging on Siemens Biograph mCT Flow with continuous-bed-motion and respiratory-gated PET, along with contemporaneous low dose CT. Gated PET scan and reconstruction parameters: 200 x 200 matrix, 8 FWHM, 21 subsets x 2 iterations, attenuation correction and scatter correction. Multiple 18F-FDG avid lung nodules visualised. Largest lung nodule with SUVmax 15.8 and dimensions 22 mm x 20 mm x 22 mm. Multiple hepatic foci suspicious for metastases found. Conclusion: The patient set up time is minimal. Respiratory gated PET is an efficient and effective imaging strategy to reduce motion artefact related to respiration. This inherently improves diagnostic accuracy in reporting metabolic activity and avidity of lung and upper abdominal disease on 18F-FDG PET scans.


   P074: Dose Optimisation: What, Why, How, My Department’s Experience Top


Nicholas Farnham*1

1SA Medical Imaging Lyell McEwin Campus, Elizabeth Vale, Australia

Background/Aims: Dose optimisation is the confirmation that the lowest radiation dose is given to the patient following the ALARA principle, while being able to provide the appropriate diagnostic information. Injected doses for procedures don’t change regularly. When assessing injected doses, you need to ask, can we do better? The first and easiest way is to compare your injected doses to the Diagnostic Reference Level (DRL’s). DRL’s give the mean, upper and lower dose values of the collection group. When comparing to the DRL’s you then can decide to match or get closer. Methods: Technology changes, further education and increasing numbers of specific scans lead us to choose bone, lung V/Q, myocardial perfusion and gated blood pool scans (GBPS). We looked at the scan injected doses and determined criteria for dose and imaging protocol change. To measure change an average injected dose for each procedure was calculated for one month’s patients in 2011 and the same month in 2017. Results: We were able to see decrease injected doses for bone scans by 8%, GBPS by 6%, and myocardial perfusion rest study by 9%. However, change was not seen in the injected doses for myocardial perfusion stress study and for ‘Standard Adult’ 99mTc-MAA. Conclusion: The process is useful in applying change that saw decreases in bone scan and GBPS injected doses. Decrease in the lung V/Q scan 99mTc-MAA dose and myocardial perfusion stress dose was the desired outcome. However, the doses are true representation and more suitable to patient habitus. The process also helped our protocol for V/Q lung imaging of pregnant patients. The future direction is to look at other studies for further dose reductions. Dose optimisation is not a daunting process and should be a priority for all departments.


   P075: Validation of a Methodology to Optimise Administered Activity of 67Ga-Citrate for Infection Imaging Top


Heidi Fearnside*1, K Willowson2, E Hemmingway1, E Bailey1

1Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, 2School of Physics, University of Physics, Sydney, Australia

Background/Aims: The whole body absorbed radiation dose from an administered dose of 200 MBq 67Ga-citrate is approximately 15 mSv, significantly higher than the majority of nuclear medicine diagnostic procedures. This is due to the longer half-life being 78 hours and administered activity. The aim of this study was to evaluate a method to reduce the administered dose to optimise image quality and reduce radiation dose. Methods: An externally triggered gated 67Ga-citrate SPECT/CT study was acquired using an Esser-Modified Jaszczek PET phantom with 8, 12, 16 and 25 mm cylinders at contrast ratios of 29:1 and 14:1. Data was acquired using 128x128 matrix with 60 projections per detector (3 degree steps) at 20 seconds per projection on a Siemens SymbiaT16. The gated SPECT raw data was rebinned using in-house software to generate 10 ungated SPECT studies each of varied time per projection (2 sec, 4 sec, 6 sec up to 20 sec) to represent 10%, 20%, 30% up to 100% of the administered dose. Studies were reconstructed using iterative reconstruction with CT-based AC, Flash-3D resolution recovery and Gaussian at FWHM 8.5 to 10mm. Regions of interest were drawn over background and the hot cylinders for all reformatted images. Mean and SD for each region for each dataset was used to calculate the signal and contrast to noise ratios (SNR & CNR) and coefficient of variation (CoV) to assess image quality. Results: Results for phantom data with a contrast ratio of 14:1 were analysed equating to an injected activity used clinically equivalent to 200 MBq 67Ga-citrate. Preliminary results of the SNR and CoV for background plateau at 12 to 14 seconds per projection with values of 12.4 and 7.8% respectively, representing 60 to 70% of total activity. The CNR values for all cylindrical sizes showed similar trends with the highest CNR seen in the 25mm and 16mm cylinders as expected based on the resolution of a SPECT system. Conclusion: Preliminary results would suggest that a reduction of total activity by 25 to 30% does not impact on image contrast and quality, therefore giving an injected dose of 150MBq with a 14 second per projection SPECT acquisition will not compromise clinical interpretation. Further clinical validations are needed on clinical cases using a gated SPECT acquisition to validate and confirm these results.


   P076: Does Oral Hydration Reduce Bladder Activity in 68Ga-Prostate Specific Membrane Antigen-11 Imaging for Prostate Cancer? Top


Meaghan Johnson*1, E Bailey1, E Hsiao1, G Schembri1

1Royal North Shore Hospital, St Leonards, Sydney, Australia

Background/Aims: 68Ga-PSMA-11 (Prostate Specific Membrane Antigen) is a PET tracer used in the imaging of prostate cancer. It is primarily excreted through the urinary system and as such is highly accumulated in the bladder. This high physiologic activity in the bladder can result in severe photopenic artifacts masking potential abnormal pelvic nodal uptake. The aim of the study is to evaluate the impact of a pre-and post-hydration protocol on activity within the bladder. Methods: A retrospective evaluation of 68Ga-PSMA scans with and without oral hydration protocols were included. The oral hydration protocol included the patient being instructed to drink up to 1000mL of water over the uptake period. The volume of water consumed during this time was recorded. Vertex to mid-thigh PET/CT scans were acquired 60 to 90 minutes after injection using a Siemens Biograph mCT/x64, reconstructed using ToF, scatter correction and CT-based attenuation correction. A region was then drawn in the middle of the bladder to define the SUVmax and SUVmean. The patients were then divided into four groups: non-hydrated, hydrated 1000 mL, hydrated 500-950mL and hydrated 100-450 mL, to assess the impact of hydration volume on bladder activity. The average SUVmean and SUVmax in the bladder for each group was calculated. Results: A total of 118 patients were included for analysis, with 33 having the non-hydration protocol and 85 having the hydration protocol. The overall average SUVmean for non-hydrated, hydrated 1000mL, hydrated 500-950mL and hydrated 100-450 mL were 67, 24, 26 and 36 respectively. For the SUVmax, the results were 81, 28, 31 and 36 respectively. As such, the highest SUVmean and SUVmax in the bladder were seen in the non-hydrated group, whilst the lowest were seen in the group hydrated with 1000mL of water. Conclusion: Based on these results, hydrating patients with a minimum of 500mL water during the uptake period significantly decreases the SUVmax within the bladder. The intensity of bladder activity is less, reducing the impact of any photopenic artefacts that may preclude visualisation of clinically significant abnormal pelvic nodal uptake.


   P077: The Evaluation of Lateral Scatter Ray of Gamma Camera Top


Jaeil Kim*1, E Lee1, K Noh1, K Kang1

1Seoul National University Hospital, Seoul, Republic of Korea

Background/Aims: Generally, a collimator that installed in front of detector set a direction of gamma ray and remove a scatter ray. By the way, a lateral or oblique scatter ray is detected into crystal through collimator. At this study, we will evaluate a mount of count and a spectrums of lateral scatter ray. Methods: We used the Skylite (Philips) as a gamma camera, and a 99mTc 1.11Gbq point source as a phantom. we located this point source at backside 50cm of detector. After acquiring 1min, we turned a detector 10 degree. Likly this, we acquired a count at every 10 degree from 0° to 360°, analysed a images and a spectrums. In case of patient study, we choose 3 phase bone scan patient who had a hand disease, because scatter ray from body would detected on crystal. After acquiring a blood flow and a blood pool scan, we analysed a image and a spectrums. Additional, we set a lead gown on his hand, let wear a gown on his body. And then we compared and evaluated 3 types of blood pool images (non-lead gown, lead gown on a hand and on body). Results: In case of phantom study, a count of phantom is same with a background count at backside (270°~90°). By the way, a count of oblique side (0°~50°, 220°~270°) ray is 100~600 cps, front side’s count is over 4Mcps. In case of patient study, a count of blood pool scan at hand is 1510cps. But a count of hand with lead gown on hand, on body are 1554cps, 1299cps at each. Conclusion: Therefore, even though there is a collimator at detector, a lateral scatter ray detect at crystal and affect at image and spectrums. Especially if there is a high activity source at outside of detector when we examine a low activity organ like hand, foot, we have to shield and remove a outside activity for a good image.


   P078: Comparison of Ischaemia Detectability due to the Difference in Myocardial Perfusion Tracer by the Same Patient using Semiconductor Single Photon Emission Computed Tomography Top


Makiko Kurihara*1, Y Suzuki1, N Iguchi1

1Sakakibara Heart Institute, Fuchu-shi, Tokyo, Japan

Background/Aims: Many previous studies on ischaemia detectability due to differences in myocardial perfusion tracer in the myocardial perfusion SPECT have been reported. Furthermore, there is no difference between 99mTc-sestaMIBI/tetrofosmin and 201TlCl in those reports. However, there is a report that the myocardial blood flow extraction fraction has a lower 99mTc-sestaMIBI/tetrofosmin than 201TlCl. We compared the ability of the same patient to detect ischaemia with 99mTc-sestaMIBI/tetrofosmin and 201TlCl with myocardial perfusion SPECT. Methods: Of the 3525 patients who underwent stress myocardial SPECT from 2014 to 2016, myocardial perfusion SPECT performed by the same patient with different tracers in the same stress method 20 cases (exercise stress: 13, adenosine stress: 7). Also, patients who received PCI and CABG during this period were excluded. Those were studied by the semiconductor SPECT (D-SPECT, Spectrum Dynamics Medical). The scanning method was taken with count scanning (1.2M counts). And then Ischaemia (% myocardium) calculated by Quantitative Perfusion SPECT software 2012ver. was compared. Results: The mean value of the ischaemia value of exercise stress is 2.00% for 99mTc-sestaMIBI/tetrofosmin and 4.14% for 201TlCl. And then the mean value of the ischaemia value of adenosine stress is 3.29% for 99mTc-sestaMIBI/tetrofosmin and 3.88% for 201TlCl. In both stress, the ischaemia value tended to be larger in 201TlCl than in 99mTc-sestaMIBI/tetrofosmin. Exercise stress has a larger difference in the ischaemia value than adenosine stress. Conclusion: 201TlCl is sensitive to detect myocardial ischaemia than 99mTc-sestaMIBI/tetrofosmin.

Disclosure of interest: Y Suzuki conflict with Spectrum Dynamics.


   P079: Facile 11C-PIB Synthesis using an On-Cartridge Methylation and Purification Showed Higher Specific Activity than Conventional Method using Loop and High Performance Liquid Chromatography Purification Top


Yongseok Lee*1, Y H Cho1, J H Lee1, H J Lee1, G W Noh1, K W Kang1

1Seoul National University Hospital, Seoul, Republic of Korea

Background/Aims: 11C-PIB synthesis has been performed by a loop-methylation and HPLC purification in our lab. However, this method is time-consuming and requires complicated systems. Thus, we developed an on-cartridge method which simplified the synthetic procedure and reduced time greatly by removing HPLC purification step. We compared 6 different cartridges (C18, tC18, tC18 environmental, alumina, HLB, CM) and evaluated the 11C-PIB production yields and specific activities. Methods: The cartridges were prewashed with 5 mL EtOH and purged with nitrogen gas. Precursor (1 mg 6-OH-BTA-0, ABX, Germany) in 100 µL of cyclohexanone was loaded each cartridge.[11C]MeOTf was synthesized by using TRACERlab FXC Pro (GEMS, Sweden) and was transferred into the cartridge by blowing with helium gas for 3 min at room temperature. To remove byproducts and impurities, cartridges were washed out by 20 mL of 30% EtOH in 0.5 M NaH2PO4 solution (pH 4.5) and 10 mL of distilled water. And then, 11C-PIB was eluted by 5 mL of 30 % EtOH in 0.5 M NaH2PO4 into the collecting vial containing 10 mL saline. Results: Among the 6 cartridges, only tC18 environmental cartridge could remove impurities and byproducts from 11C-PIB completely and showed higher specific activity than traditional HPLC purification method. This method took only 8 ~ 9 min from methylation to formulation. For the tC18 environmental cartridge and conventional HPLC loop methods, the radiochemical yields (EOS) were 12.3±2.2% and 13.9±4.4%, respectively, and the specific activities were 420.6±20.4 GBq/µmol (n=3) and 78.7±39.7 GBq/µmol (n=41), respectively. Conclusion: We successfully developed a facile on-cartridge methylation method for 11C-PIB synthesis which enabled the procedure more simple and rapid, and showed higher specific activity than HPLC purification method.


   P080: Studies on the Precision Improvement of the Heart-to-Mediastinum Ratio Measurement by using Single Photon Emission Computed Tomography/Computed Tomography Data Extracted for the Myocardium and Mediastinum Top


Ryuto Mukumoto*1, T Odagawa1, N Fujita2, S Matsuzawa1, C Hasegawa1, S Abe2, K Kato1

1Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 2Department of Radiological Technology, Nagoya University Hospital, Aichi, Japan

Background/Aims: In myocardial sympathetic nerve scintigraphy, the heart-to-mediastinum ratio (HMR) is widely used as an indicator of myocardial 123I-MIBG uptake. It is difficult to accurately measure HMR because of overlapping of the activities from the myocardium and lungs, and mixing with scatter component. In this study, we obtained the virtual planar image (synthetic planar image: SP image) by using the SPECT images and attenuation map. We aimed to improve HMR measurement accuracy by extracting the clear myocardium and mediastinum fields. Methods: We defined the radioactivity concentration ratio of the myocardium, mediastinum, liver, and lungs as 15:1:10:8, and enclosed these concentrations of 123I-MIBG solutions into the respective areas of the torso phantom. The planar image was acquired using the low-medium energy general purpose collimator. SPECT acquisition was performed for 360 degrees rotation. Images were reconstructed 360 degrees data and 180 degrees data from each projection angle with scatter correction (SC). The lung fields were extracted on the CT images, the activities from the lung fields was removed from SPECT images, and the clear myocardium and mediastinum fields were extracted. We used the attenuation map for the SPECT images and acquired SP images with or without lungs by attenuating and forward projecting the count per pixel. We compared HMR values calculated from SP images with and without lungs and the errors in setting region of interest (ROI) for the myocardium among operators. Results: HMR calculated from the planar image was 2.1. The average value of HMR calculated from SP image with lungs was 2.38 (SC+), or 2.02 (SC-), and that calculated from SP image without lungs was 1.92 (SC+), or 1.61 (SC-). It was found that lungs from SP image reduced HMR by 20%. Thus, HMR was reduced by 20% when calculated with SP image from which lungs were removed. The results indicated that accurate ROI for the myocardium could be obtained by using SP image from which lungs were removed. Conclusion: Accurate ROI for the myocardium can be obtained by using SP images from which lungs were removed and it makes the precision improvement of HMR measurement.


   P081: Health Effects of Occupational Radiation Exposure in Nuclear Medicine Technologists in Australia Top


Samantha O’Brien*1, H Warren-Forward1, D James1

1School of Health Sciences, University of Newcastle, Callaghan, Australia

Background/Aims: Exposure to ionising radiation is known to produce biological effects. As such there are limits placed on occupational exposure. Historically these occupational dose limits have been set from extrapolating data from known responses of high dose radiation exposure. Occupational ionising radiation exposure to a nuclear medicine technologist (NMT) is generally considered low level chronic exposure. The aim of the research was to conduct a literature review investigating health effects relating to occupational radiation exposure in NMTs. Methods: A literature search was performed using Embase, Medline and CINHAL catalogues using the search terms: “occupational radiation health effects”, “low dose threshold model”, “long term low level exposure”, “medical radiation exposure”, “nuclear medicine or radiologic or molecular imaging or functional imaging” with “scientist or technologist or technician or staff or personnel”. A systematic review of the literature was completed using PRISMA protocols.[2] Results: Sixty journal articles were initially identified. Thirty of these were excluded for being duplicates. The remaining 30 records were screened for eligibility. Six studies were included in qualitative synthesis. Four articles reported on cytogenetic damage and potential to cause carcinogenesis. One article discussed cataracts, leukaemia and theorised shortened life span for individuals exposed to chronic low level radiation. One article proposed good health for chronic low level radiation workers through the radiation hormesis paradigm. Conclusion: Literature on low dose levels of radiation exposure in an occupational setting is sparse, especially in the NMT cohort. One limitation of previous research on the effects of low level exposure is the lack of data on participant lifestyle factors e.g. tobacco, diet and other possible occupational carcinogenic exposures.[3] It is recommended that these factors be included in future research.

References

  1. Jacob P, Rühm W, Walsh L, Blettner M, Hammer G, Zeeb H, et al. Is cancer risk of radiation workers larger than expected? Occup Environ Med 2009;66:789-96.
  2. Moher D, Liberati A, Tetzlaff J, Altman DG; PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med 2009;6:e1000097.
  3. Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2. Washington, DC: National Academies Press; 2006.



   P082: Evaluation of Metal Artifact Reduction Software in Positron Emission Tomography Quantification for Artificial Knee Joint: Phantom Experiment Top


Takashi Ono*1, K Wagatsuma2, N Ito1, K Miyazaki1, T Miyazaki3, Y Suzuki1, Y Kudo1, Y Unno1, M Kameyama1

1Departments of Radiology and 3Orthopedic Surgery, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan, 2Research Team for Neuroimaging

Background/Aims: This study evaluated the effect of metal artifact reduction (MAR) software on positron emission tomography (PET) quantification on 18F-Na PET. Methods: We prepared a phantom using an artificial knee joint, (JOURNEY Smith & Nephew), and 20mm-diameter spheres in an acryl container. We filled 18F in spheres and the background for the radioactivity ratio was 4:1. PET/CT was conducted on a Discovery MI (GE Health care). The PET acquisition time was 90 seconds. The X-Ray tube voltage for CT was 120 kV, and tube current was 100mA to 400mA. To acquire reference values, the same acquisition parameters were used without knee joint. The reconstruction parameters for PET were 3D-OSEM (TOF+PSF, Subset 2, Iteration 17, Gaussian Filter 4mm) and Q.Clear (TOF, β =400) with/without MAR. We estimated the standardized uptake value max (SUVmax). Results: MAR did not affect SUVmax without knee joint. The streaks in the images caused by artificial knee joint were decreased by MAR. SUVmax with knee joint using 3D-OSEM without MAR was 3.8% smaller than reference values and that with MAR was 12.5% smaller than reference values. SUVmax with knee joint using Q.Clear without MAR was 2.1% smaller than reference values and that with MAR was 11.9% smaller than reference values. Conclusion: CT images were improved, but SUVmax was underestimated when using MAR. The PET quantification had accuracy within 5 % from the reference, even with metal artifacts.


   P083: Incidental Finding of a Suspected Chondrosarcoma on a Bone Scan for Arthropathy Top


Rachjany Oung*1

1Flinders Medical Centre, Bedford Park, Australia

Background/Aims: Chondrosarcomas are malignant cartilaginous tumours typically arising in middle aged patients with predominance in men. The most common site is in the long bones, particularly the femur although it can be found in other skeletal sites. Patient presentation includes pain, pathological fracture and/or a palpable mass. Methods: A 73 year old gentleman presented to the Nuclear Medicine department for a bone scan to assess the extent of arthropathy. The patient had a history of generalised joint pain and tenderness treated with methotrexate. The patient had normal inflammatory markers and was anti-cyclic citrullinated peptide (anti-CCP) antibody positive. The patient was injected with 900 MBq of 99mTc-methyl diphosphonate (99mTc-MDP) intravenously. Whole-body and regional blood pools and delayed planar images with single photon emission computed tomography/computed tomography (SPECT/CT) were obtained. Results: Increased uptake in keeping with degenerative change was demonstrated the acromioclavicular joints and thoracic spine as well as the joints of the hands and feet. Patchy increased uptake within the right distal femoral shaft was seen on SPECT/CT to correlate with medullary serpiginous sclerosis/calcification. While bony infarcts can demonstrate low grade activity at the periphery when active and minority of endochondromas can show increased uptake on bone scans, the degree of uptake raised suspicion for a low grade chondrosarcoma. A subsequent x-ray confirmed a sclerotic lesion with appearance of chondroid matrix mineralisation extending over 20cm of the femoral shaft. On magnetic resonance imaging (MRI), a large lesion involving mid-diaphysis to distal metaphysis was observed, highly suspicious for a low grade chondrosarcoma. No pathological fracture seen. Conclusion: The routine whole body scan demonstrated an unexpected bone lesion suspicious of chondrosarcoma in a patient with generalised bone pain. This case highlights the value of nuclear medicine in diagnosing bony disease in a patient, in conjunction with x-ray and MRI.


   P084: Development of Disinfection Validation Protocol for GMP in Radiopharmaceuticals Production Facility Top


Hee-Won Park*1, Y H Cho2, Y S Lee2, J H Lee2, C S Yoon2, W J In2, H J Lee2, J R Woo1, K W Kang2, Y K Kim1

1Department of Nuclear Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, 2Department of Nuclear Medicine, PET Center, Seoul National University Hospital, Seoul, Republic of Korea

Background/Aims: The validation of Disinfection in GMP facility of Radiopharmaceuticals is to confirm whether disinfectants kill microorganisms in controlled clean area such as manufacturing room, sterility test room and Class A equipment. PIC/S and the government require the disinfection validation for GMP certification but there is no protocol or method for validation of disinfection at many PET drug facilities. So, we try to develop the widely used protocol of disinfection validation and simple method. Methods: The Cavicide (Metrex Co., USA) and the TX3267 (Texwipe Co., USA) were used for this validation as disinfectant. Each main ingredient of disinfectant is Ethyl Alcohol and Isopropyl Alcohol. We purchased growth promotion test suspensions (Excelsior Scientific Co., UK) and clinical strains (Microbiologics Co., USA) for Disinfection validation. All of the clean areas were divided into portions under the PIC/S regulations and the environmental monitoring was carried out with TSA (Tryptic Soy Agar, HARDY Diagnostics Co., USA) plate media. TSA plate media were incubated at 35°C for 3 days and we identified 45 microorganisms from the colony on TSA plate media after 3 days. Among 45 microorganisms, we decided to use the 14 representative genera for validation. 14 microorganisms were inoculated 3 plate media for positive control and for Disinfection validation. Each disinfectant was sprayed on the surface of the plate media except positive control. No inoculation plate medium was used for negative control. All media were incubated at 35°C for 3 days and checked the growth in every day. Results: 10 microorganisms formed colony and 4 microorganisms did not formed colony. Control group was showed positive and negative results. The media which was sprayed Isopropyl Alcohol did not form any colony and the media which was sprayed with Ethyl Alcohol formed colony from 7 media. Conclusion: The Disinfection validation for radiopharmaceuticals GMP system was validated with reliable results and our new protocol.


   P085: Comparative Study of Glomerular Filtration Rate Measured by Single Photon Emission Computed Tomography/Computed Tomography with Low Energy High Resolution Collimator and Low Energy General Resolution Collimator Top


Qi Chi*1, Y Chen1, Z Huang1, L Zhang1

1Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou Sichuan Province, China, Luzhou, China

Background/Aims: To evaluate the differences in measuring glomerular filtration rate (GFR) by renal dynamic imaging of SPECT/CT with low energy high resolution collimator and low energy general resolution collimator. Methods: The group A which used low energy high resolution (LEHR) collimator to measure gGFR (n1=605, and the group B which used low energy general resolution (LEGR) collimator to measure gGFR (n2=228). The dGFR of all cases were measured by double-phase plasma method. Both of the two groups were respectively divided into 4 subgroups according to the results of double-phase plasma method: 1. The severely reduced group (0-29.9); 2. The medium reduced group (30-59.9); 3. The mild reduced group (60-89.9); 4. The normal group (>90) [ml. min-1/1.73 m2/1. The results of double-phase plasma method (gGFR) were used as gold standard. To test the normal distribution of the data with the Kolmogorov Smilov (K-S) method. Paired T-test was used to compare the diagnostic efficacy difference between the gold standard and each groups. Results: The standard deviations of group A and B were 21.92 and 22.73 with no statistical significance (p=0.083). There was no statistical significance between 1,3,4 groups of A and B with p-values of 0.1, 0.899, 0.864. But the difference of group 3 between group A and B was statistically significant (p<0.001). Conclusion: GFR messured by spect with LEHR and LEGP have the same efficiency in measuring GFR for group 1,3,4. The SPECT with LEGR collimator has the better efficiency in measuring the one with mild renal function loss. So, it is better to perform renal dynamic imaging measuring GFR with LEGP collimator.


   P086: Diagnosability of Dynamic Myocardial Perfusion Single Photon Emission Computed Tomography of 99mTc-Sestamibi using CZT Semiconductor Single Photon Emission Computed Tomography-Conventional Myocardial Perfusion Single Photon Emission Computed Tomography versus Myocardial Flow Reserve Top


Yasuhiro Suzuki*1, M Kurihara1,2, N Iguchi3

Departments of 1Radiology, 2Cardiology, Sakakibara Heart Institute, Fuchu-shi, Tokyo, Japan

Background/Aims: 99mTc-sestamibi has poor myocardial ischaemia detection ability as compared with myocardial perfusion PET formulation due to low extraction fraction. However, in recent years, dynamic myocardial perfusion SPECT by CZT semiconductor SPECT became possible. We examined coronary artery lesion detection ability by myocardial blood flow reserve obtained from Dynamic myocardial perfusion SPECT by CZT semiconductor SPECT. Methods: Subjects were 12 patients underwent myocardial perfusion SPECT and coronary angiography. The standard doses for rest-first 99mTc-sestamibi one day SPECT protocol used were 148MBq at rest and 592MBq at stress. Myocardial flow reserve was calculated by Stress Flow Index/Rest Flow Index and Corridor 4DM 2017 was used for analysis. First, Rest Dynamic SPECT was performed for 6 minutes, Rest Perfusion SPECT was performed for 4 to 8 minutes, adenosine stress was performed for 6 minutes, Stress Dynamic SPECT was performed 6 minutes from the start of stress 3 minutes, and lastly Stress Perfusion SPECT was performed for 2 minutes. Conventional myocardial perfusion SPECT was visually diagnosed by a cardiovascular physician. The coronary artery dominant region was defined as 9 segments of LAD, 4 segments of LCX and 4 segments of RCA. In coronary artery dominant region, a segment with Myocardial Flow Reserve of 2.0 or less was judged to be positive in 1 segment or more. In coronary angiography, stenosis of 50% or more was judged as positive. Diagnostic performance evaluation was evaluated by total of sensitivity, specificity and accuracy calculated for each coronary artery. Results: The diagnosability of visual assessment of conventional myocardial perfusion SPECT was 29.63% sensitivity, 100% specificity and 47.22% accuracy. The diagnosability of dynamic myocardial perfusion SPECT was 81.48% sensitivity, specificity 70%, accuracy 80.56%. Conclusion: Visual assessment of conventional myocardial perfusion SPECT cannot detect coronary artery lesions sensitively. However, myocardial perfusion reserve by dynamic myocardial perfusion SPECT dramatically improves the ability to detect coronary artery lesions.

Disclosure of interest: Y Suzuki conflict with Spectrum Dynamics Medical.


   P087: Application of Particle Analysis to the Evaluation of Shape of the Striatum Accumulation in 123I-Ioflupane Single Photon Emission Computed Tomography Top


Hiroyuki Tsushima*1, H Nosaka, S Kurata2

1Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 2Department of Radiological Technology, Ibaraki Prefectural Central Hospital, Ibaraki, Japan

Background/Aims: 123I-Ioflupane single photon emission computed tomography (Ioflupane SPECT) is useful for the diagnosis of diseases such as Parkinson’s disease. With Ioflupane SPECT, semi-quantitative analysis of the specific binding ratio (SBR) is widely performed. However, the evaluation of the accumulated shape of the striatum is performed visually, and a quantitative analysis has not been conducted. We therefore tried the application of the particle analysis to evaluate the shape of striatum accumulation. Methods: Ioflupane SPECT images with different accumulation shapes of the striatum were prepared by Monte Carlo simulation. Several different models of Ioflupane SPECT were created by a digital phantom. The ratio of striatum count to background count in models of Ioflupane SPECT were set at 8:1 or 4:1. In addition, we created projection data by calculating these model data with the Monte Carlo simulation code SIMIND (Lund University). Furthermore, image reconstruction of projection data was performed, and the shape of the striatum accumulation was evaluated by particle analysis software on the transverse image. Results: Particle analysis was carried out to calculate the aspect ratio and circularity of accumulation of the striatum. The aspect ratio showed a value smaller than the true value due to blurring of the SPECT image. On the other hand, the circularity became higher than the true value, and the evaluation was close to a perfect circle. In addition, as the ratio of striatum count to background count decreases, setting the threshold of binarization becomes important. Conclusion: Application of particle analysis to shape evaluation of striatum accumulation was studied in simulation images. Particle analysis could be applied to shape evaluation of striatum SPECT. It is necessary to verify the reproducibility of binarization as a future task. Application of particle analysis to shape evaluation of striatum accumulation was studied in simulation images. Particle analysis could be applied to shape evaluation of striatum SPECT. It is necessary to verify the reproducibility of binarization as a future task.


   P088: Validation of 18F-Fluoroazomycin Arabinoside Positron Emission Tomography/Computed Tomography Image-Derived Blood standardised uptake values Top


Douglass C Vines*1,2,3, D A Scollard1,3, B D Driscoll4, H Keller1,2, T Shek4, K Han1,2, D A Jaffray1,2,3,4

1Princess Margaret Cancer Centre, University Health Network, 2University of Toronto, 3STTARR Innovation Centre, 4Techna Institute, University Health Network, Toronto, Canada

Background/Aims: 18F-Fluoroazomycin arabinoside (FAZA) PET can be used for imaging hypoxia of cervix tumours by comparing the amount of FAZA in tumour to blood or a reference tissue. The purpose of this study was to validate image-derived standardised uptake values (SUV) for blood and a reference tissue by comparing image-derived to blood-sample-derived SUV (accuracy), and also by investigating intra- and inter-operator variability (precision). Methods: Patients with cervix tumours were imaged with PET/CT 2 hours after FAZA injection (12 of planned 20 scans) as part of a research ethics board approved study. A venous blood sample was taken to calculate blood-sample-derived SUV. To measure image-derived SUVmean, fixed spherical volumes-of-interest were placed using the fused CT for guidance on PET regions of the left ventricular cavity (LV), aorta, and each gluteus maximus muscle. To evaluate accuracy, image-derived SUVs were correlated to the “gold standard” blood-sample-derived SUVs. In addition, mean percentage differences (%Diff) were calculated by comparing the image-derived to blood-sample-derived SUVs. Precision was evaluated by calculating coefficients of variation (CV) of SUVs for the intra-operator and four independent operators. Results: The data demonstrate that the LV is the most accurate of the image regions. R2 and %Diff for LV were 0.97, 0.98 and-1.1%,-0.1% for both intra-and inter-operators, respectively. The %CV was also lowest for LV; 1.5 and 2.2% for both intra-and inter-operators. Overall, the highest single %CV for all three regions was only 6.4% for aorta, while the gluteus maximus values fell in between LV and aorta, indicating good precision among the four operators. Conclusion: Validation of image-derived accuracy demonstrated that the LV SUV is equivalent to blood-sample-derived SUV. Precision evaluation showed there was little difference for all three regions among all operators based on %CV, thereby demonstrating operator-independent determination of image-derived blood SUVs.


   P089: Optimization of Reconstruction Conditions for Tau Positron Emission Tomography imaging using 18F-THK5351 Top


Kei Wagatsuma*1, K Miwa2, M Sakata1, K Ishibashi1, K Oda3, T Tago1, J Toyohara1, K Ishii1

1Tokyo Metropolitan Institute of Gerontology, Tokyo, 2School of Health Science, International University of Health and Welfare, Ohtawara, 3Faculty of Health Science, Hokkaido University of Science, Sapporo, Japan

Background/Aims: Tau imaging using positron emission tomography (PET) should facilitate the detection of tau pathology in Alzheimer’s disease and tauopathies, as well as precise assessments of disease severity and therapeutic efficacy. Therefore, standardized reconstruction parameters are required for tau PET imaging. The present study aimed to establish optimal reconstruction conditions for 18F-THK5351 tau imaging using phantoms and clinical images. Methods: Hoffman and cylindrical phantoms contained 0.94MBq of 18F which was determined as described in a previous report.[1] All images were acquired using a Discovery PET/CT 710 (GE Healthcare) within 20 minutes. Phantom images were reconstructed using three-dimensional ordered-subset expectation maximization (3D-OSEM) with time-of-flight (TOF; 16 subsets, 128 × 128 matrix, and 2 mm/pixel), a variable number of iterations (1-10) and a Gaussian filter with full width at half maximum ranging from 0-10 mm. The reconstructed images were evaluated using grey/white matter contrast (%contrast; [%]) for the Hoffman phantom and uniformity (standard deviation, SD) and image noise (coefficient of variation, CV; [%]) for the cylindrical phantom.[2] The institutional review board approved the protocols for this study of three healthy participants (male, n=3; mean age, 56.3 [range 30-82] years). Optimal reconstruction conditions were determined by the consensus of a neurologist and a nuclear medicine technologist from phantom and clinical images. Results: The %contrast and SD reached convergence at more than 3 iterations and were 55.9% and 0.101 with 4 iterations and without the Gaussian filter, respectively. The CV was 15.1% with the Gaussian filter set at 5mm. We determined the Gaussian filter of 4mm by visual inspection in human images. Conclusion: The optimal reconstruction conditions in 3D-OSEM with TOF comprised 16 subsets, 4 iterations and a Gaussian filter of 4mm.

References

  1. Hsiao IT, Lin KJ, Huang KL, Huang CC, Chen HS, Wey SP, et al. Biodistribution and radiation dosimetry for the tau tracer 18F-THK-5351 in healthy human subjects. J Nucl Med 2017;58:1498-503.
  2. Akamatsu G, Ikari Y, Nishio T, Nishida H, Ohnishi A, Aita K, et al. Optimization of image reconstruction conditions with phantoms for brain FDG and amyloid PET imaging. Ann Nucl Med 2016;30:18-28.



   P090: The Optimal Acquisition Protocols for 68Ga-DOTANOC Positron Emission Tomography/Computed Tomography Imaging Based on Injected Dose and Acquisition Time Top


Lei Xu*1, L L Zhou2, Q Meng1, R Yang1, H Jiang2, F Wang1

Departments of 1Nuclear Medicine and 2Medical Equipment, Nanjing First Hospital, Nanjing Medical University, Nanjing, China

Background/Aims: This study was to determine the optimal acquisition protocols based on patient body mass index (BMI) and the injected dose per kilogram for 68Ga-DOTANOC PET/CT imaging. Methods: This study was a retrospective analysis of 51 patients who were administrated with 39.55-110.11 MBq of 68Ga-DOTANOC for PET/CT imaging, the patients had an average weight of 62.39±10.88 kg, an average height of 1.64±0.09 m, and an average BMI of 23.18±3.45 kg/m2. The study population was classified into 4 groups based on BMI: less than 18.5 kg/m2 (underweight), 18.5-23.9 kg/m2 (normal weight), 24-27.9 kg/m2 (overweight), and 28 kg/m2 or greater (obese weight). The patients were also divided into 3 groups: less than 0.74 MBq/kg (low dose), 0.74-1.48 MBq/kg (moderate dose), more than 1.48 MBq/kg (high dose). Image quality was evaluated by coefficient of variance (CV) in the liver slice. This clinical study was performed with the approval of the ethical committee. Results: The CV significantly increased with increasing weight and BMI (r=0.647, 0.483, p<0.01), and significantly decreased with increasing injected dose per kilogram (r=0.695, p<0.01). The CV differed significantly among 4 BMI-based groups, except for normal weight group versus overweight group and overweight group versus obese group (p<0.01), the ratio for overweight group and obese group to normal weight group was approximately 1.1 and 1.2, respectively. Meanwhile, The CV had a significant statistical difference among the 3 injected dose per kilogram groups (p<0.01), the ratio of that for low dose group and high dose group to moderate dose group was approximately 1.2 and 0.8.Conclusion: It is feasible to achieve good quality PET images with low dose of less than 110 MBq and shorter acquisition time. The recommended injected dose per kilogram was approximately 1.0-1.5 MBq/kg, and the maximum injected dose was about 2.0 MBq/kg in underweight patients. In addition, the injected dose in underweight patients tend to be reduce to 0.8 times, and optimal acquisition time should be at least 1.2 times longer than in patients of normal weight both in overweight patients and who received low dose less than 1.0 MBq/kg.


   Nuclear Medicine Innovation Top



   P091: Nuclear Medicine: A One Stop Shop to Performing Positron Emission Tomography/Computed Tomography, Diagnostic Computed Tomography and Ultrasound-Guided Fine Needle Aspiration under General Anaesthetic for Squamous Cell Carcinoma of the Head and Neck Top


Mikayla Dimitri*1

1Royal Brisbane and Women’s Hospital, Brisbane, Queensland, Australia

Background/Aims: Limitations exist in obtaining adequate diagnostic imaging in cases where patients present with intellectual disabilities, largely due to motion artefacts. In patients who require multiple diagnostic procedures where numerous general anaesthetics are contraindicated, there is benefit in providing a multidisciplinary service, within nuclear medicine, to drastically improve patient care. Methods: After failing multiple Positron Emission Tomography/Computed Tomography (PET/CT) attempts, the patient was referred to the Royal Brisbane and Women’s Hospital (RBWH). The patient also required a diagnostic Computed Tomography (CT) of the Head, Neck, Chest, Abdomen, and Pelvis with intravenous contrast and a Fine Needle Aspiration (FNA) biopsy of clinically suspicious submandibular nodes. To achieve succinct diagnostic testing, staff included anaesthetists, sonographer, radiologist, cytotechnologist, nuclear medicine scientists, radiographer and nurses. Patient weight was obtained for calculation of injection of 18F-Flurodeoxyglucose (18F-FDG) and the patient was left to rest for their uptake period. After one hour, the patient was anesthetized on the scanning bed for a dedicated PET/CT acquisition of the head and neck. Guided by PET/CT, FNA under Ultrasound guidance commenced, followed by cytotechnologist collection and analysis of the extracted sample, finishing with a torso PET/CT and Diagnostic CT with intravenous contrast. Ethics approval sought and confirmed for publication. Results: Initial head and neck dedicated PET/CT was able to identify 18F-FDG avid lymph nodes which guided ultrasound FNA. PET/CT identified pathological lymph nodal involvement that was normal by size criteria on diagnostic CT, representing disease functionality and progression, outlining the importance of PET/CT scanning on patient management. Conclusion: Through collaboration with several multidisciplinary teams, nuclear medicine was able to cater to the referrers and patients’ needs, reducing risks associated with multiple general anaesthetics. An intricate case study such as experienced with this patient, highlights the innovative and expanding scope of practice exhibited by nuclear medicine at the RBWH.


   P092: Impact of Mobile Phone Interference on the Performance of a Gamma Camera Top


Melissa Dowling*1, S O’Loughlin1, G Currie1

1Charles Sturt University, Wagga Wagga, New South Wales, Australia

Background/Aims: Electromagnetic interference (EMI) due to a mobile phone device has been reported to produce a detrimental effect on the function of a gamma camera system. The outcomes from this proposal will provide justification and validation of set rules and regulations regarding their use within nuclear medicine departments due to possible degradation of camera function and resulting image quality. Methods: A 3G apple iPhone 6 was tested against a thyroid phantom in four operating modes, in three positions. Testing was carried out on a Siemens E-Cam gamma camera and a GE Discovery 670 SPECT/CT gamma camera. The protocols were standardised for operation on both systems with static images obtained for assessment. Assessment was made arithmetically by means of subtraction. Results of potential EMI were determined following comparison to a baseline image. Results: Initial assessment of static images acquired provided no abnormality between modes and positions. Following the application of arithmetic processes, the inferior right lobe presented with an increased ring of activity upon activation of mobile signals regardless of position when tested on the Siemens E-Cam gamma camera. When compared to the GE Discovery 670 SPECT/CT gamma camera, these results did not appear to be present. This was confirmed numerically as a statistical significant difference was noted in count differences between the Siemens E-Cam and GE Discovery (p=0.0004). Conclusion: The function of a gamma camera has the potential to be influenced by EMI produced by mobile phone devices. Further investigation is warranted employing SPECT acquisition to assess the potential amplification of errors. The additional SPECT investigation would also allow usage and evaluation of different systems in common use. While this result was only demonstrated on one gamma camera system, it is recommended that caution be exercised when using mobile phones (in all modes) in immediate proximity to a gamma camera during data acquisition.


   P093: An Evaluation of Direct Quantification using xSPECT Quant in Everyday Clinical Practice Top


Iain Duncan*1, N Ingold1

1Garran Medical Imaging, Canberra, Garran, Australia

Background/Aims: To evaluate the clinical utility and practicality of direct quantification using xSPECT Quant in everyday clinical practice. Methods: After installation xSPECT quant in August 2016 we used direct quantification in every scan, both to standardise windowing and evaluate all lesions considered significant. Patient symptoms and available clinical data were entered into an android based database that populated a google spreadsheet. Correlative CT and MRI imaging was available in many cases. Specific cases were flagged for follow-up or more detailed review to evaluate the benefits of direct quantification in our practice. Results: Data was collected from 300 general/musculoskeletal (Tc-HDP), 60 oncology (Tc-HDP and Tc-PSMA), and 15 Cardiac amyloid (Tc-PYP) cases. xSPECT Quant has proven to be a reliable way of windowing xSPECT/CT and SPECT/CT scans, most particularly in serial evaluations. It has provided a more reliable and definitive way of serially assessing oncology cases and evaluating response to therapy. We have accumulated data regarding range of uptake values in specific pathologies, most particularly in symptomatic lesions. Specific cases are presented to illustrate the benefits of direct quantification. Conclusion: Direct and absolute quantification has become an invaluable tool in our practice. It is used in every xSPECT scan both to standardize the scan and to evaluate individual lesions. For oncology cases, it has become an integral/critical part of the evaluation. For musculoskeletal problems, it has become a guide to severity of uptake and has standardised our assessment. As criteria develop over time it may find more specific application in stress fracture grading, Paget’s disease, sacroiliitis, and in assessing periprosthetic uptake.

Disclosure of interest: I Duncan conflict with Collaboration Siemens Healthcare, N Ingold conflict with Collaboration Siemens Healthcare.


   P094: Effects of Metformin on 18F-Flourodeoxyglucose Uptake in Type 2 Diabetic Patients Top


Wen Shenh Huang*1,2,3, C H Ting1, T B T Mai4,5, Y Y Kuo6, C Y Cheng3, C H Chiu3, B Tsung Hsieh4

1Taipei Veterans General Hospital, 2Yang-Ming University, 3Department of Nuclear Medicine, National Defense Medical Center/Tri-Service General Hospital, 6National Defense Medical Center, Graduate Institute of Medical Sciences, Taipei, 4Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan, 5Ho Chi Minh City Medicine and Pharmacy University, Ho Chi Minh, Vietnam

Background/Aims: Diabetes mellitus (DM) is a common disease worldwide and metformin is the first line antidiabetic medication. It frequently encountered DM patients receiving metformin for 18F-FDG PET scans for various disorders. Effects of metformin on imaging quality, however is still not clarified. We retrospectively observed possible differences in tissue FDG uptake in patients, with and without metformin treatment. Methods: Thirty-three metformin treated patients who revealed characteristic diffused bowel uptake patterns were recruited. Twenty-five age, gender and BMI-matched non-diabetic patients with staged IA/B drug-naive lung cancer served as the controls. Imaging data were corrected with corresponding lung background (Bkg) and serum blood glucose (Bg) and analysed using PMOD software to calculate 18F-FDG mean standardised uptake value (SUVmean) of the brain (grey matter), liver, muscle tissues and lung (Bkg). Data were expressed as mean±SD (SEM). Results: The Bkg corrected meformin group revealed significantly increased SUVmean of liver and muscle compared to the controls [Liver: 3.51±1.04 (0.18) vs. 2.59±0.5 (0.1), p<0.0001; Muscle: 1.11±0.35 (0.06) vs. 0.89±0.18 (0.04), p=0.004] but significantly decreased in the grey matter [5.66±1.53 (0.27) vs. 7.66±2.12 (0.42), p<0.001]. Corrections combined Bkg and Bg provided a similar result as blood glucose correction alone [Liver: 3.56±0.91 (0.16) vs. 2.67±0.64 (0.13), p<0.0001; Muscle: 1.13±0.35 (0.06) vs. 0.92±0.25 (0.05), p=0.014]. The tissue-Bkg different ratios and Bkg corrected SUVmean brought the same results as SUVmean. Conclusion: Metformin appears increased hepatic and muscular FDG uptake yet decreased brain grey matter uptake.


   P095: Constrained List Mode Reconstruction of Activity and Attenuation Maps on the Positron Emission Tomography/Magnetic Resonance System from Emission Data Top


Alireza Kamali-asl*1, H Hemmati1, M Reza Ay2, P Ghafarian3, S Tamhidi4

1Department of Medical Radiation Engineering, Shahid Beheshti University, 2Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, 3PET/CT and Cyclotron Center, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, 4Faculty of Amirkabir University, Amirkabir University, Tehran, Islamic Republic of Iran

Background/Aims: Photon attenuation correction is a necessary step on the PET system to have accurate images. Activity and attenuation maps on the TOF PET system can be determined from emission data up to a constant term. The aim of this study is to limit the number of unknown attenuation coefficients and incorporate some additional information on the emission-based method in order to improve the estimated activity and attenuation maps. Methods: The proposed method uses a maximum a posteriori framework to incorporate the histogram-based information on the attenuation map reconstruction. It includes a successive optimization approach in which activity and attenuation maps and the hyper parameters of attenuation map are updated alternately. A single scatter simulation technique was used for scatter correction and random coincidences were estimated using a delayed window method. Results: The performance of the algorithm is studied with some simulated phantoms using Monte Carlo simulation toolkit (GATE). The simulated geometry of system was based on GE 690 PET scanner at different time resolutions. A good agreement was found between the actual images and those produced by the proposed algorithm. Also, results for time resolutions of 544 ps that are commercially available (GE 690 PET/CT) show that the proposed method can be combined with segmentation-based attenuation extraction methods on the current commercial PET/MR systems. Conclusion: The proposed method indicates a robust and reliable alternative to other methods for attenuation map extraction on the PET/MR systems. The results showed that presented method suppress the cross-talk problem of emission-based activity and attenuation reconstruction. Moreover, it the potential to be used as a stand-alone or even combined with other methods for attenuation correction on the PET/MR systems.


   P096: Basic Study on Removal of Extracardiac Uptake using Deep Learning Top


Akihiro Kikuchi*1, T Kawakami2, K Nakajima3, K Okuda4, M Kitama1, K Okada2, Y Honma1

1Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, 2Department of Information and Computer Science, Hokkaido University of Science, Sapporo, 3Department of Nuclear Medicine, Kanazawa University Hospital, 4Department of Physics, Kanazawa Medical University, Kanazawa, Japan

Background/Aims: The extracardiac uptake by technetium radiopharmaceuticals in myocardial images has influence on image diagnosis. High uptake of liver and intestinal tract may show abnormal uptake when close to the myocardial, which also causes misdiagnosis. In the past study, there are mask processing by image processing and by normalization of count, but it was not perfect. Therefore, we devised a system for image recognition and removal at the pixel level of the cardiac accumulation using deep learning out of artificial intelligence. We conducted a basic study on the accuracy of image discrimination between cardiac and extracardiac uptake. Methods: We used deep learning for artificial intelligence learning methods. From the clinical axial image of 30 cases obtained using 99mTc radiopharmaceuticals, we used the selective search for cutting out of 334 images assumed to be myocardial region and 1406 images other than the myocardial, for creating teaching data. We made these images learn two patterns other than the myocardial and the extaracardiac to the artificial intelligence system. When defining the myocardial region, the position in the image, the number of counts, etc. were determined. This time, our image recognition system used Adam. In the verification method, 35 cardiac regions and 49 other than the myocardial were excised from another patient group, and how the system identifies each image was verified. Results: The ratio of recognising that it is a cardiac image was able to be identified with accuracy of 92% as a result of 50 rounds of learning. It was also confirmed that the recognition of the extracardiac can be similarly identified with an accuracy close to 90%. Conclusion: We have learned the system with the system with 300 images (cardiac) and 1400 images (extracardiac) of 30 cases, and verified the accuracy. However, since both learning cardiac data and extracardiac data are in few cases, it is necessary to consider the case in which the myocardial and the extracardiac uptake are closely related, the extracardiac uptake is very large, and the defect of the myocardium is large. For that reason, it is necessary to increase the number of cases by verifying under various conditions. In the future, we believe that the effect of extracardiac can be alleviated by increasing the accuracy of the recognition technique for imaging myocardial images.


   P097: Basic Study on New Ischaemic Defect Model Create for Myocardial Image Evaluation Top


Akihiro Kikuchi*1, M Kitama1, T Kawakami2, H Honma3, K Nakajima4, K Okuda5, G Okuyama1, Y Honma1

1Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, 2Department of Information and Computer Science, Hokkaido University of Science, 3Ono Memorial Hospital, Sapporo, 4Department of Nuclear Medicine, Kanazawa University Hospital, 5Department of Physics, Kanazawa Medical University, Kanazawa, Japan

Background/Aims: In order to evaluate the image quality of myocardium, we evaluate lesions of simulated defects such as acrylic and plastic phantoms in myocardium. It was intended to create a defect, not a model assuming ischaemia. The ischaemic model up to now has been created in a pseudo manner by changing the thickness of the chunk of the defect. However, in actual ischaemia, defects and normal parts were mixed, and the true ischaemia model did not exist. Therefore, we examined whether a myocardial ischaemia model with normal and defect mixed can be created and used for image evaluation. Methods: We created a cylindrical myocardium model with a total length of about 200mm. There were created a total of 5 ischaemia models consisting of 4 models with a degree of ischaemia of 60% to 90% up to 10% and one model in which ischaemia continuously varies from 60 to 90%. The material of the ischaemia model was acrylic, and the entire phantom was made using acrylic material. Specific methods of creating ischaemia are: (1) Drill two different holes of 2 mm φ and 3 mm φ in acrylic to create an ischaemic model, (2) Create ischaemia with slit with adjusted depth and width. It was collected with 99mTc and 201Tl. Acquisition protocol was 180 and 360 degree, in addition the matrix was 64 and 128. We used FBP for image reconstruction and 0.5 [c/cm] for BW filter. Evaluation was used by circumferential profile curve. Results: Regardless of the acquisition angle aria and type of radiopharmaceutical used, the slit of type (2) was more sensitive to the difference of ischaemia. Regarding the ischaemic type of the hole (1), regardless of the number of holes or the number of counts, the rate of count decrease remained about 50% of the maximum count, and there was no change. On the other hand, type of slits (2), there was a gradual increase in counts in the 90% to 60% ischaemia model. In fact, it was 52% 56% 61% 74% relative to the maximum count. Conclusion: We thought that the slit type (2) to be able to create more better ischaemia model by also considering slit number, depth width. In the hole type of (1), it is considered that the radiopharmaceutical did not pass through the hole, and it entered the same state as the defect due to the entry of air. We thought that the slit type (2) to be able to create a better ischaemia model by also considering slit number, depth width.


   P098: The Role of Bone Seeking Radiopharmaceuticals in Overall Survival of Breast Cancer Patients with Multiple Bone Metastases Top


Tatiana Kochetova*1, V Krylov1, A Dolgova2, K Petrosian3

1Department of Nuclear Therapy, Medical Radiological Research Center, 2Faculty of Medicine, Institute for Nuclear Power Engineering, 3Department of Radionuclide Diagnostics, Medical Radiological Research Center, Obninsk, Russian Federation

Background/Aims: Bone is a common site of metastases in breast cancer. Bisphosphonates, denosumab, chemotherapy and hormonal therapy have proven efficacy. External beam radiation and surgery are used in complicated cases. Nuclear therapy is usually used to manage prostate cancer, it may be also useful in breast cancer cases. Nuclear therapy has proven efficacy reducing pain, but influence on survival remains unclear. The aim of this retrospective cohort study is to assess overall survival (OS) of breast cancer patients with bone metastases. Methods: 160 breast cancer patients with multiple progressive bone metastases treated with 153Sm-EDTMP (83%), 188Re-ZA (8%) or 89Sr-Cl2 (9%) were included in the study. Median age was 59 years (range 79-31). In 80% of cases, it was hormone-sensitive erb2 negative type; in 9% was hormone-sensitive erb2 positive type: in 5% was triple negative; and other cases was erb2 positive. 58% of patients at the last follow up visit had no extra-skeletal metastases. More than 20 lesions according to the bone scan at the start of the therapy were in 35% of cases; from 6 to 20 lesions in 28%; from 3 to 6 lesions in 13%, and total skeleton involvement observed in 24% of cases. Median time from diagnoses of bone involvement was 9.3 months (range from 0.04 to 125 months). In the majority of cases, nuclear therapy applied repeatedly was independent from pain syndrome. Median number of cycles were 3 (Range: 1-10), with median 4 month interval between the 1st two cycles (Range: 2-27). OS after the start of the treatment and after diagnosis if bone metastases was calculated and compared with contemporary data from the literature. Results: Median OS after the 1st cycle of nuclear therapy was significantly higher than after external beam therapy applied to painful bone sites: 33.6 and 23 months, respectively.[1] Median OS after diagnosis of bone metastases in our cohort was 5.2 years. It is much higher than the OS in two great populational studies: 2.3,[2] 2.2 and 2.5 years.[3] Conclusion: Nuclear therapy in breast cancer patients is safe and potentially life-prolonging treatment option. There is need in further evidence based trials to assess influence of the therapy on the OS compared to external beam radiation or best standard of care.

References

  1. Nieder C, Dalhaug A, Pawinski A, Mannsåker B, Haukland E. Survival after palliative radiotherapy in patients with breast cancer and bone-only metastases. In Vivo 2016;30:879-83.
  2. Harries M, Taylor A, Holmberg L, et al. Cancer Epidemiol 2014:427-34.
  3. Lipton A, Cook RJ, Major P, Smith MR, Coleman RE. Zoledronic acid and survival in breast cancer patients with bone metastases and elevated markers of osteoclast activity. Oncologist 2007;12:1035-43.



   P099: Uncovering a New Gold Standard for Prostate Cancer Imaging using 18F-DCFPyL Positron Emission Tomography/Magnetic Resonance Imaging and Positron Emission Tomography/Computed Tomography: A Case Study Top


Remi Hillery*1, J Duong1

1Princess Alexandra Hospital, Woolloongabba, Queensland, Australia

Background/Aims: A 52-year old male with a family history of prostate cancer and a rising prostate-specific antigen (PSA) level presented to the molecular imaging department in a high-risk prostate cancer bracket. His digital rectal examination was normal and his magnetic resonance imaging (MRI) concluded prostatitis. However, his biopsy resulted in a Gleason score of 4+4 (8) and 4+3 (7). Due to these results, pre-operative positron emission tomography (PET) was requested. This case study aims to show the benefits of using an imaging protocol combining both PET/MRI and PET/computed tomography (CT) for the diagnosis, staging and treatment planning of prostate cancer. Methods: 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid (18F-DCFPyL) is a radiotracer that binds to prostate-specific membrane antigen (PSMA) receptors which are found on prostate cancer cells.[1] The patient was injected with 222 megabecquerels (MBq) of 18F-DCFPyL and had an uptake time of 120 minutes. A 1-bed position PET/MRI was performed over the prostate followed by a vertex to thigh PET/CT. Ethics was approved through the Princess Alexandra Hospital local ethics committee on behalf of Metro South Health. Results: The PET images displayed a PSMA-avid focus in the right peripheral zone of the prostate with a Prostate Imaging-Reporting and Data System (PI-RADS) score of 4, suggesting it was highly suspicious of malignancy. As both modalities demonstrated a localised lesion with no metastases present, a prostatectomy was the recommended treatment pathway. Following surgery, the patient’s PSA level declined and was in the normal range. Conclusion: The PET/MRI and PET/CT imaging protocol was able to provide information to accurately diagnose stage and treat this patient. The combination of using both hybrid modalities could become the new gold standard as it provided a thorough screening of a high-risk prostate cancer patient, where other tests failed.

References

  1. Dietlein F, Kobe C, Neubauer S, Schmidt M, Stockter S, Fischer T, et al. PSA-stratified performance of 18F – And 68Ga-PSMA PET in patients with biochemical recurrence of prostate cancer. J Nucl Med 2017;58:947-52.



   P100: Improving the Patient Pathway for Breast Lymphoscintigraphy Patients Top


Suzanne McGavin*1, T Pearson1, T Halligan2, A Chan2

Departments of 1Nuclear Medicine and 2Royal Brisbane and Women’s Hospital, Herston, Brisbane, Queensland, Australia

Background/Aims: A nuclear medicine lymphoscintigraphy study is performed in conjunction with breast surgery for patients with diagnosed breast malignancies. Currently the study involves coordination of three clinicians to be present which results in waiting times greater than the target of 45 minutes. The aim of this study was to identify procedural changes to reduce patient waiting time. Methods: A baseline audit (October 2016-January 2017) was conducted. Consultation with the associated professions involved in the procedure facilitated implementation of strategies to improve the process bottlenecks in February 2017. A follow-up audit (March-July 2017) was undertaken to monitor the impact. Patient demographics and waiting times were collated and analysed. Results: The baseline audit (50 patients) identified that 30% of patients were injected within the target 45 minutes for their procedure. Procedural changes implemented included the development of a new referral template; engagement with Women’s Imaging for patients undergoing hookwire procedures; medical review of previous imaging and request forms the day prior to the procedure and confirmation of injection technique before patient arrival. Following implementation of these changes, the audit (56 patients) identified that 48% of patients were injected within the target 45 minutes. Conclusion: Procedural changes have reduced the waiting times for lymphoscintigraphy studies, however 52% of patients are still waiting longer than the target 45 minutes. Work is currently underway to expand the scope of the nuclear medicine scientists to perform the lymphoscintigraphy procedure and further reduce waiting times.


   P101: Count Rate Dependence of Sensitivity for Quantitative Single Photon Emission Computed Tomography with the GE-670 and Q.Metrix Top


Cameron Pain*1, G J O’Keefe1

1Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, Melbourne, Victoria, Australia

Background/Aims: The GE670 SPECT/CT combined with the Q.Metrix[1] toolkit provides a clinically applicable system for quantitative SPECT. By taking into account camera sensitivity, scan parameters and patient demographics, the counting statistics in the image can be mapped to activity concentration. One consideration in implementing this, is the count rate dependence of sensitivity. For 99mTc, dead time effects manifest at count rates in the clinical range decreasing the sensitivity. This work aims to characterise the count-rate dependence of the sensitivity to apply Q.Metrix over a wider operating range. Methods: The sensitivity values required for Q.Metrix are measured using the planar sensitivity measurement described in the NEMA-NU1[2] which correlates well with volume sensitivity values.[3] The planar sensitivity was measured for activities ranging from 70MBq to 1500MBq. A cylindrical uniform source with volume 6.035L was filled with 1500MBq of 99mTc and acquired over a period of approximately 30 hours. Each acquisition was then reconstructed with Q.Metrix using clinical parameters and analysed using the corresponding count-rate dependent planar sensitivity. A comparison of the reconstructed voxel activity concentration against the known activity concentration then allows for an assessment of the accuracy of Q.Metrix over a range of system count rates. Results: The measured planar sensitivities ranged from 90.1 cps/MBq at 70MBq to 68.4 cps/MBq at 1543MBq with no paralysable effects observed. Application of the count-rate dependent sensitivity to the Q.Metrix reconstruction of the uniform cylinder phantom for activity concentrations of 153.1 kBq/ml and 44.37 kBq/ml results in reconstructed voxel concentrations of 158.5 kBq/ml and 45.3 kBq/ml respectively which corresponds to approximately 3% overestimation for both cases. Conclusion: Consideration of the count rate dependent planar sensitivity is required when applying Q.Metrix in order to achieve reliable quantitation. Future work is to quantify the sensitivity of the system for a range of isotopes.

References

  1. Q.Metrix (GE).
  2. NEMA-NU1-2007.
  3. An H, Lee M, Lee J. J Nucl Med 2016;57.



   P102: Custom Apps: A New Generation of Relational Databases Top


Peter Robins*1

1Department of Nuclear Medicine, Sir Charles Gairdner Hospital, Perth, Australia

Background/Aims: To create a relational database with additional functionality to address workflow issues in a busy thyroid therapy clinic, and then assess the ease of implementation and benefits to clinicians and support staff. Methods: Several software products able to create a relational database (custom application or app) were considered with regards to functionality, cross platform compatibility, software design, cost and level of support. Development was in-house, rather than through an external developer. Secure electronic data capture needed to include all patient demographics, medical and treatment information, as well as referrer demographic data. Generation of customized clinic letters and improved communication between clinic staff, patients and referrers was also required. Following development and implementation, an electronic survey was performed to assess the ease of use, improvement in communication and documentation of patient interactions, as well as increased turn-around times of clinic letters and other a performance indicators.Results: The Thyroid Intervention Management System (TIMS) was developed on FileMaker Pro 15 over approximately 100 hours by a single physician, who had no previous programming experience. Implementation was completed over several weeks, on existing hardware and infrastructure, and all clinic staff were exclusively using TIMS within three months. Benefits included up to date patient information across the site being available to auto-populate consult notes, letters and request forms, as well as generate new bookings. Communication was improved using time-stamped logs, template emails, auto-saved documents and updated contact information. Conclusion: FileMaker Pro can be used to create custom apps that are intuitive for the user and can be modified or expanded as the need arises. In the clinical workspace, these custom apps can be used as a secure solution when managing large amounts of patient data, with benefits with regards to reduction in support resources required and turn-around times, and increased user satisfaction.


   P103: Positron Emission Tomography/Magnetic Resonance Imaging: A Retrospective Analysis of Clinical Utilisation Top


John Turner*1, J Govindasamy1, N Weinert1

1Department of Diagnostic Radiology/Molecular Imaging, The Princess Alexandra Hospital, Queensland Health, Woolloongabba, Queensland, Australia

Background/Aims: PET/MRI remains an emerging imaging modality at present. The hybrid combination of PET + MRI became a reality for clinical use in humans in 2010.[1] The Princess Alexandra Hospital (PAH) acquired the 1st clinical based PET/MRI scanner [Siemens Biograph mMR (3T)] in Australia in September 2014. Subsequently the first clinical PET/MRI scan in the Southern Hemisphere was completed on December 2nd, 2014. Our aim is to review the use of PET/MRI in routine clinical practice including pathologies investigated, radiopharmaceuticals utilised and the primary scan indications. Methods: A retrospective review of all PET/MRI studies completed at the PAH between 2nd December 2014 and 31st of October 2017 was performed, utilising local records and picture archiving and communication system (PACS) databases. The need for patient consent was waived by the institution ethics review board. Results: A total of 1775 PET/MRI studies were recorded, among which clinical scans accounted for 64.28%. This was followed by dedicated diagnostic MRI imaging (20.90%) and finally research/audit scans (14.82%). The most common radiopharmaceutical utilised was 18F-Fluorodeoxyglucose (18F-FDG) accounting for 60.44%, 68Ga-Prostate Specific Membrane Antigen (68Ga-PSMA) accounted for 30.70% and 68Ga-DOTATATE (68Ga-DOTATATE) 5.93%. The most common pathology investigated utilising the PET/MRI was prostate cancer accounting for 25.21% of cases, followed by diagnostic MRI imaging for myeloma on the PET/MRI (12.60%) and PET/MRI for colorectal cancer (8.05%). Conclusion: The clinical utility of PET/MRI in routine clinical practice continues to evolve. Prostate cancer imaging is the key clinical pathology being imaged using PET/MRI and 18F-FDG remains the most utilised radiopharmaceutical in our study. Although the most common reason to perform a PET/MRI is shown to be for clinical use (64.28%), PAH continues to perform extensive clinical trials to unveil the expanded utility of PET/MRI in clinical practice, which is key should this modality make its way into routine clinical use.

References

  1. Muzic RF Jr., DiFilippo FP. Positron emission tomography-magnetic resonance imaging: Technical review. Semin Roentgenol 2014;49:242-54.



   P104: Study on Introduction of Positron Emission Tomography Nuclides into Glutamate Transporter Inhibitor Top


Hiroshi Yamaguchi1,2, K Yamashiro3, T Sumi4, J Kang4, M Tateno4

1Graduate School of Medicine, Nagoya University, 2Brain and Mind Research Center, Nagoya University, 3Nagoya University Hospital, Nagoya, Aichi, 4Graduate School of Life Science, University of Hyogo, Ako-gun, Hyogo, Japan

Background/Aims: Positron emission tomography (PET) imaging is a useful method to analyse the biological functions of receptor and transporter in the CNS. The demonstration of the functional changes would also lead to an early diagnosis of various brain diseases. To develop useful imaging agents that bind to glutamine transporters, we have investigated tamoxifen derivatives and tetrahydrobenzopyran derivatives that are known to affect the functions of the Glt by exposing some of the compounds to [18F]F-or [11C]CH3I, [11C]methyl triflate be labeled. Methods: First, we performed an in silico-binding assay by generating various derivatives of tamoxifen and tetrahydrobenzopyran using our protein-ligand docking calculations. Next, we synthesized the precursors of the desired derivatives: The tamoxifen-derived derivatives were conjugated to those of the ketone using the McMurry coupling reaction. The derivatives of tetrahydrobenzopyran were synthesized from diketone components and cyano analogs. After purification of the reaction mixture by flash column chromatography and recrystallization, the label precursors were obtained, and were reacted with [18F]F-or [11C]CH3I, [11C]methyl triflate on an automated synthesis system. Results: In the present study, we synthesized the [11C] or [18F] labeled derivatives of tamoxifen and tetrahydrobenzopyran. At present, we are attempting to improve the yields and the resultant compounds in the labelling reaction. Conclusion: We performed an in silico-binding assay and synthesized the labeled derivatives of tamoxifen and tetrahydrobenzopyran, which are thus possible ligands of the Glt. The experiments with an in vivo small animal imaging device are also underway in our group.


   Physics Top



   P105: Development of a Novel Preclinical Positron Emission Tomography System Based on SiPM Detectors: Xtrim Positron Emission Tomography Scanner Top


Mohammad Reza Ay*1, S Sajedi1, S Kavian1, N Zeratkar1, H Khanmohammadi1, A Radnia1, M H Farahani1, K A Mozafari1, S Sarkar1

1Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aims: Small-animal research, which is widely used in laboratories for biomedical research, drug development, gene expression and novel detector technology, is an emerging field in preclinical molecular imaging with positron emission tomography (PET). Small-animal PET has been used extensively in modern biomedical research. In this study we have developed a new small-animal PET scanner. Methods: Each detector block consists of a 24×24 LYSO: Ce array with 2×2×10 mm3 pixels coupled to a SiPM device and multiplexing Printed Circuit Board (PCB) placed in aluminum housing. We used SensL ARRAYC-30035-144P which is a 12×12 array of C-series SiPM pixels. The system compromises of 10 detection blocks connecting to a digital coincidence processing unit (DCPU). We implemented time-to-digital converter (TDC) in Xilinx’s SPARTAN6 field programmable gate array (FPGA) by using a 64-tap delay line. After acquisition, the list mode data generates 3D sinogram with user configuration and then it will be ribinned to 2D sinogram. The iterative 2D OSEM is used for image reconstruction. The base design uses the single-slice re-binning (SSRB) and ordered subset expectation maximization (OSEM) image reconstruction methods. Results: The averaged energy resolution at 511 keV was about 16% for all heads with negligible differences. Spatial resolution of the system was measured as 1.8 mm at the center without resolution recovery. In addition, the sensitivity of the system was calculated as 1.2%. The reconstructed images of the rat NaF scan and image quality phantom revealed good imaging performance of the system resolving skeletal structure including acceptable resolutions for the vertebrae and the ribs. The transaxial slice of the reconstructed image of the Jaszczak phantom without resolution recovery shows that the sections containing 1.8 mm rods is visually clear with adequate resolving. Conclusion: The preliminary performance evaluation shows the system can be a reliable PET imager for preclinical molecular imaging.


   P106: Design and Development of a Dedicated Single-Photon Emission Computed Tomography System for Cardiac Imaging Top


Mohammad Reza Ay*1, B T Fard2, H Khanmohammadi1, A Akbarzadeh1, A Radnia1, S Kavian1, S Sajedi1, S Sarkar1, M H Farahani1, N N Rastgar1, S Farzanefar3, K A Mozafari1

1Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, 2Faculty of Physics and Nuclear Engineering, Amir Kabir University of Technology (Tehran Polytechnic), 3Department of Nuclear Medicine, Valiasr Hospital, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aims: Cardiac SPECT imaging have a crucial role in assessing myocardium in patients with suspended coronary artery disease. We designed and developed a dedicated cardiac SPECT system called ProSPECT to cover patients with different sizes. Also, the scanner provides both supine and prone imaging. This dedicated cardiac imaging system introduces an optimized FOV to minimize inappropriate activity uptake of other organs. It should be noted that the system increases comfort patients specially patients with claustrophobia disorder because the head of patients comes out of the bore of gantry during scanning. The aim of this study is to report the design and performance characterization of ProSPECT based on NEMA-NU2 2007 standards for gamma cameras. Methods: The scanner have two perpendicular detectors that are including NaI (Tl) crystal followed by an 4x6 array of square PMTs (76x76 mm). The use of square PMT provides full coverage of the crystal and decreases the dead zone in the detector. A non-linear recursive filter that we successfully registered as US patent is applied in readout electronics of the detector. Results: The proposed scanner has introduced acceptable uniformity (2.5% integral uniformity and 1.3% differential uniformity) and linearity (0.8 mm absolute and 0.2 mm differential linearity) in UFOV. The intrinsic and extrinsic spatial resolutions with low-energy high-resolution (LEHR) collimator on the surface of the detector were 3.7 mm and 7.5 mm, respectively. The energy resolution of the camera was determined 9.3% and the sensitivity of the system was 180 cps/Mbq. Conclusion: The performance evaluation demonstrated the proposed scanner is appropriate for cardiac imaging. The system is currently under clinical tests.


   P107: A Simple Quality Test Postservice Simulating Clinical Conditions on a GE Discovery 710 Positron Emission Tomography/Computed Tomography Camera Top


Craig Despott*1, K Katsamboukas1, J Crocker2

Departments of 1Nuclear Medicine and PET and 2Medical Physics, Alfred Health, Melbourne, Australia

Background/Aims: On a GE Discovery 710 PET/CT camera, the existing quality control routine performed post-service or after fault repair by GE Healthcare engineers does not test some elements of image quality and performance under simulated patient conditions. On one occasion, routine tests did not identify a fault which resulted in breakdown during patient scanning and a reportable radiation incident. We sought to develop a minimum impact additional quality control test in consultation with GE engineers to test the system under simulated patient conditions before returning the camera to service after fault repair or routine service. Methods: The existing well counter calibration phantom supplied with the PET/CT camera was used as a patient surrogate. It was positioned in the body position over two bed positions and filled with Gallium-68 eluate, which is readily available at our centre. A seven bed acquisition was acquired at one minute per bed in addition to CT attenuation correction scan. The images were processed as a normal patient scan and qualitatively examined for image quality, including stitching of bed positions, registration, and miscellaneous artefacts. Quantitative performance was also assessed through determination of mean standardised uptake values (SUVmean) on the attenuation-corrected images. The non-attenuation-corrected images were also examined for artefacts. Results: The quality test has been performed three times. Qualitative performance has been reproducible on a fully-functioning Discovery 710 PET/CT camera. Quantitatively, SUVmean ­values were identical between results (0.90). Additionally, the initial fault was successfully identified when the conditions under which the fault occurred were replicated. Conclusion: This test will be incorporated into the routine post-service and post-repair tests at our centre. The test will be performed collaboratively with engineers, nuclear medicine technologists and medical physicists.


   P108: Baseline 18F-Fluorocholine Positron Emission Tomography/Computed Tomography and Bone Scan in the Outcome Prediction of Patients Treated with 223Ra Top


Ana Maria Garcia Vicente*1, W M Bravo1, B G Garcia1, M Amo-Salas2, I G Carbonero3, A Y Rubio4, A V Alonso5, J C Espinosa6, J L Gómez-Aldaraví Gutierrez7, A S Castrejon1

1Department of Nuclear Medicine, University General Hospital, 2Department of Mathematics, Castilla La Mancha University, 4Department of Oncology, Hospital de Manzanares, Ciudad Real, 3Department of Oncology, Complejo Hospitalario de Toledo, Toledo, 5Department of Oncology, Nuestra Señora del Prado Hospital, Talavera de la Reina, 6Department of Oncology, University General Hospital, Guadalajara, 7Department of Oncology, University General Hospital, Albacete, Spain

Background/Aims: To establish the utility of baseline 18F-Fluorocholine PET/CT and bone scintigraphy (BS) in the outcome prediction of patients with castration-resistant prostate cancer and bone metastases (CRPC-BM) treated with 223Ra. Methods: Prospective, multicenter and non-randomized study (ChoPET-Rad study). 18F-Fluorocholine PET/CT and BS were performed before the initiation of 223Ra (basal PET/CT and BS). Bone disease was classified attending the number of lesions in baseline BS and PET/CT. PET/CT was semiquantitatively evaluated to obtain the SUVmax in the 5 bone lesions with the highest metabolism and the average SUVmax. Gleason score, baseline levels of prostate specific antigen (PSA), alkaline phosphatase (AP) and lactate dehydrogenase (LDH), time of evolution of prostate cancer, time of evolution of BM and 223Ra line were registered. Each patient was clinically and biochemically monitored. Progression free survival (PFS) and overall survival (OS) since the onset of 223Ra treatment were calculated. Therapeutic failure was considered when patient did not finish the 223Ra treatment. Relations between clinical and imaging variables with PFS and OS were evaluated by Pearson, Mann-Whitney tests and Kapplan-Meier analysis. Univariate and multivariate Cox regression analysis was performed. Results: Forty patients were enrolled. The mean±SD of PFS and OS were 4.6±2.3 and 11.2±8.1 months respectively. 33 patients progressed and 13 dead during the follow-up. The extension of the bone disease by PET/CT (p=0.011, χ2= 10.63), BS (p=0.044, χ2=8.04), SUVmax (p=0.012) and average SUVmax (p=0.014) were related to OS. No significant association was found for the PFS. ROC analysis revealed significant association of SUVmax, average SUVmax and basal PSA with OS. Only therapeutic failure was associated with OS In the multivariate analysis (HR=3.6, p=0.04). Conclusion: 18F-Fluorocholine PET/CT had prognostic aim in the prediction of OS. None clinical or imaging variable was able to predict the PFS, probably due to the high rate of progressive disease.


   P109: Assessment of the Impact of Time-of-Flight on Reduction of Metal Induced Artifact in Positron Emission Tomography/Computed Tomography Imaging: Phantom Study Top


Pardis Ghafarian*1, R Sharifpour2

1Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, 2Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aims: CT-based AC of PET data causes some artifacts in PET images such as metal artifact which affects tracer uptake value and decreases quantitative accuracy. In this study, we evaluated the impact of TOF reconstruction on reduction of metal induced artifact in PET/CT imaging. Methods: NEMA IEC body phantom was adapted to hold a pacemaker generator in the removable lung insert. Phantom background and spheres were filled with 5.3kBq/ml and 10.6kBq/ml (2:1activity-ratio), respectively. All images reconstructed using two algorithms including, non-TOF and TOF. Results: In place of pacemaker generator and its surroundings, both underestimation and overestimation were observed. Error in 18F-FDG uptake value was calculated using comparison between measured activity (SUVmax) and expected activity. In case of overestimation, percentages of overestimation were 93.8% and 32.7% for non-TOF and TOF reconstruction, respectively. Also, with integrating TOF to reconstruction, percentage of underestimation was changed from -15.5% to -6.9%. The hot spheres of phantom were also evaluated. In this case, spheres with 37, 28 and 17 mm in diameter, mostly affected by light streaks while 3 other spheres affected by dark streaks caused by metal artifact. In spheres influenced by light streaks, TOF led to reduction in SUVmax. Relative differences of SUVmax between non-TOF and TOF images were -10.4%, -4.2% and -11.6% in 37, 28 and 17 mm sphere, respectively. In other spheres which mostly influenced by dark streaks, TOF led to increase in SUVmax. Relative differences of SUVmax between non-TOF and TOF images were 1.4%, 5.7% and 1.7% in 22, 13 and 11 mm sphere, respectively. Conclusion: Pacemaker generator produced artifact which decreased accuracy of measured activity. Using the TOF technique, metal-induced artifact was reduced efficiently so that overestimation and underestimation of activity were obviously decreased. We can conclude that integrating TOF technique to reconstruction, have a potential to reduce the artifacts related to the presence of high density materials such as metallic implants.


   P110: Quantitative Assessment of Ring Diameter, Energy Window and axial field of view on the Sensitivity of Xtrim SiPM Based Animal Positron Emission Tomography Scanner Using the NEMA NU-4 Standards Top


Peyman Ghahramani*1,2, R Shahi1, M R Ay2,3

1Department of Radiation Medicine Engineering, Sharif University of Technology, 2Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, 3Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aims: In this study, the sensitivity of Xtrim animal PET system by evaluating the influence of ring diameter, energy window and axial field of view (AFOV) using Monte Carlo method has been optimised. Methods: Xtrim SiPM based animal PET system has been recently designed and developed in our department. The sensitivity of system was evaluated for five different ring diameters, eight energy window lengths and four AFOVs. The minimum ring diameters are considered, which are 133, 152, 170, 188 and 206 mm for 8, 9, 10, 11 and 12 modules respectively. The energy windows include [100-700], [250-700], [300-700], [300-650], [350-650], [375-650], [375-625], [400-600] with a length of 600, 450, 400, 350, 300, 275, 250 and 200 keV respectively. The AFOVs evaluated are 50 mm, 52 mm (adding a pixel crystal column), 60 mm and 100 mm (adding a module column). The NEMA NU 4-2008 standards were used for evaluating sensitivity. The system was well defined in the GATE Monte Carlo code in details. Results: The sensitivity for 8, 9, 10, 11 and 12 modules was respectively 1.74, 1.28, 1.42, 1.11 and 1.21%. The sensitivity for 600, 450, 400, 350, 300, 275, 250 and 200 keV energy window length was respectively 2.50, 1.75, 1.59, 1.58, 1.42, 1.38, 1.37 and 1.33%; and sensitivity for 50, 52, 60 and 100 mm AFOV was respectively 1.42, 1.60, 2 and 3.72%. Conclusion: By reducing the ring diameter, sensitivity of the system increases but states with the number of paired modules are more sensitive because they can better detect the pair gamma photons resulting from the positron annihilation. As the energy window length increases, the sensitivity of the system increases Because more photons can pass through the window. Depending on the data, by doubling the energy window, the sensitivity of the system increases 1.7 times and the system resolution decreases. By increasing the AFOV, the sensitivity of the system increases more than the other cases without reducing the system resolution, so that by doubling the AFOV, sensitivity of the system increases more than 2.6 times.


   P112: Salt Activation to Assess Neutron Flux as a Proxy for Radiation Damage in a Cyclotron Vault Top


Matthew Griffiths*1, B Wallace1

1Department of Nuclear Medicine, Royal Brisbane and Women’s Hospital, Brisbane, Australia

Background/Aims: We have modified the methods of Fujibuchi et. al. to provide a rapid assessment of relative thermal neutron flux to allow locating and shielding of electronics to avoid activation.[1] The use of bonner spheres in future work will allow assessment of damage from more energetic neutrons. Methods: Stable 23Na (100%) => 24Na emitting 1.37 and 2.75 MeV gammas with a 14.9 h ½ life. Stable 35Cl (76%) => 36Cl emitting 251keV betas with a 3.01 E+5 yr ½ life. Stable 37Cl (24%) => 38Cl emitting 1.64 and 2.17 MeV gamma with a 37 min ½ life. 2 gram samples of salt were placed around a GE PETtrace cyclotron over single productions of 100 to 400 GBq 18F. Samples were placed inside various forms of shielding to assess the relative reduction in activation. Samples were decayed for >4 hours to reduce 38Cl activity to <0.2 % before being counted in a Perkin Elmer Wizard 2480 Auto Gamma Counter with an open window for 6 minutes. The count per minute (CPM) data was corrected to the end of bombardment, normalised by mass and total cyclotron beam current. The count data was used to assess the relative shielding of boronated plastics and concrete. Results: The activation from a single cyclotron run produced good count statistics 10-30 kCPM. The 24Na 2.75 MeV gamma required the samples to be separated for counting to avoid cross talk. The mass and decay corrected counts correlate with cyclotron use. Samples of boron impregnated plastic produces reduction of activation by a factor of 5 and concrete by a factor of 9. Conclusion: The method allows a rapid assessment of neutron activation which can be used as a proxy for radiation damage.

References

  1. Fujibuchi T, Yamaguchi I, Kasahara T, Iimori T, Masuda Y, Kimura K, et al. Measurement of thermal neutron fluence distribution with use of 23Na radioactivation around a medical compact cyclotron. Radiol Phys Technol 2009;2:159-65.



   P113: Static and Moving Phantom Studies for Radiation Treatment Planning in a 4-Dimentional Positron Emission Tomography/Computed Tomography Top


Kohei Hanaoka*1, H Monzen1, Y Nishimura1, M Okumura1, S Watanabe1, Y Shibata1, H Kaida1, M Hosono1, K Ishii1, T Murakami1

1Kindai University, Osaka, Japan

Background/Aims: Respiratory motion is known to have a potential risk of inadequate target coverage in the setting of radiotherapy. In this study, static and moving phantom experiments for radiation therapy planning were conducted to validate target volume delineation using 4-dimensional (4D) PET/CT. Methods: Six sphere phantoms of 10, 13, 17, 22, 28, and 37 mm in diameter were placed in a body phantom, and the phantoms were filled with FDG solution. A body phantom (background) was filled with 1028 Bq/ml of FDG, and spheres were filled with FDG activity to achieve source-to-background (S/B) ratios of 10, 15, and 20. The body phantom with sphere phantoms was placed on a moving device and scanned by 4D PET/CT. In static phantom experiments, an appropriate threshold value was determined. In moving phantom experiments, total translations were 10, 20, and 30 mm. Moving data during CT and PET scan were recorded to generate 10 breathing phases. The maximum size of 4D PET delineation was measured in both the axial and sagittal planes. The difference between the theoretical distance (sphere diameter+translation distance) and the delineated longitudinal distance on fused PET image was calculated. Results: An appropriate threshold value for the spheres of 17 mm or more determined by static experiments was 35% of the maximum FDG activity, independent of the S/B ratio. On each breathing phase image, sizes of PET delineation with 35% threshold value were in good agreement (<2 mm) with the actual sphere diameter in both axial and sagittal planes. In terms of fused image of 10 breathing phases, sizes of PET delineation with 35% threshold value were in good agreement (<3 mm). In the translation distance of 10 mm, the differences between the theoretical and the delineated longitudinal distance of fused PET delineation of 17, 22, 28, and 37 mm sphere in the sagittal plane were 8.4, 5.8, 2.0, and 1.2 mm, respectively. In the translation distance of 20 mm, the differences were 8.6, 6.0, 5.5, and 1.4 mm, respectively. In the translation distance of 30 mm, the differences were 5.5, 6.2, 5.7, and 4.9 mm, respectively. Conclusion: This preclinical study indicates 4D PET/CT images have the potential to provide an individualized internal target volume. The fused PET delineation can be used to counter gross tumour volume when tumours are larger than 30 mm and total translation within 20 mm.


   P114: PET20.0: System Characterization of a Novel Total Body Positron Emission Tomography Scanner Based on Monolithic Detectors Top


Stefaan Vandenberghe*1

1MEDISIP, Ghent University, Ghent, Belgium

Background/Aims: Total body PET (TB-PET) is a very promising concept for new applications in the field of molecular imaging and biomedical research with the only drawback the high material costs for building the system. The aim of this study is to compare a novel PET system design with current state of the art PET/CT systems. Methods: The PET20.0 design is based on monolithic scintillator technology which should push the resolution to the lower limits for body PET. The system also has a compact bore (inner diameter of 65 cm) and limited axial FOV of 1m. Crystal thickness is set at 16 mm to optimize the spatial resolution, cost and DOI performance of the detectors. The full system performance is compared using NEMA and realistic phantoms mimicking real patients with GATE PET monte Carlo simulations. These system simulations are based on realistic detector models. Results: The total amount and cost of detectors for this Total Body PET design is about 3-4 x higher than in a current PET/CT. Scatter fraction is comparable to the current PET/CT scanner designs. System sensitivity for total body scans is 15-20 times higher for a long NEMA phantom and also for realistic FDG distributions. The spatial resolution improves to 2 mm at the system level. Conclusion: The much higher system sensitivity for imaging torso or total body is the major benefit of total body PET and can be exploited for faster imaging or lower dose. The use of monolithic technology can enable simultaneous improvements in TOF, DOI and the improved spatial resolution will have a major impact on the quality of PET imaging.

Disclosure of Interest: S. Vandenberghe Conflict with: Molecubes.


   P115: Impact of different Reconstruction Algorithms and Ordered Subset Expectation Maximization Reconstruction Parameters on Quantitative Results in SPECT/CT Top


Kemin Huang*1, Y Feng1

1Hospital of Foshan, Foshan, China

Background/Aims: To evaluate the effects of 3-dimensional ordered subset expectation maximization (3D-OSEM), 2-dimensional ordered subset expectation maximization (2D-OSEM), filtered-back projection (FBP), and the number of OSEM iterations and subsets on quantitative results in SPECT/CT. Methods: A Jaszczak cylindrical phantom and IEC body phantom were performed routine SPECT/CT using CT attenuation correction, scatter correction and 3D-OSEM reconstruct image. The system volume sensitivity (cpm/kBq) were acquired from the reconstructed image of Jaszczak phantom, the absolute activity concentration (kBq/ml) of the hot sphere from IEC phantom was calculated, which was compared with true activity concentration, then quantitative error was calculated. Changing the reconstruction algorithm (2D-OSEM, FBP) and OSEM reconstruction parameters (number of iterations and subsets) to reconstruct the IEC phantom, the difference of quantitative results from different reconstruction algorithms and OSEM iterations and subsets was compared. Results: When reconstructing images with 3D-OSEM, 2D-OSEM and FBP, the quantitative error of each sphere increased with the decrease of the spherical volume (r= -0.831, -0.831, -0.826, all P<0.05). The quantitative error of different volume spheres among three reconstruction algorithms was statistically significant (F=8.850, P<0.05), among them that 3D-OSEM was less than that of 2D-OSEM (P<0.05), 2D-OSEM was less than that of FBP (P<0.05). The quantitative error of different volume spheres decreased with the increase of number of iterations (r= -0.721, -0.681, -0.691, -0.711, -0.845, -0.893, all p<0.05), and decreased with the increase of number of subsets (r= -0.670, -0.694, -0.717, -0.852, -0.956, -0.998, all p<0.05). Conclusion: The quantitative accuracy of 3D-OSEM reconstruction based on CT attenuation correction and scattering correction is significantly better than 2D-OSEM and FBP. Choosing the appropriate OSEM reconstruction parameters is helpful to improve the quantification accuracy in SPECT/CT.

Disclosure of Interest: K. Huang conflict with: Financial Support, Y. Feng-conflict with: Technical support.


   P116: Validation of a Noninvasive Analysis Method for CBF Positron Emission Tomography Top


Masanobu Ibaraki*1, K Matsubara1, T Kinoshita1

1Akita Research Institute of Brain and Blood Vessels, Akita, Japan

Background/Aims: Quantitative brain PET with 15O-H2O can provide kinetic parameters, K1 (CBF) and k2, but requires invasive blood sampling for arterial input function (AIF). To obviate the need for blood sampling, researchers have proposed non-invasive methods, which fall into two approaches: 1) image-derived AIF; and 2) compartmental model-based analysis using tissue time activity curves (TACs). Among the tissue-curves methods proposed so far, the blind estimation method by Di Bella (PMB, 1999) is superior in terms of less assumptions and simultaneous estimation of kinetic parameters in multiple regions. The aim of this study was to investigate applicability of the Di Bella’s method to 15O-H2O PET. Methods: List-mode PET data were acquired after bolus injection of 15O-H2O (370 MBq) during 4 minutes for patients with cerebrovascular steno-occlusive disease (n=10), and were reconstructed into dynamic images (5-sec x 48-frames). AIFs measured for each patient were used with the conventional method, that is K1-k2 fitting. Tissue TACs were calculated for 30 regions of interest (ROIs). By applying the modified Di Bella’s method, we estimated the kinetic parameters, K1 and k2, simultaneously for the 30 ROIs without using AIF. In this method scaling of K1 is undetermined; R1, relative K1, was calculated with reference to white-matter region in each patient. These results were compared with the results from the conventional methods. Results: Both with R1 and k2, analysis for each patient showed a strong correlation between the conventional method and the present method. Differences in R1 estimates between the methods were lower than 5% (average over the ROIs) for all the patients. For k2, however, discrepancy of the methods was greater, such as that differences in k2 between the methods were larger than 10% for three patients with up to 34%. Conclusion: The present non-invasive method provides R1 and thus relative CBF with reasonable accuracy. When whole-brain distribution volume of water (Vd = K1/k2) is assumed, absolute CBF (K1) can be calculated from R1 and k2 estimates. However, estimation of absolute k2 has substantial errors for some patients, and absolute CBF determination is difficult without the arterial blood sampling.


   P117: Impact of Detector Geometry on Image Quality for Awake Animal Single-Photon Emission Computed Tomography Top


Peter Kench*1, D Zhang2, G Angelis1, J Gillam3, T Ma2, S Meikle1

1Brain and Mind Centre, The University of Sydney, Camperdown, 3Orygen, The National Centre of Excellence in Youth Mental Health, Parkville, Australia, 2Department of Engineering Physics, Tsinghua University, Beijing, China

Background/Aims: Conventional Single-Photon Emission Computed Tomography (SPECT) requires the animal be anaesthetised to prevent motion artefacts in reconstructed images. We are developing a purpose-built SPECT system for awake animal imaging using an adaptive detector geometry and integrated motion tracking. In this work, we investigate the ideal detector geometry for awake mouse imaging, in terms of noise, resolution and contrast recovery in the reconstructed motion corrected images. Methods: The simulated system consists of stationary detectors with parallel hole collimation beneath the animal, with pinhole collimated detectors in front and beside the housing. To maximise the tomographic information, an additional mobile (6-degrees-of-freedom) detector with pinhole collimation continuously follows the moving animal, performing an arc-like motion, so that the area of interest (e.g. brain) remains focused within the field of view. A rigid digital mouse phantom, comprised of regions of different contrast, uniform activity and lesions of varying diameter, was used to make measurements of application-specific system performance, as a function of the selected detector geometry. Both the mouse and detectors were simulated using Monte Carlo GEANT4 GATE. Simulated phantom motion was based on measured mouse trajectories. The data were corrected for motion and reconstructed using a modified version of the MLEM algorithm. The reconstructed images for different acquisition geometries were assessed using basic image quality metrics. Results: We demonstrate the variation in contrast, resolution and noise over the different geometries considered. Additionally, the trade-off between resolution and noise is explored and the flexibility to optimise requirements for specific scenarios and imaging requirements are demonstrated. Conclusion: We have demonstrated, by simulation, that the proposed SPECT system geometry permits awake animal imaging of a rigid structure such as the head. While this investigation concentrates on the flexibility of the proposed design, in future, we plan to quantify the optimal operating geometry for specific imaging tasks.


   P118: Variation in Background Activity Affects SUV-based Volumetric Measures in Differently Reconstructed Fluorodeoxyglucose-Positron Emission Tomography Images: A Phantom Study Top


Ali Ketabi*1,2, P Ghafarian3,4, M A Mosleh-Shirazi5, M R Ay 1,2

1Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, 2Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences; 3PET/CT and Cyclotron Center, Masih Daneshvari Hospital, 4Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, 5Department of Radiotherapy and Oncology, Medical Imaging Research Center and Physics Unit, Namazi Hospital, Shiraz University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aims: Volumetric PET imaging parameters such as Metabolic Tumour Volume (MTV) and Total Lesion Glycolysis (TLG) have been suggested in quantifying tumour burden for various neoplasms. To understand the effect of variation in background activity on SUV-based volumetric parameters, we determined image quantification in differently reconstructed PET/CT images. Methods: Measurements were performed on a GE D-690 PET/CT scanner. A custom-built NEMA-like phantom including six fillable cylinders (25 mm height and diameter of 10 to 37 mm) and the background activity level of 2.6 kBq/ml and 5.3 kBq/ml were applied. Images were reconstructed employing four different reconstruction algorithms: HD (OSEM with no PSF or TOF), PSF only, TOF only, and TOFPSF, with Gaussian filters of 3 and 6.4 mm in FWHM. SUVmax and SUVpeak were obtained and used as cut-off thresholding; the MTV and TLG were measured. The volume recovery coefficients (VRCs), the relative percent error (ΔMTV), and Dice similarity coefficient were assessed with respect to true values. Results: SUVmax and SUVpeak decreased and MTV increased as function of increasing the background dose. The most differences occur in smaller volumes with 3-mm filter; Non-TOF and Non-PSF reconstruction methods were more sensitive to increasing the background dose in the smaller and larger volumes, respectively. TLG value for each target volume is not significantly changed by increasing background dose. In a range of target volumes, differences between the mean ΔMTV in the high and low background dose varied from-11.8% to 7.2% using SUVmax and from 2.1% to 7.6% using SUVpeak inter reconstruction methods. Conclusion: The effect of the background activity variation on SUVs and SUV-based volumetric quantification were small; however, some reconstruction methods are more sensitive to background dose.


   P120: Fusion of Whole Body Scintigrams and Optical Images as Tool for Precise Detection of Thyroid Rest after Radioiodine Therapy in Patients with Differentiated Thyroid Carcinoma Top


Milovan Matovic*1, M Jankovic2, M Barjaktarovic2, M Jeremic3, M Vlajkovic2

1Department of Nuclear Medicine, Clinical Center Kragujevac, Center of Nuclear Medicine, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, 2School of Electrical Engineering, University of Belgrade, Belgrade, 3Medical Faculty University of Nis, Clinical Center Nis, Center of Nuclear Medicine, Nis, Serbia

Background/Aims: After radioiodine therapy of DTC sometimes is practically impossible to perform precise topographic localization of regions where is located the tissue which accumulate 131I on WB scintigram (WBS). Methods: In order to solve this problem, we have developed Vision-Fusion system for web camera (WC) image acquisition simultaneously with WBS acquisition on gamma camera (GC). We used GC ecam (Siemens, Germany) in WB acquisition modality with matrix 256x1024 pixels and bed movement of 6cm/min. For optical image acquisition, we have used WC C905 (Logitech, USA) with resolution 1600x1200 pixels, connected to head of GC. Vision-Fusion software for image acquisition and fusion was developed using NI LabVIEW programming environment (National Instruments, USA). WC is in continuous acquisition mode during patient bed movement, with frame rate of 6 frames per minute. This bed movement produces displacement step of 1cm, which is equal to displacement step of 15pixels in acquisition matrix. Software extracts on each frame the central region of interest (ROI) with the height of 15 pixels. All extracted ROIs are placed next to each other forming the optical WB image. We used two markers (small plastic vials with 1 MBq of 99mTc) visible on both images for estimate relation between length and number of pixels in both axes of matrices. Those relations we used for rescaling of WBS to fit it to WB optical image. Results: We tested our system in 10 patients with DTC 72 hours after application 3.70GBq of 131I. We found that our system ensures a precise identification of anatomical position of tissue which accumulate 131I. Conclusion: Based on our first results during clinical testing of our system, we can conclude that our system can improve diagnostic ability of WBS in patients with DTC after radioiodine therapy.


   P121: Effects of Magnetic Resonance Contrast Agent on Positron Emission Tomography Quantitation in Liver Positron Emission Tomography/Magnetic Resonance Imaging RI Study Top


Illsang Moon*1

1Seoul National University Hospital, Seoul, Republic of Korea

Background/Aims: A hybrid PET/MRI facilitates the accurate registration of metabolic and molecular imaging of the cancer with correlation to anatomical findings. The use of MR contrast agent plays an important role in PET-MRI imaging for tumour diagnosis. The purpose of this study is to evaluate the influence of MR contrast agent on PET imaging using clinical liver PET/MRI cases. Methods: In this study, patients (n=10) with 18F-FDG liver PET-MRI (Biograph mMR 3.0T, Siemens) studies were collected. PET data is acquired with before and after contrast enhancement (Gd-based MR contrast agent) for 3 minutes, respectively. PET reconstruction was performed by an enhanced 2-point dixon attenuation correction method with 3D OSEM (iteration: 3, subset: 21). PET images in normal lesion and tumour of liver applied by Pre and Post MR enhancement were assessed by SUVmax and SUVmean. Results: No significant difference was observed between SUV of pre- and post-PET images in normal lesions of liver. The SUV of post-PET images in tumour lesions were slightly increased by MR contrast agent (SUVmax 5.2%, SUVmean 4.1%). However, there was no significant relation between the SUV and MR contrast agent (p<0.01). Conclusion: The using of MR contrast agent on liver PET/MRI had only a small effect on the SUV of FDG uptake and did not change the interpretation for patients. This approach appears to be practical and valid for other kinds of tumour.


   P122: Impact of Time-of-flight for a Mismatched Respiration Phase on Positron Emission Tomography/Computed Tomography Acquisition Top


Akio Nagaki*1,2, Y Kawakami1, N Matsumoto1, K Tsuboi1, T Sibutani2, M Onoguchi2

1Department of Radiological Technology, Kurashiki Central Hospital, Kurashiki, 2Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan

Background/Aims: We evaluated the impact of time-of-flight (TOF) for an error of attenuation correction due to respiratory motion on PET/CT acquisition in phantom and clinical studies. Methods: We used a Biograph mCT with a system time resolution of 555 ps. In phantom study, we used a heart-liver phantom filled with 18F-FDG. PET scans were acquired in the matched and mismatched position with CT scans. The mismatched positions defined as displacement from the matched position to the caudocranial (CdCr) and the craniocaudal (CrCd) direction of 15, 30, and 50 mm. In clinical study, 21 patients with respiratory motion were divided into two groups by liver displacement in the CdCr (n=13) and the CrCd (n=8) directions. PET images were reconstructed using the iterative reconstruction (IR) with and without TOF (IR and IR + TOF). The impact of TOF was quantitatively evaluated regarding mean standardised uptake value (SUVmean) of the matched and mismatched liver on the PET images. Results: In phantom study, the difference of SUVmean with the IR + TOF was slightly reduced compared with the IR. The SUVmean of artifact cases was lower at the CdCr direction and higher at the CrCd direction than that of matched liver. The difference between both of SUVmean was grown with increasing the motion magnitude. In clinical study, the artifact with the IR + TOF was reduced apparently at the CdCr direction. However, at the CrCd direction, the SUVmean of the artifact with the IR + TOF was higher in anterior area and lower in posterior area than that of normal liver. Conclusion: The TOF was useful to reduce the artifact in the incorrect attenuation correction. However, the TOF might be no marked improvement for the artifact due to liver displacement in the CrCd direction.


   P123: Dose Calibrator Modelling with GEANT4 Top


Graeme J O’Keefe*1

1Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, Melbourne, Australia

Background/Aims: Dose calibrators are used for dispensing of accurate levels of radiotracer to be injected into patients undergoing quantitative diagnostic molecular imaging procedures. As a result of some uncertainty in the dose calibrator gain settings for 68G, the question of the relative contribution of high-energy positron emissions and electron capture induced K-shell x-ray emission arises. A GEANT4 simulation of the dose calibrator response was performed to compare the manufacturer tabulated gain settings across a range of isotopes with the modelled response and to determine the contribution to the response from various mechanisms. Methods: A Capintec CRC25-PET series dose calibrator was modelled calorimetrically. Based on the documented,[1] and inferred construction of the dose calibrator, a GEANT4 geometry was established. GEANT4 physics processes were defined and a set of simulations were performed with a range mono-energetic photon/electron energies and common radiotracer isotopes. Results: From the modelled results, the dose calibrator is found to receive a negligible contribution from K-shell x-rays and high energy positrons. For the positron emitters with higher end-point positron kinetic energy, there is a small contribution from the positron induced bremsstrahlung. A comparison of the emission photon energy per decay with the manufacturer recommended gain settings showed good agreement. From the modelled photon/electron response and documented beta spectra,[2] the positron/electron induced bremsstrahlung response can be calculated easily for a wide range of beta emitters. Conclusion: A GEANT4 model of a Molecular Imaging Dose calibrator yields good agreement with the manufacturer gain settings for a range of isotopes. The combination of syringe material, plexiglass insert and aluminium chamber wall ensures that the contributions to the chamber sensitivity from K-shell x-rays and high energy beta emission is negligible. Using the results of the modified NIST 18F standard,[3] excellent agreement is obtained for the 68Ga/18F ratio of the dose calibrator gain settings when compared to the calculated 68Ga/18F ratio for the energy deposition per decay. A GEANT4 dose calibrator model can be used for inferring dose calibrator gain settings for novel isotopes or non-standard source geometries.

References

  1. Capintec Dose Calibrators: CRC-15R Radioisotope Dose Calibrator Owners Manual – Rev. Y – July 2007, CRC-25PET Owners Manual-Rev.H-March 2015.
  2. MIRD Beta Spectra: Available from: http://www.doseinfo-radar.com/RADARDecay.html. [Last accessed on 2018].



   P124: The Measurement of Standard Uptake Value Stability for Philips Gemini/Ingenuity Positron Emission Tomography/Computed Tomography Cameras Top


Graeme J O’Keefe*1,2, S Gong2,3, Cameron Pain2

1School of Cancer Medicine, La Trobe University, Melbourne, 2Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, 3RMIT, Melbourne, Australia

Background/Aims: The Department of Molecular Imaging and Therapy, Austin Health operates a Philips Gemini PET/CT-64 and two Philips Ingenuity PET/CT-128 scanners. A weekly QC programme is in place to measure the stability of a range of performance parameters, one of which is the Standard Uptake Value (SUV). The SUV is a semi-quantitative measure used in PET as an indicator of regional tissue metabolism and is determined from the image derived regional tissue activity concentration, the patient injected activity and patient weight. These three parameters are in turn determined by the accuracy and stability respectively of the camera sensitivity, the dose calibrator and the weight-scales. A weekly measurement of a series of uniform phantoms provides a measure of the stability of the PET camera sensitivity and dose calibrator. Methods: The weekly QC regime includes measurements of three uniform phantoms of 68Ge, 18F and 68Ga respectively. The 68Ge (half-life 270 days) phantom consists of a cylinder (20 cm diameter, 20 cm length) filled uniformly with an epoxy gel of 68Ge. The 18F & 68Ga phantoms consist of cylinders (20 cm diameter, 30 cm length) filled uniformly with water. All phantoms have a low dose CT acquired for attenuation correction purposes and emission scans of duration 20 minutes, 15 minutes and 15 minutes respectively and encompassing 180 mm and 360 mm, 360 mm respectively. Following acquisition and standard clinical reconstruction in SUV units, the data sets are analysed with PMOD with a cylindrical Volume of Interest (18 cm diameter, 13 cm length) from which the mean SUV is derived. Results: The results of a 12 month series of weekly measurements for the Gemini PET/CT and Ingenuity PET/CT-1 &-2 respectively are given below: (1) 68Ge: 0.949 ± 0.009, 0.977 ± 0.006, 0.959 ± 0.004. (2) 18F: 0.979 ± 0.021, 1.034 ± 0.026, 1.019 ± 0.017. (3) 68Ga: 0.901 ± 0.026, 0.955 ± 0.018, 0.942 ± 0.031. Conclusion: The stability of the PET camera sensitivity indicated by the 68Ge SUV measurements ranges from 0.4-0.9%, whilst the combined stability of the PET camera sensitivity and the doe calibrator indicated by the 18F and 68Ga SUV measurements ranges from 2-3%. The Philips Gemini and Ingenuity PET/CT cameras exhibit excellent sensitivity of <1% variability. The inferred variability in SUV due to dose calibrator stability is of order 1-2%.


   P126: Comparing Performance of Gaussian Filter and Butterworth filter: A Phantom Study Top


Anil Kumar Pandey*1, C Singh Bisht1, A Negi1, V Dhiman1, C Patel1, C S Bal1, R Kumar1

1All India Institute of Medical Sciences, New Delhi, India

Background/Aims: This study was conducted to compare the performance of Gaussian and Butterworth filter. Methods: A digital phantom having image size 128 x 128 was created. It consists of 8 objects (three squares, one circle, three solitary rectangular bars, and one triangle made up of 6 rectangular bars) of different sizes. Gaussian noise (variance: 0.003 to 0.15 incremented at the rate 0.003) were added to the phantom image, thus creating 50 noisy images. Gaussian filters and Butterworth filter having sizes 3, 5, 7, 9 and 11-pixel size were implemented in spatial domain and applied to noisy images. All experiments were conducted using Matlab R2013b installed on Windows operating system. The output image quality was assessed both subjectively and objectively. The peak signal to noise ratio (PSNR) was used as an objective assessment criterion to evaluate the performance of the Gaussian and Butterworth filter. Results: The amount of noise removed from the image increased with increase in the size of the filter from 3-pixels to 11-pixel width. The excessive amount of noise when added to the image destroyed the structures present in the image, in this case, even the 11-pixel size filters could not clean the noise and restored the structures. Moreover, they blurred the edges present in the image. The filter size having 7-pixel width produced the image without excessive distortion of the structure present in the image. Butterworth filter was found to be superior in comparison to Gaussian filter as introduced less blurring at the edges. At 7-pixel width PSNR value of Butterworth filter was greater than that of Gaussian filter. Conclusion: Butterworth filter perform better than Gaussian filter based on both visual and objective assessment criterion (for filter size having 7-pixel width, PSNR for Butterworth filter = 15.6, and PSNR for Gaussian filter = 14.8).


   P127: The Effects of Different Reconstruction Algorithms on 18F-Fluorodeoxyglucose Positron-Emission Tomography/Computed Tomography Images Top


Y Parlak1, D Goksoy1, G Mutevelizade1, Elvan Bilgin*1, F Gumuser1

1Celal Bayar University, Manisa, Turkey

Background/Aims: 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET) reconstruction algorithms can have substantial influence on quantitative image data used, e.g., for therapy planning or monitoring in oncology. Reconstruction protocols in PET/CT procedure contain two modifiable parameters: Smooth/Sharp and Speed. We analysed all the possible combinations of these two parameters and the values defined internally for Relaxation, Iteration and Kernal Width parameters in these combinations. The purpose of this study was to evaluate the activity concentrations of different reconstructed FDG-PET images and to determine the influence of varying activity concentration in distribution, signal background rate (SBR) and quantification (standardised uptake value [SUV]. Methods: A nonuniform “body phantom” was prepared with 6 lesions (distance; 10mm to 35mm) and filled with 207MBq 18F-FDG-water. The phantom was scanned by positioning in the center of the PET/CT (Philips, TruFlight Select, 16 slices) gantry. PET images acquired with the nonuniform phantom simulating a ‘‘body’’ were reconstructed by using nine different reconstruction combinations. For all combinations, data analyses were carried out using SPSS 11.0. Reconstruction algorithms, sphere diameters, SBR of the reconstructed PET data were used to analyse the association between these factors. Results: When quantitative images were studied, small differences between reconstruction algorithms were found. The most effective combination with better count statistics and the highest magnitude SUVmax have 3 iterations (33 subsets) and kernel width of 18.7 cm. Conclusion: Especially patients with head and neck malignancies, we suggest that the reconstruction protocol, combination of 3 iterations and kernel width of 18.7 cm, should be used.


   P128: A Comparative Assessment of Standard Uptake Value with Positron-Emission Tomography/Computed Tomography by the Variation among Computed Tomography Devices in Positron-Emission Tomography Scans Top


Young Hwan Ryu*1, H S Kim2

1Seoul Medial Center, Seoul, 2Shinhan University, Uijeongbu-si, Republic of Korea

Background/Aims: PET scanning is being used increasingly for cancer diagnosis and determining therapeutic effects. Organizations including the European Association of Nuclear Medicine (EANM) recommend a scan using the same device to make an accurate comparison of the Standard Uptake Value (SUV) in a follow-up, thereby increasing the interest in the use of the same type of PET/CT. On the other hand, as hospital conditions make it impossible to perform a PET scan in many cases, more effort is being made to identify factors for accurate SUV comparisons and to draw up a plan to secure inter-device compatibility. Methods: From this perspective, three different types of PET/CT devices were used to estimate the SUV and determine if they were compatible with one another. Discovery 690, Discovery 690Elite, and Discovery 710 were used to estimate the SUV for an ACR phantom, NEMA IEC Body phantom, SNM Chest phantom, and 68Ge-cylinder phantom to determine the variations in SUV among the devices. Results: SUVmean and SUVmax were estimated using each device: the inter-device variation ranged from 0.19% to 3.61% in SUVmean and from 0.03% to 4.11% in SUVmax for each phantom. The variation in the SUV among the three PET/CT devices in this experiment was less than 5%, which is the permissible range of the inter-device variation in the SUV, as recommended by the manufacturers. Therefore, it is possible that different CT types will result in insignificant variations in SUV. Conclusion: Because hospitals in practice have difficulty in purchasing several devices of the same type, the use of different types of PET/CT devices with a SUV within the permissible range would result not only in higher efficiency, including appointment rescheduling, but also in greater accuracy of a quantitative assessment in a follow-up, where use of the same device is recommended.


   P130: Initial Design of Animal Positron-Emission Tomography Scanner Based on a Monolithic Scintillator and Silicon Photomultiplier Top


Amirhossein Sanaat*1,2, M S Zafarghandi1, M R Ay2,3

1Amirkabir University (Polytechnic of Tehran), 2Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, 3Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aims: In nuclear preclinical imaging systems, our striving is to obtain lowest intrinsic spatial resolution and highest sensitivity without increasing cost and complexity. Common systems based upon photomultiplier tube PMT and pixelated crystals although show fine performance, escalating cost and decreasing sensitivity. Our study shows by replacing pixelated with optimized monolithic scintillators, spatial resolution and sensitivity can make better and cost decrease. We do not use complex depth of interaction (DOI) algorithm and it make our design more fast and reliable. For optimisation we simulate physical characteristics of the scanner. Methods: We used GEANT4 Monte Carlo simulation library to simulate the optical photon processes. The simulation was performed for an Animal PET with 10 detector module which are equipped to LYSO monolithic scintillator crystals with entrance area 50.2×50.2 mm2 and thicknesses 8 mm (The optimised thickness) coupled to a silicon photomultiplier (SiPM). For validation and comparison, we simulated Xtrim Animal PET equipped 10 pixelated crystals with 2*2 mm2 pixel size and thickness of 10 mm. Results: Our simulation indicated 1.1 mm and 1.5 full width at half maximum (FWHM) of spatial resolution without any resolution recovery and DOI correction which were in a relatively good agreement with the experimental results obtained from Xtrim. Furthermore, simulation of animal PET with a centric point source showed that resolution improve for Animal PET with monolithic crystal and SiPM module. As result of removing dead area between segments in pixelated crystal in monolithic crystal the sensitivity improved more than 18 percent. Conclusion: The GEANT4 simulation established to estimate and compare the intrinsic spatial resolution and sensitivity of different animal PET system. Furthermore, using monolithic crystal decrease cost. This simulation can be used to provide an optimal design of animal PET based on monolithic detector without DOI correction and using time consuming algorithm.


   P131: Comparison of the SiPM and PMT Influence on Resolution and Sensitivity of Gamma Camera Detector, with Anger and Correlated Signal Enhancement Positioning Method by Using Monte Carlo Simulation Top


Amirhossein Sanaat*1,2, M S Zafarghandi1, M R Ay2,3, B Teymorian1,3

1Department of Energy Engineering and Physics, Amirkabir University (Polytechnic of Tehran), 2Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, 3Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aims: In imaging systems, intrinsic spatial resolution and sensitivity depend on identifying the position of interaction and the number of detected photons. These factors are affected by propagation of the scintillation photons in the scintillator, positioning algorithm and physical characteristic of the detector. This study was intended to use Monte Carlo simulation to estimate and compare intrinsic spatial resolution and sensitivity of Gamma Camera detector, between two detector configurations: one coupled to 24 PMTs and another one equipped to silicon photo multiplier SiPM. Methods: We used GEANT4 Monte Carlo simulation library to simulate the optical photon processes. The simulation was performed for an SPECT with a detector equipped to NaI (Tl) scintillator crystals with 40*25 cm2 area and thicknesses 9.5 mm coupled to 40, 12×12 SiPM with 50.2*50.2 mm2 entrance area. The simulation results compared with a commercial case named RoboSPECT with same physical features but coupled to an array of 6*4 of square PMTs with 76*76 mm2 area. Anger and Correlated Signal Enhancement (CSE) were used as positioning algorithm. Results: Our simulation predict 3.8 mm and 1.9 mm for spatial resolution in Anger and CSE for NaI (TI) detector coupled to SiPM. These results show an improvement relative to the experimental case with PMTs (Anger and CSE, 6 and 3.8 mm). Simulation of a centric point source showed that the best resolution and sensitivity obtained by CSE algorithm, showed better performance in edge and centric positioning (resolution with 15cm offset from the center of the crystal by CSE method was calculated 42% lower than Anger). As a result of decreasing dead space by using SiPM, the sensitivity improved 21%. Conclusion: The GEANT4 simulation established to estimate the intrinsic spatial resolution and sensitivity of SPECT detector with Anger and CSE positioning algorithm and also different photo detector (PMT & SiPM).


   P132: Reduction of Contrast Agent Induced Artifact in Dual Modality Positron Emission Tomography/Computed Tomography Imaging Using TOF Technique Top


R Sharifpour1, Pardis Ghafarian*2

1Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, 3Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aims: Attenuation correction of PET images using CT causes some artifacts, including respiratory-artifact, metal-artifact and contrast agent artifact. In this study, the impact of TOF reconstruction on reduction of contrast agent artifact in PET/CT imaging was evaluated. Methods: The influence of TOF on contrast agent artifact was assessed using a phantom contained 5.3KBq/ml background activity and 9 cylinders with 2.5 cm in diameter and 10 cm in height. 3 cylinders were filled only with contrast-agent and 6 cylinders were filled with combination of contrast-agent and activity (two different activity ratio including 1:1 and 2:1 with 10, 15, 30 ml/L concentration of Meglumine compound). The images were reconstructed using 2 reconstruction algorithms, including non-TOF with 3iteration, 18subset and 6.4mm filter (routine protocol), and TOF with 2iteration, 18subset and 6.4mm filter. Recovery coefficient and SUVmax were used for quantitative analysis. Results: In 3 cylinders in which any activity was not actually exist, image reconstruction using non-TOF algorithm led to produce false positive activity. Integrating TOF technique to reconstruction reduced the virtual activity. The relative differences of SUVmax between TOF and non-TOF images were-18.2%, -18.6% and -29.5% in 20, 30 and 40 ml/L concentration of Meglumine compound, respectively. In hot cylinders with 1:1 activity ratio, recovery coefficients changed from 1.01 to 0.99, 1.05 to 1.00 and 1.08 to 1.01 in 10, 15 and 20 ml/L concentration of Meglumine compound, respectively. In 3 other hot cylinders the relative differences of SUVmax were 2.9%,-3.22% and-5.0% in 10, 15 and 20 ml/L concentration of Meglumine compound, respectively. Conclusion: TOF can effectively improve contrast-agent artifact and increase quantitative analysis accuracy. In addition, the corrective effect of TOF increases with increase in contrast-agent concentration. We can conclude that the TOF technique has a potential to reduce contrast-agent artifact and can be used as a method for the artifact correction.


   P133: Three-Dimensional-Printing Standardization Across Computer-Aided Design and Manufacturing and Digital Imaging and Communications in Medicine: Proof of Concept using Positron Emission Tomography/Computed Tomography Datasets Top


Carrison Tong*1,2, L Chan1, F Choi3, O Chan2

1Department of Health Technology and Informatics, Hong Kong Polytechnic University, 2Department of Medical Physics, 3Department of Nuclear Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China

Background/Aims: Stereolithography (STL) is a technology in computer-aided design and manufacturing (CAD/CAM) for three-dimensional (3D) printing. STL is designed for manufacturing industry; it cannot capture patient information. Digital Imaging and Communications in Medicine (DICOM) standards are adopted in healthcare industry to transfer images via picture archiving and communication systems. Recent surge of patient-tailored 3D printing posed demand to integrate both standards, hence the draft “DICOM Encapsulation of STL Models for 3D Manufacturing” by DICOM Standards Committee, but no commercial solution was available yet. This research’s objective is to test a new integration method. Methods: A prototype DICOM-STL-Archive was designed to be connectable with DICOM server to query and retrieve medical images and DICOM Modality Worklist including patient demographics, accession numbers, study dates and times. Retrieved datasets were post-processed to create 3D computer models using marching cube algorithm. Models were stored as STL formats with filenames incorporating related accession numbers etc. Demographics were stored in STL file headers modified with special DICOM remarks. STL file locations and headers were stored within Archive’s database structure. Medical 3D models could be printed directly via the Archive and then subject to physician’s evaluation for accuracy. Results: The developed DICOM-STL-Archive could connect to a DICOM server and retrieve image datasets, which were converted to STL data files and could be automatically modified into the Archive’s database. STL data files could then be queried and retrieved to a computer client, verified by physician side-by-side against original PET/CT images on medical workstation before exported to a 3D-printer. The printed models were compared to original DICOM datasets to fall within an accuracy of ± 0.5 mm. This prototype was successfully tested on seven sets of complex imaging datasets obtained from hybrid positron emission tomography and computed tomography (PET/CT). Conclusion: The prototype DICOM-STL-Archive proved the concept on integration of STL and DICOM standards by a novel method of between-system connection, which is different from the recently proposed method of “DICOM encapsulation of STL models” by the DICOM Standards Committee.[1]

References

  1. DICOM Encapsulation of STL Models for 3D Manufacturing by DICOM Standards Committee.



   P134: International Measurement Traceability for Australia’s Primary Standards for 99mTc, 18F and 64Cu Top


Freda van Wyngaardt*1, S Tobin1, S Lee1, M Smith1, T Jackson1, B Howe1, M Reinhard1

1ANSTO, Lucas Heights, Australia

Background/Aims: International measurement traceability underpins the accurate measurement of radiopharmaceuticals, which contributes to improved patient outcomes, consistency of clinical trial data, obtaining quantitative data from imaging and radiopharmaceutical trade. The International Reference System (SIR) was established in 1976 at the International Bureau of Weights and Measures (BIPM) to compare radionuclide standards submitted by national metrology laboratories and to evaluate their equivalence. Due to its location in France, the SIR is inaccessible to many countries for short-lived radionuclides, and a Transfer Instrument (SIRTI) was developed by the BIPM in 2013 to compare such standards. Australia had its first opportunity to host the SIRTI and participate in this comparison during November 2017. Methods: ANSTO Radionuclide Metrology (RM) applied the 4π (LS)β-γ coincidence extrapolation technique to standardise solutions of 99mTc, 18F and 64Cu independently of any calibrated equipment. This was the first time that 99mTc-and 64Cu was measured by a primary method in Australia. The 18F primary standard developed in 2001 was updated to make this standard eligible for the SIRTI comparison. The standards were transferred to the Australian Secondary Standard Ionisation Chamber (SSIC) by the development of calibration factors for the SIR standard geometry of 3.6 mL in a glass ampoule. The SIRTI consists of a well-characterised NaI (Tl) well detector, stability check source and data acquisition system. Sources were standardised in the calibrated SSIC before being measured in the SIRTI by BIPM personnel. Results: ANSTO’s data will be analysed and the results compared to those of other participants in the SIR and the degrees of equivalence evaluated. The results will be presented at the conference. Conclusion: ANSTO RM is renewing their secondary standards for 99mTc, 18F and 64Cu for geometries relevant to nuclear medicine. Dissemination of these standards will support the calibration of PET scanners, which are generally designed to be calibrated using 18F; quantitative imaging for SPECT and PET; and 64Cu SARTATE clinical studies performed by Clarity Pharmaceuticals.

Acknowledgements

99mTc was supplied by ANSTO Health CQ, 18F was supplied by PETTECH, 64Cu was provided by Clarity Pharmaceuticals and SAHMRI.


   P135: Accuracy of I-131 Activity Quantification in Preclinical Single-Photon Emission Computed Tomography Imaging: A Phantom Study Top


Clarita Ssaldarriaga Vargas*1,2, L Struelens1, M Defrise2, M D’Huyvetter2, V Caveliers2, P Covens2

1Radiation Protection, Dosimetry and Calibrations, Belgian Nuclear Research Centre (SCK-CEN), Mol, 2In vivo Cellular and Molecular Imaging, Vrije Universiteit Brussel, Jette, Belgium

Background/Aims: Accurate quantification of radionuclide activity in mouse tissues is crucial to study the absorbed dose dependence of healthy-tissue toxicity due to radionuclide therapy. This study aimed to evaluate, by means of a phantom experiment, the accuracy of activity quantification of 131I studies using VECTor+/CT (MILabs, The Netherlands), a small-animal PET/SPECT/CT. The influence of following parameters was studied: approach for delineation of regions of interest (ROI), attenuation correction, scatter correction and number of OSEM updates used for SPECT reconstruction. Methods: SPECT/CT quantitative imaging was performed on a mouse-sized phantom filled with 131I-NaI solution. The phantom consists of multiple cylindrical objects with different diameters (1-6 mm). A high-energy general-purpose mouse collimator was used for SPECT acquisitions. ROIs of different dimensions were drawn in the center of each hot rod and activities were quantified. Reference activities were calculated from the activity concentration of the 131I solution determined with a radionuclide calibrator. Activity recovery coefficients were calculated for all settings tested. Results: Due to partial volume effects, the quantitative accuracy is strongly dependent on the rod diameter and the ROI size used for quantification. Most accurate results are obtained with small fractional ROIs, for which the recovery coefficients are around 100% for 3-6-mm hot rods and below 70% for smaller (1-2 mm) rods. Using a sufficiently high (>50) number of OSEM updates is crucial for improving the accuracy and visibility of small hot objects. Instead, the impact of scatter correction is moderate (usually <10%) and, while photon attenuation is also not negligible (13% higher with attenuation correction), its quantitative effect may be compensated by an appropriate calibration factor. Conclusion: All parameters tested have a significant effect on SPECT quantification. The optimization of ROI segmentation strategies and SPECT reconstruction settings are key for accurate 131I activity quantification with small-animal SPECT.


   P138: The Impact of Source Geometry on Radionuclide Dose Calibrator Activity Measurements Top


Bonnie Howe*1, W van Wyngaardt1, T Jackson1, M Smith1, M Reinhard1

1ANSTO, Lucas Heights, Australia

Background/Aims: Radionuclide dose calibrators are equipped with pre-set calibration numbers for a range of radionuclides. The calibration numbers are based on measurements of radionuclides in specific source geometries or derived from dose calibrator response data. The source geometries measured in clinical settings vary widely, so the impact of geometry on dose calibrator response must be well understood and quantified in order to ensure measurement accuracy. The aim of this study is to quantify the geometry dependence of medical radionuclides including 18F, 131I and 68Ga. Methods: Quantities of 18F-FDG, 131I and 68Ga solutions were compared against the Australian standard for radioactivity to establish accurate and traceable activity concentration measurements. The 18F-FDG and 68Ga were dispensed into commonly used vials and syringes in a range of different volumes. The 131I was dispensed into therapy capsules and contained in glass and plastic vials. The sources were carefully weighed to determine the quantity of activity in each. They were compared against the Australian standard and measured in commercial dose calibrators which had been calibrated against the standard. Results: Dose calibrator measurements of 18F-FDG in syringes were within 2% of the standard, however vial measurements showed discrepancies of up to 5%. Ga-68 in vials was regularly over 4% discrepant from the standard, and up to 9% for syringe geometries. The difference between measurements of 131I in solution and in a capsule was in the order of 1.5%. Capsules contained in glass or plastic vials showed a negligible difference in activity when measured using an appropriate dose calibrator. Conclusion: Accurate measurement of radioactivity contributes to effective and safe patient treatment and is an important aspect of regulatory compliance. The impact of source geometry on activity measurements must be taken into account to ensure the correctness of measurements and prevent incidences of maladministration due to dose inaccuracy.


   P139: Residual Dose Rates after Radiactive Iodine-131 Treatment in the Day of Hospital Discharge Top


Asli Ayan*1, B Gunalp1, S Donmez1, T Haciosmanoglu1, K Okuyucu1

1Department of Nuclear Medicine, Gulhane Education and Research Hospital, Ankara, Turkey

Background/Aims: Turkish Atomic Energy Authority has its own regulations for the patients who were undergone radioactive treatments. Our aim is to investigate the discharge dose rates of patients who were administered 3700 MBq I-131 treatment for thyroid cancer. Methods: A total of 91 patients (64 female, 27 male) who were totally thyroidectomised with a diagnosis of well differentiated thyroid cancer, previously and administered 3700 MBq I-131, hospitalized for two days between 2011 and 2013 included to the study. Their dose rates on the time of discharge were evaluated, statistically. Results: Discharge dose rate mean value was 1.75±0.89 mR/h (17.5 μSv/h±8.9) and the mean restriction period for recommendations up to Turkish Regulations about travel times, close contact, for public radioprotection were 13.44±4.02 days. Dose rate of eight patients were equal to legislation limits (3 mR/h). On the day of discharge three patients have dose rates above the limits. Mean residual activity measured at one meter distance at the discharge calculated by the formula (A. Iγ/d2) measured and was 307.1±156.14 MBq. Their calculated dose rates were 4 (40 μSv/h), 4 (40 μSv/h), and 5 (50 μSv/h) mR/h from one meter. Those patients who had high dose rates were not have been discharged until their dose rate decreased. In our group of patients (80/91) of patients had lower dose rates than the limits after forty eight hours hospitalisation and only 1/91 patients had one more night hospitalisation, where two patients had eight hours postpone of discharge. Conclusion: Medical radiation exposures are applied to patients when benefits of treatment overcome the damages. Radiation dose that is received by people during exposure after treatment with radionuclides, countermeasures must be taken.


   P140: Analysis and Dosimetric Control of Gamma Radiation and Fast Neutrons in the Treatment of Diseases Top


Doris Alexandra Bautista Sánchez*1, A Gutierrez1, C Farias-Castro1

1Universidad Nacional de Colombia, Bogotá, Colombia

Background/Aims: Having a control of the radiation to which the patient is subjected and the time it remains in the body is of great importance, since clinical procedures suggest methods in which the patient is continuously irradiated. However, if an asymmetric control of the radiation absorbed by the body is not maintained, it is possible that both the patient and the doctor in charge suffer a cellular deterioration due to the radiation to which they are subjected. Methods: Control estimates are made on the amount of radiation that per patient must be subjected to fast neutron rays that are produced by reactors, cyclotrons (d + Be) and linear accelerators and according to the Bergonie law and tribondeau It will determine that both cells are affected, both for the patient and for the operator of the machine. For the study, two radiation machines, one for fast neutrons and one for gamma radiation, were simulated in GEANT4; the geometric schemes and the intensities of the energies will allow us to determine how much the patient and the doctor radiate, this to take measures in the radiological safety control. Results: Under the modifications and geometric concentrations of magnetic fields or neutron detonators in the clinical instruments responsible for generating the radiation, it is possible to increase the efficiency of the instrument by collimating the radiation, decreasing the effective section of impact and decreasing the amount of radiation to which both the patient as the doctor in charge of handling the radioactive instrument are subject. Conclusion: It is possible to reduce the intensities of the radiation to which both the patient and the doctor are subject, this is achieved by proposing improvements in the instrument, geometric changes and changes in the structure of the instrument’s collimator, which allows us to reduce the intensity of the radiation. the treatment time and the levels of non-cancerous dead cells. The radiological safety controls can be controlled if the physics involved in them is well known. Within the field of physics and using simulation tools, we can analyse the advantages and failures of a radiation instrument in this case at high energies, which allows security measures to be taken and measures to increase equipment efficiency.


   P141: Analysis of the Effects and Limits Generated by the Thermal Neutron Radiation Technique applied to Patients with Cancer Under Simulation in GEANT4 Top


Doris Alexandra Bautista-Sánchez*1, C Farias-Castro, M Bautista2

1Universidad Naconal de Colombia, 2a, Bogotá, Colombia

Background/Aims: Currently research for the treatment of cancer cell elimination are aimed at developing efficient techniques and little harmful to control carcinogenic diseases; one of the techniques is based on the interaction of an initially stable nucleus with neutrons at energies of the order of 0.025 eV, such interactions are those generated by the capture of bromine atoms with neutrons. Methods: To evaluate the efficiency and the limits in which the technique of detection and elimination of cancer cells are efficient and not harmful, based on the interactions between neutrons and nuclear structures, a simulation was performed in GEANT4 where it is possible to show the amounts of radiation in which a patient depending on his physical texture and his chemical background can be radiated, and as part of this radiation affects the cancer cells in stages where they are in development and in the case where it is limited where metastasis occurs. Results: Estimates of the limits of the amount of radiation submitted by the patient as a function of time were obtained. In order to evaluate the limits in which the technique is efficient, modifications were made in the simulation which allows controlling the number of incident neutrons and the reactions generated with the nucleus, for this case, variations of nuclei were made, which, when interacting with the neutron generates radiation, led us to estimate a suitable nuclear structure for the treatment of elimination of cancer cells. Conclusion: The simulation allows us to precede causes that arise after the patient is radiated, and how the radiation to which the patient is subjected can be controlled, with the aim that this does not cause a minimal effect on non-cancerous cells. The control of radiation indices harmful to the patient are key factors in the treatment, under an estimate of the physical structure of the time it is possible to establish radiation controls to which the patient can be subjected.


   P142: A Quantitative Assessment of Biokinetic Models for Patients Undergone Nuclear Examinations: Verified with Multi-compartments Water Phantom Top


Ching-Yuan Chen*1, L K Pan1

1Graduate Institute of Radiological Science, Central Taiwan University of Science and Technology, Taichung, Taiwan

Background/Aims: The aims of study were to evaluate multiple biokinetic models using MATLAB program, to estimate internal dosage and to predict the time-dependent quantity of radiolabelled complexes in crucial organs. Methods: Five biokinetic models were separately defined by five groups of simultaneous differential equations to obtain the time-dependent radioactive concentration changes inside the water phantom. The five groups of derived time-dependent concentrations for the boxes were estimated either by a MATLAB program or by scanning via a gamma camera facility. A dimensionless agreement (AT) index was recommended to evaluate the comparison in each case. Results: The water phantom was assembled by seven acrylic boxes in four different sizes, and the boxes were linked to different combinations of hoses to signify the multiple biokinetic models from the biomedical perspective. The boxes that were connected by hoses were then regarded as a closed water loop with only one infusion and drain. 129.1 ± 24.2 MBq of 99mTc-labelled methylene diphosphonate (MDP) solution was fully infused into the water boxes before gamma scanning, then the water was replaced with de-ionized water to simulate the biological removal rate among the boxes. The water was driven by an automatic infusion pump at 6.7 c. c./min. and the biological half-life of the four different sized boxes was 4.8, 10.7, 18.8, and 45.5 min. Conclusion: The derived biokinetic model represented the metabolic mechanism in the human body and helped to solidify the internal circulatory system into reality with numerical verification.


   P143: Monte Carlo Evaluation of Radionuclides for Early Brain Metastases Targeting Top


Nadia Falzone*1, N L Ackerman2, L de la Fuente Rosales3, M A Bernal3, S G J A Peeters, M S Soto, N R Sibson, K A Vallis

1Department of Oncology, University of Oxford, Oxford, UK, 2Department of Physics and Astronomy, Agnes Scott College, Decatur, GA, US, 3Departamento de Física Aplicada, Instituto de Física, Gleb Wataghin UNICAMP, Campinas, Brazil

Background/Aims: Metastasis of breast cancer to the brain presents a pressing therapeutic challenge. Vascular cell adhesion molecule 1 (VCAM-1) is upregulated on brain endothelial cells during the early stages of metastasis and provides a target for the detection and treatment of early brain metastases. We have developed a Monte Carlo model representing brain vasculature to evaluate the efficacy of a variety of potential therapeutic nuclides; alpha-emitters: 149Tb, 211At, 212Pb, 213Bi and 225Ac; beta and Auger electron-emitters: 90Y, 161Tb and 177Lu, 67Ga, 89Zr, 111In and 124I for targeted radionuclide therapy (TRT). Methods: Histologic sections of mouse brain parenchyma were used to inform a cylindrical vessel geometry using the GEANT4 general purpose Monte Carlo (MC) toolkit. The micron-scale dose distributions from all radioactive decay products were modelled in GEANT4, as well as eV-scale interactions through the G4DNA models.[1] These interactions were then superimposed on an atomic-scale DNA model[2] to estimate strand break yields for representative beta-and alpha-emitters, 177Lu and 212Pb. Relative biological effectiveness (RBE) values were determined by only evaluating DNA damage due to physical interactions. Some of the alpha emitters have decay chains with multiple daughter nuclei; we investigate the change in dose profiles and biological effectiveness as a function of time. Results: 177Lu produced 2.69±0.08 DSB per GbpGy, without significant variation from the lumen of the vessel to a radius of 100 µm. The DSB yield of 212Pb included two local maxima produced by the 6.1 MeV and 8.8 MeV a-emissions from decay products, 212Bi and 212Po, with yields of 7.64 ± 0.12 and 9.15 ± 0.24 per GbpGy, respectively. Given its higher DSB yield 212Pb may be more effective for short range targeting of early micrometastatic lesions than 177Lu. Conclusion: MC simulation of a model of early brain metastases elucidates the potential efficacy of radionuclides for TRT. 212Pb, which has the attributes of a theranostic radionuclide since it can be used for SPECT imaging, showed a favourable dose profile and RBE.

References

  1. Bernal MA, Bordage MC, Brown JM, Davídková M, Delage E, El Bitar Z, et al. Track structure modeling in liquid water: A review of the geant4-DNA very low energy extension of the geant4 monte carlo simulation toolkit. Phys Med 2015;31:861-74.
  2. Bernal MA, Sikansi D, Cavalcante F, et al. Comput Phys Commun 2013;184:2840-7.



   P144: Validation of Abbreviated 177Lu-DOTATATE Renal and Tumour Dosimetry Protocol using Quantitative Single Photon Emission Tomography Top


Steven Goodman*1, S Patford, R Ladwa2,3, J Smith, D Wyld3,4, David A Pattison1

1Nuclear Medicine and Specialised PET Services Queensland, Royal Brisbane and Women’s Hospital, 2Department of Medical Oncology, Princess Alexandra Hospital, Brisbane, 3School of Medicine, University of Queensland, 4Cancer Care Services, Royal Brisbane and Women’s Hospital, Brisbane, Australia

Background/Aims: Dosimetry guided approaches to 177Lu-DOTATATE radionuclide therapy seek to maximise the absorbed dose to tumours while minimising toxicity to normal tissues.[1],[2] However, multi-measurement protocols (MMP) are inconvenient for patients and consume staff resources. This study aims to estimate the accuracy of renal and tumour lesional dosimetry derived from a single uptake measurement compared to a MMP using quantitative SPECT. Methods: Dosimetry data from 33 patients (33 kidneys, 32 measurable lesions > 2cm diameter) with metastatic Neuroendocrine tumour (NET) undergoing 177Lu-DOTATATE therapy within a state-wide radionuclide therapy service was analysed retrospectively. An institutional Human Research Ethics Committee approval (HREC/17/QRBW/386) for low-risk research was obtained. Renal and tumour lesional uptake measurements at single time-points (4, 21, 44, and 117 hours) were linearly correlated with cumulative activity calculated from a MMP using quantitative SPECT.[3] The derived linear relationship was used to estimate the absorbed dose from single uptake measurements and the deviation from the MMP was calculated. Results: Single uptake measurements demonstrated excellent correlation with cumulative activity calculated using the MMP. For renal uptake, squared correlation coefficients were 0.84 (p <0.001) for 4 hours, 0.90 (p <0.001) for 21 hours, 0.96 (p <0.001) for 44 hours, and 0.97 (p <0.001) for 117 hours post administration (p. a.). Lesional uptake measurements had squared correlation coefficients of 0.98 (p <0.001) for 4 hours, 0.98 (p <0.001) for 21 hours, 0.99 (p <0.001) for 44 hours, and 1.00 (p <0.001) for 117 hours p. a. Deviation between dose estimates using single uptake measurements and the MMP reduced as measurement time increased. Renal doses had mean (± 2σ) deviations of 2.1±31% for 4 hours, 1.1±23% for 21 hours, 0.3±14% for 44 hours, and 0.5±13% for 117 hours p. a. Similarly, tumour lesional absorbed doses had mean (± 2σ) deviations of 11±62% for 4 hours, 9.1±53% for 21 hours, 7.1±40% for 44 hours, and 1.9±14% for 117 hours p. a. Conclusion: Renal and tumour lesion absorbed dose estimates based on a single uptake measurement >21 hours provides a safe and clinically acceptable approximation of renal and lesion doses compared with a multi-measurement protocol.

References

  1. Celler A, Grimes J, Shcherbinin S, Piwowarska-Bilska H, Birkenfeld B. Personalised image-based radiation dosimetry for routine clinical use in peptide receptor radionuclide therapy: pretherapy experience. In: Theranostics, Gallium-68, and Other Radionuclides. Berlin, Heidelberg: Springer; 2013. p. 497-517.
  2. Del Prete M, Beaulieu A, Beauregard JM. ???. J Nucl Med 2017;58 Supp 1:242.
  3. Ljungberg M, Celler A, Konijnenberg MW, Eckerman KF, Dewaraja YK, Sjögreen-Gleisner K, et al. MIRD pamphlet no. 26: Joint EANM/MIRD guidelines for quantitative 177Lu SPECT applied for dosimetry of radiopharmaceutical therapy. J Nucl Med 2016;57:151-62.



   P145: Reproducibility of Radiation dose to Kidneys for Multiple 177Lu-DOTATATE Treatment Cycles Top


Nur Rahmah Hidayati*1, A Poon2, K Willowson3, E Eslick4, H Ryu3, D L Bailey4

1Center for Technology of Radiation Safety and Metrology, Batan, Jakarta, Indonesia, 2Department of Molecular Imaging and Therapy, Austin Health, Melbourne, 3University of Sydney, 5Department of Nuclear Medicine, Royal North Shore Hospital, Sydney, Australia

Background/Aims: Radiation dose to the kidneys in 177Lu-DOTATATE PRRT (Lutate) is considered to be the main potential side-effect from treatment. Prospective assessment of kidney dose can be made with SPECT, however, this requires an intensive imaging regime over a number of days. For this reason, a retrospective investigation of the reproducibility of kidney uptake using quantitative SPECT was performed. The aim of the study was to compare the estimated radiation dose to kidneys for each cycle, to test whether full imaging over multiple days for the initial cycle can be used to estimate kidney dose for subsequent cycles. Methods: Seventeen patients treated with Lutate for metastatic neuroendocrine tumours had full imaging for each of their treatment cycles on a Siemens Intevo SPECT/CT gamma camera. One course of treatment consisted of 3 or 4 cycles approximately 8 weeks apart spanning 6 months. SPECT/CT scans of the abdomen were acquired at 3 time points (4, 24 and 96-120 hours) after administration of ~7.8 GBq of Lutate. Nine patients received three cycles in total and eight patients had four cycles. Volumes of interest (VOIs) were defined on a CT scan co-registered with the SPECT images and repeated over all time points, to give the radioactivity in the kidney. Whole organ dosimetry was estimated using OLINDA/EXM using an exponential clearance model. This gives an estimate of radiation absorbed dose to kidney (Gy/GBq) for each treatment cycle. The mean of the 3 or 4 cycles and variation can then be determined. Results: The mean amount of Lutate administered per cycle for all 17 subjects was 7.76±0.36 GBq. From this, the average kidney dose was 0.23 Gy/GBq (range: 0.06 – 0.42) and average variation between cycles for all subjects expressed as a percentage was (12.5±7.8)% (median:11.4%, range:1.8%–29.4%). Conclusion: Estimated radiation dose to the kidneys for Lutate PRRT shows good reproducibility (typically <20% variation) within an individual across all cycles within one course of treatment (up to 4 cycles). The errors introduced by assuming that the dosimetry estimate per unit GBq administered from the initial cycle could be used for subsequent cycles within a course are unlikely to contribute significantly to the overall estimate of radiation burden and are likely to be safe.


   P146: Effective Radiation Dose of 11C-choline and 18F-Fluorodeoxyglucose ion Positron emission tomography/Computed tomography Patients with Cholangiocarcinoma and Hepatocellular Carcinoma Top


Supaporn Kongthai*1, P Wongsa1, S Vanprom1, S Suratako1, C Promteangtrong1, C Chotipanich1

1National Cyclotron and PET Centre, Chulabhorn Hospital, Talat Bang Khen, Lak Si, Bangkok, Thailand

Background/Aims: Positron emission tomography/Computed tomography (PET/CT) has been proposed as noninvasive imaging methods to assess the disease extent in patients. This study aims to assess the effective radiation dose of 11C-Choline, and 18F-FDG in PET/CT patients. Methods: The study has been approved Human Research Ethics Committees, Chulabhorn Research Institute. Twenty-four patients with cholangiocarcinoma (CCa) or hepatocellular carcinoma (HCC), aged 39-74 years (mean±SD, 55.67±14.80), were included and underwent 11C-Choline and 18F-FDG whole body PET/CT scans at National Cyclotron and PET Centre, Chulabhorn Hospital. Radiation absorbed dose to target organs and effective whole-body dose were calculated by using the biokinetic model from ICRP 106 publication for 18F-FDG and the US FDA publication for 11C-Choline. The patient dose from CT scan was calculated from dose-length product (DLP) multiplied by region-specific normalized effective dose per DLP (EDLP). Results: Mean administered activities of 18F-FDG and 11C-Choline were 358.27 MBq and 439.38 MBq respectively. The average whole-body effective dose from 18F-FDG PET scan was 6.81±1.09 mSv (4.44 to 8.60 mSv) and 12.95±3.33 mSv (6.22 to 18.55 mSv) from CT scan, resulting in a mean total patient dose of 19.76 mSv. For 11C-Choline, an effective whole-body dose was 1.90±0.40 mSv (0.89 to 2.87 mSv) from PET scan and 14.20±3.14 mSv (9.06 to 19.26 mSv) from CT scan, with a mean total patient dose of 16.01 mSv. To discuss, 11C-Choline accumulates mainly in the liver, lungs and stomach. Meanwhile, the accumulation of 18F-FDG is mainly in urinary bladder, lungs and liver. 11C-Choline PET scan gives the liver dose of 330 ± 65 µSv and dose from 18F-FDG to urinary bladder is 1.81±0.33 mSv. There is no statistical difference of effective dose between 18F-FDG and 11C-Choline CT scans. However, the effective dose of 11C-Choline PET scan is 3.6 times lower than 18F-FDG PET scan (p<0.05). Conclusion: In this study, the average effective dose for patients undergoing whole-body 18F-FDG PET was 3.6 times higher than 11C-Choline PET. Whilst, the total effective dose from 11C-choline and 18F-FDG PET/CT were 16.10 mSv and 19.76 mSv, respectively. Moreover, the effective dose from CT scan was more than 2.9 and 8.5 times greater than 18F-FDG and 11C-Choline PET scans, respectively.


   P147: Monte Carlo Evaluation of Different Targeting Strategies of Auger-electron Emitting Medical Radionuclides on Tumour Control Probability in Three-Dimensional Cellular Models Top


Boon Lee*1, N Falzone1, S Able1, J Malcolm1, K Vallis1

1CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK

Background/Aims: In the present study, we evaluate the distribution of Auger electron emitting therapeutic constructs 111In-DTPA-hEGF and 111In-Trastuzumab in a 3-D spheroid model using the microautoradiography (MAR) method and use this information together with radiobiological parameters derived from clonogenic assay experiments to predict tumour control probability (TCP) by Monte Carlo (MC) modelling. Methods: A closed packed algorithm, which accounts for the variations in cell and nucleus radii as well as random packing behaviour of cells, was used to generate a monolayer of cells for three different cell lines, namely MDA-MB-468, SQ20B and 231-H2N. The PENELOPE MC code[1] was used to model electron transport. Theoretical survival fractions were estimated using internalization data and simulated energy deposition, and the results were then compared with clonogenic assay experiments of cells treated with 111In-DTPA-hEGF and 111In-Trastuzumab for 1 and 24 hours. Radiobiological parameters deduced from the comparison were used in predicting the TCP for the 3-D spheroid model, which was similarly generated using the closed packed algorithm, based on spatial distribution of radioactivity determined from the MAR method. Results: Theoretical survival fractions were in good agreement with experiments when an increased relative biological effectiveness (RBE) was applied to self-dose deposited by sources located in nucleus. Only MDA-MB-468 spheroid treated with 111In-DTPA-hEGF could potentially achieve TCP=0.5 after several days and thus be controlled, due to higher radiosensitivity and nuclear uptake of therapeutic constructs as well as more uniform radioactivity distribution. Conclusion: It is imperative when evaluating the distribution of radionuclides in models emulating micro-metastatic disease to include biological endpoints. The spatial distribution of radioactivity is a clear indicator of biological effect and TCP as was demonstrated by this study.

References

  1. Salvat F, Fernández-Varea JM, Sempau J, editors. PENELOPE-2011 OECD Nuclear Energy Agency.



   P148: A Simulation-Based Evaluation of Voxel Level Dosimetry for Lu-177 Octreotate Top


Erin McKay*1, A Malaroda2

1Department of Nuclear Medicine, St. George Hospital, Sydney, 2Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia

Background/Aims: Internal radiation dosimetry is considered necessary for managing risk during the delivery of therapy with Lu-177 octreotate (Lutate). Voxel-level analysis has been proposed, in which region of interest (ROI) definition is deferred until after a dose distribution image has been created. This approach has been compared, using a simulated biodistribution study, against a conventional method where regions are defined prior to cumulated activity estimation. Methods: The ICRP male voxel phantom was modified by the addition of 2 roughly elliptical tumours to the liver. Radiopharmaceutical kinetics of Lutate were approximated using a linear compartment model with sources representing blood, extra-cellular fluid, kidney retention and reservoirs in liver, spleen and tumours. The GATE Monte Carlo package was used to create a reference dose distribution for the phantom. Tomographic imaging was simulated at 7 time points between 1 and 168 hours using GATE, then reconstructed using an OSEM algorithm incorporating corrections for scatter, attenuation and collimator-dependent resolution. Cumulated activity was estimated from the reconstructed images by a piecewise calculation of area under the time/activity curve, both for individual voxels and for ROIs derived from the original phantom. The absorbed dose distribution for each method was estimated from the cumulated activities using GATE, then compared against the reference dose distribution using the ratio of mean ROI doses and dose volume histograms. Results: Mean ROI cumulated activity and absorbed dose were essentially identical for both methods. The errors relative to reference values were small for the kidneys, spleen and large tumour (<20%) but significant for the liver (240%) and small tumour (30%). Dose volume histograms were highly discordant in every case. Conclusion: Voxel-level analysis can be used to estimate mean absorbed dose in ROIs but does not provide accurate information about the distribution of dose within those regions.


   P149: Current Nuclear Cardiology Practices and Radiation Exposure in Brazil: A Cross-Sectional Survey Top


Carlos Vitor Braga Rodrigues*1, F A Fernandes1, C T Mesquita1

1University Hospital Antônio Pedro, Niterói, Brazil

Background/Aims: Nuclear medicine is widely used in Latin America, particularly in Brazil. Myocardial Perfusion lmaging (MPI) represents more than 55% of tests performed in the Nuclear Medicine Services (NMS) in Brazil, in over 240,000 tests in the public health system and more than 800,000 in private practice per year. Due to the exponential growth in recent years, important concepts about radioprotection must be taken. Worldwide there are great efforts to reduce the radiation used in patients. The International Atomic Energy Agency (IAEA) promoted the research “INCAPS”, which adopts 8 “best practices” to evaluate the exposures to ionizing radiation during the MPI. The objective is to evaluate the adherence of the “best practices” and correlate with the NMS features.[1] Methods: Cross-sectional study in NMS performing MPl. Results: In a total of 63 NMS, we observed that 100% of them do not use thallium-201 as the preferred protocol. About the use of 99mTc, 57% inject activities above the threshold recommended. “Stress-only” is practiced by 6% and 19% uses camera-based dose-reduction strategies. Only 52% answered that always adjust the doses by weight and 35% manage miscalculated doses in 1-day protocol. We noted that is more frequent find better Quality Indexes in academic hospitals (p=0.046), NMS with a complete multidisciplinary team (p=0.030) and NMS that performs more MPI per month (p=0.043). Conclusion: According to the parameters adopted by INCAPS, a considerable number of NMS in Brazil do not follow the “best practices”; only 20% of NMs adopted at least six of them and we find some features in common between them. There are opportunities to improve the quality of MPl in Brazil without increasing costs. This comprehensive view of the nuclear medicine practices in cardiology may be used to plan strategies for policy-making in healthcare.

References

  1. Einstein AJ, Pascual TN, Mercuri M, Karthikeyan G, Vitola JV, Mahmarian JJ, et al. Current worldwide nuclear cardiology practices and radiation exposure: Results from the 65 country IAEA nuclear cardiology protocols cross-sectional study (INCAPS). Eur Heart J 2015;36:1689-96.



   P150: Methodology for Fully Quantitative Three-Dimensional Renal Dose Estimates in Patients Receiving 177Lu-DOTATATE (Lutate) Therapy Top


Kathy Willowson*1, E Eslick2, H Ryu3, D L Bailey2,3

1The University of Sydney, 2Department of, Nuclear Medicine, Royal North Shore Hospital, 3The University of Sydney, Sydney, Australia

Background/Aims: To present the methodology and institutional experience of performing fully 3D quantitative renal dosimetry on patients receiving Lutate therapy. Methods: Patients undergoing Lutate treatment for neuroendocrine tumours underwent SPECT/CT of the abdomen at time points 4, 24 and 96-120 hrs after injection. SPECT data were quantified using in-house software written in IDL, incorporating compensation for dead time, transmission-derived scatter and attenuation correction, and a camera-specific sensitivity factor. Co-registered data were segmented using the x-ray CT (Dosisoft, Cachan, FRA) and total radioactivity in each kidney recorded for every time point and expressed as a fraction of injected radioactivity. The time-activity curve data were fitted in OLINDA-EXM with an exponential fitting function for the appropriate adult phantom model (male/female) to estimate the absorbed dose to kidneys for each cycle. Results: To date, a total of 80 studies from 18 patients have been analysed, where one study corresponds to all time points of imaging from a given cycle of treatment. Absorbed dose has been reported in the clinic and used to maintain treatment safety adhering to current kidney dose constraints (23 Gy). The average dose per cycle was 2.60±1.01 Gy/cycle. Known limitations include errors in quantification, co-registration and segmentation, as well as errors in curve fitting and use of a standard model. A processing time of approximately 1.5 hrs was associated with assessment of one cycle of treatment when this process was performed by a trained medical physicist. Our data provide us with an opportunity to investigate the feasibility of choosing a single, optimal time point to image for dosimetry estimates. Conclusion: Fully quantitative 3D imaging and renal dosimetry is feasible in the clinical environment when scanning facilities and physics resources are available, however, it does place a great burden on facilities, staff and, of course, the patients.


   P151: Experimental Work up and Validation of 67Cu Quantitative Single-Photon Emission Computerized Tomography Top


Kathy Willowson*1, M Harris2, C Jeffery2, C Biggin2, A Hedt2, D L Bailey3

1University of Sydney, 2Clarity Pharmaceuticals, 3Royal North Shore Hospital, Sydney, Australia

Background/Aims: Copper-67 (67Cu) is a promising therapeutic agent with theranostic capabilities based on pairing with the diagnostic agent 64Cu. In view of performing patient specific dose estimates for 67Cu-SARTATE, the aim of this work was to establish the feasibility and accuracy of 67Cu quantitative SPECT. Methods: Experimental work was performed on the Siemens Intevo SPECT/CT using medium energy collimators and imaging the 185 keV photon peak with a 20% energy window width. The system scatter function and scatter fraction were modelled as well as system sensitivity and dead time. Narrow-beam attenuation correction maps were derived using interpolation of NIST values modelled on a bi-linear relationship between HU and material density. Quantitative validation was performed over a period of 7 days with decaying phantom activity (1.6–0.4 GBq) using the IEC NEMA body phantom with a sphere-to-background ratio of 8:1. Results: Based on nine separate acquisitions acquired over a 7 day period, the average difference between true and measured total activity in the phantom and measured background concentration was -2.1% and -1.7%, respectively. The 37mm diameter sphere suffered from 20% count losses due to partial volume effects when using a threshold grown VOI to derive average hot-sphere concentration suggesting the need for resolution recovery. Conclusion: Quantitative SPECT and dosimetry of 67Cu acquisition data is feasible and returns accurate measures in large warm areas. Small hot lesions can expect to under-estimate dose due to partial volume effects.

Disclosure of Interest: K. Willowson Conflict with: work financially supported by Clarity Pharmaceuticals, M. Harris Conflict with: employee of Clarity Pharmaceuticals (holder of 67Cu-SARTATE), C. Jeffery Conflict with: employee of Clarity Pharmaceuticals (holder of 67Cu-SARTATE), C. Biggin Conflict with: employee of Clarity Pharmaceuticals (holder of 67Cu-SARTATE), A. Hedt Conflict with: employee of Clarity Pharmaceuticals (holder of 67Cu-SARTATE), D. Bailey Conflict with: consultant to Clarity Pharmaceuticals.


   P152: Optimization of Radiation Protection in the Preparation and Application of 18F-Fluorodeoxyglucose Top


Jiri Bartl*1, M Schneiderova2, M Budinsky2, P Skoda

1Department of Nuclear Medicine, 2Institutional Pharmacy Department, Masaryk Memorial Cancer Institute, Brno, Czech Republic

Background/Aims: Preparation and application of radiopharmaceuticals are activities that are associated with the exposure of workers to ionizing radiation. Mobile device KARl100, on the transport of radiopharmaceuticals 18F-FDG for PET, and RAD-INJECT, for its application, offer the possibility to reduce the doses of radiation exposure to staff and the optimisation of radiation protection in the workplace. The aim of the communication is to compare the results of personal dosimetry before and after the installation of mentioned equipment. Methods: To compare was used the value of the collective dose for the years 2015 and 2016 for staff of Institutional Pharmacy Department (preparation of radiopharmaceuticals), and Nuclear Medicine Department (application of radiopharmaceuticals). The collective dose here means the sum of doses of all staff a given section in half-year. The collective dose Hp (10) determines the personal dose equivalent at a given point beneath the surface of the body at a depth of 10mm, taken as the value for the whole body dose; the collective dose HT is the equivalent dose on hand. Results: From dosimetry measurements of Institutional Pharmacy Department is evident doses reduction on finger dosimeter by more than 40% after the installation of the device KARl100. The results of the measurement of whole body dosimetry are balanced both before and after the installation of the device KARl100. The Nuclear Medicine Department initially had values decrease on the finger dosimeter and a slight rise in the whole body dosimetry, but both doses decreased by about 50% after training. Conclusion: By comparing the data from 2015 and 2016, the values of collective doses for staff of the Institutional Pharmacy Department on finger dosimeter, and from whole body dosimetry have remained at the same level, despite their slight increase in assumption. For staff of the Nuclear Medicine Department, there is a reduction in the values of collective doses to the finger and whole body dosimetry.


   P153: Perception and Awareness Regarding Radiation amongst Medical Professionals in a Tertiary Care Centre Setting in Uttarakhand in India Top


Vandana K Dhingra*1, A Panday1, M Dhingra2

1Department of Nuclear Medicine, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, 2Sri Guru Ram Rai Institute of Medical Sciences, Dehradun, India

Background/Aims: Every healthcare worker will be utilising/dealing with medical radiation directly or indirectly. There are various myths and perceptions associated with radiation and information is unstructured usually through hearsay.[1],[2] We aimed to assess perception and awareness of radiation amongst medical workers not working in radiation areas. We then provided systematic information and assessed changes. Methods: In various levels of medical professionals in a tertiary care medical centre, pre-test evaluation of all participants was done by getting a simple questionnaire with total of 15 questions based on perception (4) and knowledge (11) of radiation. Intervention in the form of a short interactive workshop was conducted followed by post-test evaluation. The pre-and post-test were compared and results assessed baseline and changes. Results: Total of 235 medical professionals at the level of interns (52), junior (92), senior residents (33) and faculty (58) participated in the study of which 100 were females. Overall, we observed assertive responses in pre-test and post-test of of 78.8% and 86.3% respectively. Overall improvement in perception and knowledge of 7.4% was seen. Maximum (9.1%) and minimum (4.8%) improvement was noted amongst faculty and interns respectively. No difference in preference for working in and around radiation areas was observed after intervention. Conclusion: Fear of cancer and infertility due to radiation were the most common negative perceptions. Improvement in positive perception and knowledge after imparting systematic knowledge to students in this sub-group of medical professionals in Uttarakhand, India.

References

  1. Puri S, Hu R, Quazi RR, Voci S, Veazie P, Block R, et al. Physicians’ and midlevel providers’ awareness of lifetime radiation-attributable cancer risk associated with commonly performed CT studies: Relationship to practice behavior. AJR Am J Roentgenol 2012;199:1328-36.
  2. Ramanathan S, Ryan J. Radiation awareness among radiology residents, technologists, fellows and staff: Where do we stand? Insights Imaging 2015;6:133-9.



   P154: Expectations, Exposure and Experience: A Decade at Westmead Positron Emission Tomography Suite Top


Jo Galea*1, D Farlow1, S Evans1, L Collins2, R Mccredie2

Departments of 1Nuclear Medicine, PET and Ultrasound and 2Medical Physics, Westmead Public Hospital, Westmead, Sydney, Australia

Background/Aims: Positron Emission Tomography (PET) is potentially a higher radiation exposure workplace. When the opportunity arose to design our PET Suite our priority was to minimise radiation exposure to the technologists to 1 µSv per patient. Shielding, equipment and patient flow were all necessary considerations in reaching this target. A retrospective analysis of the last decade was performed to determine if the 1 µSv/patient goal was met. Methods: The PET Suite was appropriately shielded in hot patient areas and staff areas were allocated away from these zones. Custom designed dispensing and injecting devices were built. Patient positioning shields were utilised to minimise staff exposure. Technologist exposure was recorded using electronic personal dosimeters (EPD), a cumulative dose equivalent (Hp (10)) was recorded daily for the rostered PET technologists. The number of technologists and patients were also recorded. Inpatient numbers and the delivered dose vial activity were assessed. Results: The number of 18F-Fluorodeoxyglucose studies has increased on average 10% annually since 2006. The rostered technologist numbers have remained at two per day. The exposure rate to technologists was consistently 1 µSv/patient, with newly trained staff receiving a higher dose initially. Twenty-four technologists have rotated through the PET Suite and all have reduced their daily exposure per patient with experience. Inpatient numbers have increased with varying degrees of illness, occasionally requiring general anaesthesia. Delivered activity in the vial has increased and is now one delivery per day, a source of increased exposure due to the large activity. Conclusion: Despite increasing our patient numbers each year on average by 10% and staff levels remaining unchanged, our doses have remained consistent with the original goal of 1 µSv/patient. Increases in inpatients as well as the delivered dose vial are areas of potential increased exposure. Department adaptations of equipment, shielding and patient flow have impacted positively on exposure rate.


   P155: Design and Implementation of Shielding to Ensure Radiological Protection for Patients, the Public and the Environment, Adapted to the Hybrid Nuclear Medicine Single-Photon Emission Computerized Tomography/Computerized Tomography at IICS-UNA Top


Graciela Gimenez*1, M G Pedrozo1, B Grossling1, T Rojas1, J Nuñez1, P Galvan1

1Ingenieria Biomédica-Medicina Nuclear, Instituto de Investigaciones en Ciencias de la Salud, Asunción, Paraguay

Background/Aims: Paraguay, as a state member, has received the support of the IAEA and, on an institutional level, through the Nuclear Medicine Service of the Department of Biomedical Engineering and Images of the Institute of Research in Health Sciences-National University of Asunción (IICS-UNA) has the only available nuclear medicine service in the public health sector found at the IICS-UNA, uses SPECT (single photon emission tomography) technology and it will provide the coupling of a CT scanner and thus will offers hybrid SPECT/CT technology for diagnosis by images, mainly benefiting patients of the public sector of the whole country.[1] Methods: IAEA expert mission and technical meetings with the different areas of the institution speciality: radiopharmacy, imaging, equipment, construction, management and directory for the shielding calculation and writing report based on calculations and considerations of design, considering, radiation scattered in the patient’s body and equipment leakage.[2],[3] Results: The data of the report were used in shielding implemented in the institution. Expert recommendations suggest that the use of own isodose curve values and variables such as studies type and frequency, activity and radioisotope type. Conclusion: The shield designed and implemented is suitable for coupling the CT, and once installed will be verified.[2],[3]

References

  1. Pedrozo MG, Giménez G, Velázquez G, Galván P, Grossling B. Medicina nuclear en el instituto de investigaciones en ciencias de la salud, universidad nacional de asunción (iics–una): Estado actual y proyecciones. Mem Inst Investig Cienc Salud 2014;12:91-10391.
  2. Mediso Imaging Systems. Pre-Installation Survey Hybrid CT Any Scan SC, Molecular Imaging System. Mediso Ltd.; 2009.
  3. National Council on Radiation Protection and Measurements, Structural Shielding for Medical X-Rays Imaging Facilities, National Council on Radiation Protection and Measurements Report N 147; 2004.



   P156: Assessment and Comparison of Occupational Radiation Exposure in the Department of Molecular Imaging and Therapy: a 7-year Review Top


Sylvia Gong*1,2, G J O’Keefe1,3

1Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, 2Department of Medical Radiations, School of Health and Biomedical Sciences, RMIT, 3School of Cancer Medicine, La Trobe University, Melbourne, Australia

Background/Aims: In compliance with the key aspects of the statutory and regulatory requirements enacted by the Australian Federal and Victoria State government in protecting workers against ionising radiation hazards, the employees exposed to radiation in the Department of Molecular Imaging and Therapy (MIT) were regularly monitored. This study assessed and compared the occupational radiation exposures to all monitored staff members in the department. Methods: A total of 5150 dose records of the personal radiation monitors worn by the monitored workers were registered in the period from 2011 to 2017. The dose records of short-term staff were excluded from the analysis. Annual and monthly effective doses were calculated in individuals and compared among different professional groups. Extremity monitoring was also provided for the workers involved with high radiation activity procedures. All equivalent dose records of finger TLDs were included for analysis. Results: There were no cases of effective doses exceeding the annual limit of 20 mSv or equivalent doses to hands exceeding the annual limit of 500 mSv during the period. The average monthly dose of all the records with non-zero values was 0.20±0.18 mSv in MIT. The radiopharmacy group received the highest exposure with the monthly effective dose of 0.30±0.22 mSv and hand equivalent dose of 14.63±12.15 mSv. Nurses and Molecular Imaging Technologist were the largest exposed groups with significant individual differences in radiation exposure. Imaging Technologist in NM and PET received the monthly doses of 0.22±0.17 mSv, comparing with 0.03±0.02 mSv in Bone Mineral Density Unit. Nurses only working in MIT received higher monthly dose of 0.09±0.05 mSv, comparing with those rotated in both the Departments of Radiology and MIT (0.04±0.03 mSv). Conclusion: Radiation exposure control and continuous occupational dose reduction have been achieved in the investigated department. The waiting time in identifying the exceptionally high effective doses was minimised by employing new monitoring technique. Therefore, the assessment and audit of radiation events for recommending correction actions of related work practice could be implemented in more timely fashion.


   P157: Whole Body Counting of Thorium-227 for Monitoring of Staff Top


Søren Holm*1

1Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark

Background/Aims: with alpha-emitters is rapidly evolving. Th-227 is a promising candidate. It decays (T½=18.7d) through Ra-223 (T½=11.43d) to stable Pb-207 in 7 steps (5 alpha, 2 beta) with short half-lives (ms to minutes). Total energy is 34 MeV. X-ray/gamma lines (~1% of energy) at 50-400 keV allow external detection. Dose coefficients for (Th-227/Ra-223) are high: (7.8E-6/6.9E-6)Sv/Bq for inhalation and (8.9E-9/1.0E-7)Sv/Bq for ingestion (ICRP119). Effective dose of 1mSv may be received by a single inhalation of <130 Bq. Radiation authorities request documentation for staff compliance with dose limits (20 mSv/y). Methods: Our low-background whole-body-counter (WBC) is underground in a construction built from selected low-activity materials, shielded with 15 cm steel and lined with Pb and Cd. Four detectors (6*4” NaI-cylinders) are placed above and below the bed. We measure ½h in a 20-445 keV window. Sensitivity (cps/Bq) and background uncertainty determine minimal detectable activity (MDA) limits (Currie 1968). Sensitivity was calibrated with a known Th-227 sample under realistic conditions. Background (TB) was either person-based (paired measurements) or modeled as the sum of empty-chamber value (CB) and a spill-down value estimated as individual K-40 counts times a BMI dependent factor (BMIF) determined by linear regression including 18 persons with no history of radionuclide-work (BMI 20-44). Four persons handling Th-227 have subsequently been measured 33 times in total. Results: Calibration factor for uniformly distributed pure Th-227 was 80 Bq/cps in a 77kg phantom. CB=17.1±0.1 cps. BMIF=(0.0733BMI+1.82, r2=0.76). Average (n=18) BMIF=3.69, average K-40 value =1.93 cps, average TB= 24 cps. No Th-227 was detected in the 4 (33) persons, mean/std (-10±25) Bq. Conclusion: Our detection limits with WBC are sufficient to document compliance with dose limits if measuring shortly (week) after handling. Knowledge of true background is essential. The model can be refined including body-size dependent shielding effects on CB, measured with K-40 free water phantoms.


   P158: Nuclear Medicine Department Radiation Waste Disposal: A New Method of Monitoring Top


Lauren Hudswell*1, J Bradley1, P Bowen1, I Jong1

1Department of Nuclear Medicine, Monash Health, Clayton, Australia

Background/Aims: Radiation waste disposal is a common problem experienced by Nuclear Medicine departments worldwide, particularly in those using radionuclides with longer half-lives such as 131I and 32P. Monitoring of waste for disposal after storage results in unnecessary exposure to the technologist from items not yet decayed sufficiently. Though there are tracking systems available commercially, we have developed a simple in-house method for accurate storage and disposal, limiting unnecessary exposure to staff at effectively zero cost to the department. Methods: A Microsoft excel worksheet has been developed to track movement of radioactive waste in and out of the department. This worksheet has the ability to categorise waste via staff input, in terms of radiation level at time of entry and waste type, provide clear locations within our storage room and identify the required storage time and estimated date of disposal for when radiation levels are approximately background. This is accomplished through radiation decay algorithms, Microsoft excel formulas and features, simple data entry requirements of staff and colour-coded output values. Results: Through the implementation of this process, the ability to track and manage radiation waste has improved. Identification of waste ready for monitoring and likely disposal has been simplified and the burden of unnecessary waste storage has been reduced. As a result, we have also experienced lower exposure time and dose to staff due to the reduced need to handle and monitor waste that is not ready for disposal. Waste disposal can also be documented more effectively and is retrievable at any instance. Conclusion: Through more efficient procedures for radioactive waste management, departments can more accurately track radiation waste in and out of the department as well as reduce staff exposure levels to radiation in the process of waste disposal.


   P159: The Analysis of Radioactive Concentration in Drainage when Using Radioiodine Top


Kyung Jae Lee*1, J H Sul1, I W Lee2, Y J Park2

Departments of 1Radiation Safety and 2Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, Republic of Korea

Background/Aims: With regard to the use of radioiodine in domestic medical institution, the case of exceeding the allowance of Nuclear Safety Act about radioactive concentration in drainage was found. Through understanding the cause of exceeding case and analysing radioactive concentration in drainage, evaluating the relationship of the public waters in surroundings and usefulness. Methods: From November 1, 2014 to April 30th, 2015, the research is aiming at domestic twenty hospitals for six months. By Using a HPGe gamma-ray spectrometer (Canberra DSA-1000) and GENIE-2000 Analysis software for comparative analysis, measuring a radioactive concentration of radioiodine in drainage. Results: Consequently, we confirm the excess of radioactive concentration of radioiodine in seven medical institutions. Conducting a survey of twenty hospitals and average radioactive concentration of radioiodine in drainage appears 42,100 Bq/m3. The features of domestic hospitals where show a high radioactive concentration are a number of medical treatment patient when using radioactive iodine and the absence of private rest room. During I-131 whole body scan, the pre-treatment procedure of urinating is considered emission of residual Iodine. Conclusion: In public waters, the cause of exceeding detection of radioactive concentration in drainage suppose a diagnostic radioactive iodine. We confirm the importance of enhanced education, providing safety control instructions and installing private restrooms for patients who were injected a low capacity radioiodine. Also, constructing institutional and legal management system is considered about the emission management standard in drainage.


   P160: Learning from Incidents – Australian Radiation Incident Register Top


Paul Marks*1, C Nickels2

1Medical Radiation Services, ARPANSA, Yallambie, 2Regulatory Services Branch, ARPANSA, Miranda, Australia

Background/Aims: The Australian Radiation Incident Register (ARIR) is a national database to which Commonwealth, state and territory regulators across Australia submit details of radiation incidents.[1] Regulators acquire de-identified information about incidents from licence holders within the relevant jurisdictions. Methods: The ARIR forms part of a national radiation-reporting framework, which aims to ensure that radiation incidents are not only managed on a local level, but lessons learned can be shared across institutions and national jurisdictions. The ARIR is a powerful tool, which enables the identification and analysis of radiation incidents and hazards as well as the effectiveness of controls across Australia. Results: The most recent report, which includes all incidents that occurred in 2016, incorporates a feature section focusing on nuclear medicine practices. The ARIR annual report and this presentation provides highlights of the learnings of licence holders, and the outcomes of the analysis of the findings. This information provides a method to learn from mistakes rather than repeat them and to help focus resources on important issues and hazards. This presentation will also highlight some recent enhancements made to ARIR, including a web-based reporting system. Conclusion: Practitioners in the nuclear medicine community can have a significant impact on the ARIR through the reporting of incidents, identifying causes and suggesting solutions that could be adopted in other practices across the country. The strength of a register such as ARIR relies on the data submitted and hence clinical facilities can play an important role in reporting through their local jurisdictions. This data and subsequent analysis will aid in increasing the safety culture within nuclear medicine facilities.

References

  1. Available from: https://www.arpansa.gov.au/regulation-and-licensing/safety-security-transport/australian-radiation-incidents-register. [Last accessed on 2018].



   P161: Development of a Ceiling-mounted Radionuclide Therapy Patient Monitor with Predictive Exposure Rate Capability Top


C Munoz-Ferrada1, U Rehman1, S Smith1, Dale L Bailey*2,3

1Gammasonics Medical Research Institute, 2Department of Nuclear Medicine, Royal North Shore Hospital, 3University of Sydney, Sydney, Australia

Background/Aims: Patients receiving large doses of radionuclides for therapy often require admission to a specialized ward where they can be isolated from staff and the public until their external radiation exposure rates have decreased to acceptable levels. Our newly developed ceiling-mounted radiation monitor has an innovative detector design which continuously monitors exposure rates and is integrated into the hospital IT network to allow monitoring from any PC that can access the detector, either internally or externally. Methods: Based on a solid state sensor and a small GM detector, the device is contained in a uniquely designed casing to distinguish it from other ceiling-mounted devices such as fire alarms, smoke detectors, sprinklers and CCTV cameras. It is activated by Power Over Ethernet (POE). It has an ethernet interface for connection to the hospital LAN. The system is located approximately 1.8 meter above the patient bed but the detector is calibrated for this and gives the estimated “exposure at 1 meter”. Multiple detectors in different rooms can be supported on one PC. The software performs real-time curve fitting (assumed mono-exponential) and extrapolation to estimate when the radiation exposure from the patient will be lower than the local regulatory limit. Results: Samples were collected at 1 minute intervals starting approximately 10 minutes after administration until discharge. We have studied clearance patterns in 13 subjects. Soon after administration the exposure rate from patients who have received a 4GBq capsule of I-131 can exceed 250 micro-Sv/hr which is 10 times greater than the local limit for discharge back into the public. In patients who had radioiodine ablation with thyroglobulin pre-treatment and normal renal function the effective clearance half-time measured was 10.5±1.1 hours. However, one patient with impaired renal function had an effective t-half of >40 hours. Upon discharge, at approx. 40 hours after administration, the majority of radioiodine patients have exposure rates of between 2–20 micro-Sv/hr @ 1 m (local limit is 25 micro-Sv/hr). Many could be discharged earlier than is done with our current practices. Conclusion: This device helps to optimally manage patients admitted for radionuclide therapy. It can be used for any radionuclide that emits photons where minimising exposure to the public must be ensured.

Disclosure of Interest: C. Munoz-Ferrada Conflict with: Gammasonics Institute for Medical Research Pty Ltd.


   P162: An E-Learning System for Medical Staff about Ionizing Radiation and Radioactive Materials. A Nuclear Physicians’ Approach in Japan Top


Kazuko Ohno*1, T Higashi2, C Okuyama3, K Endo4, M Hasegawa5

1Kyoto Collage of Medical Science, 4Department of Radiological Technology, Kyoto College of Medical Science, Nantan, 2Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences, Chiba, 3Department of PET Imaging, Shiga Medical Center Research Institute, Moriyama, 5Department of Radiology, Nara Medical University, Kashihara, Japan

Background/Aims: Systematic learning about ionizing radiation and radioactive materials is not easy for medical staff. After a nuclear accident at the Fukushima Daiichi Nuclear Power Station on March 11, 2011, many patients in Japan declined radiological examinations despite doctors’ recommendation. It is important for nuclear physicians to encourage medical staff to have knowledge to correct prejudiced public understandings on ionizing radiation and human health, especially at low radiation doses. Methods: We had been taking more than 30 classes for medical staffs from 2011 to 2016. Based on questions and answers in these classes, our e-learning system was created, and 127 physicians had taken this e-learning. We also provided self-check tests after e-learning. Results: Following five contents for e-learning system were chosen; 1: Radiation around us; 2: Devices for measuring radiation; 3: Effects on humans; 4: Internal exposure; 5: Radiation emergency medicine. The results of the self-check test showed that estimation of internal radiation doses was the most difficult to understand. Conclusion: E-learning system was created for medical staffs which can correct the misunderstanding about the effect of ionizing radiation on human health.


   P163: Management of 11C radioactive Waste Gas from Cyclotron Production Top


Harris Panopoulos*1, H Tochon-Danguy1, T Dinh1, S Poniger1, G J O’Keefe1,2, J Sachinidis1

1Department of Molecular Imaging and Therapy, Austin Health, 2School of Cancer Medicine, La Trobe University, Melbourne, Australia

Background/Aims: The synthesis of 11C-PET radiotracers produces radioactive waste gases, which require careful management to ensure minimisation of release and compliance with regulatory requirements. The Austin Health Department of Molecular Imaging and Therapy produces multiple 11C radiotracers for clinical trials (eg 11C-PIB, 11C-PK11195), hence work was undertaken to monitor production and release of radioactive 11C gas from our cyclotron facility. Methods: A management plan for 11C gas release was implemented, requiring the installation and modification of a range of equipment. Further radiation monitoring systems were installed throughout the facility ventilation system with special attention made to release points. Synthesis module waste systems were modified to address challenges in gas handling, while hotcell ventilation design was revised to accommodate an Air Compression System (ACS) to allow delay and decay capabilities. Results: Release of 11C gas was reduced to levels as low as 9MBq per production, corresponding to a 24 hour disposal concentration of 32 Bq/m3 and a release of 0.008% of total activity. Internal exposure from inhalation at the release point on the facility roof was estimated to be less than 2.6 nSv per production. Conclusion: Release concentrations have been effectively reduced to safe levels, and detailed information on dosimetry and disposal of 11C to air has been obtained. These results highlight the importance of monitoring and management of 11C gas byproduct of production of 11C radiotracers.


   P164: A Flexible Magnetic Resonance Imaging-Compatible Mobile Personal Radiation Shield and Radiopharmaceutical Delivery device for Single Photon Emission Computed Tomography, Positron Emission Tomography and Radionuclide Therapy Top


C Munoz-Ferrada1, V Alves Silva1, S Smith1, Dale L Bailey*2,3

1Gammasonics Medical Research Institute, 2Department of Nuclear Medicine, Royal North Shore Hospital, 3University of Sydney, Sydney, Australia

Background/Aims: The development of PET/MRI necessitated a high degree of technological innovation. However, most radiation survey devices and personal shielding systems are incompatible with operation in the MRI suite & thus further technological innovation is required. This prompted us to develop a system for administering PET radiopharmaceuticals in this environment while adhering to the ALARA principle of maximally protecting staff. Methods: The device, called “Syriporter+”, consists of a 300-mm wide vertical lead barrier with 15 mm Pb shielding designed to achieve >10-fold reduction in exposure rates for PET radionuclides. It currently has a 35mm thick Pb-glass window (15 mm Pb equivalent) but this will be replaced by a touch screen PC and camera in future versions. The lead barrier contains an up/down drive motor to adjust for different individuals’ heights. The system supports both syringe (in syringe shield) and infusion pump administration of radiopharmaceuticals with saline flush. The radiopharmaceutical is typically loaded from a shielded container in the facility’s radiopharmacy and wheeled to the patient bedside for injection. Importantly, after the delivery of the radiopharmaceutical to the patient the operator remains protected behind the radiation shielding unlike other automated delivery systems. Measurements for a range of different radionuclides (Co-57, Lu-177, Ga-68 and Cs-137) with different photon energies and emissions in the form of point sources or liquid in a flask have been made to evaluate the transmission rate when using the barrier. Results: Indicative transmission rate reductions measured through the Pb-glass viewing window were: (i) Co-57 (122 keV)->100x, (ii) Lu-177 (113, 208 keV) – 19.1x, (iii) Ga-68 (511 keV) – 13.3x, and (iv) Cs-137 (663 keV) – 18.2x. Variations in available source geometries might account for some apparent inconsistencies between the measurements. Conclusion: The Syriporter+ is suitable for all applications involved in administering radiopharmaceuticals for general nuclear medicine or PET, for PET/CT or PET/MRI, and for radionuclide therapies. Future versions will support interfacing to the hospital information system to minimise errors. It has the advantage of protecting the operator during and subsequent to automated or manual delivery of the radiopharmaceutical.

Disclosure of Interest: C. Munoz-Ferrada Conflict with Gammasonics Medical Research Institute,


   P165: A Study on the Strategies to Lower Technologist Occupational Exposure According to the Performance form in Positron Emission Tomography Scan Procedure Top


Young Hwan Ryu*1, H S Kim2

1Seoul Medical Center, Seoul, 2Department of Radiology, Shinhan University, Uijeongbu-si, Republic of Korea

Background/Aims: For nuclear medicine technologists, it is difficult to avoid or be separate from radiation sources compared to workers who are using radiation generating devices. When technologists are familiar with work practices, their work in nuclear medicine is recognized as an optimized method. The aims of this study are to measure radiation exposure of technologists’ working in PET and to evaluate the occupational radiation dose after the implementation of strategies to lower exposure. Methods: We divided into four working types: QC for PET, injection, scan and etc. in PET scan procedure. In QC for PET, we compared the differences in radiation exposure when controlling the table next to the 68Ge cylinder phantom and controlling the table in console room remotely. In injection, we compared the radiation exposure when guiding a patient in the waiting room before the injection and after injection. In the scan procedure of PET, we compared the differences in radiation exposure between moving the table using the control button located next to the patient and moving the table using the control button located a farther distance away. The Personal Electronic Dosemeter (PED), TracercoTM was used for measuring exposed radiation doses. Results: The average doses of exposed radiation were 0.27±0.04 µSv when controlling the table directly and 0.13±0.14 µSv when controlling the table remotely while performing QC. The average doses of exposed radiation were 0.97±0.36 µSv when guiding the patient after injection and 0.62±0.17 µSv when guiding patient before injection. The average doses of exposed radiation were 1.33±0.54 µSv when using the control button located next to the patient and 0.94±0.50 µSv when using the control button located in far distance while acquiring image. As a result, there were statistically significant differences (p<0.05). Conclusion: From this study, we found how much radiation technologists are exposed to on average at each step of the PET procedure while working in a PET center and how we can reduce the occupational radiation dose after the implementation of strategies to lower exposure. If an effort is made to seek other methods to reduce technologist occupational radiation, we can minimize and optimize the amount of exposed radiation in departments of nuclear medicine.


   P166: An Australian Local Diagnostic Reference Levels for Paediatric fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Top


Essam Alkhybari*1, T Kitsos2, K Willowson3, M McEntee1, P Brennan1, R Howman-Giles2, P Kench1

1Faculty of Health Sciences, The University of Sydney, 2Department of Nuclear Medicine, The Children’s Hospital at Westmead, 3Institute of Medical Physics, The University of Sydney, Sydney, Australia

Background/Aims: The radiation dose associated with PET/CT is of particular concern in paediatric patients. If local diagnostic reference levels (DRLs) exceed the national DRL, there may be a need for optimisation of the PET/CT protocol. The aim of this study was to establish the local DRL for paediatric patients undergoing PET/CT examinations at one Australian centre. Methods: A survey was sent to retrospectively assess 12 months of 18F-FDG PET/CT data in order to establish the local DRL based on the 50th percentile for the infant/baby (0-4 years) and child (5-14 years) age categories. Collected data included administered radioactivity (MBq), CT dose index volume (CTDIvol) and the CT dose length product (DLP). Total effective dose (ED) was also calculated. Results: The 50th percentiles for administered total activity (MBq) and activity normalised to body weight (MBq/kg) in the infant/baby category (n=21) were 81.36 MBq and 5.61 MBq/kg, respectively. For the children category (n=92) these were found to be 145 MBq and 3.85 MBq/kg, respectively. The 50th percentiles for CTDIvol and DLP for the infant/baby category were 0.81 mGy and 71 mGy.cm, respectively. The total PET/CT ED for infant/baby and child groups were 8.79 mSv and 6.96 mSv, respectively. The ED from administered radioactivity was higher than CT dose. The MBq/kg administered radioactivity for the infant/baby group was higher than child age group due to independent minimum administered activity (60 MBq) required for diagnostic image quality. Conclusion: A local DRLs for paediatric 18F-FDG PET/CT imaging has been determined. This is an important first step in establishing an Australian national DRL for paediatric PET/CT examinations.

Disclosure of Interest: T Kitsos Conflict with: The University of Sydney, Faculty of Health Sciences, K Willowson Conflict with: The University of Sydney, Faculty of Health Sciences.


   Radiopharmaceutical Sciences Top



   P167: A New W-188/Re-188 Generator Top


Hossein Abbasi*1, H Khosrounejad1, M Davarpanah1

1Pars Isotope Co, Tehran, Islamic Republic of Iran

Background/Aims: The advantage of Re-188 for radionuclide therapy including its inexpensive and availability from the W-188/Re-188 generator is been proven in nuclear medicine. Our efforts in PARS Isotope Co. towards the development of therapeutic radionuclides was focused on production of W-188/Re-188 generator which can be used in hospitals and nuclear medicine centers as a radioisotope supplier for production of therapeutic radiopharmaceuticals. Methods: This new W-188/Re-188 generator with the name of PARSRhen is a system where W-188 as tungstic acid adsorbs on a column of alumina. After W-188 loading the manufactured generators are slowly washed (1mL/min) with 0.9% NaCl solution (100-150 mL) and completely air dried before dispatch. PARSRhen uses high specific activity W-188 and modified alumina sorbent. Suitable formulation for W-188 was obtained and sufficient shielding for decreasing operator exposure were designed and manufactured. The quality control test such as radionuclide and radiochemical tests were done on the eluted Re-188 from the generator. Results: Re-188 elution yields in PARSRhen were generally 75% to 80% of the available Re-188. W-188 breakthrough values were typically in the range of 10-6. Chemical, Radiochemical, radionuclide and sterility tests which are regular in the world were evaluated according to pharmaceutical standards. Eluted Re-188 from PARSRhen was labeled with different agents and tested on animals and patients. All the results were based on standards and satisfying. Conclusion: At the moment, a portable W-188/Re-188 generator with usability in nuclear medicine centers is designed and introduced all over the world to develop using of Re-188 radiopharmaceuticals for needy patients.


   P168: Potential of Prelabelling Method for On-Site Preparation of Radiometal-Labeled Antibody Top


Putri Andriana*1, H Hanaoka2, A Yamaguchi2, Y Tsushima1

Departments of 1Diagnostic Radiology and Nuclear Medicine and 2Bioimaging Information Analysis, Gunma University, Maebashi, Japan

Background/Aims: Imaging with a radiolabelled antibody would be a promising strategy to select patients suitable for the respective antibody treatment. Nevertheless, widespread application of this approach is limited due to the complexity related to conventional radiolabelling technique, including requirement for time, cost, and germ-free condition during chelate-antibody conjugate preparation. Pre-labelling technique, which the radiometal complex is formed first and then conjugated to the antibody, has the potential to become useful method since this technique save labour for advance preparation of chelate-antibody conjugate. Pre-labelling technique would be more efficient and applicable for general use in clinical field, if highly-reactive and easily separable radiometal complex is available. Our aim was to develop a new bifunctional chelating agent and establish a purification method suitable for pre-labelling technique. Methods: DO3A-PEG4-COOH was obtained by solid phase synthesis. DO3A-PEG4-COOH or DOTA was labeled with 111In in acetate buffer or HEPES buffer. Radiochemical yield was analysed by cellulose acetate electrophoresis. To establish a method to separate antibody from unconjugated radiometal complex, purification study was performed using a mixture of 111In-DO3A-PEG4-COOH and 125I-labeled antibody. The mixture was applied to a size-exclusion cartridge, then the tracers were eluted with phosphate buffered saline, and the fractions were collected into tubes. Radioactivity of each tube was measured by γ-counter. Results: When the standard radiolabelling condition of 111In-DOTA was applied, radiochemical yield of 111In-DO3A-PEG4-COOH was approximately 91%. By using HEPES buffer instead of acetate buffer, 111In-DO3A-PEG4-COOH was obtained with radiochemical yield of more than 95%. The separation with size-exclusion cartridge yielded 125I-labeled antibody in high purity (containing less than 5% of 111In-DO3A-PEG4-COOH or 111In-DOTA) and recovery yield of approximately 50%. Conclusion: DO3A-PEG4-COOH enabled 111In-labelling with high radiochemical yield. The resulting radiometal complex was easily separable from antibody by using a size-exclusion cartridge. These results suggest that DO3A-PEG4-COOH would be a promising chelate for pre-labelling technique.


   P169: Do we Really Need an Onsite Cyclotron? The RNS Hospital Experience Top


Alireza Aslani*1,2, L Yasmin1, D L Bailey1,2, Paul Roach1,2

1Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, 2Sydney Medical School, University of Sydney, Sydney, Australia

Background/Aims: Currently there are over 1200 cyclotrons being used in nuclear medicine worldwide for the production of radioisotopes. Radioisotopes produced in cyclotron decay by either positron emission or electron capture. Although there is no (or plan for) cyclotron at RNSH, there is a growing list of positron emitting and cyclotron-produced radiopharmaceuticals being used for routine and research applications. Here we report on the RNSH experience. Methods: The number of patients being treated and/or diagnosed with cyclotron-produced and positron-emitting radiopharmaceuticals was obtained using GE RIS/PACS for the most recent year (2016). These were then separated into in-house-generator produced and cyclotron-produced radiopharmaceuticals. The percentage of total scans for each radiopharmaceutical was determined. 99mTc-based radiopharmaceuticals were excluded for the comparison. Results: The results showed that the cyclotron-produced 18F-FDG was the most common (72%) followed by the in-house-generator produced 68Ga-DOTATATE (13%) and 68Ga-PSMA (12%). A list of these and their applications are summarised below. There are other cyclotron-produced radiopharmaceuticals at development stage and will be entering into mainstream use in the foreseeable future.

[18F]-FDG (deoxyglucose) : Cancer, brain, cardiac, inflammation

[18F]-FET (tyrosine) §: Cancer – DNA synthesis

[18F]-FLT (thymidine): Cancer – “Ki67 analogue”

[18F]-FMISO§: Hypoxia

[18F]-NaF: Bone scan, atherosclerosis

[18F]-Florbetaben (soon): Cerebral amyloid (Dementia)

[18F]-PBR111 (TSPO) § (soon): Cerebral microglial activation

[68Ga]-DOTATATE§: Somatostatin receptor imaging (NETs, meningioma)

[68Ga]-PSMA§: Prostate cancer

[68Ga]-Citrate§: Infection

[68Ga]-Galligas (GaCl2) §: Lung ventilation

[68Ga]-MAA§: Organ (lung) perfusion

[124I]-Minicells (EnGeneIC) §: Chemotherapy/drug delivery vehicle

[89Zr]-Nanoparticles§: PET/MRI imaging/drug delivery

[90Y]-SIR-Spheres: Post-SIRT dosimetry

Imported §Radiolabelled in-house.

Conclusion: Although cyclotron-produced radiopharmaceuticals are currently in demand, an on-site cyclotron is not essential in order to carry-out most, if not all, of the PET/CT scans. This is on the provision that there are commercial cyclotrons available within distance allowed by the radionuclide’s half-life. The generator-produced PET radionuclides (eg 68Ga) can be used on-demand.


   P170: Production of 64Cu, 89Zr, 68Ga and 45Ti on a GE PETtrace Cyclotron Using the Comecer ALCEO Solid Target Top


Johan Asp*1, C Lang1, W Tieu1, K Kuan1, M Malinconico2, F Boschi2, G Guidi2

1Molecular Imaging and Therapy Research Unit, South Australian Health and Medical Research Institute, Adelaide, 2Comecer Spa, Castel Bolognese, Italy

Background/Aims: The ALCEO solid target system has been developed by Comecer for cyclotron production of 64Cu and 89Zr. The aim of this work was to expand on the utility of the ALCEO system for the production of 68Ga and 45Ti radioisotopes. Production and labelling results for all four isotopes will be presented. Methods: Enriched 64Ni was electroplated onto a target shuttle and irradiated with 14.4 MeV protons to produce 64Cu, which was then separated from the irradiated 64Ni using AG® 1-X8 resin (Biorad). Natural yttrium was irradiated with 14.4 MeV protons to produce 89Zr, while natural scandium was irradiated with 12.1 MeV protons to produce 45Ti. Both radioisotopes were separated from their irradiated starting materials using ZR resin (TRISKEM). 68Zn was electroplated onto a target shuttle and irradiated with 12.1 MeV protons to produce 68Ga. The 68Ga was separated from the irradiated 68Zn using LN resin (TRISKEM), then labelled to PSMA-11 and DOTATATE using Eckert & Ziegler’s Modular-Lab eazy synthesis module. Results: 64Cu was routinely produced with a yield of 131±40 MBq/µAh (n = 20) and was successfully utilised for the process validation of [64Cu]Cu-SARTATE (n = 3) conducted at SAHMRI. 89Zr was produced with a yield of 22.4±1.5 MBq/µAh (n=2), while 45Ti was produced with a saturation yield of 312 MBq/µA (n=1). 89Zr was labelled to DFO-trastuzumab with radiolabelling yield >80% and radiochemical purity >90% (n=2). 68Ga was produced with a saturation yield of 1330±590 MBq/µA (n=2), and was labelled to PSMA-11 (radiolabelling yield=79%) and DOTATATE (radiolabelling yield=76%), with radiochemical purity of 99% and 91% respectively. Conclusion: The Comecer ALCEO solid target system has been successfully used to produce 64Cu, 89Zr, 68Ga and 45Ti. Future work includes optimisation of the separation processes, and production of 44Sc.

Disclosure of Interest: M Malinconico Conflict with: Comecer spa; F Boschi Conflict with: Comecer spa, G Guidi Conflict with: Comecer spa.


   P171: Initial Standardisation of Next Generation Theranostics: Preparation for Clinical Trials with Cu-64 SARTATE Top


Colin Biggin*1, B Howe2, F van Wyngaardt2, C Jeffery1,3, P Roselt4, J Asp5, V Kumar6, B Wallace7, A Payne8, A Hedt1

1Clarity Pharmaceuticals, 6Westmead Hospital and The Children's Hospital at Westmead, Westmead, Sydney, 2Department of Radionuclide Metrology, ANSTO, Lucas Heights, 3Centre for Advanced Imaging, University of Queensland, 7Nuclear Medicine and Queensland PET Service, Royal Brisbane and Women`s Hospital, Brisbane, 4Peter MacCallum Cancer Centre, Melbourne, 5MITRU, SAHMRI, Adelaide, 8Cyclotek Pty Ltd, Bundoora, Australia

Background/Aims: In preparation for clinical studies with Cu-64 SARTATE in children with neuroblastoma, Clarity Pharmaceuticals and ANSTO Radionuclide Metrology have collaborated to develop an initial Cu-64 standard for clinical manufacturing sites and clinical research sites. This initial standard will be updated late in 2017 when ANSTO performs a Cu-64 primary standardisation and compares this standard with the International Reference System using the SIRTI transfer instrument (BIPM). By harmonising the dose calibrators dial settings between sites, more confidence is gained in the dosimetry estimates from PET images collected at clinical sites. This is especially relevant for next generation theranostic radiopharmaceuticals such as Cu-64 SARTATE and Cu-67 SARTATE, where personalised dosimetry can be used to optimise therapeutic efficacy while maintaining patient safety. Cu-64 SARTATE is a positron-emitting radiopharmaceutical that has important advantages over current PET agents. Clarity’s therapeutic product is Cu-67 SARTATE, a beta emitter, which has the potential to be used to treat a range of cancers including neuroendocrine tumours, meningioma, and neuroblastoma in paediatric patients. Methods: ANSTO developed an initial calibration factor for their Secondary Standard Ionisation Chamber (SSIC) through interpolation of its response curve. A Cu-64 solution provided by Clarity’s contract manufacturer was then standardised using this calibration factor. ANSTO established preliminary dial settings for Cu-64 on their dose calibrators from the same standardised solution. Additional Cu-64 was sub-dispensed into vials, standardised by measurement in the SSIC, then sent to clinical and manufacturing sites involved in Clarity’s Phase 1 study for establishing dial settings. Results: All clinical and manufacturing sites were able to establish dial settings for Cu-64 that were within ±1.1% of the value measured from ANSTO. Conclusion: By establishing measurement equivalency between clinical manufacturing and research sites at the outset of the trial, more consistent and meaningful data can be obtained.

Disclosure of Interest: C Biggin Conflict with: Clarity Pharmaceuticals, C Jeffery Conflict with: Clarity Pharmaceuticals, A Hedt Conflict with: Clarity Pharmaceuticals.


   P172: An Improved, Highly Reproducible Formulation of (Tc-99m) TRODAT-1 for Routine Clinical Use Top


Dilip Boddeti*1,2, A Kankean1,2, V Kumar1,2,3

1Department of Nuclear Medicine and PET, Westmead Hospital, 2Department of Nuclear Medicine, The Children’s Hospital at Westmead, Westmead, 3Sydney Medical School, University of Sydney, Sydney, Australia

Background/Aims: The tropane derivative, TRODAT-1 when labelled with [Tc99m] has been shown to bind dopamine transporter (DAT) with high affinity and selectivity. In this study, we have modified and standardized the procedure for TRODAT-1 cold kit formulation. We investigated if the labelling procedure could be improved by using a heating-block and to be more efficient and consistent than using autoclaving or boiling water-bath methods as described previously. Methods: Briefly, 1mg of TRODAT-1 was dissolved in 100µl of ethanolic-HCl. To this solution 440µg SnCl2, 160mg sodium glucoheptonate, 19mg EDTA were added and mixed. The bulk solution containing TRODAT-1 was aseptically dispensed in 1mL aliquots and stored at-80°C. TRODAT-1 was radiolabelled by adding 1.4GBq of [Tc-99m]pertechneate in 3ml saline and heated for 30min at 100oC using a heating-block enclosed with a lid. The radiochemical purity (RCP) was analysed using iTLC-SG paper with saline as the solvent and HPLC was performed using 0.1% TFA/H2O & ACN. As proof of concept, biodistribution of [Tc-99m]TRODAT-1 was studied in a rabbit model. Animals were injected with 30MBq of [Tc-99m]TRODAT-1 and images were acquired at 60min post-injection with a SPECT/CT (Siemens Symbia) camera. Results: Previous studies have used autoclaving method or a boiling water bath for radiolabelling TRODAT-1 with [Tc-99m]. These methods had the limitation of water evaporating during boiling, uncontrollable temperatures, variable yield and possibility of contamination. To ensure consistent temperature and eliminate the possibility of contamination we used heating-block. RCP of [Tc-99m]TRODAT-1 (Rf=0.0) by iTLC was >99% and reproducible. The retention time by HPLC for labelled product was16min and for free [Tc99m] was 2.5 minutes with radiolabelling yield of >99%. Animal biodistribution studies showed brain hippocampus uptake of 0.32±0.08 %ID/g at 60min post-injection. As expected, kidney uptake was high as the agent is excreted renally. Conclusion: This study describes a simple formulation and method of preparation for [Tc-99m]TRODAT-1,which is reproducible with high yield and purity (RCP >99%).The pre-clinical results in rabbits indicated specific binding to dopamine receptors and therefore has the potential for use in DAT imaging in patients.


   P173: Radiopharmaceutical Laboratory on Chip Top


Adam Čepa*1,2,3, D Seifert1, J Červenák1,3, M Kleinová1, P Vlastník1, J Ráliš1, O Lebeda1

1Department of Radiopharmaceuticals, Nuclear Physics Institute of the Cas, Řež, 2Group of Experimental Toxicokinetics and Radiopharmacology, Faculty of Pharmacy, Charles University, Hradec Kralove, 3Department of Nuclear Medicine, General University Hospital in Prague, Prague, Czech Republic

Background/Aims: The aim of this paper is to present the novel concept of labelling the technetium-kit-like radiopharmaceuticals using microfluidic chip systems. Methods: We designed and tested the labelling of the technetium compounds on microfluidic chip systems using the following commercially available kit lyophilisates: Technescan HDP (Mallinckrodt Medical B. V, Holland), Technescan MAG3 (Mallinckrodt Medical B. V, Holland), CARDIOSPECT (MEDI-RADIOPHARMA Ltd., Hungary), SENTISCINT (MEDI-RADIOPHARMA Ltd., Hungary), Tektrotyd (POLATOM, Poland), VASCULOCIS a TECEOS (CIS bio International, France). The labelling was performed with 99mTc-eluate from Drytec 99Mo/99mTc generator (GE Healthcare Limited, Great Britain) on non-commercial chips “One in–One out” PMMA GSlite (Department of Radiopharmaceuticals, Nuclear Physics Institute of the CAS) with canal dimensions width-neck-depth: 0.5-0.1-0.05 mm and total canal length of 15 cm equipped with turbulent mixers. Activity used in these studies varied from 1 to 5 GBq and the eluate was applied on the chip with various flow-rate. The transchelatation lyophilysates were labelled using a heating magnetic stirrer (set on 90 °C). Radiochemical purity was determined according to SPC using radiochromatographic scanner Scan 2 (EMPOS & BQM, Czech Republic). Results: Radiochemical purity of studied substances was always ≥ 95%. Labelling of every studied substance took in general 50% less time than when compared to kit-like preparation of radiopharmaceuticals with a high radiochemical yield and the whole process was remotely controlled. Conclusion: The presented method of labelling of technetium-kit-like pharmaceuticals using microfluidic chip systems is a more rapid, reliable and high radiochemical purity providing alternative for daily radiopharmaceutical practice. Moreover, this modern approach allows for simple scaling of the precursor’s amount and decreases significantly personnel’s radiation burden.


   P174: Conjugation, Radiolabelling and In vitro Studies of VAP-P1, a Vascular Adhesion Protein-1 Targeting Peptide Top


Jaroslav Cervenak*1,2, A Cepa1,2,3, J Ralis1, M Tomes1, K Kontrova1, O Lebeda1, M Vlk4

1Department of Radiopharmaceuticals, Nuclear Physics Institute of the Czech Academy of Sciences, Řež, 3Experimental Toxicokinetics and Radiopharmacology, Faculty of Pharmacy, Charles University, Hradec Kralove, 2Department of Nuclear Medicine, General University Hospital, 4Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering of the CTU, Prague, Czech Republic

Background/Aims: Vascular adhesion protein-1 (VAP-1) is an endothelial glycoprotein present on the endothelial surface of tissues affected by infection/inflammation that recruit lymphocytes from blood. VAP-P1 is a VAP-1 selective peptide (sequence GGGGKGGGG) which, according to previous studies, conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and labelled with 68Ga, could be used as imaging agent capable to differentiate between normal bone healing and bone infection. The aim of this paper is to study the potential of 1,4,7-triazacyclononane-triacetic acid (NOTA)-conjugated, 68Ga and 64Cu labelled VAP-P1 peptide for possible clinical applications. Methods: Synthesised peptide VAP-P1 was conjugated with NOTA-SCN, purified using semi-prep HPLC and lyophilized. The conjugate was then labelled with 68Ga or 64Cu. In vitro plasma protein binding and stability in human serum in time (0, 30, 60 and 120 min) were determined using transfected Chinese Hamster Ovary cells (CHO) that express human VAP-1 and HT-29 (negative control). Each experiment was performed in octaplicate, and the data were reported as percentage of total added activity. Results: The peptide was conjugated with NOTA chelator and labelled with 68Ga and 64Cu with radiochemical purity ≥ 95 %. Radiolabelled analogue [64Cu]NOTA-VAP-P1 presented here was rapidly internalized into CHO cells versus negative control HT-29. The internalization of the surface bound peptide was time-dependent. It sharply increased during the first 30 min reaching internalization levels of 80–90%. Conclusion: In vitro studies showed that NOTA-VAP-P1 labelled with 68Ga or 64Cu may provide a faster and a simpler method of diagnostics of inflammation/infection compared to the method of labelled leucocytes. The concept deserves to be tested in vivo.


   P175: Fully Automated Production of 86Y Top


T Dinh*1, S Poniger1, H Panopoulos1, H Tochon-Danguy1

1Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Australia

Background/Aims: 86Y has applications in preclinical and clinical studies as a molecular imaging partner to 90Y-labelled particle, peptide and antibody therapy. We have implemented 86Y production via the 86Sr (p, n)86Y reaction, using a 13MeV proton beam and purified with an automated disposable-cassette based module which was manufactured in-house. In this study, we aimed to introduce an efficient way of preparing the 86SrO target that allows longer irradiations and higher currents, as well as simplifying purification procedures. Methods: 30mg of 86SrO was ground into a fine powder, and then left in a desiccator overnight. The powder was then pressed into a cylindrical cavity in a Niobium disk using a bench vice and held under pressure for 5 minutes. The target was then kept in a desiccator overnight for irradiation the following day. The irradiated target was then dissolved and purified by an in-house developed automated module, which uses a selective DGA Normal resin column (N, N, N’,N’-tetra-n-octyldiglycolamide, 50-100µm particle size) to purify the 86Y. The purified 86Y was then eluted from the column with ultrapure water. Results: Proton irradiation of the 86SrO target material at 10µA for 2 hours yielded approximately 800 MBq at EOB, with no significant target material losses observed. Typically, 75-80% of the activity is recovered in the elution volume. Gamma spectrum analysis using an HPGe detector has shown that the final purified solution contains 0.45% 87Y and 0.1% 88Y when normalised against 86Y. Conclusion: Optimization of target preparation methodology has shown significant improvements in target stability at higher beam currents compared to the widely used method of 86SrCO3 as the target material.1 Use of an in-house developed automated module has also minimized radiation safety concerns by eliminating manual handling procedures as well as improving accuracy and reproducibility of productions. The final purified 86Y solution is obtained in a small volume appropriate for subsequent radiolabelling.

References

  1. Rösch F, Herzog H, Qaim SM. Pharmaceuticals 2017;56. [doi: 10.3390/ph10020056].



   P176: Automated Synthesis of 131I-Lipiodol via Isotopic Exchange: Role of Phase Transfer Catalyst/Melt Down Methodologies Under GMP Guidelines Top


Manish Dixit*1, N Shanker1, P Saxena1, S Gambhir1

1Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India

Background/Aims: Primary hepatocellular carcinoma (HCC) is the most common form of primary hepatic carcinoma, particularly in Asia and sub-Sahara Africa. The therapeutic modalities such as chemotherapy, radiotherapy, and trans-hepatic arterial embolization (TAE) gave unsatisfactory results. Alternative methods of therapy using Lipiodol as a carrier for chemotherapeutic agents or radioisotopes are currently under investigation. Synthesis of 131I-labelled Lipidol is a challenge in order to make under strict recommendation of regulatory authority along with maintaining the worker safety. Time is required to fully automate the process to synthesise the required quantity and quality of radiotracer. Methods: In this study, we describe the fully automated labelling of 131I with lipiodol, using Sumitomo’s CFN MPS-100 automated synthesis module with minor modification in software and module intake of reagents. Synthesis was performed at around 100oC having mixture of iodized-lipiodol (LIPIODOL Ultra Fluid supplied by Guerbet, France) and carrier-free 131I. The reaction was catalyst by phase transfer catalyst such as Crown ether (PTC) or Pivalic acid melt down method. At different concentration of PTC or acid, the radiolabelling yield were studied. After variable time of incubating, the mixer was transfer to product vial by passing through 0.22µm sterile filter. All quality control tests were performed for being used as clinical product. Results: The overall radiochemical yield in the range of 85-95% with the labelling purity is more than 98%. The reproducibility of this automated synthesis module is very high. Conclusion: we have developed a protocol for reliable, repeatable fully automated chemistry protocol for clinical grade 131I-Lipiodol.


   P177: A Freeze-dried Multi-dose Kit Solution for Optimized Preparation of 68Ga-DOTA-Tyr3-octreotate and More Efficient Human Application Top


Thomas Ebenhan*1, B B Mokaleng1, J Mahapane2, B Marjanovic-Painter3, J R Zeevaart1,4, M Sathekge1

1Department of Nuclear Medicine, University of Pretoria and Steve Biko Academic Hospital, 2Department of Nuclear Medicine, Steve Biko Academic Hospital, Pretoria, 3Department of Radiochemistry, The South African Nuclear Energy Corporation, Pelindaba, 4Department of Science and Technology, Preclinical Drug Development Platform, North West University, Potchefstroom, South Africa

Background/Aims: Peptide receptor radionuclide therapy (PRRT) has emerged to be a significant asset to nuclear medicine involving generator-based gallium-68 (68Ga) that became opportunely available to hospital radiopharmacies. The supply of 68Ga-DOTA-Tyr3-octreotate tremendously facilitates patients undergoing 177Lu-DOTA-Tyr3-octreotate-PRRT, which is used successfully in South Africa.[1] Lacking a commercially-available radiochemical synthesiser, higher attention was given to a flexible, cost-efficient 68Ga-DOTA-Tyr3-octreotate radiolabelling solution including a “safe-and-simple” handling protocol suitable for a hospital radiopharmacy. We describe an optimized 68Ga-DOTA-Tyr3-octreotate preparation using in-house-manufactured, freeze-dried, multi-dose prepared kits and demonstrate the significance towards human application. Methods: A 0.9-2.0 ml 68Ga-GaCl3 fraction was yielded from a newly-manufactured 68Ge/68Ga-generator; 25 consecutive manual 68Ga-DOTA-Tyr3-octreotate (13.3±1.3 µM) productions were compared with 10 kit-based radiosyntheses (14.2±0.4 µM; p=0.101). Kits were manufactured containing DOTA-Tyr3-octreotate in sodium acetate buffer to warrant pH of 3.5-4 during radiolabelling. Radiolabelling was carried out as detailed.[2] Ethical approval for tracer injections was given. Results: DOTA-Tyr3-octreotate was obtained with radiochemical purities of 98.8–100%, from freeze-dried formulations after reconstitution with 30% less 68Ga-GaCl3 (P=0.003) than required for manual radiolabelling (≥95.6%). All kit-based productions were significantly better than the average manual production (labelling efficiency of 86±5% vs. 48±26%; p<0.001) and led to reduction of production time (26±5 minutes; p<0.001), 68Ga-colloids (7.5±3.6%; p=0.014), free 68Ga (H2O)6 (6.3±2.2%; p<0.001) and C18-cartridge-bond radioactivity (3.0±1.9%; p=0.019). Consequently, 1.7-fold higher radiochemical yield (678±174; p<0.001), 2.0-fold increased specific activity (26±10 MBq/nmol; p<0.001) and 1.4-fold more radioactivity for tracer administration (499±89 MBq; p=0.037) was accomplished. From one DOTA-Tyr3-octreotate kit, two patient doses (2.2±0.8 MBq/kg; 17±6 nmol DOTA-Tyr3-octreotate, p=0.026; N=14) were obtained and safely administered. Conclusion: Significant improvements accompanied our kit-based 68Ga-DOTA-Tyr3-octreotate radiolabelling approach with reduced radiation exposure to operating personnel.

References

  1. Lawal IO, Ololade KO, Lengana T, Reyneke F, Ankrah AO, Ebenhan T, et al. Gallium-68-dotatate PET/CT is better than CT in the management of somatostatin expressing tumors: First experience in Africa. Hell J Nucl Med 2017;20:128-33.



   P178: Efficient Single-vial Radiolabelling Solution for NODAGA-Zoledronate Accommodating Gallium-68 from a Tin-dioxide-based 68Ga/68Ge-generator and Administration into Humans Top


Thomas Ebenhan*1, J Mahapane2, I Lawal1, N Pfannkuchen3, M Meckel4, F Rösch3, M Sathekge1

1University of Pretoria and Steve Biko Academic Hospital, 2Steve Biko Academic Hospital, Pretoria, South Africa, 3Institute of Nuclear Chemistry, Johannes Gutenberg University, Mainz, 4ITG Isotope Technologies Garching GmbH, Garching, Germany

Background/Aims: PET/CT using 18F-sodium fluoride is a sensitive imaging technique for diagnosis of bone metastases but their efficient treatment remains a clinical challenge. Zoledronate (ZOL), a bisphosphonate with superior affinity to hypoxyapatite, was recently conjugated with bifunctional chelators such as 1,4,7-triazacyclononane,1-glutaric-acid-4,7-acetic-acid (NODAGA), allowing for 68Ga-labelling[1],[2] to monitor endoradiotherapeutic efficiency. We demonstrate a single-vial solution for quantitative 68Ga-NODAGA-ZOL radiolabelling. The procedure was modified to accommodate the more-acidic 68Ga-eluate of a SnO2-based 68Ga/68Ge-generator. Additionally, the safety of the tracer administration was tested in a small patient population. Methods: A 68Ga/68Ge-generator was fractionally eluted yielding 85% (697±27 MBq) or 93% (862±50 MBq) of the elutable 68Ga-activity in 1.2 or 2.0 ml, respectively. The radioactivity was buffered with 2.5 M sodium acetate to yield a pH of 4.0-4.5 before mixing it into a vial containing 74 nmol NODAGA-ZOL. After 10 min incubation at 95˚C, the mixture was sterile-filtered into buffered saline to yield tracer formulation (pH 6.7) for human administration. Quality control measures included radiochemical and radionuclidic purities, pH and sterility. Given ethical consent, 68Ga-NODAGA-ZOL was administered intravenously to ten patients followed by whole-body PET/CT imaging at 60 minutes.[1] Results: Quantitative 68Ga-NODAGA-ZOL radiolabelling (%LE=94.2-97.0; 68Ga-colloids <7.0%, RCP >98.5%; n=6) was achieved using 30 µM precursor, but not with NODAGA-ZOL concentrations <20 µM (%RCP 73.5±3.7; n=3). The radiochemical yield of 480±59 MBq was sufficient to dispense two doses/radiosynthesis. The 5.5-10.5 ml intravenous 68Ga-NODAGA-ZOL bolus injection (2.5±0.8 MBq/kg containing 31±8 nmol NODAGA-ZOL; specific activity 7.3±0.9 GBq/µmol; n=10) did not cause any adverse effects in humans. PET images were of high quality with no unexpected tracer distribution. Conclusion: The herein produced 68Ga-NODAGA-ZOL is a safe-to-administer radiopharmaceutical which can be further evaluated towards its value as a PET/CT imaging agent, monitoring outcome of personalised endoradiotherapies of bone metastases, such as particle-emitting radiopharmaceutical therapy.

References

  1. Fannkuchen N, et al. Pharmaceuticals 2017;10:45.
  2. Pfannkuchen N, et al. J Nucl Med 2017;58 Suppl 1:324.



   P179: 18F-PBR111-d4: An Improved 2nd Generation Deuterated Radiotracer for Imaging Inflammation Top


Ben H Fraser*1,2, N Wyatt1, M Safavi-Naeini1,3, A Wotherspoon3, A Arthur3, A P Nguyen3, A Parmar3, H Hamze3, C M Day2, D Zahra3, L Matesic2, E K Davis3, G L Rahardjo3, N R Yepuri4, R K Shepherd1, R B Murphy4, T Q Pham2, V H Nguyen1,3, P D Callaghan1,3, P J Holden4, M-C Gregoire1, T A Darwish4

1Human Health Research, 2Radioisotopes and Radiotracers, 3Radiobiology and Bio-Imaging, 4National Deuteration Facility, The Australian Nuclear Science and Technology Organisation, Sydney, Australia

Background/Aims: The translocator protein (TSPO) is a receptor complex located in mitochondria in human.[1],[2] TSPO is a bio-marker for inflammation associated with numerous diseases including cancer, multiple sclerosis, Parkinson’s and Alzheimer’s diseases, stroke, Huntington’s disease and HIV encephalitis.[3],[4] Consequently there is significant interest in radiolabelled TSPO ligands as new radiotracers. This includes [18F]PBR111 which shows potential for imaging neuroinflammation[5],[6] but suffers from significant de-fluorination in vivo. This leads to non-ideal bone uptake and non-ideal specific and non-specific binding in vivo, which ultimately leads to lower quality PET images. To address these problems, a deuterated 2nd generation radiotracer has been synthesised and its metabolic stability compared to regular [18F]PBR111. Methods: Radiolabelling precursors and non-radioactive standards were synthesised following an adaptation of our previous method.[5] The deuterated side chain synthon was synthesised via a three step reaction sequence of LiAlD4 reduction, bromination and protection. Radio-synthesis were performed on a Synthra RNplus synthesis module following an adaption of a previous method.[5] In vitro microsomal assays were performed with either rat or human liver microsomes, and subsequent radio-metabolite analysis was performed using radio-HPLC. SPE analysis of radio-metabolites were performed using Waters Oasis HLB cartridges. Results: The rate of in vitro metabolism (using rat and human microsomes) of [18F]PBR111-d4 is reduced compared to non-deuterated [18F]PBR111. In vivo PET imaging in rats showed a 42% reduction of the median [18F]PBR111-d4 uptake in bone (vertebrae) compared to non-deuterated [18F]PBR111. Conversely, in the adrenal glands (where TSPO is expression is high) a 30% increase of the median [18F]PBR111-d4 uptake was observed. Conclusion: A deuterated radiotracer-[18F]PBR111-d4-was developed and evaluated in vivo in rats, demonstrating that it is more resistant to metabolic breakdown compared to non-deuterated [18F]PBR111. Careful choice of the site of deuteration resulted in a decreased rate of de-fluorination and a notable increase in the median uptake in regions with high TSPO expression. Work to evaluate [18F]PBR111-d4 in animal models of excitotoxin-induced neuroinflammation is currently underway and will be reported on in future publications.

References

  1. Braestrup C, Squires RF. Specific benzodiazepine receptors in rat brain characterized by high-affinity (3H)diazepam binding. Proc Natl Acad Sci U S A 1977;74:3805-9.
  2. Snyder SH, Verma A, Trifiletti RR. The peripheral-type benzodiazepine receptor: A protein of mitochondrial outer membranes utilizing porphyrins as endogenous ligands. FASEB J 1987;1:282-8.
  3. Li F, Liu J, Garavito RM, Ferguson-Miller S. Evolving understanding of translocator protein 18 kDa (TSPO). Pharmacol Res 2015;99:404-9.
  4. Papadopoulos V, Lecanu L. Translocator protein (18 kDa) TSPO: An emerging therapeutic target in neurotrauma. Exp Neurol 2009;219:53-7.
  5. Fookes CJ, Pham TQ, Mattner F, Greguric I, Loc’h C, Liu X, et al. Synthesis and biological evaluation of substituted [18F]imidazo[1,2-a]pyridines and [18F]pyrazolo[1,5-a]pyrimidines for the study of the peripheral benzodiazepine receptor using positron emission tomography. J Med Chem 2008;51:3700-12.
  6. Dedeurwaerdere S, Callaghan PD, Pham T, Rahardjo GL, Amhaoul H, Berghofer P, et al. PET imaging of brain inflammation during early epileptogenesis in a rat model of temporal lobe epilepsy. EJNMMI Res 2012;2:60.



   P180: A Strategy to Implement Professional Standards and a Workplace Training and Assessment Program for the Practice of Radiopharmaceutical Science in Australia. Top


Jennifer Guille*1, A Katsifis2

1Department of Nuclear Medicine and PET, Prince of Wales Hospital, Randwick, 2Department of Nuclear Medicine and PET, Royal Prince Alfred Hospital, Camperdown, Sydney, Australia

Background/Aims: A strategy to implement professional standards and a workplace training and assessment program for the practice of Radiopharmaceutical Science in Australia. Methods: For new graduates entering the radiopharmaceutical sciences, our strategy included the implementation of a postgraduate degree in basic radiopharmaceutical science, and a mentored, workplace training and assessment program resulting in professional certification. For the existing workforce, a process of professional certification has been established to ensure standards are understood and practiced. Results: A Clinical Training Guide encompassing essential knowledge and skills, arranged into competencies was developed by a panel of expert RPSS to ensure safe clinical practice in radiopharmaceutical science. Experienced RPS seeking certification, submit an application, with supporting evidence against these competencies, which is assessed by a panel of peers. Applicants demonstrating proficiency in standards of practice, were eligible for admission to the Register of RPS Specialists, administered by ACPSEM. In parallel, and in collaboration with the Australian Council for Education Research, the RPS Training, Education and Assessment Program (TEAP), was developed for trainees, incorporating contemporary theory and practice in education, training and assessment. TEAP design incorporates practical assessment as a driver of the learning process using progressive assessment. Each competency area has clear outcomes against which the submitted assessment task is evaluated, to ensure consistency, quality and validity of assessment. Conclusion: Strategies were developed to support the education and training requirements for a growing radiopharmaceutical workforce through progressive learning, training and practical assessment directly in the workplace.


   P181: The Simultaneous Measurement Method for the Molar Radioactivity, Radiochemical Purity, and Chemical Impurity of the 11C-choline injection Top


H Hashimoto1, Kazunori Kawamura1, K Furutsuka1,2, K Kariya1, N Nengaki1,2, M R Zhang1

1Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, 2SHI Accelerator Service, Tokyo, Japan

Background/Aims: 11C-choline has been extensively used clinically for imaging prostate cancer.[1] 11C-Choline is prepared by 11C-methylation of [11C]methyl iodide and 2-dimethylaminoethanol (DMAE). It is important to determine accurately the quantity of DMAE in the final product. The most common method for the determination of the substance of 11C-choline or DMAE was by co-injection of carrier-choline or DMAE method, and by two separate analysis LC system and gas chromatography.[2],[3],[4] The quality control procedures for 11C-labeled radiopharmaceuticals is acquired rapid assessment due to short half-life radionuclide (about 20 minutes). Thus, we developed a rapid and simultaneous measurement method for the molar radioactivity, radiochemical purity, and chemical impurity of the 11C-choline injection using the radio-HPLC coupled with the corona-charged aerosol detector (CAD). Methods: The molar radioactivity, radiochemical purity, and chemical impurity (DMAE) of the 11C-choline injection was measured using the radio-HPLC-CAD with the post-column method. We also validated the measurement of choline and DMAE using this HPLC, and evaluated these parameters of the accuracy, precision, specificity, quantitation of limit, and linearity. Results: The molar radioactivity, radiochemical purity, and chemical impurity were over 130 GBq/μmol (over 0.1 μg/mL) at end of synthesis (EOS), over 95% at EOS, and less than 0.5 μg/mL of DMAE, respectively. In the validation, the percentages of recovery of choline and DMAE were within 100±5%. The RSD of choline and DMAE were less than 10%. Resolution between obtained choline and DMAE peak was over 1.5. The limit of quantitation of choline and DMAE was 0.1 and 0.5 μg/mL, respectively. The coefficient of correlation (R2) of choline (0.1-50 μg/mL) and DMAE (0.5-50 μg/mL) found to be >0.9999. Conclusion: We developed and optimized the simultaneous measurement method for the molar radioactivity, radiochemical purity, and chemical impurity of the 11C-choline injection using the radio-HPLC-CAD with the post-column method.

References

  1. Giovacchini G, Giovannini E, Leoncini R, Riondato M, Ciarmiello A. PET and PET/CT with radiolabeled choline in prostate cancer: A critical reappraisal of 20 years of clinical studies. Eur J Nucl Med Mol Imaging 2017;44:1751-76.
  2. Mishani E, et al. Nucl Med Biol 2002;39:359-62.
  3. Shao X, et al. Appl Radiat Isot 2011;69:403-9.
  4. Biasiotto G, Bertagna F, Biasiotto U, Rodella C, Bosio G, Caimi L, et al. Description of high purity and high specific activity of [11C]Choline synthesis using TRACERlab FXc module, and detailed report of quality controls. Med Chem 2012;8:1182-9.



   P182: Preparation of 68Ga-Mg-Ca-phytate Colloid and Its Evaluation as a Liver Imaging Agent Top


William Hsieh*1, C Tsopelas1

1Department Nuclear Medicine & Bone Densitometry, Royal Adelaide Hospital, Adelaide, Australia

Background/Aims: 99mTc-(Ca)-phytate colloid continues to persist as the routine radiopharmaceutical for hepatosctintigraphy because of its particle size. The commercially available pharmaceutical phytic acid is reconstituted with 99mTc-pertechnetate to yield 99mTc-phytate, and in the presence of calcium ions it forms 99mTc-(Ca)-phytate colloid. More recently the radiopharmaceutical chemistry of Gallium-68 has been investigated to prepare potential PET scanning agents. The aim of this study was to prepare a 68Ga-mixed metal-phytate colloid with suitability for liver imaging. Methods: The radiocolloid was prepared by mixing an aqueous solution of phytic acid, 68Ga3+ ions, a dispersant, Mg2+ and Ca2+ ions, and then heating the contents at 100°C for 5 minutes. After cooling the vial to 5°C, the solution was basified to pH 5 and stored in the cold. The best formulation was characterised for radiochemical purity, radioactive particle size, and the biodistribution in normal rats. Ethics approval was obtained in advance of the study. Results: The resulting product contained 92±3% of 68Ga-colloidal particles and 8±3% of soluble 68Ga-Mg-Ca-phytate. Radioactive particle size distribution of the formulation was 6±4% <20 nm, 90±6% 20 to 200 nm, and 4% were >200 nm in diameter. The biodistribution of the 68Ga-colloid in rats resulted in 93% uptake by the liver plus spleen, 1% lungs, 1% total blood, and 6% in the carcass after 20 minutes. This optimal formulation remained stable at 5°C for 1½ hours in vitro, and it resulted in the same biodistribution as the formulation prepared at t = 0 hours. Conclusion: 68Ga-Mg-Ca-phytate colloid was successfully synthesised and characterised by different methods. The preclinical data so far indicate that is has excellent potential as a liver imaging agent.


   P183: GMP-Compliant Automated Production and Whole-body microPET Imaging of xCT-Tracer [18F]FSPG in Mice Top


Ya-Yao Huang*1, M F Cheng1,2, Y N Cheng1, C H Wu3, L W Hsin3,4, H Hagu5, Y W Tien6,7, K Y Tzen1,3, R F Yen1,3, C Y Shiue1,3,8

1Department of Nuclear Medicine, PET Center, National Taiwan University Hospital, 2Institute of Occupational Medicine and Industrial Hygiene, 3Molecular Imaging Center, 4School of Pharmacy, College of Medicine, National Taiwan University, 5PharmaSynth AS, Tartu, Estonia, 6Department of Surgery, National Taiwan University Hospital, 7Department of Surgery, College of Medicine, National Taiwan University, 8Department of Nuclear Medicine, PET Center, Tri-Service General Hospital, Taipei, Taiwan

Background/Aims: [18F]FSPG has been proved to be a promising tracer for imaging xC-transporter (xCT-) and clinically applied in various oncological studies.[1],[2],[3] In order to fulfil the clinical need of several studies in Taiwan, we have modified TracerLab FxFDG module to automatically synthesize [18F]FSPG with GMP compliance and studied its whole-body biodistribution in mice using microPET before human studies are undertaken. Methods: Based on reported radiosynthesis method,[3] the [18F]FSPG was automatically produced with a modified TracerLab FxFDG module and its complete QC tests were carried out for qulaity confirmation. For animal study, male ICR mice (30-40 g) were injected with a bolus of about 300 μCi of [18F]FSPG. By using small-animal Argus PET/CT scanner, dynamic sinograms were produced and VOIs were defined on co-registrated PET/CT images. Results: The radiochemical yield of [18F]FSPG synthesized by this method was ?8% (EOS, n>3) in a synthesis time of ?80 min from EOB. Both the chemical and radiochemical purity of [18F]FSPG were >95% with a specific activity of 377±162 mCi/µmol. Whole-body microPET imaging in normal mice showed that the radioactivity in kidneys, pancreas and bladder increased with time suggesting [18F]FSPG was eliminated via the renal systems. Conclusion: With the modified FxFDG module, [18F]FSPG could be reliably produced for preclinical and clinical studies. After preclinical imaging validation studies, clinical study of [18F]FSPH for cancer patients is ongoing now at NTUH.

References

  1. Baek S, Choi CM, Ahn SH, Lee JW, Gong G, Ryu JS, et al. Exploratory clinical trial of (4S)-4-(3-[18F]fluoropropyl)-L-glutamate for imaging xC- transporter using positron emission tomography in patients with non-small cell lung or breast cancer. Clin Cancer Res 2012;18:5427-37.
  2. Baek S, Mueller A, Lim YS, Lee HC, Lee YJ, Gong G, et al. (4S)-4-(3-18F-fluoropropyl)-L-glutamate for imaging of xC transporter activity in hepatocellular carcinoma using PET: Preclinical and exploratory clinical studies. J Nucl Med 2013;54:117-23.
  3. Koglin N, Mueller A, Berndt M, Schmitt-Willich H, Toschi L, Stephens AW, et al. Specific PET imaging of xC – Transporter activity using a 18F-labeled glutamate derivative reveals a dominant pathway in tumor metabolism. Clin Cancer Res 2011;17:6000-11.



   P184: Centralised Manufacture of 64Cu-SARTATE for Clinical Trials Top


Charmaine Jeffery*1,2, K Kuan3, N Siebert3, J Asp3, C Lang3, C Biggin1, D Smyth3, P Takhar3, M Harris1

1Clarity Pharmaceuticals, Sydney, 2Centre for Advanced Imaging, University of Queensland, Brisbane, 3Molecular Imaging and Therapy Research Unit, South Australian Health and Medical Research Institute, Adelaide, Australia

Background/Aims: 64Cu-SARTATE is a promising radiopharmaceutical for PET imaging of neuroendocrine tumours, paediatric neuroblastoma, and meningioma. 64Cu-SARTATE is an analogue of octreotate, incorporating a chelator (MeCOSar) that has superior radiolabelling characteristics specifically for copper radioisotopes. Copper-64, with its longer half-life (12.7hr) relative to other PET radioisotopes, offers the ability to centrally manufacture radiopharmaceuticals and distribute drug product to multiple locations. The advantages of centralised manufacture are that manufacturing resources are controlled within one facility, leading to efficiencies in the costs of production and staff resources; and the clinical sites receive a ready-to-use drug product. This project aimed to establish centralised manufacture of 64Cu-SARTATE at MITRU-SAHMRI, for distribution within 24 hours of manufacture to interstate hospitals undertaking clinical trials on behalf of Clarity Pharmaceuticals. Methods: Clarity Pharmaceuticals developed the manufacturing and QC processes required for 64Cu-SARTATE. MITRU are an ideal site for centralised manufacture of 64Cu-SARTATE, having a TGA licenced facility that can supply radiopharmaceuticals Australia-wide; and who have a well-developed Cu-64 production program. Technology transfer and site validation (including full manufacture and full QC) were undertaken to establish that 64Cu-SARTATE could be produced to meet Clarity Pharmaceuticals final drug product specifications. Final drug product was supplied to multiple interstate hospitals. Results: Process validation (n=3) was successfully completed, with all drug product specifications met. The model for centralised manufacture and distribution to clinical sites for injection within 24 hours has been proven to be feasible. Conclusion: Centralised manufacture of 64Cu-SARTATE was established and validated at MITRU-SAHMRI, for supply of GMP-like, ready-to-use drug product to multiple sites. This centralised manufacture model will also be utilised to supply 64Cu-SARTATE within the United States. The model has advantages for clinical sites that wish to perform PET imaging with octreotate analogues, but who do not have access to a dedicated radiopharmaceutical production facility.

Disclosure of Interest: C Jeffery Conflict with: Clarity Pharmaceuticals; C Biggin Conflict with: Clarity Pharmaceuticals; M Harris Conflict with: Clarity Pharmaceuticals.


   P185: Study on the Synthesis and the Biological Activity of 131I-RGDyC-PAMAM Top


Jinhe Zhang*1, H Xu2, J Yin1

1Liuhuaqiao Hospital, 2The First Affiliated Hospital, Jinan University, Guangzhou, China

Background/Aims: Synthesis of 131I-RGDyC-PAMAM and research if it can target to tumour cells and the effect of radiation inhibition in vitro and in vivo of the animal. Methods: The nano probe 131I-RGDyC-PAMAM was prepared. Observed the inhibitory effect of 131I-RGDyC-PAMAM on cells. Injecting 131I-RGDyC-PAMAM into a tumour-burdened mouse and imaging by SPECT at different timing after injection of drugs; After injection, analysis the distribution of different organs of radioactive drugs at different timing. Analyse the inhibit tumour growth in vivo and do weight analysis. Results: The nano probe 131I-RGDyC-PAMAM was prepared succesfully. 131I-labelled RGDyC-PAMAM rate at about 86%, 131I-RGDyC-PAMAM have good stability in different solution. Cell uptake and elution experiment: compare to free 131 I, 131I-RGDyC-PAMAM nano probe can combine with A549 cell specifically, and its stability is good. The cell inhibition and apoptosis in vitro experimental results show that the 131I-RGDyC-PAMAM has certain inhibitory effect on the A549 cells. Under the condition of high dose, 131I-RGDyC-PAMAM has certain effect on promoting apoptosis and destruction of A549. The zoological experimental shows: 131I-RGDyC-PAMAM in tumour local has a longer retention time. The biological study in vivo distribution shows in A549 tumour nude mice, the perturbation values of tumour is significantly higher than the normal organs. The treatment experiment shows, 131I-RGDyC-PAMAM treatment group was obviously inhibited tumour compared with the control group and with significant difference (p<0.05). Conclusion: Can successfully get 131I-RGDyC-PAMAM. Subsequent cell in vitro experimental results showed that 131I-RGDyC-PAMAM on A549 cell has certain inhibitory effect of growth, promoting apoptosis destruction. 131I-RGDyC-PAMAM can be better gathered in a tumour-burdened mice tumour site. In subsequent tumour-burdened anti-tumour effect in mice showed 131I-RGDyC-PAMAM inhibit the growth of A549 tumour.


   P186: Peptide Targeted Liposomes for the Treatment of Inflammatory Arthritis Top


Anne Kankean*1,2, D Boddeti1,2, V Kumar1,2,3

1Westmead Hospital, 2The Children’s Hospital at Westmead, Westmead, 3Sydney Medical School, University of Sydney, Sydney, Australia

Background/Aims: Delivering drugs to inflamed joints remains a major therapeutic challenge which may be overcome by incorporating synovium targeting peptides in liposomes. The aims of this study were to determine the therapeutic efficacy of long circulating polyethylene glycol (PEG) liposomes coupled to targeting peptides (RGD or HAP-1) containing prednisolone or a therapeutic peptide. Liposomes were labelled with 99mTC to determine the bio-distribution and uptake in inflamed joints. Methods: Glutathione (GSH) loaded liposomes were prepared and labelled with 99mTc-HMPAO-GSH for biodistribution studies. Targeting peptides (HAP-1 or RGD) were conjugated to the surface of liposomes to localise to the synovia. Prednisolone or peptide encapsulated liposomes were synthesised, sized and used to treat adjuvant induced arthritic joints in rats. Arthritis was induced with an injection of heat killed Mycobacterium tuberculosis suspended in 100μl of squalene, at the base of the tail of the individual rat. Rats were deemed to be arthritic when there was redness or swelling in the same joint(s), over two consecutive days. One day after the first sign of arthritis was noted, the therapeutic liposomes were administered by IVI on two consecutive days each injection containing 0.5 mg peptide or prednisolone/0.5 mL/250g rat/day. The parameters for measurements were determined by: affected joint numbers, overall joint swelling, weight loss and histological assessment of joints. Results: Imaging studies showed that 99mTc-HMPAO liposomes accumulate in the joints of normal and arthritic rats. With this proof of evidence, therapeutic studies were commenced in a rat model with liposomes containing drugs. Prednisolone containing liposomes slowed the progression of arthritis, however arthritis flared once treatment ceased. Rats treated with HAP-1 targeted liposomes loaded with prednisolone slowed down the progression of arthritis while on treatment and led to the alleviation of arthritis over a 2 week period. By contrast rats administered therapeutic peptide liposomes conjugated with HAP-1 were fully treated of their arthritis and this was sustained until the experiment finished 2 weeks after the last treatment. Conclusion: 99mTc-labelled liposomes can be engineered to target and carry a variety of drugs to inflamed synovium.


   P187: Evaluation of 11C-labelled S-methyl-(S)-α-methylcystein as a Novel Positron Emission Tomography Tracer for Tumour Imaging Top


K Kato*1, H Tateishi2, H Sudo2, A Sugyo2, A B Tsuji2, T Higashi2

1National Center of Nelurology and Psychiatry, Kodaira, 2National Institute of Radiological Sciences, QST, Chiba, Japan

Background/Aims: Recently, Tang et al reported the syntheses and PET studies using tumour model mice of 11C-labeled S-methyl-L-cysteine (LMCY) and its D-isomer (DMCY).[1],[2] They concluded DMCY has more potential for tumour imaging than the L-isomer. Unnatural amino acids often have different transporter selectivity and metabolic pathways from natural ones. These properties result in unique characters as PET tracers therefore their radiolabelling is an attractive target for tracer development. In this context, we decided 11C-labelling of α-methyl analog of S-methyl-L-cysteine as a novel PET tracer because methyl group incorporation yields high metabolic stability for deamination and causes varied transporter recognition.[3] Here we describe whole body distribution of 11C-labeled S-methyl-(S)-α-methylcystein (SMMCY) and comparison with LMCY in tumour-bearing mice. Methods: SMMCY and LMCY were synthesized by the methylation using [11C]methyl iodide and Hunig base at room temperature for 3 min. Tumour-bearing mice were prepared by subcutaneously inoculating small cell lung cancer SY cells. These mice were intravenously injected with each tracer and biodistribution at 1, 20, and 60 min was evaluated and 60-min PET imaging was conducted. Tracer uptake was semi-quantified as % injected dose (ID)/g tissue. All animal experiments described here have approval under local and ethical rules. Results: The 11C-labelling of (S)-α-methylcystein and L-cysteine gave SMMCY and LMCY respectively without significant amount of 11C-labeled byproducts. The biodistribution studies showed that distribution of SMMCY and LMCY was different and high accumulation was observed in the pancreas (66%ID/g) for SMMCY and the liver (21%ID/g) and pancreas (27%ID/g) for LMCY at 20 min. Tumour uptakes of SMMCY and LMCY increased time-dependently until 60 min and SMMCY uptake in tumour (11%ID/g) was higher than LMCY (7%ID/g) at 60 min. These results were confirmed by dynamic PET studies. Conclusion: SMMCY is a promising PET tracer for tumour imaging.

References

  1. Deng H, Tang X, Wang H, Tang G, Wen F, Shi X, et al. S-11C-methyl-L-cysteine: A new amino acid PET tracer for cancer imaging. J Nucl Med 2011;52:287-93.
  2. Huang T, Tang G, Wang H, Nie D, Tang X, Liang X, et al. Synthesis and preliminary biological evaluation of S-11C-methyl-D-cysteine as a new amino acid PET tracer for cancer imaging. Amino Acids 2015;47:719-27.
  3. Tsuji AB, Kato K, Sugyo A, Okada M, Sudo H, Yoshida C, et al. Comparison of 2-amino-[3-¹¹C]isobutyric acid and 2-deoxy-2-[18F]fluoro-D-glucose in nude mice with xenografted tumors and acute inflammation. Nucl Med Commun 2012;33:1058-64.



   P188: New Theranostic Probe for Molecular Imaging and Radionuclide Therapy of Medullary Thyroid Cancer and other Cholecystokinin-2 Receptor Expressing Tumours Top


M Klingler1, P Garnuszek2, R Mikołajczak2, A Hubalewska-Dydejczyk3, P Laverman4, Elisabeth von Guggenberg*1

1Department of Nuclear Medicine, Medical University of Innsbruck, Innsbruck, Austria, 2Radioisotope Centre POLATOM, National Centre for Nuclear Research, Otwock, 3Department of Endocrinology, Jagiellonian University, Medical College, Krakow, Poland, 4Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands

Background/Aims: Thyroidectomy is the primary treatment of medullary thyroid carcinoma (MTC), whereas the use of vandetanib and cabozantinib is restricted to patients with advanced or progressive MTC. An urgent need of alternative imaging and treatment options exists for patients with persistent disease or recurrence. We present a new theranostic probe targeting the cholecystokinin-2 receptor (CCK2R) overexpressed in >90% of MTC allowing for high sensitivity imaging and radionuclide therapy. Methods: Different minigastrin derivatives (MGS1-5) were synthesised and conjugated with the macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Radiolabelling was optimized for 111In, 177Lu and 68Ga in order to achieve quantitative yield and radiochemical purity >91%. A thorough preclinical evaluation allowed the selection of one most promising peptide analogue. All animal studies were approved by the National authorities. A kit formulation was developed to allow a standardized preparation of the radiopharmaceutical in the clinical setting. Results: The peptide derivative DOTA-MGS5 showed the highest receptor affinity as determined using A431 cells transfected with human CCK2R and 28-68% cell uptake after 2 hour incubation when radiolabelled with different radiometals. HPLC analysis of the blood of BALB/c mice injected with 111In-DOTA-MGS5 revealed that >69% of the radiopeptide remained intact up to 1 hour post injection (p. i.). An impressively high tumour uptake was found in xenografted BALC/c nude mice (111In: 23.5±1.2% 4 h p. i.; 177Lu: 24.5±3.1% 4 h p. i.; 68Ga: 23.2±4.7% 1 h p. i.), as well as high tumour-to-kidney ratios (111In: 6.1; 177Lu: 6.5; 68Ga: 4.1) and elevated target-to-background ratios in Nano-SPECT/CT. Conclusion: A new highly specific peptide analogue targeting CCK2R was developed for peptide receptor imaging and therapy. A first proof of concept of high sensitivity PET imaging in patients with advanced MTC is envisaged to pursue the clinical translation. This new theranostic concept promises to improve the patient follow-up and prognosis of patients with CCK2R expressing tumours.


   P189: Development of H2-ATSM Labelling with Copper-64 on Modular-Lab PharmTracer Top


Kevin Kuan*1, J Seemann2, P Schweighöfer2, W Tieu1, P Takhar1

1Medical Imaging and Therapy Research Unit, South Australian Health and Medical Research Institute, Adelaide, 2Eckert and Ziegler Eurotope GmbH, Berlin, Germany

Background/Aims: The Molecular Imaging and Therapy Research Unit (MITRU) at SAHMRI has successfully completed the development of copper-64 production process for the manufacture of [64Cu]Cu-SARTATE, a novel radiopharmaceutical agent of Clarity Pharmaceuticals Ltd. as part of a phase 1 clinical trial. Recently, there has been a renewed interest in the development of radiolabelled copper with diacetyl-bis (N4-methylthiosemicarbazone) (H2-ATSM) for hypoxia imaging.[64Cu]Cu-ATSM has a relatively low molecular weight, is highly lipophilic, and therefore has high membrane permeability – all of which are desirable properties for rapid diffusion into cells. With a half-life of 12.7 hours, copper-64 is an ideal radioisotope for hypoxia imaging. Another advantage of such long lived radioisotope is the ability for the radiopharmaceutical agent to be manufactured in-house and delivered to multiple scanning facilities. The aim of this project is to expand on the synthetic utility of [64Cu]CuCl2, by labelling onto H2-ATSM on the Modular-Lab PharmTracer. Methods: The manufacture of [64Cu]CuCl2 begins with the plating of enriched nickel-64 onto an Pt beaker in an aluminium shuttle. The target was irradiated, the crude product was taken up in 6 M HCl solution, and then purified using an ion exchange resin (BioRad AG 1-X8). The purified product, [64Cu]CuCl2 was then reconstitute to the desired HCl concentration (0.05 M) and used for the manufacture of [64Cu]Cu-ATSM using Eckert & Ziegler’s Modular-Lab PharmTracer synthesiser. Results: Initial results from the radiolabelling of [64Cu]CuCl2 onto H2-ATSM showed promising results, with a radiolabelling yield of 73% (n=6). RCP yields of >99% across all samples were achieved with starting activity ranging between 110MBq to 1490MBq. Conclusion: The radiosynthesis of [64Cu]Cu-ATSM has been successfully demonstrated on the Modular-Lab PharmTracer. Future work will focus on the optimisation of the radiolabelling yield and radiosynthesis at higher starting activities.


   P190: 68Ga and 18F-PSMA – the Radiopharmaceutical Laboratory Perspective and Experience Top


Melissa J Latter*1,2, S Tapper1, P Coogan1, S Millar1, G Maguire1, D Scott1,2, C Tai1, M Bartlett1, S Lummis1, A Ergenekon1, G Brown1, D A Pattison3, Paul Thomas2,3,4

1Q-TRaCE, Nuclear Medicine and Specialised PET Services QLD, Royal Brisbane and Women’s Hospital, 2Faculty of Medicine, University of Queensland, 3Nuclear Medicine and Specialised PET Services QLD, Royal Brisbane and Women’s Hospital, Brisbane, 4Herston Imaging Research Facility, Herston, Australia

Background/Aims: The introduction of radiopharmaceuticals that contain urea based pharmacophores targeting PSMA has had widespread impact on prostate cancer research. We present the site validation, data trends and efficiencies of production of 68GaPSMA-11 and 18FPSMA-1007, for use in clinical research. Methods: 68GaPSMA-11 is manufactured (Scintomics GRP Synthesiser) using kits (ABX SC-01), PSMA-11 (GMP, ABX 9919.0000.010) and 68Ge/68Ga generators (iThemba 50 mCi, IGG100 50 mCi and/or 65 mCi). 18F-PSMA-1007 is manufactured (GE Tracerlab MX) using kits (ABX PEPS-0095-R/H including precursor) with F-18 generated on-site. Quality control testing of each batch aligns with monograph guidelines for related radiopharmaceuticals. Each batch is reviewed by the Quality Assurance Manager prior to release for use in clinical research programs. Results: 68Ga-PSMA-11 has been produced at Q-TRaCE for more than 3.5 years and a summary of data trending (>800 batches) will be presented. Data analysis supports a reliable and robust process that yields high-quality, sterile injectables suitable for use in human trials. Process optimisation enabled the implementation of multiple generator inputs to increase the product activity, which translates to greater patient throughput per batch and/or improved transport logistics. Additional analytical testing (quantitative) was also adopted for the reaction buffer (HEPES), which is classified as an impurity if detected in the product formulation. This resulted in a Vmax restriction applied to each batch to comply with monograph guidelines and ensure patient safety. The more recent implementation of 18F-PSMA-1007 offered efficiencies through use of a longer lived radioisotope and higher starting activities. Product yields are typically >20% and further work to increase product activity is planned. Conclusion: Validation work undertaken at Q-TRaCE has resulted in the availability of 68Ga-PSMA-HBED-CC and 18F-PSMA-1007 for use in clinical research programs focused on improved diagnosis and management for prostate cancer patients. In particular, the availability of a cyclotron based PSMA radiopharmaceutical increases access to PET imaging, and potentially widens the patient recruitment catchment in research trials due to the logistics of supplying a longer lived radiopharmaceutical in a statewide network.


   P193: Synthesis and Evaluation of a N-18F-fluorodeoxyglycosyl Amino Acid as One Novel Dual-transported Agent for Tumour Metabolism PET Imaging Top


J Ma1, H Wang1,2, C Li1, S Li1,2, Zhifang Wu*1,2

1Department of Nuclear Medicine, First Hospital of Shanxi Medical University, 2Molecular Imaging Precision Medical Collaborative Innovation Center, Taiyuan, China

Background/Aims: As the limitations of 2-deoxy-2-18F-fluoro-D-glucose (18F-FDG) imaging, e. g., high uptake of FDG in brain and in non-malignant, inflammatory cellular elements, amino acid metabolism positron emission tomography (PET) imaging is one important supplement for the clinical FDG application. In the present study, a novel N-18F-fluorodeoxyglycosyl amino acid (18F-FDGly-NHPhe), was synthesised. We also evaluated its characteristics as a potential tumour metabolism imaging agent. Methods: The (18F-FDGly-NHPhe) was prepared from directly condensation of 18F-FDG with L-4-aminophenylalanine in acidic condition, and purified with semi-preparative-high performance liquid chromatography (HPLC). The in vitro stability wds conducted in PBS (pH 6.5-9.18) at room temperature (RT) and in fetal bovine serum at 37 °C. The preliminary cellular uptake studies were tested in Hep-2 cell with comparison to that of 18F-FDG. To give an indication of the transport pathways, a competitive inhibition experiments was performed. The bio-distribution studies, PET imaging and metabolism studies were performed and compared with 18F-FDG on ICR mice. Results: The radiochemical yield of 18F-FDGly-NHPhe was 20.20±3.21% (n=10), with high stability in PBS at pH 6.5-9.18 and fetal bovine serum. The preliminary cellular study showed that the tracer could be transported via both glucose and amino acid transporters. The competitive inhibition experiment showed that 18F-FDGly-NH-Phe was primarily transported by Na+-dependent various systems including L, A, ASC systems, and not incorporated into proteins. The bio-distribution in normal ICR mice showed faster blood radioactivity clearance, lower brain and heart uptake rates than 18F-FDG. PET imaging of 18F-FDGly-NHPhe with excellent tumour visualization and high tumour to background ratios was achieved, while no accumulation of inflammatory lesions compared to 18F-FDG. Metabolism studies indicated the high in vivo stability in plasma and urine and the acid sensitive decomposition in tumour acid microenvironment. Conclusion: All the above results indicated that 18F-FDGly-NHPhe as a novel tumour-specific PET tracer mediated with two transporter systems shows the capability of differentiating tumour from inflammation, and has the potential of further routine clinical applications.


   P194: Australian Two Centre Experience in First 103 Patients Using 68Ga-based kit for the production of 68Ga-PSMA-11 Top


D Meyrick*1, J Crouch2, M Trifunovic3, A Henderson2, N Lenzo1,4

1Department of Nuclear Oncology, Theranostics Australia, East Fremantle, 3Department of Nuclear Medicine, Macquarie Medical Imaging, Sydney, 2Department of Nuclear Medicine, Perth Radiological Clinic, 4Department of Medicine and Pharmacology, University of Western Australia, Perth, Australia

Background/Aims: 68Ga-PSMA has been rapidly accepted as a major advance in imaging prostate cancer patients. The classic radiolabelling method for 68Ga-PSMA-11 requires a long preparation time, high level of expertise and relatively expensive infrastructure. This limits the clinical and commercial utility. A simple GMP kit based formulation has been developed by ANMI (Belgium). Stability studies have shown this kit to be stable for 18 months following manufacture. We present our experience in 103 patients at 2 separate Theranostic Australia sites with this novel kit based PSMA imaging solution. Methods: IRE 68Ge/68Ga generator eluted; mixed with buffer in PSMA-11 vial. Mixed at room temp. 5 min. Radiochemical purity (RCP) of 68Ga-PSMA-11 determined by ra­dio-TLC (stationary phase: iTLC-SG paper; stationary phase: NH4OAc 1M/MeOH 1:1 (v/v); Rf of free and colloidal 68Ga: 0-0.2; Rf of 68Ga-PSMA-11 = 0.8-1). Following QC, if RCP determined to be >95% agent administered into patients. Imaging performed on GE PET camera 30-45 minutes after administration. Delayed imaging of up to 120 minutes performed in selected patients. Dose between 120-180 MBq. Image quality assessed by 2 experienced imaging specialists with local experience in reporting over 500 68Ga-PSMA scans (HBED, I&T). Results: From August to November 2017, 43 kits and 103 patient doses prepared. Average RCP of 98%. RCP < 90% reported on 4 occasions (due to incomplete transfer of buffer to reacting vial). Otherwise, incident-free, rapid, with minimal radiation exposure. Total production and QC time approx. 20 min, yielding 850-900 MBq product from new IRE 68Ge/68Ga generator. Patients experienced no adverse effects from tracer administration. All studies of diagnostic quality with typical PSMA biodistribution. Image quality determined to be at least equivalent to other 68Ga-PSMA agents. Conclusion: Our experience with PSMA-11 GMP sterile cold kit production in 103 patients confirms an easy, rapid and cost-effective solution for prostate carcinoma imaging. It displays excellent imaging characteristics and safety data appears equivalent to current agents. Given the robustness, simplicity and high yield of the kit, the technology is readily accepted by a range of personnel. The minimal set up costs and high yields makes this a potential viable option in regional/outer metropolitan areas as well as in high volume practices.

Disclosure of Interest: N. Lenzo Conflict with: Australian Distributor.


   P195: Factors Impacting Synthesis Efficiency of Routine 2-Deoxy-2-[18F]fluoroglucose Production at Sir Charles Gairdner Hospital Over 2017 Top


Simon Osborne*1

1Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Australia

Background/Aims: Sir Charles Gairdner Hospital in Perth houses the only cyclotron in WA for PET radiopharmaceutical production. As the sole local provider of 18F-FDG (2-Deoxy-2-[18F]fluoroglucose) for patients in the state, our site is motivated to seek greater efficiencies to continue to service ever-growing clinical demands. An overview of 18F-FDG production data was undertaken to identify which combination of practices may yield greater efficiency. Methods: For this study synthesis efficiency was taken as the ratio of EOS (end of synthesis) to EOB (end of bombardment) expressed as a percentage. The EOB was the activity of 18F measured in the lines from the cyclotron to the synthesis unit whilst the EOS was the activity of 18F-FDG to arrive in the dispensing unit directly after synthesis was completed. These values were not adjusted for decay. RAPID houses an IBA Cyclone 18/18 cyclotron installed in 2003 (upgraded in 2012), with both sources being proton beams. Available targets were IBA Conical 12, Conical 8, XXL and LV. There were three varieties of synthesis units in use-a GE Fastlab2, an IBA Synthera and two GE MX units of differing ages. A retrospective analysis of data from all successful routine production runs was analysed to determine which of the following factors lead to a favourable synthesis efficiency: ion source, target, target fill volume, bombardment time, synthesis unit, synthesis kit (Citrate single vs Citrate Duo on GE Fastlab2) and time since last service. Further determinants are ongoing. Results: The greatest determinant upon synthesis efficiency was the synthesis unit used. The GE Fastlab2 gave consistently higher synthesis efficiencies than the other units available. When using the GE Fastlab2, the duo kits showed a minor improvement over the single use. None of the other factors showed any significant effect. Conclusion: Our group will favour Fastlab2 duo kits for production of 18F-FDG in 2018.


   P196: An Indium-111-Labelled Membrane-targeted Peptide for Cell Tracking with Radionuclide Imaging Top


J Pruller1, J E Blower2, P Charoenphun3, M Morais2, K Sunassee2, G E Mullen2, R A G Smith4, P J Blower2, Michelle T Ma*2

1Randall Division of Cell and Molecular Biophysics, King’s College, 2School of Biomedical Engineering and Imaging Sciences, King’s College London, 3Department of Diagnostic and Therapeutic Radiology, Mahidol University, Bangkok, Thailand, 4MRC Centre for Transplantation, King’s College London, London, UK

Background/Aims: Cell-based therapies are potentially transformative treatments. To support development of cell-based therapies, cell labelling agents that enable longitudinal in vivo tracking of administered cells are required. We report the first use of a radiolabelled peptide that adheres to extracellular membranes for cell tracking using SPECT imaging. Methods: A radiolabelled “cytotopic” peptide (CTP), 111In-DTPA-CTP, was prepared. This consists of (i) myristoyl groups for insertion into the phospholipid bilayer, (ii) positively-charged lysine residues for electrostatic association with negatively-charged phospholipid groups and (iii) a diethylenetriamine pentaacetate derivative that coordinates gamma-emitting 111In3+. In vitro cell uptake, retention and viability was assessed in 5T33 murine myeloma cells, and compared with that of clinically-used 111In-(oxine)3. In vivo SPECT/CT imaging of (i) 111In-DTPA-CTP-labelled 5T33 cells, (ii) cell-free 111In-DTPA-CTP, and (iii) 111In-(oxine)3-labelled 5T33 cells was undertaken (with institutional ethics approval) in a mouse model for which the biodistribution of these cells is well characterised (initial lung localisation). Results: In vitro, 111In-DTPA-CTP binds to 5T33 murine myeloma cells, but 77% of radioactivity is released after 2 h incubation (compared to release of 24% of radioactivity in the case of 111In-(oxine)3-labelled cells). Cells labelled with 111In-DTPA-CTP demonstrate higher viability than cells labelled with 111In-(oxine)3. In vivo SPECT/CT imaging demonstrates that although initial lung migration of 111In-DTPA-CTP-labelled 5T33 cells is observed, 5T33 cells release 111In-DTPA-CTP, resulting in high liver 111In accumulation 2 h post-injection. This contrasts the behaviour of 111In-(oxine)3-labelled cells, which demonstrate high lung retention 2 hours post-injection. Conclusion: 111In-DTPA-CTP enables qualitative SPECT tracking of myeloma cells’ migration to lungs immediately after intravenous administration. Although 111In-DTPA-CTP dissociates from cell membranes rapidly and thus falls short of cell adhesion stability requirements for quantitative long-term cell tracking, this proof-of-principle study demonstrates the simplicity and feasibility of using synthetic cell membrane binding/penetrating peptides for radiolabelling cells.


   P197: Preparation of Aqueous Solution of 211At-sodium astatide (Na211At) in High Radiochemical Purity and its Biological Properties in Rats Top


Yoshifumi Shirakami*1, K Kaneda-Nakashima2, T Watabe1, Y Liu1, A Toyoshima2,3, E Shimosegawa4, A Shinohara5, J Hatazawa1

1Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, 4Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Suita, 2Core for Medicine and Science Collaborative Research and Education, Project Research Center for Fundamental Sciences, Graduate School of Science Osaka University, 5Department of Chemistry, Graduate School of Science Osaka University, Toyonaka, 3Advanced Science Research Center, Japan Atomic Energy Agency, Tokai Ibaraki, Japan

Background/Aims: 131I-sodium iodide (Na131I) is widely used for internal radiation therapy of patients with thyroid cancer. Na131I, however, has several limitations due to relative long range of β-particles resulting in a relapse eventually. 211At, an α particle emitter, is known as one of the promising nuclides for radiotherapy and behaves as a halogen similarly to iodine. While a crude product of Na211At dissolved in water often contains oxides of 211At. Aims of this study are to prepare Na211At aqueous solution in high radiochemical purity and to evaluate its biological properties in rats. Methods: 211At is produced by a 209Bi (α,2n)211At nuclear reaction and dissolved in water after dry distillation of 211At in a target material. To the 211At solution (5-20MBq/mL) ascorbic acid was added in a concentration of 1% under a weak basic condition (pH8-9), and the solution was stirred for 30min. The resulted solution was analysed by thin layer chromatography (G60; ACN/water/TFA=67/33/0.5). The solution was intraveously injected to rats (1MBq/rat). The rats were imaged by a SPECT camera at 30min, 3hr, 6hr and 24hr after the injection. The rats were sacrificed at the 24hr time point and organs (thyroids, lungs and others) were counted by a gamma counter. The protocol was approved by the Animal Care and Use Committee of the Osaka University Graduate School of Medicine. Results: The 211At aqueous solution treated with 1% ascorbic acid afforded Na211At in a high radiochemical purity (>95%), although the radiochemical purity of the crude solution was low. The planer images and the biodistribution study revealed that the 211At aqueous solution treated with 1% ascorbic acid provided 3-5 times larger uptake in thyroids than the crude solution did. Conclusion: Ascorbiic acid can be used for the preparation of Na211At aqueous solution in the high radiochemical purity.

Acknowledgements

This work was supported by JSPS KAKENHI Grant number T16K102770.


   P198: Towards the Development of Novel Fluorine-18 Agents as Alternatives to Ceretec for Neuroimaging Top


Damion Stimson*1, T Venkatachalam1, P Bernhardt2, G Pierens1, K Mardon1,3, D Reutens1, R Bhalla1

1Centre for Advanced Imaging, 2School of Chemistry and Molecular Biosciences,3National Imaging Facility, The University of Queensland, Brisbane, Australia

Background/Aims: 99mTc-HMPAO (Ceretec) is a SPECT imaging agent which is a small molecule technetium complex and is both neutral and lipophilic[1] (logP of 1.9) enabling blood brain barrier permeability. We are interested in the development of novel fluorine-18 labelled compounds that have comparable properties to Ceretec, since these may be useful as PET neuroimaging agents. Synthesis of metal-fluorine complexes are of particular interest since recent studies have demonstrated the formation of stable metal-18F bonds.[2],[3] The metal-18F complexes previously reported are hydrophilic and therefore the focus of this work is to develop lipophilic metal-fluoride moieties which can be incorporated into new radiopharmaceuticals for potential applications in neuroimaging. Methods: A series of substituted thiosemicarbazone gallium nitrate complexes have been synthesised.[4],[5] We have investigated the exchange of the nitrate with 19F-fluoride and have characterised these fluoride complexes with NMR and X-ray crystallography. Lipophilicity of these fluoride complexes was assessed by measuring the octanol/water partition coefficient. The thiosemicarbazone gallium nitrate complexes have been reacted with 18F-fluoride and imaging studies of 18F-diphenylthiosemicarbazone gallium fluoride in mice were performed using preclinical PET/CT. Results: We have synthesised Ga-18F complexes of thiosemicarbazones from the corresponding nitrate derivatives. The resultant complexes are lipophilic and the measured logP of 19F-diphenylthiosemicarbazone gallium fluoride is 1. PET imaging studies in mice showed rapid uptake of the 18F-diphenylthiosemicarbazone gallium fluoride complex in the brain with an injected dose per gram of around 2 to 3%. Conclusion: We have synthesised the first lipophilic metal-fluorine-18 complexes, and these thiosemicarbazone gallium fluoride complexes are neutral. Lipophilicities of these compounds are comparable to Ceretec and imaging studies have demonstrated uptake in the brain, highlighting the potential of using 18F-thiosemicarbazone gallium fluoride compounds as radiopharmaceuticals for neuroimaging with PET.

References

  1. Moretti JL, Caglar M, Weinmann P. Cerebral perfusion imaging tracers for SPECT: Which one to choose? J Nucl Med 1995;36:359-63.
  2. McBride WJ, Sharkey RM, Goldenberg DM. Radiofluorination using aluminum-fluoride (Al18F). EJNMMI Res 2013;3:36.
  3. Bhalla R, Darby C, Levason W, et al. Chem Sci 2014;5:381.
  4. Venkatachalam T, Pierens G, Bernhardt P, et al. Aust J Chem 2016;69:9.
  5. Venkatachalam T, Bernhardt P, Stimson D, et al. Aust J Chem 2017. Available from: https://www.doi.org/10.1071/CH17334. [Last accessed on 2018].



   P199: Production of High Specific Activity Electron Linear Accelerator Produced 67Cu for use in Radionuclide Therapy Top


Jon Stoner*1, T Gardner1, M Harris2, C Jeffery2, C Biggin2

1Idaho Accelerator Center, Idaho State University, Pocatello, US, 2Clarity Pharmaceutical Ltd., Sydney, Australia

Background/Aims: Cu-67 (t1/2 = 2.6 days) decays via beta/gamma emission to stable Zn-67. The energy of the beta emissions (Emax = 561.7kev) is highly suitable as a therapeutic radionuclide, while the gamma emission (185keV) introduces the option for quantitative SPECT imaging of patients treated with Cu-67. We developed an improved process for producing high quality Cu-67 using an electron linear accelerator (e-LINAC) instead of a high energy proton accelerator. The beta/gamma emitting radionuclide Cu-67 was created using the (g, p) reaction on isotopically enriched Zn-68 (nominally 40g, 98% enrichment). Methods: The high energy photons were produced by Bremsstrahlung conversion of electrons from a 45 MeV e-LINAC. A specially designed water cooled converter, end station and target were built and utilized for the transmutation. An additional system was designed and constructed for remote removal of the activated target. Following transmutation, the Cu-67 was separated from the isotopically enriched Zn-68 target using a two-step process: physical separation using low pressure evaporation/sublimation (<0.001 mbar, 600oC) and purification using anion exchange column chromatography (BIORAD TM AG 1X8, 200 mesh). The specific activity and radionuclidic purity of the final product was determined using an ICP-MS and an HPGe detector. Cu-67 produced from the process was used to radiolabel SARTATE (Clarity Pharmaceuticals) with radiochemical purity >95%, yield 75±10%. SARTATE utilizes the sarcophagine chelator, MECOSAR conjugated to octreotate, and has the potential to treat a range of diseases including neuroendocrine tumours, meningioma in adults and neuroblastoma in paediatrics. Results: Production yields are >50 microCi (1.85MBq) g-1.kW-1.hr-1 with a Cu-67 specific activity routinely >200 Ci (7.4TBq)/mg. Conclusion: High specific activity and high purity Cu-67 is being produced routinely, shipping to customers in USA and Australia on demand, and at lower cost than proton accelerator-produced isotope. Cu-67 has been used to successfully produce Cu-67 SARTATE for development for first-in-human clinical trials.

Disclosure of Interest: M Harris: Conflict with Clarity Pharmaceutical Ltd, C Jeffery: Conflict with Clarity Pharmaceutical Ltd, C Biggin: Conflict with Clarity Pharmaceutical Ltd.


   P200: Identifying Unknown Peaks in 18F-Fludeoxyglucose High-Performance Liquid Chromatography Chromatograms Top


Stephen Taylor*1, W Noonan1, S Naidoo1, S Som1, P Lin1

1Liverpool Hospital, Liverpool, Australia

Background/Aims: The Molecular Science Cyclotron Facility (MSCF) of Liverpool Hospital recently commenced in-house manufacture of 18F-Fluorodeoxyglucose (FDG). A component of the method validation was a study aimed at optimising the HPLC conditions used during the QC and identifying peaks in the ECD (electrochemical detector) chromatogram not associated with the product. Methods: FDG was produced from [18F]F-(GE PETtrace 880 cyclotron, 16.5 MeV protons, Huayi H218O) by automated synthesis (GE FASTlab-2). Formulated product was sterilised by filtration, sampled for QC, and dispensed into multidose vials for distribution. HPLC analysis of the chemical and radiochemical purity was conducted using a Shimadzu Prominance HPLC on a Carbopac PA 10 (Dionex, 150 x 3.0mm, 6mm) column running 50mM NaOH as the mobile phase at 0.5mL/min. Chemical and radiochemical detection was achieved by EC (Antec Leyden Decade Elite) and scintillation (1’ NaI, Flow-RAM LabLogic) detectors in series. Standards and other reference compounds were purchased from ABX, Sigma Aldrich and CarboSynth. Mannose triflate, citrate buffer, ethanol and acetonitrile were obtained from a used FASTlab cassette. All injections were 2 mL. Standards were 50 μg/mL, solvents 1000 μg/mL. Results: The results of the study revealed 50 mM NaOH gave a retention time of 11.7 min for FDG and a resolution of 2.6 for FDM/FDG. Glucose, 1,6-anhydroglucose and ethanol are identifiable in the FDG chromatogram. The glucose derivatives form by base-catalysed decomposition of unreacted mannose triflate and FTAG. Acetonitrile, kryptofix, water, citrate buffer, sodium triflate, sodium acetate, chlorodeoxyglucose, and isosaccharinic acid-1,4-lactone were injected and did not correspond to peaks in the FDG chromatogram. Conclusion: Using 50 mM NaOH as the mobile phase gave excellent FDG/FDM resolution and a run time of <25 minutes. Ethanol, glucose and 1,6-anhydroglucose were identified components of FDG. Other compounds in the FDG chromatogram remain unidentified; however, they form during the base-catalysed hydrolysis of labelled intermediate/unreacted mannose triflate.

References

  1. GE Healthcare: White Paper, FASTlab Regulatory Support Information FDG Citrate Cassette. DOC1049454; 2011.



   P201: Design, Synthesis and Investigation of 89Zr Chelators Top


William Tieu*1, P Fyfe2, A Abell2

1Molecular Imaging and Therapy Research Unit, South Australian Health and Medical Research Institute, 2School of Physical Sciences, University of Adelaide, Adelaide, Australia

Background/Aims: Zirconium-89 (89Zr) holds great promise as a radionuclide in novel radiotracers for immuno-positron emitting tomography (PET) imaging. This is due to the prolonged half-life of 89Zr (3.3 days), which allows sufficient time for a 89Zr-antibody agent to localise at target site of interest. However, there is a limited number of Zr (IV) chelators reported that could be ideally used for immuno-PET imaging. The only clinically proven 89Zr ligand is desferrioxamine B (DFOB). Despite successes with 89Zr-DFOB based PET radiopharmaceuticals, sub-optimal in vivo stability for clinical applications has been observed with skeletal uptake of liberated 89Zr. To this end, the aim of the project describes four chelators designed and synthesised to possess improve Zr4+ complex stability compared to DFOB. Each chelator retains the hydroxamate binding group as found in DFOB, however these chelators are structurally different to DFOB. Methods: The library consist of linear and macrocyclic hexadentate ligands and linear and macrocyclic octadentate ligands. All chelators were synthesised from the same starting monomeric subunit (7-(2-amino-N-hydroxyacetamido)heptanoic acid). The synthesis of the monomeric subunit follow adapted synthetic procedures as previously reported.1 Each chelator were synthesised using the monomeric subunit and following standard HATU peptide coupling protocols. The stability of the chelators were assessed by incubating each 89Zr-chelator with EDTA, serum and 1 mM ferric chloride in PBS buffer. Results: The synthesis of linear hexadentate chelator was achieved in 5% yield over 8 steps. The synthesis of linear octadentate chelator was achieved in 11% yield over 9 steps. Both chelators were confirmed by HPLC, MS and NMR. Preliminary results by radio-TLC have indicated both linear hexadentate and octadentate chelator had comparable 89Zr-complex stability profile to the gold standard DFOB. Conclusion: We have confirmed the feasibility of the proposed synthetic strategy. Current efforts are focused on macrocyclisation of both linear chelators and completion of radiochemical characterisation.

References

  1. Tieu W, Lifa T, Katsifis A, Codd R. Octadentate zirconium(IV)-loaded macrocycles with varied stoichiometry assembled from hydroxamic acid monomers using metal-templated synthesis. Inorg Chem 2017;56:3719-28.



   P202: Preliminary Investigation of Reusing Sep-pak Alumina N Cartridges in Determining Radiochemical purity for 99mTc-Sestamibi Top


Amanda To*1, A Livori1, K Young1, G Chan1

1Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Australia

Background/Aims: Currently, there are several accepted methods of radiochemical purity testing for 99mTc-Sestamibi (Methoxyisobutyl Isonitrile). They commonly involve thin layer chromatography (TLC) using various stationary and mobile phases or solid phase extraction. The latter is more expensive, yet fast and convenient option utilised at Austin Health. Radiochemical purity is tested by separation of radioactive impurities such as free [99mTc]-TcO4-, [99mTc]-TcO2 from 99mTc-Sestamibi. Sep-Pak alumina N cartridges are the stationary phase, and 100% (v/v) ethanol is used as the mobile phase. There is no available information validating the reuse of these Sep-pak cartridges and its expiry for 99mTc-Sestamibi quality testing. Methods: A number of experiments were conducted to analyse the effectiveness of the cartridge in accurate separation of the impurities and 99mTechnetium-Sestamibi at different time points of the cartridges lifetime. Additionally, [99mTc]-TcO4-was added to some cartridges to evaluate its influence on radiochemical purity and whether 0.9% sodium chloride wash could help reduce any effects it may produce. TLC method of analysis involving Silica Gel strips and acetone were also used to compare against the cartridge method. Results: Cartridges up to three months old (which had at least once weekly use) compared to fresh cartridges showed a ~2% decrease in calculated radiochemical purity. Despite these differences, the results passed the radiochemical purity limit (>90% 99mTc-Sestamibi). Conclusion: Although there is a decrease in observed radiochemical purity, it does not pose harm to product quality and patient safety. There is the potential of yielding false negative results which are then retested with a new Sep-pak for confirmation. Recycling of cartridges is a viable method to reduce costs yet, still maintain integrity in product quality of 99mTc-Sestamibi.


   P203: New Multi-purpose Cyclotron “CYPRIS MP-30” for In-house Production of Theranostic Radioisotopes Top


Satoshi Ueno*1, T Oda1, M Taniguchi1, M Nagayasu1, F Guerra-Gomez1, J Kato1, H Ito1, T Ishizuka1, T Morita1, T Hiasa1

1Sumitomo Heavy Industries, Ltd., Ehime, Japan

Background/Aims: Recently the cyclotron production of alpha/beta emitting radionuclides has been attracting an increasing attention because of the progress in the field of Theranostics. In order to address this demand, Sumitomo Heavy Industries, Ltd. has developed a “Multi-Purpose” cyclotron named CYPRIS MP-30 that accelerates proton, deuteron and alpha particle beams for the production of a wide variety of radionuclides. In this work, some features of the CYPRIS MP-30 cyclotron system are presented. Methods: The cyclotron was designed for proton/deuteron beam formation with continuously variable energy by adjusting the stripper foil. The alpha particle beam is extracted through an electrostatic deflector at fixed energy. Irradiation energy of alpha particles is optimized using an energy degrader. The beam is transported to a vertical irradiation system that accommodates target materials in different forms and shapes. An automatic target transport system provides safe handling of the target after irradiation and a dissolution station located on the irradiation room allows the transfer of irradiated targets to the hot cell as a solution. Results: The system achieved the expected beam performance for proton (15-30 MeV; 100 uA), deuteron (8-15 MeV; 50 uA), and alpha particles (32 MeV; 30 uA). The production of several radionuclides, such as Zn-62, Tc-99m, Ge-68, Lu-177, and At-211 was also accomplished. Conclusion: A versatile cyclotron with a vertical irradiation system, target transport system, target dissolution system, as CYPRIS MP-30, was newly developed. The performance tests proved the system to be flexible and able to safely and efficiently produce alpha and beta emitting radionuclides. Development to increase the production yield of At-211 is currently undergoing. The CYPRIS MP-30 Cyclotron System will undoubtedly contribute to the development of new radionuclides for the targeted alpha therapy.


   P204: High Tumour Accumulation and Rapid Background Clearance for Radio-theranostics by Using Liposomes Encapsulating Radionuclide-ligand Complexes Top


Izumi Umeda*1, S Hamamichi1, H Fujii1

1National Cancer Center, Kashiwa, Japan

Background/Aims: Radiolabelled liposomes are promising for tumour imaging and radionuclide therapy because of their capacity to accumulate in the tumours. However, conventional liposomes also accumulate non-specifically in the normal tissues, especially in the liver, hindering their clinical application. In this study, we devised a new strategy, i. e., to quickly expel radionuclides from the liver after accumulation through rapid urinary excretion, by combination of liposomes and unique radionuclide-ligand complexes. Methods: Liposomes encapsulating 111In-ethylenedicysteine (EC), 111In-NTA or 111In-DTPA were prepared using active loading methods. They were intravenously injected to sarcoma-180-bearing or FaDu-bearing mice and time-dependent biodistribution were evaluated. This study was approved by the Institutional Animal Care and Use Committee and carried out according to its regulation. Results: Striking time-dependent contrasts were observed in the biodistribution of novel 111In-EC-liposomes and conventional 111In-NTA-or 111In-DTPA-liposomes. While 111In-EC-liposomes were once taken up by the liver, radioactivity was subsequently cleared from the liver while maintaining good retention in the tumour. Urinary excretion of 111In was rapid, and the original complex structure of 111In-EC was kept intact in the urine. By contrast, large amount of 111In remained in the liver for a long time with 111In-NTA-liposomes and 111In-DTPA-liposomes. Subsequent HPLC analysis demonstrated that liposomes mostly remained intact in the tumour whereas they were well degraded in the liver. Liposomes that were broken in the liver should released encapsulated radionuclide-ligand complexes. 111In-EC had a unique character, in which it was able to escape from the liver and consequently be excreted in urine. The original complex structure of 111In-EC was found to keep intact in the urine.111In-EC liposomes successfully achieved both sufficient tumour accumulation and rapid BG clearance. In vivo SPECT/CT imaging also depicted it well. Conclusion: 111In-EC-liposomes achieved sufficient tumour accumulation and rapid background clearance, consequently radionuclides accumulated almost only in the tumour. Our concept is applicable to diagnostic and therapeutic radionuclides, such as 111In, 90Y, and 177Lu. These findings should become driving force targeting radionuclide therapy and radio-theranostics.

Disclosure of Interest: H Fujii Conflict with: Nihon Medi-Physics Co. Ltd.


   P206: A Study of the Effect of 131I Therapy on Ovarian Function in Female Patients with Differentiated Thyroid Carcinoma of Childbearing Age Top


Xiaopeng Yu*1

1Fujian Provincial Hospital, Fuzhou, China

Background/Aims: To explore the effect of 131I therapy on ovarian function in female patients with differentiated thyroid carcinoma (DTC) of childbearing age. Methods: 71 women of childbearing age were chosed who were postoperative patients with thyroid cancer that were treated with 131I. Compared the changes of menstrual cycle before and after treatment. Compared the differences of FSH, LH, E2, AMH with normal level after therapy. Results: There were 3 patients had menstrual irregularities before therapy, and 34 women after therapy. The average age of patients who had menstrual irregularities were significantly higher than that had no menstrual irregularities (37.41±5.389 vs. 34.14±6.417 years, p=0.023). There was no significantly difference in the dose of the last treatment (3.7GBq and γ5.55GBq) and the median cumulative dose of 131I (7.4GBq vs. 3.7GBq) between women who experienced menstrual irregularities and did not after therapy. Patients with higher serum levels of FSH were more likely to have oligomenorrhea (p=0.004). In a period of 5 to 20 weeks after treatment, the serum levels of AMH were significantly lower than that before treatment (p<0.05). Conclusion: 131I therapy of DTC may lead to a transient failure in ovarian function in women of childbearing age, and the damaging can be repaired by itself. There were not a significant relationship between the risk of ovarian dysfunction after 131I therapy of DTC and the cumulative dose, or dose of latest treatment, if the dose of 131I was 3.7 ~ 9.25GBq in a single therapy. Compared with FSH, LH and E2, AMH can be used to evaluate the ovarian function more accurately and early.


   P207: Automated Radiosynthesis and Biodistribution of Fluorine-18 Labelled D-Allose Top


H Yamamoto1, Jun Toyohara*2, T Tago2, M Ibaraki1, T Kinoshita1

1Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita, 2Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan

Background/Aims: D-allose is a C-3 epimer of D-glucose with 80% of the sweetness of sucrose. D-allose is one of many rare sugars that exist in very small quantities in nature. This sugar has potential biological activities such as anti-inflammatory, anti-oxidative, and anti-proliferative activities against tumour cell growth. Because of growing interest in the biological properties of D-allose, two 18F-labeled analogues, 3-deoxy-3-[18F] fluoro-D-allose (3-[18F] FDA) and 6-deoxy-6-[18F] fluoro-D-allose (6-[18F] FDA), were synthesized as probes for bio-functional analysis. Methods: 1,2,4,6-tetra-O-acetyl-3-O-trifluoromethanesulfonyl-β-D-arabinose and 1,2,3,4-tetra-O-acetyl-6-O-trifluoromethanesulfonyl-β-D-arabinose were used as precursors for radiolabelling of 3-and 6-[18F] FDA, respectively. Automated radiosynthesis was performed by nucleophilic 18F-fluorination of each corresponding precursor with Kryptofix/K2CO3-activated [18F] fluoride ion, followed by acidic hydrolysis of the acetyl protecting groups. The reaction mixture was diluted with water and purified by passing through a series of solid-phase extraction cartridges. Preliminary biodistribution studies of 3-and 6-[18F] FDA in male ddY mice were performed. The Institutional Animal Care and Use Committee approved the animal studies. Results: The total synthesis times of both 3-and 6-[18F] FDA were within 45 minutes from the end of bombardment. The decay-corrected radiochemical yields based on [18F] fluoride at the end of synthesis of 3-and 6-[18F] FDA were 35% and 33%, respectively, with >98% radiochemical purity. Biodistribution studies showed high blood levels of radioactivity of both tracers. The brain uptake of 3-[18F] FDA peaked at 30 min after injection and gradually decreased thereafter. In contrast, 6-[18F] FDA did not show any significant uptake into the brain. No significant uptake in the bone was found, indicating the absence of de-fluorination in mice. Conclusion: 3-and 6-[18F] FDA were successfully synthesized with an automated synthesizer. 3-[18F] FDA, but not 6-[18F] FDA, showed significant uptake into the brain.


   P208: A High Performance Liquid Chromatography Quality Control Method for 4-[18F] Fluorobenzyl Dexetimide (4-[18] FDEX) Top


Kenneth Young*1, U Ackermann1, A Livori1, A To1, V Villemange1, C Rowe1, G Chan1

Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, Australia

Background/Aims: 4-[18F] FDEX is a new radioligand for positron emission tomography (PET) imaging of muscarinic acetylcholine receptors (mAChR) particularly M1 subtype. This radioligand is promising diagnostic agent for cognitive dysfunction in schizophrenia. Our department has developed and optimised the HPLC quality control method to evaluate the in-house radiosynthesis of 4-[18F] FDEX for human clinical trial. Methods: Phenomenex Luna 5µm C18 75 x 4.6mm column with 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B) at a flow rate of 0.5 mL/min with a gradient from 5% (B) to 90% (B) in 16 minutes. Shimadzu HPLC system with FlowRam radioactive detector was used for UV absorbance and radioactive detection. LabSolution software from Shimadzu was used for analysis. FDEX, flurobenzaldehyde (precursor 1) and nordexetimide (precursor 2) reference were prepared to determine the separation efficacy of our HPLC method. Serial dilution of each was also performed to determine the minimum detectable concentration and establishing standard a curve for specific activity calculation. Results: Baseline separation was achieved with retention times of flurobenzaldehyde, FDEX and nordexetimide were approximately 7, 11 and 14 minutes respectively. Standard curve of FDEX yielded a r2 value of 1 with a minimum detectable limit of 1 µg/mL. Conclusion: We have developed a robust HPLC method to evaluate the in-house production of 4-[18F] FDEX for human trial.


   P209: Preparation and Preclinical Evaluation of Al18F-NOTA-PEG6-TATE for Targeting the Somatostatin Receptor Top


Jilin Yin*1, R Zhang1, X Wang1, J Zhang1, R Wang1, W Huang1, Z Chen1

1Department of Nuclear Medicine, General Hospital of Guangzhou Military Command of Chinese PLA, Guangzhou, Guangdong, China

Background/Aim: Recent studies have demonstrated the high sensitivity of positron emission tomography (PET) imaging with 68Ga-labeled octreotide derivatives for the detection and staging of neuroendocrine tumours. A somatostatin receptor ligand that is easily radiolabelled with 18F-fluoride could improve the availability of PET imaging of neuroendocrine tumours. However, their laborious, multistep radiosynthesis represents a major obstacle to their clinical translation. Thus, we investigated a one-step, one-pot approach for preparing the radiolabelled analogue, Al18F-NOTA-PEG6-TATE, and examined its utility in a murine model. Methods: NOTA-TATE was radiofluorinated via an Al18F intermediate based on two reaction solutions, sodium acetate buffer (pH 4) and acetonitrile, to synthesize Al18F-NOTA-PEG6-TATE. After the tracer was purified using a C18 column, its specific cell binding and retention properties were analysed in U87MG cells. The tumour targeting efficacy and in vivo profile of Al18F-NOTA-PEG6-TATE were evaluated in a subcutaneous U87MG glioblastoma xenograft model through biodistribution and micro PET analyses. Results: Al18F-NOTA-PEG6-TATE was successfully prepared within 60 minutes, with a decay-corrected yield of 70-100% using the sodium acetate buffer and 64-74% using acetonitrile. Al18F-NOTA-PEG6-TATE is highly hydrophilic and stable in plasma with rapid, cellular uptake and efflux. High tumour uptake was also observed along with rapid urinary system clearance. However, high uptake of Al18F-NOTA-PEG6-TATE was also observed in the bone and could not be blocked with an excess of unlabelled precursor, which is suggestive of in vivo defluorination of the probe. Conclusion: Al18F-NOTA-PEG6-TATE may represent a potential PET tracer candidate for monitoring neuroendocrine neoplasm. Its favourable in vivo performance and easy production warrant further optimisation of this probe as well as a radiofluorination strategy to accelerate the clinical translation of 18F-labeled somatostatin analogues.


   Renal Top



   P210: To Assess the Effect of Hypothyroidism on Kidneys by Renal Scintigraphy Top


Ayesha Ammar*1, M A Saeed1, S Butt1, K Mir1, S Fatima1, M Faheem1

1NORI, Atomic Energy Hospital, Islamabad, Pakistan

Background/Aims: This study is planned to see the hypothyroid effects on renal function using GFR value as a marker of renal function., and camera based GFR assessment. Methods: Total of 58 patients were involved in this study. Out of 58 patients, 53 patients were had thyroid carcinoma, in whom hypothyroidism was due to discontinuation of thyroxine (51 patients) or injection of rTSH (2 patients). The remaining 5 hypothyroid patients were post-radioactive iodine for hyperthyroidism. Renal function tests (urea/creatinine) and serum electrolytes followed by 99mTc-DTPA renal scan for GFR assessment (GATES’ method) were carried out in all subjects twice during the study-one study during hypothyroid state (TSH > 30mIu/ml), and the other during euthyroid state (TSH between 0.4 to 4 iU/ml). In addition, renal function was assessed with creatinine clearance in those subjects who showed raised creatinine values in either of study (hypothyroid or euthyroid state). Results: The results of student’s t-test showed significant difference in renal functions. In case of creatinine, the paired t-test revealed a mean of 1.014±0.428, with standard error of 0.669, for creatinine clearance the mean was 80.11±14.12 with standard error of 1.94, for urea the mean was 28±12.13 with standard error of 1.607 and for GFR of individual kidneys is 38.056±8.56 with standard error of 1.3717. Conclusion: Hypothryoidism, irrespective of the cause, impairs renal function to a significant level and hence needs to be prevented and corrected as early as possible.


   P211: Prediction of Short Term Outcome of Renal Transplantation with Postoperative 99mTc-DTPA Scan Top


Ari Chong*1, J M Ha1, N K Choi1, M H Shin1

1Chosun University Hospital, Gwangju, Republic of Korea

Background/Aims: The aim of this study was to find out predictive factors of postoperative 99mTc-DTPA scan for predicting rejection of renal transplantation within 3 months. Methods: Total of 45 patients who underwent early postoperative renal scan within 8 days after transplantation were enrolled retrospectively. Rejection group was determined by renal biopsy which was done within 3 months after transplantation. Normal group was determined either by renal biopsy which was done within 3 months or by level of serum creatinine which was maintained as normal (<1.5 mg/dL) during the 1 year of follow-up. Variables from renal scan were GFR, Hilson perfusion index, time to peak and peak to 1/2 peak. Other clinical variables of age, sex, height and weight at the timing of renal scan were also analysed. P<0.05 was considered as significant. Results: GFR and scaled GFR were significantly different between groups. Less than 44.48 ml/min of GFR at postoperative renal scan could predict rejection within 3 months (sensitivity 88.9%, specificity 64.7%, AUC 0.724, p=0.0067). Less than 39.05 of scaled GFR can predict it (sensitivity 77.8%, specificity 81.2%. AUC 0.76, p=0.0045). There is no significant difference between AUCs. However, other factors were not different between groups. Conclusion: Lower GFR or scaled GFR of baseline renal scan could predict rejection within 3 months.


   P212: Impact of Method used for Tumour Bed Closure (Standard Sutures versus Tissue Adhesive) on the Functional Renal Volume Preservation Following Nephron Sparing Surgery: Assessment by Quantitative SPECT of 99mTc-Dimercaptosuccinic Acid Scintigraphy Top


M Gorenberg*1, O Avitan1, O Nativ1

1Bnai Zion Medical Center, Haifa, Israel

Background/Aims: NSS is now considered as the preferable treatment for most patients with organ-confined renal cancer. Such approach provides excellent cancer control comparable to that obtained after radical nephrectomy with the advantage of renal function preservation. The aim of our study was to compare the degree of functional renal tissue preservation after lesion removal between patients where the tumour bed was closed with absorbable sutures rather than closed with biologic Glue for the same purpose. Methods: Sixty-nine adults (30 women and 39 men), mean age 60.33 years (range 29-85 years) with enhancing solid renal mass who underwent NSS at our institution were included in the study. Patients were divided into 2 groups, group 1 (43 patients): tumour bed was closed with absorbable sutures, group 2 (26 patients): tumour bed was closed with biologic glue. Baseline patient characteristics were similar for both groups. QDMSA before and 3–6 months after surgery was used for evaluation differences in renal function volume preservation of each kidney. Statistical calculations of the functional volume were done with SPSS v. 20. Ethic approval was granted from Bnai Zion Helsinki committee. Results: Comparison of QDMSA before and after surgery demonstrated a decrease in the functional renal volume of 11.67±15.83% in group 1 and a decrease of 3.99±15.85% in group 2 (p=0.49). QDMSA in the non-operated contralateral kidney shown a decrease of 1.61±10.87% in group 1 and 4.65±3.66% in group 2. Conclusion: The utilization of biologic glue rather than sutures in NSS allows a better volume preservation of a functional kidney tissue after lesion removal.


   P214: Description of GFR and Diuretic Renogram in Obstructive Uropathy Cases in Nuclear Medicine and Molecular Imaging Department RSUP Hasan Sadikin 2012–2016 Top


Megawati Setia Budhi*1, B Hidayat1, H Budiawan2, E A Soeriadi2, A H S Kartamihardja2, B Darmawan2, A R Dewi2, J S Masjhur1

1Hasan Sadikin General Hospital/Universitas Padjadjaran, 2Department of Nuclear Medicine and Molecular Imaging, Hasan Sadikin General Hospital, Bandung, Indonesia

Background/Aims: It is well known that obstructive uropathy (OU) can cause acute renal failure and chronic renal failure (CRF). Beside renal function, obstruction degree should be known for OU treatment. Therefore, it is necessary to perform GFR and diuretic renography on OU cases. The aim of this study was to describe the GFR and diuretic renogram results of OU cases in RSUP Hasan Sadikin Bandung in 2012-2016. Methods: This study was a descriptive retrospective analysis. Data was taken from medical records of adult OU cases undergoing diuretic renography and GFR examinations which were performed simultaneously about 30 minutes using the 99mTc-DTPA and gamma camera. Gates method was used to quantify GFR value. Based on GFR value, cases were divided into 15-30 ml/minute and >30 ml/minute groups. While based on obstruction degree (response to furosemide), cases were divided into responsive (declining of the excretion slope), partial (slightly declining of excretion slope) and unresponsive (continuously rising curve) groups. Results: There were 53 OU cases [38 (72%) male; 15 (28%) female], with age ranging between 18-77 years old. Bilateral OU was observed in 17/53 cases. Cases of GFR 15-30 ml/min was observed in 36/81 (45%) and GFR > 30 ml/min in 45/81 (55.5%). Responsive, partial, and unresponsive to frusemide were observed in 3/81 (3.7%), 66/81 (81.48%) and 12/81 (14.80%) respectively. All responsive cases had renal GFR value of > 30 ml/min. In partial group, 29/66 (43.9%) cases had GFR value of 15-30 ml/min, the remaining 37/66 (56.1%) cases had GFR value of > 30 ml/min. While in unresponsive group, 7/12 (58.3%) cases had GFR of 15-30 ml/min and the remaining 5/12 (41.7%) cases had GFR of > 30 ml/min. Conclusion: Similar number was observed between OU cases with GFR value of the affected kidney >30 ml/min and 15-30 ml/min. Most cases showed excretion phases that slightly declining with frusemide intervention. The appearance of diuretic renogram (F+15) of the kidney with OU apparently related to the value of GFR.


   P215: Glomerular Filtration Rate in Cases of Chronic Renal Disease and Its Role in Determining the Need of Renal Transplantation Top


Tri Pera Sucianti*1, B Hidayat1, H Budiawan1, E Affandi1, B Darmawan1, A R Dewi1, A H S Kartamihardja1, J S Masjhur1

1Dr. Hasan Sadikin General Hospital, Bandung, Indonesia

Background/Aims: Kidney transplant can be performed in RSUP Dr. Hasan Sadikin. Glomerular filtration rate (GFR) study is not only important for determining the stage of chronic renal disease (CKD), but also for the need of kidney transplant. Kidney transplantation is required when GFR < 15 ml\min (CKD stage 5) and recommended in adulthood. The aim of this study was to know the profile GFR value in cases of CKD and the number of CKD cases that require renal transplant. Methods: Descriptive retrospective research based on medical records of CKD patients undergoing GFR in 2012-2016. 99mTc-DTPA dynamic imaging was performed for 7 minutes using a gamma camera. The GFR value was determined based on the calculation of Gates. Data were analysed based on CKD groupings according to GFR: stage 1: >90ml/min, stage 2: 60-89ml/min, stage 3: 30-59ml/min, stage 4:15-29 ml/min, and stage 5: <15 ml/min. Results: There were 3062 GFR studies from 2012-2016 (2116 men and 946 women). Average age of patients was 50 years old. The number of patients in stage 1, 2, 3, 4 and 5 were 190 (6%), 248 (8%), 667 (23%), 658 (21%), and 1299 (42%) respectively. The number of patients that was referred for kidney transplants based on CKD staging and age (18-65 years) was 1061 (34.6%). Conclusion: Most CKD patients in this study had GFR value <15 ml/min (CKD stage 5). In the period of 2012-2016 there were 34.6% patients eligible for kidney transplant based on GFR result and age.


   GMS Poster Award Top



   P216: The Challenges of Treating an Autistic Child with Radioiodine for Thyroid cancer Top


Victoria Sigalas*1, I Kirkwood1, G Bibbo1, A Gannoni2, C Whyte3, T Benger1, V Rubino1, K Cameron3, T Zutlevics4, M Osborn3, H Tapp3

1Women’s and Children’s Hospital, North Adelaide, Australia, 2Department of Psychological Medicine, 3Michael Rice Centre for Haematology and Oncology, 4Women’s and Children’s Hospital, North Adelaide, Australia

Background/Aims: In February 2017, an eleven year old boy with autism was referred for radioiodine therapy post total thyroidectomy for papillary thyroid carcinoma. Routine treatment requires the child to swallow a capsule containing radioiodine and remain isolated (usually 48 to 72 hours) until the level of radioactivity satisfies discharge guidelines. The Women’s and Children’s Hospital in Adelaide has a purpose built, child-friendly therapy room. From the first consultation, it was clear that the complex needs of this patient would make isolation a challenge. The child co-slept with his mother, was not responsible for his own personal hygiene including aspects of toileting and exhibited social and behavioural issues due in part to autism. His parents demonstrated apprehension to progress his independence and were concerned that he would not be able to comply with restrictions. Methods: Options for successful management during treatment were considered and explored including extended general anaesthesia, restraint, medication, behavioural therapy and treatment at home. Each option held its own risks and challenges. During this time, diagnostic imaging demonstrated metastatic spread and the need to fast track treatment. Treating the patient as soon as possible without sedation was pursued with regular, frequent contact between the child’s parents, clinical psychologist, play therapist and nuclear medicine personnel for counselling and behaviour modification; familiarisation of the child with the staff and procedures including trial visits, capsule swallowing and admission; and identifying the child’s tolerances and preferences. Results: Following extensive collaboration with a multidisciplinary team and the patient’s family, the patient was successfully treated with radioiodine therapy in October 2017. Radiation exposure to the family, staff and general public was lower than expected. Conclusion: Utilising the expertise of a diverse group of professionals, a complex paediatric patient was successfully isolated and treated with radioiodine therapy, despite overwhelming obstacles.


   P217: The Role of 68Ga-DOTA-Octreotate Positron Emission Tomography and Computed Tomography in Follow-up of Patients with Succinate Dehydrogenase: Associated Pheochromocytoma and Paraganglioma Top


Grace Kong*1, T Schenberg2,3, A Iravani1, M Hofman1, A Ravikumar1, T Akhurst1, R Hicks1

1Cancer Imaging, 2Familial Cancer Centre, 3Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia

Background/Aims: Germline succinate dehydrogenase (SDHX) mutation carriers, especially SDHB, are at increased malignancy risk and require life-long surveillance. Current guidelines recommend biennial whole body MRI[1],[2] but several series have documented superior lesion sensitivity with GaTate PET/CT.[3],[4],[5] We assessed the incremental value of GaTate PET/CT compared to MRI or CT in such patients. Methods: Twenty consecutive patients (median 46 years, 10 males) were retrospectively reviewed. Detection of number of lesions on restaging/surveillance GaTate PET/CT were compared to MRI/CT, and management changes were assessed. Proof of lesions were based on histopathology or clinical/imaging follow-up. Results: Fourteen patients had SDHB, 4 SDHD, 1 SDHC and 1 SDHA mutation, median age at diagnosis 30 years. Two had no known lesions, 2 organ of Zukerkandl primary, 2 pheochromocytoma, 14 with PGL (3 abdominal, 2 pelvic and 9 head and neck). Fourteen patients had prior surgery ± radiotherapy. Nine were imaged for surveillance without known disease, 9 with known disease, and 2 for raised catecholamines. Median time from PET/CT to MRI/CT was 1.5 months (MRI contraindicated/not performed in 2 patients). GaTate PET/CT correctly identified more lesions in 10 of 18 patients (56%), and correctly clarified negative disease in 1 of 3 patients with equivocal MRI/CT (no follow-up is yet available for the 2 other cases). No false-positive avid lesions identified. Change of management resulted in 8/20 patients (40%): 3 identified with limited disease had localised treatment, 1 changed to observation due to extra disease detected, and 4 with metastatic disease had peptide receptor radionuclide therapy. Conclusion: Incremental diagnostic information from GaTate PET/CT compared to conventional anatomical imaging was frequently observed with consequent management impact in SDHX-PPGL. We suggest incorporation of this modality and alternating GaTate with MRI on an annual or biennial basis to minimise life-time radiation exposure while ensuring more accurate long-term follow-up of such patients.

References

  1. Risk Management for Paraganglioma-Phaeochromocytoma Predisposition Syndromes (SDHA, SDHB and SDHC Gene Mutations) Cancer Treatments Online, Cancer Institute NSW.
  2. Risk management for Paraganglioma-Phaeochromocytoma Predisposition Syndromes (SDHD and SDHAF2 Gene Mutations). Cancer Treatments Online, Cancer Institute NSW.
  3. Janssen I, Chen CC, Taieb D, Patronas NJ, Millo CM, Adams KT, et al 68Ga-DOTATATE PET/CT in the localization of head and neck paragangliomas compared with other functional imaging modalities and CT/MRI. J Nucl Med 2016;57:186-91.
  4. Janssen I, Chen CC, Millo CM, Ling A, Taieb D, Lin FI, et al. PET/CT comparing (68)Ga-DOTATATE and other radiopharmaceuticals and in comparison with CT/MRI for the localization of sporadic metastatic pheochromocytoma and paraganglioma. Eur J Nucl Med Mol Imaging 2016;43:1784-91.
  5. Janssen I, Blanchet EM, Adams K, Chen CC, Millo CM, Herscovitch P, et al. Superiority of [68Ga]-DOTATATE PET/CT to other functional imaging modalities in the localization of SDHB-associated metastatic pheochromocytoma and paraganglioma. Clin Cancer Res 2015;21:3888-95.



   P218: Normal Brain Metabolism on Fluoro-D-Glucose Positron Emission Tomography–Magnetic Resonance Imaging during Childhood and Adolescence Top


Thomas Barber*1,2, D Veysey3, B Billah4, P Francis3

1Department of Nuclear Medicine and PET, The Alfred Hospital, Departments of 2Medicine and 4Epidemiology and Preventive Medicine, Monash University, Alfred Hospital, 3Department of Nuclear Medicine, The Royal Children’s Hospital, Melbourne, Australia

Background/Aims: To investigate the normal patterns of brain metabolism determined by FDG PET/MRI during childhood and adolescence. Methods: A retrospective analysis was performed on all paediatric patients who underwent FDG PET/MRI at The Royal Children’s Hospital, Melbourne, Australia between March 2016 and August 2017. Exclusion criteria were proven or suspected neurological disease, central nervous system metastases, previous chemotherapy/radiotherapy, general anaesthesia/sedation and medications suspected to affect cerebral metabolism. SUVmean and SUVmax were calculated for 12 brain gray matter regions on the left and right sides. Subgroup analysis of childhood (≤10 years old) and adolescence (≥ 11 years old) was also performed. Results: From 492 FDG PET/MRI scans, a total of 28 patients (11 children and 17 adolescents) met the inclusion criteria and were deemed representative of normal brain metabolism. Both SUVmean and SUVmax increased with age in all brain regions. The highest rates of increasing SUVmean were demonstrated in the thalamus, basal ganglia, frontal lobes, insula and occipital lobes. Higher SUVmean was demonstrated in the right frontal lobe, right lateral temporal lobe, right temporal pole, right cingulate/paracingulate, right thalamus, left occipital lobe, left basal ganglia, left insula and left cerebellum compared to the contralateral side. This left/right asymmetry in SUVmean was present in both childhood and adolescence in the majority of regions. The highest rates of increasing SUVmax with age were demonstrated in the occipital lobes, frontal lobes, thalamus and central region. There was no left/right asymmetry in SUVmax in the majority of regions. Conclusion: This FDG PET/MRI study demonstrates that normal brain metabolism measured by SUVmean and SUVmax increases with age in all brain regions, proceeding at different rates between distinct anatomical sites. Our results suggest there is mild asymmetry in SUVmean but mostly symmetric SUVmax during normal development.


   P219: Correlation of Clinical Outcome with Stimulated Cholescintigraphy Results in Patients with Suspected Chronic Acalculous Cholecystitis Using a Standardised Ensure Plus Fatty Meal Protocol Top


Thomas Barber*1,2, H Yue1, H Kavnoudias3, P Beech1, M Cherk1,2, H Barton1, K Yap1

1Department of Nuclear Medicine and PET and 3Radiology, The Alfred Hospital, 2Department of Medicine, Monash University, Melbourne, Australia

Background/Aims: To correlate clinical outcome with stimulated cholescintigraphy results in patients with suspected chronic acalculous cholecystitis using a standardised Ensure Plus fatty meal protocol. Methods: A retrospective study was performed on patients referred to our institution for evaluation of suspected chronic acalculous cholecystitis between March 2013 and November 2016. All patients with gallbladder visualisation 60 minutes after administration of Tc-99m DISIDA underwent fatty meal stimulation using 240 mL of Ensure Plus. A gallbladder ejection fraction (GBEF) of < 33% was considered abnormal. Clinical outcome was determined using a gallbladder symptom questionnaire. Follow-up was performed a minimum of 3 months after scanning or 3 months after surgery in patients treated with cholecystectomy. Results: A total 101 patients consented to participate in the study. Median follow-up time was 27 months (range 9 – 48 months). Of the 101 patients, 29 (29%) had an abnormal GBEF, 70 (69%) had a normal GBEF and 2 (2%) had no gallbladder visualisation on initial imaging. Of the 29 patients with an abnormal GBEF, 19 (66%) underwent cholecystectomy and 10 (34%) received conservative management. Overall improvement in symptoms occurred in 18/19 (95%) patients with abnormal GBEF who underwent a cholecystectomy and in 5/10 (50%) patients with abnormal GBEF who were managed conservatively (p=0.01). Of the 2 patients with no evidence of gallbladder visualisation, both underwent cholecystectomy with subsequent overall improvement in symptoms. Conclusion: Stimulated cholescintigraphy using the Ensure Plus fatty meal protocol is a useful technique to predict good surgical outcome in patients with suspected chronic acalculous cholecystitis.


   P220: Investigating Suitable Voxel Size for Patients of Varying Body Mass Index to Enhance Image Quality of Positron Emission Tomography and Computed Tomography Images Top


Jessica Welch*1, S U Berlangieri1, G J O’Keefe1,3, Kunthi Pathmaraj1, Andrew Scott1,2,3,4

1Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, 3Olivia Newton-John Cancer Research Institute, Austin Health, Heidelberg, 2School of Cancer Medicine, La Trobe University, Melbourne, 4Department of Medicine, The University of Melbourne, Melbourne, Australia

Background/Aims: PET emission reconstructions are routinely performed at 4mm for clinical whole body studies. At Austin Health, an additional 2mm reconstruction is generated for patients with head & neck cancer, a Body Mass Index (BMI) <23, or on request by the Consultant. The reconstruction server does not allow for two concurrent reconstructions, therefore reconstructing a 2mm image for each patient increases the computational burden on the server causing a backlog and inefficient workflow. The aim of this study was to compare the contrast resolution and image quality of the 4mm and 2mm whole body PET reconstructions for patients in different BMI categories and to determine which is best suited for each category. Methods: BMI categories were set to <25, 25.1–30 and >30. Ten oncology patients were selected for each of these categories. The PET emission data was reconstructed for all patients as a standard 4mm reconstruction and additionally as 2mm reconstruction with varying relaxation parameters. The reconstructions for each patient were visually analysed by two senior Consultants, who were blinded by the BMI of the patient, and a decision was made to which reconstruction was best suited. Results: Analysis of image datasets revealed that image contrast was enhanced whilst not compromising image quality when reconstructed as a 2mm voxel for all patients. The 2mm reconstruction with a relaxation parameter of 5 was the preferred reconstruction for patients with a BMI >25, where a relaxation parameter of 3 was preferred for a BMI <25. Conclusion: Enhanced contrast resolution can be achieved when reconstructing image data to a 2mm voxel with an appropriate relaxation parameter for all patients, regardless of their BMI. Hence, lesion detectability may also be increased as a result of enhanced contrast resolution. Performing one preferential reconstruction per patient reduces computational burden on the reconstruction server and optimises workflow.


   P221: Lung Conundrum: A Case Study Top


Leica Baker*1

1Medicine, Lady Cilento Children’s Hospital, South Brisbane, Australia

Background/Aims: A 15 year old male presented to the Lady Cilento Children’s Hospital with known Ebstein’s anomaly, complicated surgical history, acute pleuritic chest pain and elevated D-dimer. This poster aims to highlight a rare congenital condition and the modified Ventilation/Perfusion (V/Q) lung scan performed to exclude pulmonary embolism after an inconclusive Computed Tomography Pulmonary Angiogram (CTPA) and Computed Tomography Coronary Angiogram (CTCA) due to atypical cardiovascular anatomy. Methods: A protocol was determined using knowledge of the patient’s anatomy; the patient’s weight was obtained and procedure explained. Ventilation was performed using 99mTc-Diethylenetriaminepentaacic Acid (DTPA) via cadema and Single Positron Emission Computed Tomography (SPECT) and statics were acquired. A half dose 99mTc-Macro Aggregated Albumin (MAA) injection was given via left arm cannula and the first perfusion SPECT and statics were acquired. A second half dose 99mTc-MAA injection was given via left foot cannula and the perfusion SPECT and statics were repeated. Quantitative analysis was performed to determine differential blood flow. Ethics approval and patient consent were obtained to publish a case study poster. Results: Ventilation images showed a defect aligning with known right lower lobe atelectasis, bilateral pleural effusions and an enlarged cardiac silhouette. Images following injection into the left arm showed no left lung perfusion. Images flowing injection into the left foot showed perfusion to the left lung, with minimal increase in the right lung. There were no segmental perfusion defects in either lung. Quantitative analysis demonstrated preferential perfusion of the right lung from blood returning via the superior vena cava, and relatively symmetric perfusion to both lungs from blood returning via the inferior vena cava. Conclusion: Performing modified V/Q scans to exclude pulmonary embolism in patients with atypical cardiovascular anatomy could significantly reduce duplication of inconclusive exams, anxiety, cost to patients and the healthcare system and radiation exposure while maintaining image quality.


   P222: Assessment of Background Parenchymal Uptake on Molecular Breast Imaging in an Australian Population with Mammographically Dense Breast Tissue Top


Rhonda Harrup*1, J Cardaci1

1Diagnostic Nuclear Imaging, Nedlands, Australia

Background/Aims: Molecular Breast Imaging (MBI) is a novel technique employing dual Cadmium Zinc Telluride (CZT) direct conversion detectors, providing high resolution functional imaging of the breast. MBI was developed in response to the requirement for an effective supplemental screening technique in women with mammographically dense breast tissue who are at increased risk of developing breast cancer. Mammography has reduced sensitivity in dense breasts. MBI has shown to be highly sensitive and specific for the detection of breast cancer independent of breast density. Varying levels of Background Parenchymal Uptake (BPU) have been depicted on MBI studies overseas.[1],[2],[3],[4],[5] BPU is assessed as one of four categories: Photopenic, Minimal to Mild, Mild to Moderate or Marked. Mild to Moderate and Marked BPU has been associated with an increased incidence of breast cancer, suggesting it could serve as a functional imaging biomarker. The aim of this study is to assess levels of BPU on MBI in an Australian dense breast population and potentially use this data to identify a subgroup with a higher risk of developing breast cancer. Methods: MBI was performed for supplemental screening in the standard projections of Craniocaudal and Mediolateral Oblique after intravenous injection of 240-280MBq of 99mTc-Sestamibi. BPU was assessed by two readers using a visual analogue 4-point scale. Results: Preliminary results show that MBI depicts Minimal to Mild BPU in the majority of cases. Correlation between the two readers was high suggesting good inter-observer reproducibility. Conclusion: In an Australian dense breast population, Molecular Breast Imaging demonstrated Minimal to Mild Background Parenchymal Uptake in most patients, placing this group at reduced risk of developing breast cancer compared to those with higher levels of BPU. We anticipate that BPU on MBI may serve as a risk stratification tool to identify women at increased risk, enabling closer monitoring in this group to aid early detection.

References

  1. Boyd NF, Guo H, Martin LJ, et al. N Engl J Med 2007;356:227-362.
  2. Rhodes DJ, Hruska CB, Conners AL, et al. AJR 2015;204:241-53.
  3. Shermis RB, Wilson KD, Doyle MT, Martin TS, Merryman D, Kudrolli H, et al. Supplemental breast cancer screening with molecular breast imaging for women with dense breast tissue. AJR Am J Roentgenol 2016;207:450-7.
  4. Hruska CB, Scott CG, Conners AL, et al. Br Cancer Res 2016;18:425.
  5. Hruska CB, Rhodes DJ, Conners AL, Jones KN, Carter RE, Lingineni RK, et al. Background parenchymal uptake during molecular breast imaging and associated clinical factors. AJR Am J Roentgenol 2015;204:W363-70.


Disclosure of Interest: R. Harrup Conflict with: Owner of MBI system.


   P223: Selective Mitogen Activated Protein Kinase Pathway Inhibition in Radioiodine Refractory Differentiated Thyroid Cancer: A Single Center Experience Top


Amir Iravani1, G Kong1, M L Hofman1,2, A R Kumar1, T Akhurst1,2, B Solomon2,3, R Hicks1,2

Departments of 1Cancer Imaging and 3Oncology, Peter MacCallum Cancer Centre, 2Department of Oncology, University of Melbourne, Melbourne, Australia

Background/Aims: Some patients with advanced differentiated thyroid cancer (DTC) lack iodine avidity and are therefore unsuitable for radioactive iodine (RAI), the most effective treatment of DTC. Limited experience in the literature suggests selective mitogen activated protein kinase (MAPK) pathway inhibitors can restore expression of the sodium–iodide symporter, hence rendering patients amenable to RAI treatment.[1],[2] Methods: Patients at Peter MacCallum Cancer Center who were treated with a MAPK kinase inhibitor for redifferentiation of metastatic DTC were reviewed retrospectively. Selection criteria mandated mutation testing, imaging and biochemical progression despite treatment with RAI within the past twelve months or metastatic disease that had never been RAI-avid. The patients with NRAS mutation were treated with the MEK-inhibitor Trametinib (2mg daily), and BRAF-V600E mutation with combined Trametinib (2mg daily)/and BRAF-inhibitor Dabrafenib (150mg twice-daily) for four weeks. Concurrently the patients underwent withdrawal of thyroid hormone replacement except one patient whom received recombinant human thyroid stimulating hormone, due to underlying comorbidities. Restoration of RAI uptake and administered activity of RAI was based on two time-point 124I PET/CT imaging. Imaging and biochemical response were assessed at three months post RAI. Results: From 2015 to 2017, four patients (age range 46 to 70, three female) received redifferentiation therapy. Three patients had NRAS mutations (two with Follicular TC (FTC) and a poorly differentiated (PDTC) component, one with PDTC), and one patient had BRAF V600E mutation papillary TC (PTC). Two of four patients demonstrated satisfactory restoration of RAI uptake and proceeded to RAI (150-250mCi). One patient with NRAS mutation demonstrated partial imaging response (RECIST 1.1) with 60% reduction in thyroglobulin at three months which was durable at two-year follow-up. The patient with BRAF mutation showed stable imaging and 38% reduction in thyroglobulin at three months. Two patients developed grade 3 acneiform rash without satisfactory restoration of RAI avidity, and were subsequently managed with ongoing tyrosine kinase inhibitors. Conclusion: MAPK pathway inhibition is a promising strategy to re-differentiate RAI refractory DTC in a sub-set of patients, including FTC.

References

  1. Ho AL, Grewal RK, Leboeuf R, Sherman EJ, Pfister DG, Deandreis D, et al. Selumetinib-enhanced radioiodine uptake in advanced thyroid cancer. N Engl J Med 2013;368:623-32.
  2. Rothenberg SM, Daniels GH, Wirth LJ. Redifferentiation of iodine-refractory BRAF V600E-mutant metastatic papillary thyroid cancer with dabrafenib-response. Clin Cancer Res 2015;21:5640-1.



   P224: The Optimal Imaging Time for Imaging Cardiac Amyloidosis - Single-Photon Emission Computed Tomography-Computed Tomography Analysis Top


Scott G Evans*1, D Farlow1

1Westmead Hospital, Westmead, Sydney, Australia

Background/Aims: 99mTc-diphosphonate Imaging for cardiac amyloidosis is generally performed at 1 or 3 hours post injection but the optimal imaging time remains unclear. SPECT images at 1 and 3 hours have been acquired in a group of clinical patients and analysed for comparison to clarify this issue. Methods: Sixty-five patients were referred for detection of suspected/possible cardiac amyloidosis. Depending on referral urgency the patients were scanned with 99mTc-DPD (technetium-3,3-diphosphono-1,2-propanodicarboxylic acid) (56/65) after SAS approval or with 99mTc-PYP (technetium-pyrophosphate) (9/65) if the referrer requested (as requested by the referrer). As part of our imaging protocol chest SPECT/CT (Siemens Symbia T6) was acquired at 1 hour and for comparison a SPECT at 3 hours. A IDL (RSI Systems) program was developed to segment the patients CT scans to provide bone, lung, liver heart and fat volumes of interest. Uptake within these regions were compared to a reference region on the aortic arch for the 1 and 3 hour SPECT images which were corrected for attenuation and scatter. Results: Myocardial uptake greater than blood pool was identified on 1 and 3 hour SPECT for 28/65 patients which is typical of transthyretin related (TTR) cardiac amyloidosis. Tissue samples were available for 25/28 myocardial positive patients and all demonstrated cardiac amyloid deposition (4 TTR, 20 TTR subtypes, 1 amyloid light chains). Uptake was generally stable in cardiac (29/65) and liver (32/65) however increases (Cardiac 17/65, Liver 13/65) and decreases (Cardiac 19/65, Liver 19/65) between time points of more than 5% were demonstrated. Accumulation of tracer in lung (50/65), bone (55/65) and fat (46/65) was identified. Conclusion: Changes in uptake indicate that early and delayed imaging focused on the heart and liver will both be required. Bone, lung and fat uptake is less variable and only delayed imaging of these areas will be necessary. Imaging protocol can be adjusted given these findings.


   Poster Presentatations-Sunday Top



   Neuroscience Top



   P001: Cerebral Glucose Metabolic Alteration by Forniceal Deep Brain Stimulation in Severe Alzheimer’s Disease: A Case Report Top


Weiqi Bao*1, J Ge1, C Zuo1, W Lin2

1PET Center, Huashan Hospital, Fudan University, Shanghai, 2Department of Neurosurgery, 101 Hospital of PLA, Wuxi, Jiangsu, China

Background/Aims: The lack of effective therapeutic approaches against Alzheimer’s Disease (AD) makes it one of the leading ten death causes worldwide. While FDA-approved medications including cholinesterase inhibitors have limitations in altering the disease course of AD dementia, deep brain stimulation (DBS) has recently shown promising treatment effect as an alternative treatment for AD. Previous forniceal DBS (f-DBS) studies focused on mild to moderate AD dementia, showing this surgical technique could benefit the patients as demonstrated by neuropsychological scaling as well as by 18F-fluorodeoxyglucose positron emission tomography 18F-FDG PET. However, whether f-DBS could also benefit severe AD patients has not yet been validated. Methods: We performed an f-DBS exploration on one severe AD patient and conducted followed-ups with both neuropsychological tests and 18F-FDG PET scans. Results: Only ADL score decreased (from 65 points) to 47 points, indicating the quality of the patient’s daily living improved distinctly. Meanwhile, MMSE, MoCA-B, CDR and GDS remained unchanged, suggesting that no distinct improvement of the patient’s cognitive function was observed. Follow-up 18F-FDG PET scan demonstrated increased glucose metabolism in the classical AD-related brain regions. Conclusion: The recovery of ADL scores occurred along with the recovery of hypometabolism in multiple cerebral cortical regions responsible for different cognitive functions.


   P002: Implementing the Centiloid transformation of 18F-Florbetaben and 18F-NAV4694 using CapAIBL Top


P Bourgeat1, Vincent Doré*1,2, S Williams2, D Ames3,4, R Martins5,6, C Masters7, O Salvado1, V L Villemagne2,8, C C Rowe2,8

1The Australian eHealth Research Centre, CSIRO, Brisbane, 2Austin Health, 3University of Melbourne, 4The National Ageing Research Institute, 7The Florey Institute of Neuroscience and Mental Health; 8Melbourne University, Melbourne, 5Edith Cowan University’s Centre for Excellence in Alzheimer’s Disease Research and Care, Perth; 6Macquarie University, Sydney, Australia

Background/Aims: The Centiloid scale was developed to allow the expression of Aβ burden in the brain as assessed by different PET tracers in a single universal scale. We have previously validated the PET-only quantification method CapAIBL (milxcloud.csiro.au) for Centiloid quantification using the Centiloid Level-1 11C-PiB data. In this study, we extended the use of CapAIBL for the Centiloid transformation of F-18 tracers, namely 18F-NAV4694 (NAV) and 18F-florbetaben (FBB). Methods: The 34 young controls (YC) and 45 Alzheimer’s disease (AD) patients PiB PET calibration scans from the Centiloid level-1 study were used to calibrate CapAIBL against the prescribed Centiloid SPM pipeline. Additionally, 991 PiB PET scans and their matching MRI from the AIBL study were used to refine the regression against the SPM pipeline. Ten YC and 47 elderly participant that underwent PiB, NAV and MRI, and another 10 YC and 24 elderly participants, that underwent PiB, FBB and MRI from Centiloid Level-2 studies, were quantified using CapAIBL and SPM. For both SPM and CapAIBL, NAV and FBB SUVR were then converted into a PiB-like SUVR using linear regression. The resulting SUVR were converted into Centiloids using the equation obtained with the Centiloid Level-1 PiB images. A linear regression between standard SPM-Centiloids and CapAIBL-generated Centiloids allowed the final transformation of CapAIBL-generated Centiloids into Centiloids. Results: The correlation between SPM and CapAIBL PiB-like NAV SUVR was very high (R2=0.99, sum of square of the residuals (SSr)=0.11). The same results were found for the corresponding PiB SUVR. The correlation between SPM and CapAIBL PiB-like FBB was also very high (R2=0.99, SSr=0.13), and so it was for the corresponding PiB SUVR (R2=0.99, SSr=0.06). The difference between SPM and CapAIBL derived Centiloids was not significant for either tracer. Conclusion: Robust and reliable Centiloid estimates can be obtained for PiB, NAV and FBB using the PET-only CapAIBL method. SPM and CapAIBL showed good agreement for both F-18 tracers (R2=0.99) and had low SSr. The PET-only CapAIBL validation using other F-18 tracers (18F-flutemetamol and 18F-florbetapir) is currently underway.


   P003: MilxCloud: A Web-Based Platform for Positron Emission Tomography and Magnetic Resonance Quantification Top


Pierrick Bourgeat*1, V Doré1,2, P Raniga1, J Fripp1, C L Masters3, C Rowe2, V Villemagne2, O Salvado1

1AeHRC, Health and Biosecurity, CSIRO, Herston, 2Department of Molecular Imaging and Therapy, Austin Health, 3The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Australia

Background/Aims: Visual reading of PET and MR images is part of the standard of care for supporting the diagnosis of neurodegenerative diseases. Visual reading can however be subjective, and with MR images, is typically limited to the identification of gross changes in the mesial temporal lobe and ventricles in AD, or the in the frontal lobe for FTD. When reading Aβ PET images, separating negative from positive subjects can also be challenging, especially when different tracers are used. We introduce MilxCloud, a publicly available cloud computing platform for PET (CapAIBL: Computational Analysis of PET from AIBL) and MR quantification (CurAIBL: Computational qUantification of mRi from AIBL). These tools facilitate visual inspection with quantitative values, z-score maps, and normative graphs in relation to a reference population. Methods: CapAIBL is a PET-only method tool that allows quantification of FDG and all Aβ PET tracers without the need of a corresponding MRI. Results are presented in terms of SUVr and Centiloid. CurAIBL implements a pipeline that segments and parcellates brain MR images. Cortical GM and hippocampal volumes are reported on a graph with confidence intervals for an aged-matched normal population. Computed z-score maps of cortical thickness are displayed over a normalised template. Both tools provide key quantitative values, graphs and mesh rendering on a pdf report which is emailed to the user at the end of the procedure. Results: CapAIBL showed great accuracy, with errors less than 5% compared to MR-based quantification. CurAIBL was evaluated on the AIBL database, and showed similar results to that of FreeSurfer. Conclusion: CurAIBL provides an efficient clinical inspection and quantitative tool for MR imaging and complements PET assessments (such as FDG or Aβ PET) with CapAIBL, offering a comprehensive neuroimaging tool for the assessment of Alzheimer’s disease and other neurodegenerative conditions. Both tools are available at milxcloud.csiro.au.


   P004: 18F-AV1451 tau Quantification without Magnetic Resonance Imaging Top


P Bourgeat1, V L Villemagne2,3, Vincent Doré*1,2, D Ames3,4, R Martins5,6, C L Masters7, O Salvado1, C C Rowe2,3, J Fripp1

1The Australian eHealth Research Centre, CSIRO, Brisbane, 2Austin Health, 3The University of Melbourne, 4The National Ageing Research Institute, 7The Florey Institute of Neuroscience and Mental Health, Melbourne, 5Edith Cowan University’s Centre for Excellence in Alzheimer’s Disease Research and Care, Perth, 6Macquarie University, Sydney, Australia

Background/Aims: In vivo tau imaging with PET is a promising new modality that offers a unique insight into Alzheimer’s disease (AD) pathology. 18F-AV1451 is a tau tracer currently being evaluated in both AIBL and ADNI. While MR-based quantification remains the gold standard, there is great interest in PET-only quantification techniques. We evaluate 3 PET-only methods and compare them to MR-based quantification in both AIBL and ADNI. Methods: 18F-AV1451 and MR images from AIBL (N=94) and ADNI (N=87) were used. The pons was used for SUVR normalisation. Global SUVR was defined as the mean of the 3 ROIs from the MeTeR scale (Mesial-temporal (Me), Temporoparietal (Te) and Rest of neocortex (R)). Global SUVR was measured using MR images and 3 PET-only methods: spatial normalisation to a mean PET atlas; adaptive PET atlas based on the linear combination of a negative and positive atlases (based on the 75th percentile of the global SUVR); PCA-based adaptive atlas. The ADNI dataset was used to build the atlases/PCA models and test them (in a leave one out fashion), while the AIBL dataset was used as an independent test dataset. Results: The 3 approaches produced comparable results in both cohorts, with an average quantification error close to 2% (was 2.9% in PiB). Therefore, the simpler mean atlas approach appears to be sufficient, although the PCA approach might be closer to MR quantification in the Me. Looking at the PCA decomposition, it is interesting to note that hippocampus uptake is mostly driven by spill over from the choroid plexus (CP). The CP is prominently represented in the mean image, and in the 3rd mode (5% of the variability). Uptake in the CP is therefore fairly consistent across the population, and variations in its uptake are independent from tracer retention in the Me. While not significant, there was a trend association between increasing CP uptake and increasing age in both AIBL (p=0.10) and ADNI (p=0.25) cohorts. Conclusion: Results show that all quantification performed using PET-only normalization approaches did equally well, with an average quantification error around 2% in both cohorts. Partial volume correction might however be required to account for spill over.


   P005: The Impact of APOE ε4 Carriage and Gender on the Age of Onset of Amyloid Deposition Top


S Burnham1, S Laws2, V Doré3, P Bourgeat4, O Salvado4, C L Masters5, C C Rowe3, Victor L Villemagne*3

1Health and Biosecurity, CSIRO, 4eHealth and Biosecurity, CSIRO, Brisbane, 3Department of Molecular Imaging and Therapy, Austin Health, 5The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, 2School of Medical Sciences, Edith Cowan University, Perth, Melbourne, Australia.

Background/Aims: Knowledge of the onset and the rate of neocortical Aβ-amyloid deposition is paramount to elucidating disease mechanisms and optimising the timing of therapeutics. Reports have suggested that APOE ε4 carriage may alter the metabolism, onset, or accumulation of neocortical Aβ-amyloid and that this may be further modulated by gender. This study evaluates the impact of APOE ε4 carriage, gender and their interaction on neocortical Aβ-amyloid deposition and its age of onset. Methods: Cox proportional hazards models of survival and Kaplan-Meier plots were employed to determine the age at which 317 AIBL participants reached abnormal levels on Aβ deposition (SUVR≥1.4). Further analyses elucidated the effects that gender and APOE ?4 carriage had on the age of onset. Results: Findings indicate the natural history of neocortical Aβ-amyloid deposition was similar between APOE e4 carriers and non-carriers, however a shift was observed showing higher Aβ-amyloid levels 15 years earlier in APOE e4 carriers. In APOE e4 carriers, the threshold of Aβ-amyloid abnormality was reached at age 62 in comparison to non-carriers at age 77. No differences were observed in the natural history of Aβ-amyloid deposition for gender, either in its own right or in interaction with APOE e4. Conclusion: Understanding genetic and potential sex-based differences in the pathogenesis of Alzheimer’s disease, are essential for informing clinical trials to provide the best chance of success in delaying and preventing this debilitating disease.


   P006: Tau, Aβ-Amyloid, and Cognitive Function Following Service-Related Traumatic Brain Injury in Vietnam War Veterans Top


Tia Cummins*1,2, A Elias3, M Hopwood3, J Rosenfeld4, V Doré1,5, F Lamb1, R Williams2, R Guzman1, O Salvado5, C Masters2, V Villemagne1,2, C C Rowe1,2

1Department of Molecular Imaging and Therapy, Austin Health, 2Florey Institute of Neuroscience and Mental Health, 3Department of Psychiatry, The University of Melbourne, 4Department of Surgery, Monash University, 5The Australian eHealth Research Centre, CSIRO, Brisbane, Australia

Background/Aims: Often labelled the “signature wound” of modern day warfare, Traumatic Brain Injury (TBI) has been diagnosed in over 355,000 US military service personnel since 2000. Epidemiological research indicates that veterans with TBI are 2-4 times more likely to develop dementia than controls; however, mechanisms contributing to this relationship are poorly understood. The aim of this study was to investigate if Vietnam war veterans without mild cognitive impairment or dementia, but with TBI show evidence of Alzheimer’s disease (AD) pathological markers, as assessed by Aβ-amyloid, tau and glucose metabolism using PET, alongside neuropsychological testing. Methods: Fifty-five male participants-29 veterans with TBI (aged 68.1±2.25 years) and 24 veteran controls (aged 69.6±5.29 years)-underwent neuropsychological assessment, FDG, tau (18F-AV1451) and Aβ-amyloid PET (18F-Florbetaben) scans. Standardized Uptake Value Ratios (SUVR) for all PET tracers were calculated using the cerebellar cortex as reference region. Analyses were adjusted for scores on the Geriatric Depression Scale and Clinician-Administered PTSD Scale. Results: The TBI group performed significantly worse than controls on a number of measures across cognitive domains: WMS Logical Memory I & II (10.24±3.78 vs. 14.33±3.91, p<0.001; 8.48±3.90 vs. 11.63±4.89, p=0.01), MoCA (25.59±2.24 vs. 28.12±1.85, p<0.001) and MMSE (27.76±1.70 vs. 28.67±0.96, p=0.02). However, the TBI cohort did not differ significantly from controls in 18F-AV1451 (1.17±0.09 vs. 1.15±0.08, p=0.29), 18F-Florbetaben (1.34±0.20 vs. 1.27±0.20, p=0.23), nor FDG tracer retention (1.08±0.09 vs. 1.08±0.07, p=0.95). Conclusion: These preliminary findings suggest that whilst TBI is associated with later-life cognitive deficits, these deficits are not associated with AD pathology. Further study is needed to confirm our observations and to determine if direct brain injury can be detected to explain these later life deficits.


   P007: Pathological Correlates of 18F-THK5351 Positron Emission Tomography in Tauopathies Top


Ryuichi Harada*1, A Ishiki2, H Kai3, K Furukawa4, S Furumoto5, M Tashiro5, R Iwata5, T Kitamoto3, Y Kudo2, H Arai2, N Okamura4,5, K Yanai1,5

1Department of Pharmacology, 2Institute of Development, Aging and Cancer, 3Department of Neurological Science, Tohoku University, 4Tohoku Medical and Pharmaceutical University, 5Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan

Background/Aims: Human blocking studies using selegiline have shown that 18F-THK5351 PET signal contribute the binding to monoamine oxidase B (MAO-B). The aim of study was to validate 18F-THK5351 PET signal in autopsy-confirmed cases of tauopathies such as Alzheimer’s disease (AD) and progressive supranuclear palsy (PSP). Methods: We performed postmortem examination of brain samples from autopsy-confirmed an AD case and two PSP cases who underwent 18F-THK5351 PET before death. Case 1 was clinically diagnosed as AD. Case 2 and 3 were clinically diagnosed as Richardson syndrome (PSP-RS) and progressive non-fluent aphasia (PNFA), respectively. In vitro autoradiography of 3H-THK5351 was performed using frozen brain sections. We quantitatively measured tau pathology, amyloid-β, MAO-B, and GFAP in autopsy brain tissues and examined the correlation between 18F-THK5351 retention and each substrate. This study was approved by the Ethics Committee of the Tohoku University Hospital. Results: 18F-THK5351 PET showed prominent tracer retention in the inferior temporal lobe as well as hippocampus in AD, while significant 18F-THK5351 retention was observed in the globus pallidus and midbrain in case 2 (PSP-RS). In case 3 (PNFA), additional 18F-THK5351 retention was observed in the temporal cortex. In in vitro autoradiography, the specific THK5351 binding was detected in the area of antemortem 18F-THK5351 retention, and the binding was substantially reduced by MAO-B inhibitor lazabemide. THK5351 binding to PHF-tau was also detectable in the brain samples from AD case, while the binding was completely displaced in the brain samples from PSP cases. Regional 18F-THK5351 SUVR in ante-mortem PET image was significantly correlated with the density of reactive astrocytes as well as tau pathology at postmortem examination. Conclusion: 18F-THK5351 PET signals reflect MAO-B expressing reactive astrocytes associated with tau accumulation in tauopathies.

Disclosure of Interest: S Furumoto Conflict with: GE Healthcare and CLINO Ltd; Y Kudo Conflict with: GE Healthcare and CLINO Ltd; N Okamura Conflict with: GE Healthcare and CLINO Ltd.


   P008: Global Tau Burden Correlates with Basal Forebrain Atrophy in Healthy Aging Subjects Top


N Hearn1, Vincent Doré2,3, J Fripp2, M Grothe4,5,6, S Teipel4,6,7, S Williams3, C L Masters8, C C Rowe3,9, E Coulson1, V L Villemagne3,9

1University of Queensland, 2The Australian eHealth Research Centre, CSIRO, Brisbane, 3Austin Health, Melbourne, 8The Florey institute of Neuroscience and Mental Health, 9The University of Melbourne, Melbourne, Australia, 4German Center for Neurodegeneration Diseases (DZNE), 5University Medicine Rostock, 6University of Rostock, 7Department of Psychosomatic Medicine, University Medicine Rostock, Rostock, Germany

Background/Aims: Alzheimer’s Disease (AD) is characterised by the presence of certain pathological hallmarks: extracellular Aβ-amyloid (Aβ) plaques, intracellular neurofibrillary tangles (NFT) of tau, and associated neurodegeneration of the cortex, hippocampus and basal forebrain. In this study, we investigated if the presence of high tau global retention in cognitively normal elderly controls (NC) was associated with early signs of neurodegeneration. Methods: Fifty-four cognitively normal subjects from the AIBL cohort underwent a MRI and two PET scans. Aβ-amyloid imaging was undertaken through 18F-flutemetamol or 18F-florbetapir and tau imaging was acquired with 18F-THK5351 or 18F-AV1451. PET scans were normalized using CapAIBL. For each tau tracer, a threshold was obtained as the 75th percentile of the normal controls, resulting in a 18F-THK5351 SUVRPons threshold of 0.926 and a 18F-AV1451 SUVRPons threshold of 1.33. The basal forebrain volumes were estimated on the MRI using SPM and were corrected for intra-cranial volume and age. Results: From the population of 54 NC, 17 (32%) had a high global tau (tau+). There were no significant differences in age, sex or education between tau+ and tau-subjects. Tau+ NC subjects had a significantly smaller posterior basal forebrain volume (mean volumes: tau-0.0887cm3, tau+ 0.0838cm3, p<0.05). Conclusion: These findings are consistent with previous imaging studies in MCI and AD populations showing associations between basal forebrain, Aβ-amyloid and tau markers, and with post-mortem histological data and suggest that before cognitive impairment is evident, neurodegenerative changes in the basal forebrain associated with tau accumulation have already occurred.


   P010: Validation of mGluR5 as a Imaging Biomarker for Alzheimer’s Disease Top


M K Lee1, H J Lee2, J A Park3, Y H Ryu4, S M Lim5, K C Lee3, Jae Yong Choi*3

1Department of Nuclear Medicine, School of Medicine, Inha University, Incheon, 2Division of Radiation Effects, 3Division of RI-Convergence Research, Korea Institute of Radiological and Medical Sciences, 4Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, 5Department of Nuclear Medicine, Korea Institute of Radiological and Medical Sciences, Seoul, Korea

Background/Aims: Glutamate is the major excitatory neurotransmitter in central nervous system and it regulates learning and memory. Previous studies demonstrated that Aβ oligomers (Aβo) directly impose deleterious effects on glutamatergic neurotransmission, particularly on the metabotropic glutamate receptor type 5 (mGluR5). Dysregulation of mGluR5 by Aβo synaptic toxicity is known to be related with the early symptom of cognitive dysfunction in Alzheimer’s disease (AD). The purpose of this research is to validate the potential of mGluR5 as a biomarker for AD by means of positron emission tomography. Methods: Four male 5xFAD transgenic mice as a rodent model of Alzheimer’s disease and same number of wild type mice as age-matched controls. The mice were anesthetized with 2.5% isoflurane in oxygen and 18F-FPEB was intravenously administered. Simultaneously PET scan was performed for 90 minutes in list mode. Volumes of interests (VOIs) are hippocampus, striatum, and cerebellum. Results: Brain PET imaging revealed that radioactivity in the mGluR5 rich regions such as hippocampus and striatum showed 18-21% lower uptakes in the 5xFAD group compared with control group. Also, non-displaceable binding values based on the cerebellum for 5xFAD were 22-25% lower than those for control group. Conclusion: mGluR5 levels in 5xFAD mice were down regulated in the limbic system. From this perspective, mGluR5 is considered as an effective imaging biomarker for AD.


   P011: Assessment of Severity of Alzheimer’s Disease by Application of Easy Z-Score Imaging Systems in Brain Single-Photon Emission Computed Tomography Study-Initial Experience in Bangladesh Top


Nasreen Sultana*1, H Matsuda2, A K Sarker, S Sultana1, S M F Begum1, J A Haque1, S Salekin1, K K Nath1, S Islam1, R Hussain1, M R Islam3

1National Institute of Nuclear Medicine and Allied Sciences, Bangladesh Atomic Energy Commission, 3BSM Medical University, Dhaka, Bangladesh, 2Integrative Brain Imaging Center National Center of Neurology and Psychiatry, Saitama, Japan

Background/Aims: Decreased regional cerebral blood flow (rCBF) in posterior cingulate gyri, precunei and parietal lobe on brain perfusion SPECT images had long been a qualitative identifier of Alzheimer disease (AD). Aim of this study was to apply easy Z-score imaging system (e-ZIS) on brain SPECT images for quantitative evaluation of perfusion deficit severity in patients with clinically suspected AD and find out association of Z-score with clinical mini mental state examination (MMSE) scoring. Methods: Patients were divided into two groups on the basis of MMSE score (group A= 20 or higher, group B = less than 20). All patients were underwent brain SPECT study from February to July 2017 with dual head SPECT camera with IV Tc-99m ethyl cysteinate dimer (ECD). For the quantification of perfusion deficit, e-ZIS version 3 \was used. Results: Brain SPECT was performed on 20 patients (six female) with clinically suspected AD with mean age of 60.6±9 years (range 45-77) and mean duration since clinical onset of 10.7±5.3 months (range 6-24). Mean MMSE and mean severity scores were 23.2±0.63 and 0.99±0.40 in group A (n=10) while 17.7±0.95 and 2.82±0.45 in group B (n=10), respectively. Categorically on the basis of e ZIS scoring, five patients were normal (Z score 0-1), six had slightly decreased perfusion (Z score 1-2), six had moderate disease (Z score 2-3) and three had significantly decreased perfusion (Z score >3). There was strong negative correlation between MMSE and e ZIS score (r = 0.96, paired sample t = 21.10, p=0.000, 95%CI 16.7-20.4). Conclusion: Quantification of perfusion deficit with a ZIS score correlated well with clinical MMSE scoring in this study group. This was the first time application of e ZIS in brain perfusion SPECT imaging in Bangladesh.


   P012: Posterior Cortical Atrophy Variant of Alzheimer’s Disease Presenting As Homonymous Hemianopia: An Unusual Presentation of a Rare Disease Variant Diagnosed by Hexamethylpropyleneamine Oxime Cerebral Perfusion Single-Photon Emission Computed Tomography Imaging Top


Angela Woodcock*1, I Larkin1, K Chung2, K Lee1

1Bankstown Lidcombe Hospital, 3Chung and Lim Neurology and Endocrinology Services, Sydney, Australia

Background/Aims: An 81 year old female complained of impaired vision and was found to have a right homonymous hemianopia (HH) by an ophthalmologist. There were no hallucinations or reported cognitive function concerns, although on closer examination she had great difficulty completing clock face drawing and scored 13/30 on Montreal Cognitive Assessment. Brain CT, MRI and MRA showed no cause for right HH. She was referred for a HMPAO (hexamethylpropyleneamine oxime) cerebral perfusion scan to investigate the possibility of a neurodegenerative or neuroinfective process. Methods: Cerebral perfusion SPECT images were acquired one hour post administration of 1Gbq 99mTc-HMPAO over 24 minutes on a GE Discovery 670 camera with fan beam collimators. Images were iteratively reconstructed with Chang attenuation correction and statistical analysis was performed using Neurostat. Results: Large, moderately severe perfusion defects were demonstrated in the associative parietal cortices extending into the temporo-occipital cortices bilaterally, with involvement of the primary visual cortices bilaterally (worse on the left), and the precuneus/posterior cingulate cortices bilaterally. The scan findings were consistent with the posterior cortical atrophy (PCA) variant of Alzheimer’s disease (AD), with involvement of the left primary visual cortex in keeping with right HH. Neuropsychological assessment subsequently demonstrated significant impairment in multiple domains, worse in visual processing, suggestive of PCA variant of AD, in keeping with the HMPAO scan findings. Aricept was commenced with good effect as part of the AD management plan. Conclusion: PCA is a rare, progressive neurodegenerative disorder in which the predominant symptoms are higher visual cognitive dysfunction.[1] HH has been rarely described in this syndrome1 and this case is especially unusual because this patient presented with a visual field defect rather than cognitive impairment. The HMPAO scan was especially helpful in making the diagnosis of PCA variant of AD and led to early appropriate management with beneficial treatment.

References

  1. Formaglio M, Krolak-Salmon P, Tilikete C, Bernard M, Croisile B, Vighetto A, et al. Homonymous hemianopia and posterior cortical atrophy. Rev Neurol (Paris) 2009;165:256-62.



   P013: Cerebrovascular Pathology in Alzheimer’s Disease: Findings From the Australian Imaging, Biomarkers and Lifestyle study of Aging Top


Y Xia1, N Yassi2,3, P Bourgeat, P Raniga, P Desmond4, J Fripp, D Ames5,6, P Maruff3,7, C Fowler3, R Martins8, V Villemagne9,20, C Masters4, C Rowe9,20, Olivier Salvado*1

1The Australian e-Health Research Centre, CSIRO Health and Biosecurity, Brisbane, 2The Royal Melbourne Hospital, 3The Florey Institute of Neuroscience and Mental Health Research, 4Department of Radiology, The Royal Melbourne Hospital, University of Melbourne, Parkville, 5National Ageing Research Institute, 6Academic Unit for Psychiatry of Old Age, University of Melbourne, 7Cogstate, Melbourne, 8Centre of Excellence for Alzheimer’s Disease Research and Care, Edith Cowan University, Joondalup, 9Department of Medicine, University of Melbourne, Austin Health, 20Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, Australia

Background/Aims: Cerebrovascular disease often coexists with Alzheimer’s disease (AD), likely having a synergistic effect on cognitive decline.[1] However, it remains unclear how cerebrovascular pathology contributes to dementia. This study investigates the relationship of Aβ-amyloid deposition and cerebrovascular pathology in the Australian Imaging, Biomarkers and Lifestyle (AIBL) cohort. Methods: 311 AIBL participants (aged 60-89, F/M: 151/160) with both PET and MR imaging were involved in the study and included 50 AD patients, 56 patients with mild cognitive impairment (MCI) and 205 healthy controls (HC). Neocortical Aβ-amyloid deposition was quantified from PiB-PET images using CapAIBL,[2] where SUVR ≥ 1.4 indicated the presence of Aβ-amyloid pathology. Cerebrovascular pathology was assessed on 3D FLAIR images in terms of brain infarction screened by a neurologist and WMH that were automatically segmented using HIST.[3] Periventricular and deep WMH were classified based on the distance from and confluence with ventricles. The presence of cerebrovascular pathology was defined as subjects with a brain infarct and/or WMH over 0.71% of the total intracranial volume, which was estimated from non-demented AIBL participants aged over 70 as the threshold of the top tertile.[4] Results: No significant correlation was observed between Aβ-amyloid load and WMH in either HC, MCI or AD group. The same findings were obtained for periventricular and deep WMH. Moreover, logistic regression analysis, controlling for age, sex, education, APOE ε4 and clinical diagnosis, showed that the presence of Aβ-amyloid pathology was not significantly associated with the WMH burden or brain infarction. Similarly, there was no statistically significant association observed between the neocortical SUVR and the presence of cerebrovascular pathology, after correction for the mentioned factors. Conclusion: Our study provided cross-sectional evidence suggesting an independence of the association between amyloid deposition and cerebrovascular pathology. To confirm these findings, future longitudinal studies are needed.

References

  1. Jellinger KA, Attems J. Prevalence and impact of cerebrovascular pathology in Alzheimer’s disease and parkinsonism. Acta Neurol Scand 2006;114:38-46.
  2. Bourgeat P, et al. Neurobiol Aging 2015;36 Suppl 1:S159-66.
  3. Manjón JV. et al. In: Wu G, Coupé P, et al., editors. Patch-Based Techniques in Medical Imaging. Springer International Publishing; 2016. p. 92-9.
  4. Vemuri P, et al. Brain 2015;138:761-71.



   P014: The Synthesis and Evaluation of 18F-FEONM as a Novel Tau Protein Imaging Agent in the Streptozotocin-Induced Alzheimer’s Disease-Like Model Top


Cheng-Yi Cheng*1, J T Chen2, T K Chou1, L F Lin1, K H Ma3

1Department of Nuclear Medicine, Tri-Service General Hospital, National Defense Medical Center, 3Department of Biology and Anatomy, National Defense Medical Center, Taipei, 2Institute of Nuclear Energy Research, Taoyuan, Taiwan

Background/Aims: Tau protein is a microtubule-associated protein which abundant in the neurons. The abnormal aggregation of tau protein could be found in some neurodegenerative disorders, such as Alzheimer’s disease (AD). Under pathological situations, tau protein is hyperphosphorylation and aggregated in the neurons, which resulted in paired helical filaments and neurofibrillary tangles. Tau protein aggregation is a progressively process, no obvious clinical symptom in the early onset of neurodegenerative diseases, is difficult to diagnosis. The positron emission tomography (PET) provided functional images and important evidence for early detection of tauopathies and diagnosis. 18F-FEONM, a novel PET radioligand basing on 18F-FDDNP structural modification, expected to noninvasively detect abnormal aggregation of tau protein in brain. In this study, we validated the feasible and sensitivity of 18F-FEONM as a tau protein imaging agent in the streptozotocin intracerebralventricular (STZ-icv)-induced AD-like rat model. Methods: The 18F-FEONM was synthesised and analysed the purification of product by HPLC. The 8-week-old rats were grouped into sham and STZ-icv groups. The STZ-icv rat received STZ (3 mg/kg in citrate buffer) injection in the lateral ventricles. The radial arm maze (RAM) test and 18F-FEONM/small animal-PET were performed to evaluate the learning memory and the phosphorylated tau protein. The images were analysis and presented by standardized uptake values (SUVs). All animal experimental studies have approval from Institutional Animal Care and Use Committee (IACUC), National Defense Medical Center. Results: At 4 weeks after the STZ-icv, the STZ-icv rat showed the impairment of memory in RAM test. The time-activity curve of 18F-FEONM in normal and STZ-icv rat were analysed from dynamic imaging. The SUVs of 18F-FEONM in STZ-icv rat were higher than those of sham rat. Conclusion: The results of this study will assistance to estimate the validity and sensitivity of 18F-FEONM as a tau protein imaging agent. These results will be important for future clinical applications.


   P015: The Associations of Comparative In vitro and In vivo Quantifications of Tau Deposits with Neurodegeneration in Tauopathy Mouse Models Top


Bin Ji*1, Ni1, Ono1, Sahara1, Zhang1, Aoki1, Suhara1, Higuchii1

1National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan

Background/Aims: Fibrillary tau aggregates in tauopathies including Alzheimer’s disease (AD) and allied neurodegenerative disorders have been visualized in-vivo by positron emission tomography (PET), while mechanistic links between PET-detectable tau deposits and neurotoxicity remain elusive. Here, we took advantage of transgenic mouse models of tauopathies to evaluate associations between PET and postmortem measures of tau probe binding and their relation to neuronal loss. Methods: PET with a tau probe, 11C-PBB3, and volumetric magnetic resonance imaging (MRI) were performed for rTg4510 and non-transgenic mice. Binding of 11C-PBB3 and its blockade by another tau binding compound, AV-1451 (also known as T807), in homogenized brains of tauopathy patients (AD and progressive supranuclear palsy (PSP)) and rTg4510 and PS19 mice were quantified, and PBB3-positive and phosphorylated tau lesions in sectioned brains of these mice were assessed. Results: In-vivo 11C-PBB3 binding to the rTg4510 forebrain was increased relative to controls, and was correlated with local atrophy. In-vitro 11C-PBB3 binding in the forebrain was also well correlated with in-vivo radioligand binding and regional atrophy in the same individual rTg4510 mice. By contrast, in-vitro 11C-PBB3 binding was elevated in the brainstem but not hippocampus of PS19 mice, despite a pronounced loss of neurons in the hippocampus rather than brainstem. Finally, PBB3 and AV-1451 showed similar binding properties between mouse models and tauopathy patients. Conclusion: The present findings support the distinct utilities of 11C-PBB3-PET along with MRI of rTg4510 and PS19 mice for quantitatively pursuing mechanisms connecting PET-detectable and PET-undetectable tau aggregations to neuronal death, which recapitulate two different modes of tau-provoked neurotoxicity.


   P016: Cannabinoid Receptor 1 is Associated with the Pathogenesis of Alzheimer’s Disease-A Longitudinal 18F-FMPEP-d2 PET study with APP/PS1-21 Mouse Model Top


Jatta S Takkinen*1,2, F López-Picón1,2, A Kirjavainen1,3, R Pihlaja1,2, A Snellman1,2, T Ishizu2,4, E Löyttyniemi5, O Solin3,6,7, J O Rinne1,8, M Haaparanta-Solin1,2

1Turku PET Centre, 2MediCity Research Laboratory, 3Radiopharmaceutical Chemistry Laboratory, 4Institution of Biomedicine, 5The Department of Biostatistics, University of Turku, 6Accelerator Laboratory, Åbo Akademi, 7The Department of Chemistry, University of Turku, 8Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland

Background/Aims: The role of type 1 cannabinoid receptor 1 (CB1R) in the pathogenesis of Alzheimer’s disease (AD) is unclear, hampering the elucidation of disease mechanism.[1],[2],[3],[4] We aimed to evaluate the brain profile of CB1Rs in an aging APP/PS1-21 mouse model of AD using longitudinal PET with 18F-FMPEP-d2, a CB1R inverse agonist. Methods: 18F-FMPEP-d2 binding ratios were measured with 30-min static PET/CT scans 90 min after injection using thalamus as a reference region. Male APP/PS1-21 (n=8) and wild-type (WT) control (n=8) mice were imaged at 6, 9, 12 and 15 months of age. Additional APP/PS1-21 (n=29) and WT (n=26) mice were employed for ex vivo 18F-FMPEP-d2 brain autoradiography studies. Western blot and immunohistochemistry analyses were performed to evaluate the tracer binding, pretreatment with rimonabant to verify the binding specificity, and thin-layer chromatography to evaluate tracer metabolism in plasma and brain. All animal experiments were approved by the Regional State Administrative Agency for Southern Finland with guidelines of the International Council of Laboratory Animal Science. Results: APP/PS1-21 mice had lower (p<0.05) 18F-FMPEP-d2 binding ratios in the parietotemporal cortex and hippocampus than age-matched WT mice. Western blot demonstrated no differences between APP/PS1-21 and WT mice in the CB1R abundance, whereas lower (p<0.05) receptor expression was observed in 9-month-old male mice compared to female mice. One radioactive metabolite was found in the brain, and the amount of unchanged 18F-FMPEP-d2 in the brain was 84% 240 minutes after the injection. Conclusion: The results provide the first demonstration that 18F-FMPEP-d2 PET imaging can be used in APP/PS1-21 mice to monitor impairments in CB1R availability, but not receptor density. This radioligand is a promising PET imaging tool for AD research in terms of CB1R function, which may further facilitate ongoing development of novel therapeutic approaches based on endocannabinoid regulation.

References

  1. Ahmad R, Goffin K, Van den Stock J, De Winter FL, Cleeren E, Bormans G, et al. In vivo type 1 cannabinoid receptor availability in Alzheimer’s disease. Eur Neuropsychopharmacol 2014;24:242-50.
  2. Kalifa S, Polston EK, Allard JS, Manaye KF. Brain Res 2011;1376:94-100.
  3. Kärkkäine E, Tanila H, Laitinen JT. Functional autoradiography shows unaltered cannabinoid CB1 receptor signalling in hippocampus and cortex of APP/PS1 transgenic mice. CNS Neurol Disord Drug Targets 2012;11:1038-44.
  4. Manuel I, González de San Román E, Giralt MT, Ferrer I, Rodríguez-Puertas R. Type-1 cannabinoid receptor activity during Alzheimer’s disease progression. J Alzheimers Dis 2014;42:761-6.



   P017: Noninvasive Metabolic Analysis in Rat Brains Using L-[3-11C]lactate with Positron Emission Tomography Top


Takeshi Temma*1,2, H Kawashima2,3, N Kondo1,2, M Yamazaki2, K Koshino2, H Iida2

1Osaka University of Pharmaceutical Sciences, Takatsuki, 2Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita, 3Radioisotope Research Center, Kyoto Pharmaceutical University, Kyoto, Japan

Background/Aims: While recent researches suggest a possibility of lactate to be utilized as an energy source and a signaling molecule in living brains, it lacks clear evidence based on in vivo data. We thus aimed to synthesize L-[3-11C]lactate in one-pot enzymatic synthetic procedure, evaluate chemical forms in the blood after intravenous administration, and perform in vivo positron emission tomography (PET) scans with normal and fasted rats followed by pharmacokinetic analysis. Methods: The study protocol was approved by animal welfare committee of our institute. Racemic [3-11C]alanine was obtained by 11C-methylation of the corresponding precursor and a deprotection step, which was followed by the reaction with an enzyme mixture to provide L-[3-11C]lactate via [3-11C]pyruvate. The chiral purity was measured by an HPLC method using a Shodex ORpak CRX-853 column. Radioactive chemical forms in the arterial blood of SD rats 10 min after bolus iv injection of L-[3-11C]lactate were evaluated by an HPLC method using a Cosmosil HILIC column. PET scans were performed in normal and fasted SD rats administrated with L-[3-11C]lactate followed by 1-tissue-2-compartment model analysis. Results: L-[3-11C]lactate was synthesized with 13.4% radiochemical yield, >95% radiochemical purity, and >99% enantiomeric excess within 50 min. The blood radioactivity reached its peak immediately after L-[3-11C]lactate injection, rapidly decreased to the bottom level within 90 sec, and slowly cleared thereafter. The blood radioactivity existed mainly as [11C]glucose (78.9%) and slightly as L-[3-11C]lactate (12.1%). Insulin pretreatment partly inhibited the glyconeogenesis conversion leading to 55.4% as [11C]glucose and 38.9% as L-[3-11C]lactate. The fasted rats showed a higher rate constant for radioactivity transfer from blood to brain than normal rats. Conclusion: We successfully synthesized L-[3-11C]lactate in one-pot enzymatic synthetic procedure and revealed a rapid metabolic conversion to [11C]glucose in the blood. The pharmacokinetic PET analysis indicated a possibility of active lactate usage in the brains in vivo.


   P018: Validation of Computer-aided Diagnosis of Diffuse Lewy Body Disease Using Cerebral Blood Flow Studies Top


Ashleigh Hull*1, K Hickson2, E Bezak1,3, R Casse2

1School of Health Sciences, University of South Australia, 2Department of Nuclear Medicine, The Queen Elizabeth Hospital, 3Department of Physics, University of Adelaide, Adelaide, Australia

Background/Aims: Diffuse Lewy body disease (DLB) is a complex neurodegenerative disorder whose diagnosis may be assisted by cerebral perfusion single-photon emission computed tomography/computed tomography (SPECT/CT). However, the low specificity of cerebral perfusion SPECT/CT and overlapping features of neurodegenerative disorders can impair image interpretation and diagnosis.[1] NEUROSTATTM, a computer-aided diagnostic system, may improve this interpretation. We aim to examine the usefulness of NEUROSTATTM for the investigation of DLB by clinicians with varying years of experience and in patients of different age ranges. Methods: Cerebral perfusion SPECT/CT data of 58 patients with suspected DLB was retrospectively retrieved from two sites and classified into possible or probable DLB by two experienced clinicians. Four clinicians of varying years of experience individually interpreted the SPECT/CT data twice for each patient. Firstly, the data was visually interpreted with no additional software used. The data was re-interpreted after at least a one-month break with the addition of NEUROSTATTM. For each patient and interpretation, the clinicians selected a diagnosis of not DLB, possible DLB or probable DLB. The clinicians’ diagnoses from the initial and NEUROSTATTM interpretations were compared for each patient. The influence of NEUROSTATTM was analysed on the basis of the clinicians’ experience (in years) and the age-ranges of the patients (e. g. 50–59, 60–69, 70–79 years old). This study received ethical approval from the SA Health Human Research Ethics Committee and the University of South Australia Human Research Ethics Committee. Results: NEUROSTATTM may be a useful asset when investigating suspected DLB on cerebral perfusion SPECT/CT imaging. The additional value of NEUROSTATTM was deemed greater in clinicians of lesser experience. Conclusion: A combination of visual interpretation and NEUROSTATTM has demonstrated value in improving the specificity of cerebral perfusion SPECT/CT studies, and is useful in the diagnosis of DLB.

References

  1. Imabayashi E, Yokoyama K, Tsukamoto, et al. EJNMMI 2016;6:67.



   P019: Cingulate Island Sign Temporally Changes in Dementia with Lewy Bodies Top


T Iizuka1, Masashi Kameyama*2

1Department of Neurology, Fukujuji Hospital, Kiyose, 2Department of Diagnostic Radiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan

Background/Aims: The cingulate island sign (CIS) that reflects sparing of the posterior cingulate cortex (PCC) relative to the precuneus plus cuneus on FDG-PET and brain perfusion SPECT, has been proposed as a feature of dementia with Lewy bodies (DLB). As the CIS is influenced by concomitant Alzheimer’s disease (AD)-type neurofibrillary tangle (NFT) pathology, we postulated that the CIS gradually disappears as DLB progresses. Methods: To determine temporal changes in the CIS, 24 patients with mild DLB and 7 with prodromal DLB underwent 123I-IMP–SPECT and MMSE twice at an interval of two years. The CIS was evaluated as a ratio that was derived by dividing IMP accumulation in the PCC with that in the precuneus plus cuneus. Results: We found that the CIS changed over time and that the relationship between CIS ratios and MMSE scores was inverted U-shaped. We have fitted the relationship with quadratic function and the peak was in the vicinity of an MMSE score of 22 and it gradually diminished as the MMSE score decreased. Moreover, a lower CIS ratio in mild DLB was associated with a worse prognosis for cognitive decline, presumably due to concomitant AD-type NFT pathology. Conclusion: Our findings of the temporal change of CIS would provide a foundation for the appropriate usage of CIS as a biomarker.


   P020: Additional Role of 18F-FP-CIT Positron Emission Tomography in Treatment of Multiple System Atrophy of the Cerebellar Type Top


Young Jin Jeong*1, D Y Kang1

1Department of Nuclear Medicine, Dong-A University Hospital, Busan, Republic of Korea

Background/Aims: We evaluated the difference in the status of dopamine transporters (DATs) depending on Parkinsonism, cerebellar, and autonomic features using 18F-FP-CIT positron emission tomography (PET) in multiple system atrophy with cerebellar ataxia (MSA-C). We also assessed whether the DAT PET could be useful in the management of MSA-C. Forty-nine patients who were clinically diagnosed as possible to probable MSA-C were included. Methods: Forty-nine patients who were clinically diagnosed as possible to probable MSA-C were included. 18F-FP-CIT PET images were classified into normal and abnormal scans by visual and quantification analysis. The differences in patient characteristics, clinical symptoms and drug response between the normal and abnormal scan groups of 18F-FP-CIT PET were evaluated. Results: Based on the 18F-FP-CIT PET results, patients were classified into normal (n=25) and abnormal (n=24) scan groups. There were statistically significant differences in rigidity, bradykinesia, postural instability, asymmetry, and specific uptake ratio (SUR) between the two groups but no significant differences in tremor and cerebellar/autonomic symptoms. Dopaminergic medications were administered to 22 patients. All seven patients with normal scans showed no change, while 10 of the 15 patients with abnormal scans showed clinical improvement. There was a trend of a negative correlation between levodopa equivalent dose and SUR, but it was not statistically significant. Conclusion: DAT imaging, such as 18F-FP-CIT PET, may be useful in predicting the response to dopaminergic medication regardless of cerebellar/autonomic symptoms in MSA-C. In addition to being used for the diagnosis of the disease, it may be used as a treatment decision index.


   P021: Dopamine Transporter Imaging with 18F-FE-PE2I Positron Emission Tomography versus DaTSCAN™ Single-Photon Emission Computed Tomography: A Clinical Comparison Top


Susanna Jacobson Mo*1,2, J Axelsson2,3, A Larsson3, L Jonasson1,2,4, M Ögren1, A Varrone5, S af Bjerkén4,6, J Linder6, K Riklund1,2

1Diagnostic Radiology, 2Umeå Centre for Functional Brain Imaging (UFBI), 3Radiation Sciences, Radiation Physics, 4Integrative Medical Biology, Umeå University, 6Pharmacology and Clinical Neuroscience, Umeå University, Umeå, 5Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden

Background/Aims: The highly selective Dopamine Transporter (DAT) tracer 18F-FE-PE2I[1] is under evaluation within the PEARL-PD-study (Eudra CT: 2015–003045-26). One aim is to compare the diagnostic performance of DAT-imaging with 18F-FE-PE2I PET to conventional 123I-FP-CIT SPECT (DaTSCAN™, GE Healthcare). A head-to-head comparison of striatal DAT-activity with 18F-FE-PE2I and DaTSCAN™ is done in healthy controls (HC) and de novo Parkinson´s Disease patients (PD). Initial results from the first clinical study comparing these ligands are presented. Methods: A baseline DaTSCAN™, a dynamic 18F-FE-PE2I PET (separated by 5-21 days) and a 3T-MRI were acquired in 27 HC (mean age 69 years) and 8 patients (mean age 68 years) with newly onset PD according to United Kingdom´s Parkinson´s Disease Brain Bank criteria. MRI-based segmented volumes of interest (FreeSurfer v 6.0.0), manually delineated substantia nigra (SN), and thresholding of PET-data were used for [18F]FE-PE2I binding potential quantification. The commercially available software DaTQuant™ was used for DaTSCAN™ semi-quantitative image analysis (reference values derived from our HC cohort). Results: DAT-measurements correlated satisfactory between 18F-FE-PE2I and DaTSCAN™ (ICC>0.8, p<0.001). However, in HC the caudate/putamen-ratio was inverted between methods and striatal DAT-binding correlation with age was slightly higher for 18F-FE-PE2I (R=-0.523, p=0.005) than DaTSCAN™ (R=-0.396, p=0.041). Four patients had normal DAT-uptake (mean of left and right side) in striatal compartments with both methods and in the SN with 18F-FE-PE2I; remaining patients had significantly reduced DAT-uptake in the caudate and putamen with both methods (p <0.001) and also in the SN with 18F-FE-PE2I (p<0.001). Conclusion: A good agreement of striatal DAT-binding with 18F-FE-PE2I PET and DaTSCAN™ suggests comparable basic diagnostic performance. The possibility of DAT-quantification in the SN with 18F-FE-PE2I PET, which might add important diagnostic information, is an advantage. Ongoing analysis in a larger group of patients will further elucidate these findings.

References

  1. Fazio P, Svenningsson P, Forsberg A, Jönsson EG, Amini N, Nakao R, et al. Quantitative analysis of ¹8F-(E)-N-(3-iodoprop-2-enyl)-2β-carbofluoroethoxy-3β-(4’-methyl-phenyl) nortropane binding to the dopamine transporter in parkinson disease. J Nucl Med 2015;56:714-20.



   P022: Effect of Copper Treatment on Striatal D2 Receptor Expression in a Mouse Model of the Copper-Deficient Parkinson’s Disease Brain: A 11C-Raclopride Positron Emission Tomography Study Top


Gita Rahardjo*1, K Aoun2, A Parmar1, E Suryana2, S Meikle3, M Safavi-Naeini1, D Zahra1, A Arthur1, G Emvalomenos4, K Double2

on behalf of Pre-clinical Parkinson’s Disease Research Laboratory, Florey Institute of Neuroscience and Mental Health, Parkville, Australia

1NSTLI Radiobiology and Bioimaging, ANSTO, Lucas Height, 2Discipline of Biomedical Science and Brain and Mind Centre, 3Brain and Mind Centre, 4The University of Sydney, Sydney, Australia

Background/Aims: Studies in patients with Parkinson’s disease suggest that selective dopaminergic neuron vulnerability is associated with a regional copper deficiency. Furthermore, copper delivery to the brain is beneficial in different animal models of Parkinson’s disease. In this study, we investigated the dopaminergic system in genetically-modified mice exhibiting a copper-deficiency in the CNS and how it is affected following copper treatment utilising PET imaging using 11C-Raclopride, a radiolabelled selective antagonist on D2 dopamine receptors. Methods: Thirty two Slc31a1tm21Djt/J Ctr1+/-mice were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (45mg/kg MPTP) to induce substantia nigra dopamine cell loss. Randomly selected animals were treated with daily oral administration of 3mg/kg of copper(II)-bis(thiosemicarbazonato) (Cu-GTSM) (or vehicle) for 21 days and allowed 7 days acclimatisation following interstate transportation. A group of eight non-MPTP-treated were used as control. Animals were imaged on an Inveon PET/CT system following administration of 11C-Raclopride. Following scan, animals were sacrificed and dissected for further in vitro analysis. Use of animal for this experiment was approved by Sydney University Animal Ethics Committee. Results: In vitro experiments showed reduction in striatal levels of dopamine (60.5% reduction, p=0.01) and the primary dopamine metabolite (DOPAC, 50.8 reduction, p=0.006) following MPTP lesion. In Cu-GTSM treated MPTP lesioned mice, striatal levels of dopamine and DOPAC were not significantly different to unlesioned vehicle-treated controls, suggestive of a mild neuroprotective effect. PET showed no significant difference between any of the groups in the binding potential of 11C-Raclopride to the D2 receptor in the striatum. Conclusion: Our data suggests copper delivery to the CNS may attenuate MPTP-induced dopamine loss in the striatum in this mouse model, however, this effect appears to be independent of the binding potential of D2 dopamine receptors. Further investigation of, for example, other dopamine receptor subtypes or dopaminergic markers of nigrostriatal integrity is required to understand the mechanism underlying these observed changes.


   P023: Count-Based Method for Specific Binding Ratio Calculation in 123I-FP-CIT Single-Photon Emission Computed Tomography Analysis Top


M Rahman1, M Islam1,2, T Tsujikawa1, K Sugimoto1, Hidehiko Okazawa*1

1Biomedical Imaging Research Center, University of Fukui, Eiheiji-cho, Japan, 2Department of Biomedical Engineering, Khulna University of Engineering and Technology, Khulna, Bangladesh

Background/Aims: Dopamine transporter (DAT) imaging using [I-123]ioflupane (FP-CIT) SPECT is widely used for clinical assessment of the nigrostriatal function in patients with parkinsonian syndromes (PS). For evaluation of functional reduction, semi-quantitative values of specific binding ratio (SBR) are usually obtained using various methods. To calculate the SBR appropriately with a simple and easy way, a new count-based striatal extraction method was developed. Methods: A total of 200 patients (mean age 72 ± 10 years) who were suspected of PS or dementia with Lewy body (DLB) were included in this study. The patients were divided into 3 groups of PS (n=100), DLB (n=11) and non-PS (n=89) after the DAT-SPECT and clinical follow-up. The patients underwent FP-CIT SPECT/CT 3-4 hours after the 167MBq tracer injection. The image data were reconstructed into three images, with attenuation and scatter correction (ACSC), only with CT attenuation correction (CTSC) and without any correction (NAC). The SBR values for each patient were obtained using the Tossici-Bolt’s method and our new method. The new method extracted striatal voxels and counts using the average volume of the striata, and calculated the SBR with reference counts in the occipital cortex. Results: There were no differences in the mean age and gender in the 3 groups. The mean SBR values for the 3 groups and the two methods were significantly different each other. The coefficients of variation (CV) of the SBR were significantly smaller in the new method compared with the Tossici-Bolt’s method (p<0.0001, F-test) except for the CTAC reconstruction images. There were no differences in the SBR results between two operators if they used the new method. Conclusion: Our new method for SBR calculation in the FP-CIT SPECT showed less CV with high reproducibility, which would be useful in clinical setting.


   P024: A Feasibility Study of Parkinson’s Disease by Sequential Imaging with 18F-FP-CIT Positron Emission Tomography/Magnetic Resonance Imaging and Adjunctive T2 FFE Magnetic Resonance Imaging (T2*-weighted Magnetic Resonance Imaging) Top


Minki Yoon*1

1Department of Nuclear Medicine, Hallym General Hospital, Incheon, Republic of Korea

Background/Aims: A cause of Parkinson’s disease (PD) is well known as dysfunction of nigrostriatal pathway. 18F-FP-CIT PET is a useful tool for evaluation of Parkinson’s disease (PD), based on the mechanism of dopamine transporter (DAT). T2 FFP (T2-fast field echo) MRI has demonstrated nonspecific findings of substantia nigra (SN) in parkinsonism such as hypointensity of SN and ‘smudging sign’ (the ambiguity between the SN and the red nucleus, RN). We tried a sequential imaging with 18F-FP-CIT PET/MRI and T2 FFE MRI (T2*-weighted MRI) to diagnose PD. Methods: Five patients (4 male, ages 52, 61, 67, 70 respectively, and one female, age 81) with hand tremor or gait disturbance underwent 18F-FP-CIT PET/MRI (tandem type). PET/MRI images were acquired at 3 hours after 185 MBq 18F-FP-CIT administration. T2 FFE MRI (field strength: 3T) images were obtained before the PET imaging. 18F-FP-CIT uptake of striatum and signal intensity of SN were visually assessed by a nuclear medicine physician. Results: We performed sequential imaging of 18F-FP-CIT PET/MRI and T2 FFE MRI successfully without any difficulties. Three patients demonstrated hypometabolic state of DAT in the striatum by 18F-FP-CIT PET/MRI. T2 FFE MRI also showed the hypointensity or smudging sign of the SN in these patients. Two patients demonstrated that there was no abnormal metabolism of DAT in the striatum nor abnormal findings in the SN. Conclusion: A combined model of 18F-FP-CIT PET/MRI and adjunctive T2 FFE MRI imaging is feasible to evaluate parkinsonism. It can be a useful modality without position change of the patient, especially in the field of brain study. It needs more data and experiences to establish the usefulness of 18F-FP-CIT PET/MRI and adjunctive T2 FFE MRI in PD.


   P025: Validation of 131I-MIBG Cardiac Scintigraphy in Parkinsonism: A Preliminary Study Top


Wenjia Zhu*1, Huo1, Xu2, Wang2

1Nuclear Medicine, 2PUMCH, Beijing, China

Background/Aims: 123I-MIBG cardiac scintigraphy could be helpful in differentiating Parkinson’s disease (PD) from other neurodegenerative parkinsonism. The purpose of the present study is to validate the feasibility of 131I-MIBG scintigraphy in differential diagnosis of Parkinson syndrome. Methods: We prospectively recruited 9 patients with PD, 12 patients with Parkinson plus syndrome (PPS), including 9 patients with multiple-system atrophy (MSA) and 4 patients with progressive supranuclear palsy (PSP), and 6 controls who had no neurodegenerative disorder. After a 60-min resting period, patients and controls received an intravenous injection of 111MBq 131I-MIBG. A 5-min planar image of the chest was obtained in an anterior view at different time points (15min, 30min, 1h, 2h, 4h, 1D, and 2D post-injection). Regions of interest (ROI) were manually drawn over the heart contour (H), the upper mediastinum (M), and the left lung (L) for each planar image. Average counts per pixel in the ROIs were used to calculate heart-to-mediastinum (H/M), heart-to-left lung (H/L) ratio, and washout rate. Total counts per image (TC) at different imaging time points were also recorded. The discriminative index (DI) was defined as the difference between cardiac and lung uptake. Results: There was no significant difference in either gender, H-Y stage or disease duration between groups. Patients in PD group were significantly older than those in PPS group. TC decreased gradually, but remained above 200K within 4-hour post-injection. DI at 4h post-injection is significantly higher than those at other time points (P<0.05). The H/M ratios and WR in PD patients were significantly lower than those in PPS patients, or controls at all imaging time points (P<0.05). The threshold values of H/M at 4h post-injection that distinguished PD patients and PPS patients were 2.02 (sensitivity, 83.3%; specificity, 100%; accuracy, 85.7%). The threshold values of WR at 4h post-injection that distinguished PD patients and PPS patients were 35% (sensitivity, 91.7%; specificity, 88.9%; accuracy, 90.4%). Conclusion: 131I-MIBG scintigraphy is a feasible and economical method to depict cardiac sympathetic activity and the diagnostic performance is comparable to that of 123I-MIBG.


   P026: 18F-Fludeoxyglucose Positron Emission Tomography in Bottom of the Sulcus Dysplasia; a Focal Surgically Remedial Epileptic Lesion Top


Salvatore U Berlangieri*1, M Pedersen2, M Semmelroch2, R Kalnins3, G Jackson2,4

1The University of Melbourne, Melbourne, Australia, 2Melbourne Brain Centre, Florey Institute for Neurosciences, 3Anatomical Pathology, Austin Health, Heidelberg, 4Department of Medicine, The University of Melbourne, Melbourne, Australia

Background/Aims: Bottom of the sulcus dysplasia (BOSD) is a common cause of apparently lesion negative epilepsy after initial MRI. There is often an ‘easy to miss’ small area of increased signal in the base of a sulcus and sometimes a transmantle tail on MRI. Despite the features that define the existence of a dysplasia, even in expert centres 20% of these are not identified on initial assessment of the MRI study. In these patients with an initially negative MRI assessment, 18F-FDG PET has a potential role in identifying subtle abnormality on structural imaging. The aim of this study is to explore the role of 18F-FDG PET and MRI in identifying BOSD in patients with focal epilepsy. Methods: We identified 20 patients with pathologically proven BOSD from the Austin Hospital Comprehensive Epilepsy Surgery program. All had MRI positive findings on a high-quality MRI, although 5 were not identified on initial assessment. Results: In three cases the MRI abnormality was detected only after finding a focal abnormality on the 18F-FDG PET study and re-examination of this area on the structural MRI study. In all cases that had a 18F-FDG PET study there was focal or regional abnormality associated with the BOSD. Good seizure free outcome from highly focal surgical resection was achieved in most cases. Conclusion: Bottom-of-sulcus dysplasia is a distinctive malformation of cortical development that can be diagnosed based on imaging characteristics. 18F-FDG PET has an important role in suggesting the presence of these lesions as they are typically hypometabolic in a focal cortical area. Reliable identification of this type of malformation of cortical development is clinically important because the lesion is highly epileptogenic and the prognosis for seizure control is excellent after focal resection. Focal 18F-FDG PET hypometabolism should suggest an intense review of the MRI for these lesions.


   P027: Metabotropic Glutamate Receptor Subtype 1 Positron Emission Tomography Imaging in Medial Temporal Lobe Epilepsy Patients with Hippocampal Sclerosis Top


Motoki Inaji*1, T Nariai1, S Hayashi1, K Wagatsuma2, J Toyohara2, K Ishii2, T Maehara1

1Department of Neurosurgery, Tokyo Medical and Dental University, 2Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan

Background/Aims: Metabotropic glutamate receptor subtype 1 (mGluR1) is a crucial target in the development of new medications to treat central nervous system disorders including epilepsy. Though some previous basic research suggested that the mGluR1/5 contributed to the formation of the epileptogenesis, their behaviour was still unknown in the epilepsy patients. We have recently developed newly radiotracer, which was specific to the mGluR type1, N-[4-[6-(isopropylamino)pyrimidin-4-yl]-1,3-thiazol-2-yl]-4-11C-methoxy-N-methylbenzamide (11C-ITMM), which made mGluR1 in vivo imaging possible using positron emission tomography (PET). We report the initial mGluR1 PET images of medial temporal lobe epilepsy (mTLE) patients with hippocampal sclerosis (HS). Methods: Four mTLE patients with HS were included in this study. They completed three different PET studies preoperatively: 18F-FDG, 11C-flumazenil (FMZ) and 11C-ITMM. Regions of interest (ROIs) were drawn manually on each MRI. Template ROIS included hippocampus, amygdala, parahippocampal gyrus, lateral temporal cortex, and frontal cortex. Template ROIs were applied to each subject’s PET image and mean voxel values were extracted for each ROI. Values of ipsilateralside were compared to the contralateral side. Results: 11C-ITMM PET images showed that mGluR1 binding decreased in both sclerotic hippocampus and amygdala (78% of contralateral binding, 82%), but they unchanged in the lateral temporal and frontal cortex. 11C-FMZ PET images revealed binding to the central benzodiazepine receptors decreased at hippocampus and amygdala (61%, 71 %), similar to the 11C-ITMM PET study. 18F-FDG PET showed glucose metabolism decreased in amygdala, hippocampus, parahippocampal gyrus and lateral temporal cortex (78%, 90%, 85% and 90%). Conclusion: Binding to the mGluR1 decreased at sclerotic hippocampus and amygdala, similar to the 11C-FMZ PET study. These data suggested mGluR1 receptor decreased at epileptic foci because of the neuronal loss. 11C-ITMM PET has potential to diagnose and visualize epileptic focus. Furthermore, 11C-ITMM PET might be useful clinical imaging tool to clarify the mGluR1 contribution to the epilepsy.


   P028: Adenosine A1R Positron Emission Tomography Imaging in Mesial Temporal Lobe Epilepsy Patients Top


Motoki Inaji*1, T Nariai1, S Hayashi1, M Sakata2, K Oda2, K Ishiwata2, K Ishii2, T Maehara1

1Tokyo Medical and Dental University, 2Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan

Background/Aims: The positron emission tomography (PET) radioligand for adenosine A1 receptor (A1R) [1-methyl-11C] 8-dicyclopropylmethyl-1-methyl-3-propylxanthine (MPDX) has recently been developed for human brain imaging. In the present study, we evaluated the alteration of the A1R in patients with mesial temporal lobe epilepsy (mTLE) in vivo. Methods: Fourteen patients with mTLE were included in this study. Three PET examinations were sequentially performed to measure A1R binding with 11C-MPDX, glucose metabolism with 18F-fluorodeoxyglucose (FDG), and central benzodiazepine receptor binding with 11C-flumazenil (FMZ), decreases of 11C-FMZ uptake indicate neuronal loss. Results: 11C-MPDX did not depict any lesion with significantly decreased nondisplaceable binding potential (BPND) in comparison to healthy controls in ROI analysis. Instead, it showed a significant increase of BPND in the frontal and lateral temporal cortex (p<0.01) in ROI analysis. In 18F-FDG PET, the standardized uptake values (SUV) were decreased in the mesial temporal lobe to controls (p< 0.01). In 11C-FMZ PET, the SUV was also decreased in medial temporal lobe in ROI analysis (p<0.01). The area with significantly increased 11C-MPDX binding did not overlap with the areas of neuronal loss showing decreased 11C-FMZ binding, and did not overlap with reduced18F-FDG uptake areas. Conclusion: We obtained the first 11C-MPDX PET images reflecting the A1R BPND in mTLE patients. 11C-MPDX depicted increased A1R BPND in the areas surrounding the injured brain, whereas 18F-FDG demonstrated reduction areas throughout the brain. The results suggested that A1R might continuously confer neuroprotective or neuromodulatory effects in mTLE patients.


   P030: Automated Injector for Ictal Single-Photon Emission Computed Tomography in Epilepsy Top


Xavier Setoain*1, O Vernet2, F Gil2, M Mayoral1, N Sanchez1, F Campos1, P Roldan3, A Perissinotti1, M Carreño4

Departments of 1Nuclear Medicine, 2Neurology, 3Neurosurgery and 4Neurology, Hospital Clínic, Barcelona, Spain

Background/Aims: To present the main features of the first remotely controlled automated injector system for ictal SPECT (epiJET, LemerPax, Nantes, France) used in patients with refractory epilepsy. We report the results of injection time (Ti) and seizure focus (SF) localisation with ictal SPECT using epiJET. Methods: Ti and SF localisation using epiJET in 35 patients were compared with Ti (t-test) and SF localisation (X2) of the retrospective database of the historic pool of 126 patients injected manually during 2011-2015. Injection dose error and radiation dosimetry were analysed. Results: EpiJET injects the full volume of the perfusion radiotracer (3-8 ml) in 3,5 s on average (2-6 s) and all injections were performed without any problem. Ti with epiJET, using the remote control system and doing the injection from the control-EEG room was 13±7,1 s. Manual Ti was 17±11,7 s on average (p<0,001). Otherwise, when the manual injection took place with the operator waiting the seizure from the control room (same conditions used in epiJET), the Ti in these group of 54 patients was 24±12 s (P<0,001). When the manual injection took place with the operator waiting the seizure inside the patient room (bedside and worse conditions compared with epiJET), the average Ti in these 72 patients were 13±9,7 s (P=0,04). Ictal SPECT with epiJET localized SF in 27/33 (81%) patients and with manual injection in 89/117 (76%) of patients (p>0.05). EpiJET calculate the volume to inject in real-time accounting of the 99mTc decaying, so injection dose error decreased from <12% with manual injection to <5% with epiJET. EpiJET reduce the risk of radiation contamination and decreases radiation dosimetry of nurses. The closed cartridge avoid any manipulation of radioactive tracer in the epilepsy unit. Radiation exposure is also very low, so with the syringe filled with 3700 MBq of 99mTc, the radiation exposure at 50 cm was 0.07 µSv/h. Conclusion: EpiJET, the first commercially available dedicated automated injector for ictal SPECT simplify the methodology for injecting radioactive doses during seizure, making ictal SPECT more accessible. First results using epiJET are promising in reducing injection time and improving SPECT accuracy.


   P031: A Comparison of the Different Attenuation Correction Methods for Calculating Semiquantitative Parameters of TRODAT-1 SPECT Top


C J Chen1, Yu-Hung Chen*2, S H Liu2

1School of Medicine, Tzu Chi University, 2Department of Nuclear Medicine, Tzu-Chi General Hospital, Hualien, Taiwan

Background/Aims: Chang’s method has long been used as an attenuation correction (AC) method for brain SPECT. Nonetheless, AC by CT is robust and presumes to be the reference standard. The aim of this study is to compare the semiquantitative TRODAT-1 binding ratio derived from these two AC methods. Methods: Twenty-two 99mTc-TRODAT-1 brain SPECT/CT were reviewed. The study has been approved by the local Institutional Review Board and Ethics Committee. A waiver of consent has also been obtained. Regions-of-interest (ROI) were placed on the caudate nuclei, putamina, and occipital cortices. The binding ratio was calculated in average counts: (ROI of caudate nucleus or putamen-occipital cortex)/occipital cortex. Difference between two AC methods was analysed by paired T-test. Pearson’s correlation was used to study the correlation between these 2 methods and the Bland-Altman plot was used to study the bias. erived from these two AC methods. Results: The binding ratio in all 4 (bilateral caudate nuclei and bilateral putamina) striatal regions showed significant difference between two AC methods (p<0.01). The biases between two AC methods in the 4 striatal regions were around 0.1, with higher value using Chang’s method. The Pearson’s correlation coefficient constantly showed excellent correlation across all 4 regions between these two AC methods (r>0.9). Conclusion: Chang’s AC method slightly overestimates the binding ratio with statistical significance. Suggesting that the normal reference values for these two AC methods can not be used interchangeably. Nevertheless, the correlation between two AC methods is excellent. Suggesting that Chang’s method still can reliably be used to estimate striatal TRODAT-1 binding ratio.


   P032: A New Noninvasive Graphical Method for Quantification of Cerebral Blood Flow with [123I] N-isopropyl-p-iodoamphetamine Top


Masashi Kameyama*1, K Watanabe2

1Department of Diagnostic Radiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, 2Department of product planning, Nihon Medi-Physics Co., Ltd., Tokyo, Japan

Background/Aims: [123I] N-isopropyl-p-iodoamphetamine (123I-IMP) is an ideal perfusion tracer for single photon emission computed tomography (SPECT), which shows good linearity between cerebral blood flow (CBF) and accumulation. However, quantification of CBF using 123I-IMP without arterial blood sampling was challenging and previous methods needed regression formulae to calculate CBF. Methods: We have developed a new non-invasive quantification method for CBF using 123I-IMP and dynamic planner images. Our method does not need any regression formulae and it can measure CBF value by itself. Results: CBF obtained by our method showed significant correlation with established autoradiograph (ARG) method. Conclusion: Our method was proved to be easy to execute and reliable.

Disclosure of Interest: M Kameyama Conflict with: Nihon Medi-Physics, K Watanabe Conflict with: Nihon Medi-Physics.


   P033: Cerebral Blood Flow and Oxygen Metabolism in Chronic Cerebral Hypoperfusion Model of Rat Top


Hiroki Kato*1, T Watabe1, K Isohashi1, Y Kanai1, S Naka1, G Horitsugi1, M Tatsumi1, E Shimosegawa1, J Hatazawa1

1Japan, Osaka University, Suita, Japan

Background/Aims: Cerebral perfusion and oxygen metabolism has not yet been clarified in the cerebral hypoperfusion rat model by occlusion of bilateral common carotid arteries (BCAO). We aimed to evaluate cerebral perfusion and oxygen metabolism in BCAO rat model. Methods: O-15 PET images were acquired in the BCAO and the sham rats in the acute phase (1 week after the surgery) or in the chronic phase (6 weeks after the surgery) by using small-animal PET system based on O-15 gas steady-state inhalation method mice under isoflurane anesthesia with repeated arterial blood sampling described in our previous study.[1] Results: As a result of PET study, in the BCAO, significantly lower CBF and significantly higher OEF than in the Sham in the acute phase, and significantly lower CMRO2 and significantly higher CBV than in the Sham in the chronic phase were observed. Conclusion: Cerebral perfusion and oxygen metabolism in the cerebral hypoperfusion rat model in the acute and the chronic phases under anesthesia were clarified by O-15 PET based on steady-state method.

References

  1. Watabe T, Shimosegawa E, Watabe H, Kanai Y, Hanaoka K, Ueguchi T, et al. Quantitative evaluation of cerebral blood flow and oxygen metabolism in normal anesthetized rats: 15O-labeled gas inhalation PET with MRI fusion. J Nucl Med 2013;54:283-90.



   P034: Scintigraphic Pattern of 18F-FDG Brain Uptake in Autoimmune Limbic Encephalitis: A Case Report Top


Muhammad Umar Khan*1, J Al-Ajmi1, Z S Abdullah1

1Nuclear Medicine, Al-Jahra Hospital, Kuwait, Kuwait

Background/Aims: Diagnosis of non-infectious autoimmune mediated limbic encephalitis (LE) is largely based on clinical criteria including detection of specific anti-neuronal autoantibodies. MR imaging is frequently employed. However, few case reports in published literature are available where PET/CT imaging is utilized to depict a characteristic scintigraphic configuration of brain 18F-FDG uptake. PET/CT imaging is primarily done to exclude concurrent malignancy. This case report aims to describe the representative scintigraphic pattern of 18F-FDG uptake in the brain in a patient with LE. Methods: An 18 year old female with history of epilepsy and clinical query of LE was referred to Nuclear Medicine Department, Al-Jahra Hospital Kuwait for 18F-FDG imaging as part of work up to exclude concurrent malignancy. Her serum autoantibodies result was pending at the time of imaging. She had MR Brain done prior to nuclear imaging. Her BMI was 24.56kg/m2. She underwent PET/CT imaging vertex to mid-thigh acquisition with 8.3mCi (307.1MBq) F-18 FDG, 60 minutes post injection. A dedicated Brain protocol was also acquired at 120 minutes post injection. Results: Symmetrical hypermetabolism was seen in the mesio-temporal region (SUVmax: Right 9.9; Left 11.4). Further hypermetabolism of the basal ganglia was also noted with patchy distribution in the right basal ganglia. No significant active focal hypermetabolic abnormality was observed elsewhere to suggest any tracer avid malignant process. MR Brain was unremarkable. Conclusion: Scintigraphic pattern of 18F-FDG brain uptake in this patient with LE appear to be concordant with the representative pattern observed in published literature.


   P035: PET Study on Traumatic Olfactory Loss Patients Top


Yoriko Murata*1, F Okutani2, H Iwasa1, K Miyatake1, N Hayashi1, N Akagi1, T Yamagami1

Departments of 1Radiology and 2Occupational Health, Otolaryngology, Kochi Medical School, Nankoku, Japan

Background/Aims: Head trauma is one of major causes of olfactory dysfunction. It is well known that traumatic brain injury induces severe olfactory loss, which does not respond well to conventional treatment compared to post infectious or sinonasal olfactory disorders. Pathological study showed that around brain region microglia accumulate as a neuroinflammation process for tissue recovery. Since the agent, PK11195 binds to benzodiazepine receptors on microglia, assessment of 11C-PK11195 binding by Positron Emission study is useful for observation of brain tissue restoration. It was reported 11C-PK11195 binding is enhanced for many years, meaning brain restoration continues for long time. Therefore, we analysed whole brains of the patients with posttraumatic olfactory loss twice with 6-month interval. Methods: Five patients with traumatic olfactory loss were recruited. It was confirmed that they had neither sinonasal disease nor neurodegenerative disease. Their olfactory functions including odor detection and recognition were assessed by T&T olfactometry. PET experiments were conducted twice with 6-month interval using PET scanner. At 11C-PK11195 injection we started dynamic PET scan for 60 minutes. Results: In 1 case who did not show improvement in olfactory recognition, high activity in bilateral thalamic area was depicted. Remaining cases, however, showed low activity or no change in the thalamus. Conclusion: Thalamic nuclei is the gateway to the cerebral cortex. It interconnects between the orbitofrontal cortex and olfactory cortex. High activity in 11C-PK11195 indicates that neuroinflammation involving microglia takes place in the thalamus. Our results show inflammation in the thalamus correlates brain restoration under improvement of olfactory recognition.


   P036: Brain Over Body-conscious Regulation of Cold Perception Top


Otto Muzik*1, V Diwadkar1

1Wayne State University, Detroit, United States

Background/Aims: Autonomous mechanisms of thermoregulation are only weakly affected by top-down modulation, allowing only transient tolerance for extreme cold. There is however, anecdotal evidence of a unique set of individuals known for extreme cold tolerance. Here we present a case study of a 57-year old Dutch national, Wim Hof, the so-called “Iceman”, with the ability to withstand frequent prolonged periods of extreme cold exposure based on the practice of a self-developed technique involving a combination of forced breathing, cold exposure and meditation (referred to as WHM). The relative contributions of the brain and the periphery that endow the Iceman with these capabilities is unknown. To investigate this, we conducted multi-modal imaging assessments of the brain and the periphery using a combination of fMRI and PET/CT imaging. Methods: Thermoregulatory defense was evoked by subjecting the Iceman (and a cohort of typical controls) to a fMRI paradigm designed to generate periods of mild hypothermia interspersed by periods of return to basal core body temperature. fMRI was acquired in two separate sessions: in a typical (passive) state and following the practice of WHM. In addition, the Iceman also underwent a whole body PET/CT imaging session using the tracers C11-hydroxyephedrine (HED) and 18F-fluorodeoxyglucose (FDG) during both thermoneutral and prolonged mild cold conditions. Results: fMRI analyses indicated that the WHM activates primary control centers for descending pain/cold stimuli modulation in the periaqueductal gray (PAG), possibly initiating a stress-induced analgesic response. In addition, the WHM also engages higher-order cortical areas (left anterior and right middle insula) that are uniquely associated with self-reflection, and which facilitate both internal focus and sustained attention in the presence of averse (e.g. cold) external stimuli. However, the activation of brown adipose tissue (BAT) was unremarkable. Conclusion: Our results provide compelling evidence for the primacy of the brain (CNS) rather than the body (peripheral mechanisms) in mediating the Iceman’s responses to cold exposure. They also suggest the compelling possibility that the WHM might allow practitioners to develop higher level of control over key components of the autonomous system.


   P037: Postural Orthostatic Tachycardia Syndrome Associated to Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: Brain Perfusion Findings Top


Sonia Neubauer*1, B Hyde2, J Cornejo1

1Clinica Las Condes, Santiago, Chile, 2The Nightingale Research Foundation, Ottawa, Canada

Background/Aims: Postural orthostatic tachycardia syndrome (POTS) is a form of dysautonomia associated with abnormal increase in heart rate, blood pressure, lightheadedness, dizziness and fainting caused by postural changes from lying to standing/sitting. The severity of symptoms deteriorates patient quality of life. Possible factors involved in POTS include impaired vascular innervation, high plasma norepinephrine concentrations, immune mediated factors, α-receptor sensitivity, β-receptor hypersensitivity and baroreceptor dysfunction. In our experience, some severe myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) patients also have POTS. Our aim is to describe brain perfusion abnormalities in ME/CFS patients with POTS. Methods: We report on 99mTc-HMPAO brain perfusion SPECT findings in six ME/CFS and POTS patients diagnosed according to the Canadian Consensus Criteria by one of the investigators (BH). HMPAO-SPECT studies obtained in Canada were reprocessed in Chile to obtain an age-matched normal database comparison by means of Segami OASIS – Neurogam software. Results are expressed in standard deviations from the normal mean and visually analysed. Results: All ME/CFS patients show significant unilateral temporal hypoperfusion and associated marked hypoperfusion of the cingulate gyrus. In POTS, there is hypoperfusion (a) particularly severe in Brodmann’s 38 (b) in the medial aspect of the cerebellum in 5/6 patients (bilateral in 4) and (c) hypoperfusion of the frontoparietal operculum (overlying the insular cortex) in 5/6 patients. In all ME/CFS patients, multifocal non-organized cortical hypoperfusion can be found in the frontal, parietal and occipital lobes. Conclusion: We suspect that our abnormal perfusion findings in the temporal lobe(s), operculum and/or cerebellum in ME/CFS patients can be the cause of POTS or the consequence of dysautonomic episodes of these symptomatic POTS patients. Further evaluation of brain perfusion in pure POTS patients is needed.


   P038: Acetazolamide Stress Brain Perfusion Single-Photon Emission Computed Tomography First Time in Bangladesh: A Case Report Top


Azmal Kabir Sarker*1, N Sultana1, H Matsuda2, F E Milad3, S Salekin1, S Islam1, N Khatun1, R Hussain1

1National Institute of Nuclear Medicine and Allied Science, 3Department of Neurosurgery, National Institute of Neurosciences and Hospital, Dhaka, Bangladesh, 2Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Tokyo, Japan

Background/Aims: Nuclear neuroimaging techniques have been used in Bangladesh for last 20 years within limited scopes of occasional planar and SPECT imaging. In 2017, with IAEA’s support for neuroimaging skill development, Bangladesh has started performing brain perfusion SPECT/CT and PET/CT on regular basis. This is a report of a brain Perfusion SPECT with cerebral vasodilator challenge which to our best knowledge is the first one in Bangladesh. Methods: Our patient was a 30 years old female with five month history of right sided hemiplegia, left middle cerebral artery territory (MCA) infarct and a totally occluded left common carotid artery. She, with an aim to evaluate cerebrovascular reserve before a revascularization bypass surgery, underwent brain perfusion SPECT with vasodilator challenge at National Institute of Nuclear Medicine and Allied Sciences (NINMAS), Dhaka. A one day split dose baseline-stress sequence was followed that used a dual head gamma camera and Tc-99m ECD. For vasodilator challenge, 1250 mg of acetazolamide (ACZ) was administered orally. Easy Z-score imaging system (eZIS) v3 was applied for image analysis. Results: Baseline images revealed a big photon deficient area in left fronto temporal region with reduced perfusion in ipsilateral basal ganglia, thalamus and frontal lobe; indicating infarct in left MCA territory. Normal perfusion was maintained in right hemisphere. Post ACZ images showed diminution of the perfusion deficit area in comparison to the baseline images. An inference of moderate peri-infarct ischaemia or perfusion reserve in left MCA territory was made. The patient was kept under medical management. Improvement of neurological deficits was seen after four months. Conclusion: This was the first brain perfusion SPECT with ACZ as well as the first experience of using eZIS for evaluation of cerebrovascular reserve in Bangladesh which was clinically influential because the course of management was changed resulting in a satisfactory outcome.


   P039: Usefulness of Radioiodinated 2-[4-(2-iodophenyl)piperidino]cyclopentanol (OI5V) for Early Diagnosing Neurodegenerative Disorder Caused by Stress Top


T Shigeno1, M Takahashi1, T Kozaka1, Y Kitamura1, M Kamide1, M Hamamoto1, K Yoshida1, K Ogawa2, Kazuhiro Shiba*1

1Advanced Science Research Center, 2Graduate School of Pharmaceutical Sciences, Kanazawa University, Kanazawa, Japan

Background/Aims: Sigma-1 receptor (σ-1R) is associated with adjustment of the nerve transmission of the central nervous system and learning memory, cognitive function. Furthermore, sigma-1 receptor plays an important role of remission of the stress. We had already reported that 123I-OI5V, vesamicol analogue with 5-membered ring structure, showed characteristics of sigma-1 receptor radioligand with high affinity and selectivity. In this study, we investigated change of the regional brain distribution of the stress model mice made by the forced immobilization test, and evaluated the potential usefulness of radioiodinated OI5V as a sigma-1 receptor mapping agent for early diagnosing neurodegenerative disorder caused by stress. Methods: 125I-OI5V was prepared from o-tributylstannyl-cyclopentanevesamicol (OT5V) by iododestannylation reaction under no-carrier-added conditions. 125I-OI5V was injected intravenously into the stress model mice and normal mice. The mice were sacrificed at 30 minutes post-injection and interest regional brain region were collected, weighed and counted to investigate the regional brain distribution. Results: 125I-OI5V was obtained with radiochemical purity of greater than 99%, and the radiochemical yield was 79%. The uptake of 125I-OI5V in cerebral cortex, striatum, cerebellum and rest brain in the normal mice and the stress model mice showed 16.53±4.28, 14.55±3.86, 18.33±4.68, 14.87±4.78, and 10.43±1.25, 9.17±0.91, 13.82±0.89, 9.34±1.10, respectively. The uptake of 125I-OI5V in cerebral cortex and striatum, reduced significantly in comparison with normal mice. Conclusion: These results showed that sigma-1 receptor of the central nervous system are decreased by chronic stress. Radioiodinated OI5V as a sigma-1 receptor mapping agent may be useful for early diagnosing neurodegenerative disorder caused by stress.


   P040: Decomposition of the Functional Magnetic Resonance Imaging BOLD Signal Into Neural and Vascular Components Using Simultaneous Functional Magnetic Resonance Imaging and Functional 18F-Fludeoxyglucose Positron Emission Tomography Top


Phillip G D Ward*1,2,3, F Sforazzini1, S D Jamadar1,2,3, J Baran1, S Li1,4, Z Chen1,4, G F Egan1,2,3

1Monash Institute of Cognitive and Clinical Neurosciences, Monash University, 2Monash Institute of Cognitive and Clinical Neurosciences, Monash University, 3Centre of Excellence for Integrative Brain Function, Australian Research Council, 4Department of Electrical and Computer Systems Engineering, Monash University, Melbourne, Australia

Background/Aims: Functional magnetic resonance imaging (fMRI) uses the blood-oxygen level dependent (BOLD) response to generate high spatial (~1-3mm) and moderate temporal (~1-2seconds) resolution images of brain function. The oxygenated blood that produces the BOLD contrast originates in the tissue and drains through venous vasculature. In this work, we used continuous infusion 18-F Flurodeoxyglucose positron emission tomography (FDG-fPET) simultaneously acquired with fMRI, to identify and map the vascular component of the BOLD-fMRI signal. Methods: The institutional ethics committee approved this study. Ten volunteers were scanned (3T Biograph mMR Siemens, Erlangen) during a continuous-infusion of FDG (100MBqs, 36 mL/hr) with 90-minutes of PET list-mode data collection. BOLD-fMRI was simultaneously acquired. An embedded on/off design (32/16-seconds), flickering checkerboard (8 Hz) task was performed for 10 minutes (10-minute rest periods before and after). List-mode data was reconstructed into 1-minute bins, corrected for motion[2] and photon attenuation,[3] and spatially normalised to MNI space. Both the fMRI and fPET data was smoothed (5mm). Two independent component analyses[4] (ICA) were performed on the fMRI and fPET data. Per-subject Z-score maps were generated using dual regression.[5] A joint ICA[6] was performed on the fMRI and fPET Z-score maps. Results: Separate analyses of the fMRI and fPET time series produced activation maps of the visual cortex. Two distinct components were obtained in the joint analysis. The first joint component showed positive correlation of visual cortex activity between fMRI and fPET. The second component contained a predominantly positive fMRI signal, with similar but smaller spatial extent to the separate analysis, which was negatively associated with the fPET signal in the venous vasculature. Conclusion: The simultaneous fPET and fMRI imaging strategy provided high temporal resolution functional and metabolic imaging, and enabled the deconstruction of the BOLD-fMRI signal into neural tissue and vascular components.


   P041: Case report: Early Detection of Shunt Fracture on Cerebrospinal Fluid Shunt Study with Incidental Dominant Thyroid Nodule Top


A Burke1, Chong Chew*2

1Department of Nuclear Medicine PET and Bone Mineral Densitometry, 2Department of Nuclear Medicine, PET and Bone Mineral Densitometry, Royal Adelaide Hospital, Adelaide, Australia

Background/Aims: Ventriculoperitoneal shunts are used to treat hydrocephalus. To investigate for shunt malfunction, radionuclide shunt study complements other imaging tests. Other organs are also imaged by the recycled radiopharmaceutical. Methods: A 40 year old male with a VP shunt for congenital hydrocephalus presented with a one week’s history of increasing headaches, nausea and vomiting. Shunt blockage was suspected but not confirmed on head CT and plain X rays. A radionuclide CSF Shunt Study was thus ordered. The study was performed with 60MBq of filtered 99mTc-pertechnetate. Serial planar images of the head, neck and abdomen were then acquired followed by SPECT/CT. This case report was approved by the ethics committee of our hospital. Results: The initial images showed prompt flow of radiotracer down the distal limb of the shunt into the abdominal cavity, suggesting shunt patency. However focal tracer accumulation was noted near the angle of the mandible. This was external to the tubing on the SPECT/CT indicative of shunt fracture. Another right sided prominent focus in the neck was localised to the right lobe of thyroid on SPECT/CT. The rest of the thyroid was suppressed. Conclusion: CSF shunt study allows early diagnosis of shunt fracture undetected by other imaging. Pathology in other organs which are pertechnetate-avid such as a dominant thyroid nodule maybe incidentally identified. CSF shunt study is for evaluating shunt patency. Although patent, the VP shunt in this case was fractured. This was confirmed on SPECT/CT. The fracture was not detected in structural imaging that relied on demonstration of catheter discontinuity and distal fragment migration. The recycled radiopharmaceutical also allowed an incidental detection of a dominant hypermetabolic thyroid nodule.


   P042: Radionuclide Cisternography for Spontaneous Intracranial Hypotension Top


Ka Cheong Leung*1, J Wong1, W T Ngai1, F Choi1

1Pamela Youde Nethersole Eastern Hospital, Hong Kong, China

Background/Aims: Spontaneous intracranial hypotension (SIH) is a rare condition of low cerebrospinal fluid (CSF) volume caused by leakage through a dural defect along the neuroaxis. There is a lack of clinical guideline or established management algorithm. This study aims to evaluate the value of radionuclide cisternography in SIH. Methods: This study retrospectively reviewed consecutive referrals for clinically suspected or diagnosed SIH. The samples were recruited from a 1600-bed regional hospital over 16 years between June 2001 and May 2017. Radionuclide cisternography was performed using a standardized protocol: 18.5 MBq 111In-diethylenetriaminepentaacetic acid administered intrathecally followed by serial imaging up to 48 hours. Single-photon computed emission tomography and low-dose computed tomography was performed for anatomical localization of abnormal tracer activity. Positive finding for CSF leak was defined as accumulation of radiotracer in the extra-arachnoid space. Presence of indirect findings of CSF leakage included early visualization of urinary activity within 4 hours and non-visualization of activity over brain convexities by 24 hours. Results: There were a total of eight subjects (6 male, 2 female: aged 26 to 64 years) suspected to have SIH. Five (63%) subjects had positive findings for CSF leakage on radionuclide cisternography. Three (60%) had CSF leakage localised at thoracic spinal level, two (40%) at cervical spinal level, and all 5 studies were positive for both indirect findings of CSF leakage. Of the 5 cases with positive findings on radionuclide cisternography, two had history of severe subdural haematoma associated with decrease in conscious level requiring operative drainage. Of the 3 cases with negative findings on radionuclide cisternography, one developed subdural haematoma but spontaneously improved. One (20%) subject with leakage demonstrated at cervical level received targeted epidural blood patch with subsequent resolution of symptoms. Conclusion: Radionuclide cisternography may be a useful investigation in detecting and localising CSF leakage in patients suffering from SIH for it potentially guides local treatment of any dural defect. Positive findings on radionuclide cisternography may be associated with more severe symptomatology or complications of SIH and would warrant further investigations to confirm this observation.


   P043: Ventriculopleural Shunt Dysfunction Due to a Loculated Pleural Collection Demonstrated on Single-Photon Emission Computed Tomography/Computed Tomography Imaging Top


Brianna Powe*1, J Szajer1, R Russo1, R Mansberg1

1Concord Repatriation General Hospital, Concord, Australia

Background/Aims: A 35-year-old female presented with increasing drowsiness and lethargy on a background of childhood meningitis and hydrocephalus managed with a ventriculopleural shunt. Her cerebral Computed Tomography (CT) and chest X-ray were unchanged from previous imaging and did not identify significant pathology. Due to clinical suspicion of cerebral spinal fluid (CSF) shunt dysfunction, she was referred for a CSF shunt study. Methods: Dynamic and planar imaging was performed following the intrathecal administration of 38MBq of double filtered 99mTc-diethylene-triamine-pentaacetate (99mTc-DTPA) to assess for ventriculopleural shunt dysfunction. Delayed planar scintigraphy demonstrated an irregular pyramidal-shaped accumulation of tracer at the left chest. Single Photon Emission Computed Tomography (SPECT) with CT was performed. Ethics is not required as this is a retrospective case report. Results: Tracer accumulation was demonstrated within a loculated pleural collection at the costodiaphragmatic recess of the left lung at the distal tip of the catheter. Ventriculopleural shunt dysfunction was confirmed by the absence of tracer dispersion elsewhere throughout the pleural cavity. Conclusion: Ventriculopleural shunts are rarely used as a long-term measure for CSF diversion.[1] Ventriculoperitoneal shunts are preferred due to fewer and less severe complications.[2] The use of ventriculopleural shunts are generally used as a temporary measure when a ventriculoperitoneal shunt has failed, or in the presence of peritoneal adhesions or peritonitis.[1],[3] Shunt dysfunction is relatively common, with up to 50% failing within 2 years and 70% within 10 years after placement.[4],[5] The most common locations for shunt obstruction are at the ventricular catheter tip and shunt valve. One possible complication, as seen in this patient, is the formation of pseudocysts around the distal catheter tip due to adhesions caused by chronic pleural irritation.[6] The addition of SPECT/CT to conventional imaging aided in characterising the shunt dysfunction and nature of the pathology; and altered the patient’s management.

References

  1. Küpeli E, Yilmaz C, Akçay S. Pleural effusion following ventriculopleural shunt: Case reports and review of the literature. Ann Thorac Med 2010;5:166-70.
  2. Browd SR, Ragel BT, Gottfried ON, Kestle JR. Failure of cerebrospinal fluid shunts: Part I: Obstruction and mechanical failure. Pediatr Neurol 2006;34:83-92.
  3. Kanev PM, Park TS. The treatment of hydrocephalus. Neurosurg Clin N Am 1993;4:611-9.
  4. Browd SR, Gottfried ON, Ragel BT, Kestle JR. ???. Pediatr Neurol 2006;34:171-6.
  5. Bergsneider M, Egnor MR, Johnston M, Kranz D, Madsen JR, McAllister JP 2nd, et al. What we don’t (but should) know about hydrocephalus. J Neurosurg 2006;104:157-9.
  6. Wallace AN, McConathy J, Menias CO, Bhalla S, Wippold FJ 2nd. Imaging evaluation of CSF shunts. AJR Am J Roentgenol 2014;202:38-53.



   P044: Imaging Characteristics of Radionuclide Cisternography in Spontaneous Intracranial Hypotension Syndrome Top


Zhiyi Lin*1, W Chen1

1Department of Nuclear Medicine, The Provincial Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, China

Background/Aims: To investigate the imaging characteristics and clinical significance of radionuclide cisternography (RNC) in patients with spontaneous intracranial hypotension syndrome (SIHS). Methods: 19 patients with SIHS underwent lumbar puncture and 99mTc-DTPA was injected into the spinal subarachnoid space. Multitemporal RNC was performed. SPECT/CT tomography was added to the abnormal distribution. Comprehensive analysis of RNC image features. Results: 12 cases (12/19) of direct cerebrospinal fluid (CSF) leakage were detected on the basis of radioactive abnormal concentration in epidural. The detection rate was 63.2%, including 8 cases of CSF leakage in cervical and thoracic segment joint, 1 case in lumbar spine, 2 cases of CSF rhinorrhea. Indirect CSF leakage in 5 cases. No direct CSF leakage was found in these cases. But found that radionuclide quickly disappeared in the subarachnoid space (<4 hours), and/or premature appearance (< 2.5 hours) in the bladder, or radioactivity is difficult to rise to the base pool to the brain, and intracranial radioactivity is less than normal. CSF circulation was normal in 2 cases. Comparing the MRI findings of 17 patients, there was no significant difference between MRI and RNC in the diagnosis of low intracranial pressure (χ2 = 3.01, P> 0.05), but RNC was superior to MRI in detecting CSF leakage (χ2 = 12.5, P <0.005). In this study, except for one case of high-flow CSF leakage who was cured by invasive epidural blood plaster, the remaining 18 patients were cured by conservative treatment. Conclusion: RNC can assist the diagnosis of SIHS by direct or indirect signs and is superior to MRI in detection of CSF leakage. It can also reflect the amount of CSF leakage and facilitate individualized treatment, which has important value in diagnosis and treatment of SIHS.


   P045: Differential Diagnosis of Neurodegenerative Dementias Using Metabolic Phenotypes on F-18 Fludeoxyglucose Positron Emission Tomography/Magnetic Resonance Imaging Top


Ruixie Cui*1, N Niu1, J Yuan1

1Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China

Background/Aims: Positron emission tomography (PET) imaging with F-18 fluorodeoxyglucose (FDG) can be used as a hallmark of neurodegenerative dementia. Characteristic patterns of regional glucose metabolism have been used to classify the dementia subtypes, namely Alzheimer’s dementia (AD), frontotemporal dementia (FTD), diffuse Lewy body (DLBD), vascular dementia (VD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), etc. PET/MRI benefits neurologic clinical care and research by providing spatially and temporally matched anatomic and metabolic imaging. We undertook this study to assess the utility of FDG-PET/MRI in the differential diagnosis of dementia subtypes. Methods: Fourty patients diagnosed with dementia had FDG-PET/MRI performed. Imaging-based diagnosis of dementia type was established by visual assessment of individual scans by PET physician blinded to the clinical diagnosis. Concordance of visual analysis of FDG-PET/MRI scans with clinical diagnosis of the dementia type was evaluated. Results: This concordance was 90% for various subtype diagnosis of dementia by the metabolic pattern of FDG PET from PET/MRI with clinical diagnosis. MRI provided accurate anatomic information. Simultaneous PET/MRI provides efficient acquisition of multiple temporally matched datasets, and opportunities for motion correction and improved anatomic assignment of PET data. Conclusion: 18F-FDG PET/MRI performed after the initial work-up of dementias is useful for supporting the clinical diagnosis of dementia subtype.


   Cardiology Top



   P046: Place of the Scintigraphy Imaging in French-speaking Black African Cardiological Practice Top


Kokou Adambounou*1, M Mbodj2, B Achy3, M Amoussou-Geunou4, T Tapsoba5, S Seck-Gassama2

1Department of Medical Imaging, FSS-UL, Lome, Togo, 2Department of Nuclear Medicine, HOGGY Dakar, UCAD, Dakar, Senegal, 3Department of Nuclear Medicine, Cocody, Université d’Abidjan, Abidjan, Côte d’Ivoire, 4Department of Nuclear Medicine, Cotonou, UAC, Cotonou, Benin; 5Department of Nuclear Medicine, CHU YO, University of Ouaga, Ouaga, Burkina Faso

Background/Aims: To estimate the place of the scintigraphy imaging in French-speaking black African cardiological practice. Methods: Cross-sectional study conducted from February 1st till May 30th, 2017 including 97 cardiologists practicing in French-speaking black African countries. The accessibility and the frequency of prescription of the examinations of nuclear cardiology as well as the interest carried in these examinations by the cardiologists were analysed. Results: A department of nuclear medicine existed in their country, city and hospital of exercise respectively in 56.3%, 49.5% and 14.4% of cases. A great majority of the cardiologists had never prescribed a myocardial perfusion scintigraphy (70.1%), or pulmonary perfusion scintigraphy (81.4%) and a multigated acquisition (MUGA) scan (94.8%). Only 5.2% of the cardiologists asserted prescribing often the myocardial perfusion scintigraphy and pulmonary scintigraphy and rarely the MUGA scan. The low frequency of prescription was connected with the rarity of nuclear medicine departments in 82.6%, and with the weak diagnostic contribution in 8.2 % of the cases. The most sensitive examination for the diagnosis of the ischaemia or the myocardial infarction was coronarography according to 66% of them and myocardial scintigraphy according to 26.8%. In the evaluation of left ventricle function, 64.9% considered that echocardiography is the most satisfactory with 35.1% for MUGA scan. To eliminate a pulmonary embolism in front of a normal thoracic radiography, only 14.4% would ask for a pulmonary perfusion scintigraphy. Conclusion: The place of the scintigraphy imaging is unsatisfactory in French-speaking black African cardiological practice and a raising awareness of the cardiologists on the diagnostic interest and forecasts of the nuclear cardiology is imperative so that it occupies its special place.


   P047: Differences in Perfusion and Regional Functional Abnormalities Identified by Rest Gated Myocardial Perfusion Scintigraphy in Dilated Cardiomyopathy Patients with Ischaemic and Non-Ischaemic Aetiology Based on Coronary Angiography Results Top


Mohammad Shahzad Afzal*1, M S Akhtar1, M B Imran1, M Iqbal1, O Bin Qadeer1

1Punjab Institute of Nuclear Medicine, Faisalabad, Pakistan

Background/Aims: Dilated cardiomyopathy (DCM) is a common problem and it is very important to differentiate its ischaemic cause from non-ischaemic for management and prognostic purposes. This study was conducted to evaluate rest gated myocardial perfusion scintigraphy (GMPS) in patients with ischaemic and non-ischaemic DCM, and to compare mean summed perfusion score (SPS), mean summed thickening score (STS) and mean extent of perfusion abnormality (EPA) between them. Methods: This descriptive case series study was conducted at the nuclear cardiology department of Punjab Institute of Nuclear Medicine (PINUM), Faisalabad over a period of six months from 01-01-2013 to 30-06-2013. Resting GMPS were performed in 102 patients with known DCM (aged 17 to 70 years, mean age 49.12 ± 11.8 years, M: F = 86:16) by injecting 20 mCi of 99mTc-MIBI. Patients were subdivided into ischaemic (n=74) and non-ischaemic group (n=28) by using the coronary angiography results. SPS, STS EPA were calculated by using twenty segment model. Results of GMPS were compared between ischaemic DCM and non-ischaemic DCM by using independent samples t-test. P-value of <0.05 was taken as statistically significant. Results: SPS and EPA are significantly higher in ischaemic than non-ischaemic subgroups (26.46±10.80 vs. 7.86±5.13 p<0.001; and 7.16±1.97 vs 4.32±1.70, p<0.001 respectively). STS was significantly higher in non-ischaemic group than ischaemic group of DCM patients (33.21±7.13 vs. 23.99±7.81). Conclusion: Our study shows that there are statistically significant differences in the values of summed perfusion score, summed thickening score and extent of perfusion abnormalities between ischaemic and non-ischaemic DCM groups, calculated by using rest gated myocardial perfusion scintigraphy. Combined evaluation of the perfusion and wall thickening on rest gated myocardial perfusion scintigraphy is useful to identify ischaemic and non-ischaemic aetiology of DCM.

Disclosure of Interest: M B Imran Conflict with: Punjab Institute of Nuclear Medicine; M Iqbal Conflict with: Punjab Institute of Nuclear Medicine; O B Qadeer Conflict with: Punjab Institute of Nuclear Medicine.


   P049: Three Renin-Angiotensin-Aldosterone System -Related Gene Polymorphisms are Linked to Abnormal Myocardial Perfusion: Correlations Based on Myocardial Gated Single Photon Emission Computed Tomography Imaging Top


G Angelidis1, M Samara2, M Papathanassiou2, M Satra3, V Valotassiou1, I Tsougos1, D Psimadas1, C Tzavara1, S Alexiou1, J Koutsikos4, N Demakopoulos4, G Giamouzis5, F Triposkiadis5, J Skoularigis5, P Kollia6, Panagiotis Georgoulias*1

1Department of Nuclear Medicine, Departments of 2Pathology and 3Biology and Genetics, University of Thessaly, Larissa, 4Department of Nuclear Medicine, Army Share Fund Hospital (417 NIMTS), Athens, 5Department of Cardiology, University of Thessaly, Larissa, 6Department of Genetics and Biotechnology, National and Kapodistrian University of Athens, Athens, Greece

Background/Aims: Renin-angiotensin-aldosterone system (RAAS)-associated gene polymorphisms have been implicated in the development of coronary artery diease.[1] However, little evidence is available regarding the direct correlations of these polymorphisms with myocardial perfusion.[2] We evaluated the associations between three polymorphisms and myocardial perfusion, using gated single photon emission computed tomography (SPECT). Methods: The study sample consisted of 810 patients who were referred to our departments between December 2015 and February 2017, for a clinically indicated myocardial perfusion imaging. Summed stress score (SSS), summed rest score (SRS), suumed difference score (SDS), transient ischaemic dilation (TID), and lung/heart ratio (LHR) were recorded. Three RAAS-associated gene polymorphisms were investigated: angiotensin-converting enzyme (ACE) insertion/deletion (I/D), angiotensinogen (AGT) T174M, and angiotensin II type 1 receptor (AT1R) A1166C. Results: The heterozygotes or homozygotes on ACE D allele were 7.54 times more likely to have SSS ≥3 (p<0.001), and the homozygotes of ACE D had significantly higher values on TID (p=0.005) and LHR (p=0.006). The AGT (T174M) heterozygotes were 5.19 times more likely to have abnormal SSS (p=0.023), and had higher values on TID (p=0.012). Moreover, the AT1R heterozygotes had greater odds for having abnormal SSS (p=0.029), and had significantly higher values on LHR (p=0.010). Finally, the patients carried AT1R homozygosity of C allele had significantly higher values on TID (p=0.050). Conclusion: According to our results, ACE D allele had the strongest association with abnormal myocardial perfusion.

References

  1. Durante A, Peretto G, Laricchia A, et al. Curr Pharm Des 2012;18:981-1004.
  2. Georgoulias P, Wozniak G, Samara M, Chiotoglou I, Kontos A, Tzavara C, et al. Impact of ACE and apoE polymorphisms on myocardial perfusion: Correlation with myocardial single photon emission computed tomographic imaging. J Hum Genet 2009;54:595-602.



   P050: Can Nuclear Medicine Detect a Broken Heart? Top


Nadia Ayars*1, D Bartholomeusz1

1PET and Bone Densitometry, Royal Adelaide Hospital, Adelaide, Australia

Background/Aims: A 72 year old female presented for a Myocardial Perfusion study (MPS). She initially presented to the hospital with chest pain and associated rise in troponin levels. The patient had a recurrent history of Takotsubo Cardiomyopathy, the last episode occurring 18 months prior. Takotsubo Cardiomyopathy is also referred to as stress induced cardiomyopathy or broken heart syndrome. It is typically temporary and can be brought on by a stressful incident occurring. Its symptoms are similar to that of a heart attack, however no blockages are present. The chambers within the heart itself can enlarge or change shape which ultimately affects its ability to contract effectively. Methods: The patient underwent a MPS within our department. This involved administering 39mg of Dipyridamole to the patient to ‘stress’ the heart. Once an optimum heart rate was achieved they were injected with 382MBq of 99mTechnetium-Sestamibi (99mTc-MIBI). The patient then underwent a Single-Photon Emission Computed Tomography (SPECT) study in conjunction with a low energy Computed Tomography scan (CT). There was then a delay of three hours, after which the patient returned to us and was then re-administered with 950MBq of 99mTc-MIBI, and subsequently had another SPECT scan. Results: The MPS showed an area of fixed, reduced activity within the anterior and anterolateral wall. There was no evidence of reversible myocardial ischaemia elsewhere. The gated image showed a left ventricle which was within a normal size range, but with reduced movement; this can be further reflected with an ejection fraction of 39%. Conclusion: In regards to the MPS, reduced systolic function and ejection fraction was seen within the left ventricle, as well as the fixed defects mentioned previously. With this in mind, and after the patient underwent subsequent Magnetic Resonance Imaging showing similar findings, it was deemed that the patient was suffering from another episode of Takotsubo Cardiomyopathy.


   P051: 25-Hydroxyvitamin-D Deficiency in Patients of Northern Greece with Coronary Artery Disease. Correlation with Single Photon Emission Computed Tomography Myocardial Scintigraphy Top


L Baloka1, A Strataki2, AThomaidou-Ntanasel3, V Balomenos4, K Georgiadi4, A Tsartsarakis2, A Pistola2, V Aristotelidou, K Bonelis5, D Benti, V Efstratiou, A Balomenos6, A Zissimopoulos*4

1Department of Molecular Biology and Genetics, Democritus University of Thrace, 2Department of Nuclear Medicine, 3Department of Cardiology, University General Hospital of Thrace, 4Department of Nuclear Medicine, 5Department of Medicine, Democritus University of Thrace, Alexandroupolis, 6Department of Nuclear Medicine, Sotiria General Hospital of Athens, Athens, Greece

Background/Aims: Recent have reported that low serum vitamin D levels are associated with a variety of diseases, including cardiovascular disease and in particular ischaemic heart disease. The evaluation of 25-hydroxyvitamin-D serum levels in patients with CAD, as a prognostic factor of the disease severity, in correlation with SPECT myocardial scintigraphy. Methods: We studied 108 patients (63 male and 45 female) aged between 37 and 68 years old (median 52±6 years) with CAD. All patients came from the Cardiology Clinic of the University Hospital of Evros. Blood samples were taken for (25-OH-D) determination and after this in everyone SPECT myocardial scintigraphy with 99mTc-MIBI was performed. The vitamin D status was measured by radioimmunoassay method with kits Diasorin at Nuclear Medicine Dept. Results: 57 patients with myocardial infarction had low values of vitamin D deficiency (p<0.005). In this group, there is statistical significance in the relationship between very low values of vitamin D and patients with extensive myocardial infarction (p<0.005). Therefore, the very low levels are associated with impending patient death. These patients might need more intensive monitoring. 39 patients with reversible myocardial ischaemia had low values of vitamin D 20-40 ng/mL (p<0.005). Therefore, the very low levels associated with the progression of the disease. 12 patients with normal myocardial scintigraphy had normal vitamin D values >40ng/mL (p<0.005). Conclusion: In conclusion, low vitamin (25-OH-D) levels may underlie established cardiovascular risk factors. The very low levels associated with the severity of (CAD) disease and the impending death of patients. The determination of vitamin D levels in patients with CAD is essential to monitor patients in the treatment and outcome of disease.


   P052: The Prognostic Value of Diastolic and Systolic Mechanical Left Ventricular Dyssynchrony among Patients with Coronary Heart Disease Top


S Borges-Neto*1, M Fudim2, L Shaw3

1Duke University School of Medicine, 2Department of Cardiology, Duke University, 3Department of Cardiology, Duke Clinical Research Institution, Durham, United States

Background/Aims: Systolic left ventricular dyssynchrony measured by gated single photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI) is associated with worse outcomes. Novel analytical algorithms now allow for evaluation of diastolic left ventricular dyssynchrony. Our aim was to examine if diastolic dyssynchrony has independent and incremental prognostic value in patients with coronary artery disease (CAD). Methods: We included patients who presented to Duke University for GSPECT MPI between 2003 and 2009. Patients had at least one major epicardial CAD. Dyssynchrony variables were computed using Emory Toolbox software and compared to a control population without CAD. We performed unadjusted Cox proportional hazard modelling for diastolic dyssynchrony variables with all-cause mortality and cardiovascular mortality as outcomes. Adjusted modelling included clinical baseline characteristics, electrical dyssynchrony (QRS duration, left bundle branch block), left ventricular ejection fraction and diastolic as well as systolic dyssynchrony parameters. Results: Total of 1310 patients were included in the analysis. Of them 69.7% were male and 73% Caucasian, with a median age of 64 years. About 8% of patients had significant mechanical dyssynchrony. After mean follow-up of 6.7 years, 543 deaths occurred. At 5 years, the mortality estimate was 21.2% among patients with low degree of diastolic left ventricular mechanical dyssynchrony (LVMD) and 41.7% among those with a high degree of LVMD (p<0.001). The addition of diastolic dyssynchrony to the model of clinical variables, electrical dyssynchrony and systolic LVMD had incremental predictive value (global Chi-square of 211.9 vs. 222.8, p=0.004) for cardiovascular mortality. Conclusion: Systolic and diastolic LVMD, measured by GSPECT MPI is prevalent amongst patients with CAD. Both systolic and diastolic dyssynchrony have a strong association with poor clinical outcomes. However, diastolic dyssynchrony appears to have incremental predictive benefit on top of clinical, electrical dyssynchrony and cardiac functional assessment.


   P053: The Importance of Appropriate Reporting and follow-up of Incidental Findings on Computed Tomography Attenuation Correction Images in Myocardial Perfusion Scintigraphy: A Case Report Top


Francis Delaney*1, J Lee2

1Gold Coast University Hospital, Gold Coast, 2The Prince Charles Hospital, Brisbane, Queensland, Australia

Background/Aims: Prior reviews of incidental findings on computed tomography attenuation correction (CTAC) images in myocardial perfusion scintigraphy (MPS) have reported cases of newly diagnosed lung cancer.[1],[2],[3],[4],[5] Patients undergo MPS for evaluation of coronary artery disease which shares many risk factors with lung cancer and therefore represent a high-risk group. The routine review of CTAC images is controversial however and has been advised against.[4],[6] Methods: This case was identified as part a retrospective audit of incidental CTAC findings in MPS. Electronic and paper-based medical records and databases were used to obtain all relevant information. Ethical approval was granted by the local Human Research Ethics Committee. Results: We present the case of a 74-year-old man who underwent MPS as part of a pre-operative assessment prior to abdominal aortic aneurysm repair. A suspicious 10-millimetre subpleural opacity within the right lower lobe was incidentally noted on CTAC images and described in the MPS report, with further investigation with diagnostic CT directly advised. Unfortunately, appropriate further evaluation of the incidental finding was not carried out based on the MPS report. Diagnostic CT 14 months following MPS showed that the lesion had more than doubled in size to 23 mm with associated hilar lymphadenopathy. Biopsy revealed lung squamous cell carcinoma and diffuse hepatic metastases were identified on staging. Urgent chemotherapy was commenced but the patient died within two months. Conclusion: This case highlights the importance of routine review of CTAC images in MPS. The crucial role of effective communication between nuclear medicine and treating physician following identification of any suspicious incidental finding is clear. Further, referring physicians must follow-up and appropriately investigate potentially significant incidental findings promptly. Failure at any step can result in adverse patient outcomes.

References

  1. Goetze S, Pannu HK, Wahl RL. Clinically significant abnormal findings on the “nondiagnostic” CT portion of low-amperage-CT attenuation-corrected myocardial perfusion SPECT/CT studies. J Nucl Med 2006;47:1312-8.
  2. Husmann L, Tatsugami F, Aepli U, Herzog BA, Valenta I, Veit-Haibach P, et al. Prevalence of noncardiac findings on low dose 64-slice computed tomography used for attenuation correction in myocardial perfusion imaging with SPECT. Int J Cardiovasc Imaging 2009;25:859-65.
  3. Coward J, Lawson R, Kane T, Elias M, Howes A, Birchall J, et al. Multi-centre analysis of incidental findings on low-resolution CT attenuation correction images. Br J Radiol 2014;87:20130701.
  4. Coward J, Lawson R, Kane T, Elias M, Howes A, Birchall J, et al. Multicentre analysis of incidental findings on low-resolution CT attenuation correction images: An extended study. Br J Radiol 2015;88:20150555.
  5. Husmann L, Tatsugami F, Buechel RR, Pazhenkottil AP, Kaufmann PA. Incidental detection of a pulmonary adenocarcinoma on low-dose computed tomography used for attenuation correction in myocardial perfusion imaging with SPECT. Clin Nucl Med 2010;35:751-2.
  6. Coward J, Nightingale J, Hogg P. The clinical dilemma of incidental findings on the low-resolution CT images from SPECT/CT MPI studies. J Nucl Med Technol 2016;44:167-72.



   P054: Diagnostic Performance of Vasodilator Stress Myocardial Single Photon Emission Computed Tomography According to Radiotracers using Cadmium-Zinc-Telluride Camera System as Assessed by Fractional Flow Reserve Top


Satoshi Hida*1, Y Igarashi1, K Hirose1, T Hatano1, T Morishima1, T Saitoh1, T Chikamori1

1Tokyo Medical University, Tokyo, Japan

Background/Aims: Although stress myocardial perfusion imaging (MPI) using a cadmium-zinc-telluride (CZT) camera is reported to have good diagnostic accuracy, few studies have shown the diagnostic value according to the type of radiotracer in the detection of functionally significant stenosis among the intermediate coronary narrowing as assessed by fractional flow reserve (FFR) measurements. Methods: We retrospectively evaluated 234 consecutive patients who underwent both ATP stress MPI and CAG with FFR measurements within 3 months’ interval. FFR measurements were performed in 323 coronary vessels (184 201Tl, 139 99mTc-radiotracers) considered to have intermediate lesions excluding infarct-related vessels. Severe coronary artery stenosis of >90% diameter narrowing or mild stenosis of <40% narrowing was not evaluated with FFR measurements. An FFR≤0.80 was defined as significant stenosis. Results: FFR value was similar in coronary vessels when 201Tl or 99mTc-radiotracers was applied for MPI (0.79±0.10 vs 0.79±0.10; p=ns). To detect individual coronary stenosis with 201Tl, the respective sensitivities, specificities, accuracies were 90%, 32%, 72% for LAD, and 60%, 76%, 70% for non-LAD. In contrast, with 99mTc-radiotracers, the respective sensitivities, specificities, accuracies were 60%, 47%, 57% for LAD, and 48%, 85%, 73% for non-LAD. Conclusion: These results suggested that the CZT camera system may be superior when using 201Tl to 99mTc-radiotracers in the detection of functionally significant coronary stenosis, at the expense of specificity for myocardial ischaemia.


   P055: Diagnostic Usefulness of the Integrated Risk Scores Combined with Myocardial Single Photon Emission Computed Tomography for Patients with Suspected Coronary Artery Disease Top


Kimihiko Hirose*1, S Hida1, T Saitoh1, Y Igarashi1, T Chikamori1

1Tokyo Medical University, Tokyo, Japan

Background/Aims: Recently, the integrated risk scores (IRS) based on coronary risk factors and symptoms are reported to identify high-risk CAD patients. We sought to better diagnose CAD patients by combining IRS with stress myocardial SPECT using cadmium-zinc-telluride camera. Methods: We retrospectively studied 527 patients with suspected CAD who underwent stress myocardial SPECT and coronary angiography within 3 months’ interval. Each SPECT image was analysed using the 17-segment model. An SDS ≥2 was defined as myocardial ischaemia. A diameter stenosis ≥90% and/or fractional flow reserve ≤0.80 was considered as hemodynamically significant stenosis. IRS for each patient was assigned depending age, gender, hypertension, diabetes mellitus, family history, current smoking habits, and chest symptoms (either 0 or 1, except for age). In addition, IRS of lower than 2SD was categorized as the low-risk group. Results: Of 527 patients, IRS average was 8.8±1.4, and the area under curve was 0.71. Significant stenosis was observed in 319 patients. On SPECT, sensitivity, specificity, and accuracy were 88%, 49%, and 72% in detecting significant CAD while 88% sensitivity, 48% specificity and 74% accuracy were similar in 492 patients in the intermediate to high-risk group. In 35 patients in the low-risk group, only 3 of 18 patients with positive SPECT had significant CAD (75% sensitivity, 52% specificity and 54% accuracy), whereas 1 of 17 patients with negative SPECT also had CAD (p=0.603). Conclusion: IRS helps better identify false positive findings of myocardial SPECT by categorising the low-risk group.


   P056: Effect of Different Acquisition Arcs on the Appearance of each Left Ventricular Wall in Myocardial Perfusion Single Photon Emission Computed Tomography Top


Kemin Huang*1, Y Feng1

1Hospital of Foshan, Foshan, China

Background/Aims: Conventional single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is performed in the supine position range RAO45°−LPO45°, but the effect of other acquisition arcs on imaging quality are not well described. In this study, we compared radioactivity activity over left ventricle walls as measured by different acquisition arcs to identify optima for specific applications. Methods: In total,125 low-risk coronary heart disease patients underwent 99mTc-MIBI stress MPI, of which 52 received 360° acquisition with reconstruction using different 180° projections and the remaining 73 received conventional 180° (LPO45°−RAO45°) and left-side 180°(POST180°−ANT0°) acquisition consecutively. Statistically compare the radioactive activity and defect score of each left ventricular wall from different acquisition arcs. Voluntary informed consent was obtained from all study population. The work described in this abstract has appropriate approval under local ethical rules. Results: Myocardial slices reconstructed from POST180°−ANT0° yielded highest radioactivity uptake from inferior, lateral, and septal walls, LPO45°−RAO45° from the anterior wall, and LPO35°−RAO55° from the apical region. Compared to conventional 180° acquisition, the segments with decreased defect scores were observed in 27.67% (101/365) using left-side 180° acquisition. The proportion was significantly higher for males (p=0.035) and patients with high BMI (p=0.036). Segments with decreased defect score were mainly in inferior, septal, and lateral walls, and a greater proportion of males than females exhibited in inferior wall (p=0.004). Conclusion: The different arc of data acquisition could significantly affect the appearance of each wall of the left ventricle, POST180°−ANT0° acquisition arc represents a useful and significantly enhanced imaging quality of inferior walls especially in males.

Disclosure of Interest: K. Huang Conflict with: Financial Support, Y. Feng Conflict with: Technical support.


   P057: Diagnostic Accuracy of Right Ventricular Visualization in Resting Thallium Myocardial Perfusion Scan in Identifying Right Ventricular Hypertrophy among Patients with Coronary Artery Disease Top


Nicole Patricia Hui*1, M Ogbac1

1Philippine Heart Center, Manila, Philippines

Background/Aims: Accurate evaluation of right ventricular function and structure is challenging because of its complex geometry. Cardiac magnetic resonance imaging is said to be precise for quantitation of ventricular volumes and morphology. However, due to cost and availability, 2-D echocardiography is most commonly used. Visualization of right ventricle in thallium myocardial perfusion scan (MPS) is usually seen in patients with right ventricular pressure and/or volume overload. This study aims to establish the accuracy of visual assessment of right ventricular uptake on myocardial perfusion scan in identifying right ventricular hypertrophy compared with 2-D echocardiography and to establish the association of right ventricular uptake with right ventricular dysfunction seen in echocardiography. This could aid in the interpretation of future cardiac scintigraphy in identifying patients at a higher risk as compared to those without right ventricular uptake on MPS. Methods: Chart review of a total of 227 adult patients with angiographically proven coronary artery disease, who underwent resting thallium MPS and had echocardiography results within three months for the past five years was performed. Hypertrophy was indicated by right ventricular wall thickness of >0.5cm and systolic function by right ventricular fractional area change (normal value of >35%) in echocardiography. Presence of right ventricular uptake on MPS was analysed visually by two experienced observers blinded to the findings of echocardiography. Results: Right ventricular visualization on MPS has a sensitivity of 95.7% and specificity of 65.4% in identifying right ventricular hypertrophy, with overall accuracy of 80.6%. An association between right ventricular uptake on MPS and right ventricular dysfunction measured by echocardiography was demonstrated (Cramer’s V=0.5911, p<0.0001). Patients with right ventricular uptake also showed lower left ventricular ejection fraction (p<0.001). Conclusion: Right ventricular visualization on resting thallium-201 MPS had high sensitivity (95.7%) but limited specificity (65.4%) in identifying right ventricular hypertrophy, with overall accuracy of 80.6%. There was an association between right ventricular uptake on MPS and right ventricular dysfunction measured by echocardiography.


   P058: Utilization of Myocardial Perfusion Imaging, other Diagnostic Tests and Percutaneous Coronary Intervention for Coronary Artery Disease in Taiwan Top


Guang-Uei Hung*1

1Chang Bing Show Chwan Memorial Hospital, Changhua, Taiwan

Background/Aims: Myocardial perfusion imaging (MPI) has been found to be useful for diagnosis, risk stratification and potentially for decision-making of invasive coronary procedures for coronary artery disease (CAD). The purpose of this study was to investigate the utilization of MPI, other diagnostic tests and treatment with percutaneous coronary intervention (PCI) for CAD in Taiwan. Methods: Taiwan’s National Health Insurance (NHI) system is a single-payer social insurance program organized by the government under the jurisdiction of the National Health Insurance Administration (NHIA), Ministry of Health and Welfare. NHI system was funded was established in 1995 and now covers more than 99% of the population. In this study, we investigated the total numbers of MPI, treadmill exercise test (TET), stress echocardiography (SE), invasive coronary angiography (CAG) and PCI in 2016 from the data provided by NHIA. Cardiac MRI and CT were not reimbursed by NHI for CAD, therefore these two tests were not included in this study. Results: In 2016, the total numbers were 151254 for MPI, 190227 for TET, 1750 for SE, 91137 for CAG and 49806 for PCI, respectively. The utilization rate of MPI was 643 per 100000 of the population, which was only inferior to USA in the world. The TET to MPI ratio was only 1.26, however, MPI to SE ratio was as high as 86.43. The MPI to CAG ratio was 1.66 for Taiwan, but only 0.39 for Japan in 2016 and 0.24 for Germany in 2012. The MPI to PCI ratio was 3.04 for Taiwan but only 0.55 for Germany in 2012. Conclusion: Taiwan has a high MPI utilization rate for the work-up of CAD. MPI now is playing an important role of gatekeeper for invasive coronary procedures. This experience is useful and valuable for other countries on the promotion of appropriate use of MPI for CAD.


   P059: Usefulness of Posterior Leads Derived from the 18-Lead Electrocardiogram in the Diagnosis of Posterior Myocardial Infarction Top


Yuko Igarashi*1, S Hida1, K Hirose T Saito1, T Hatano1, T Morishima1, T Chiamori1

1Tokyo Medical Unversity, Tokyo, Japan

Background/Aims: Although abnormal Q-waves in the posterior leads (V7-9) suggest prior posterior myocardial infarction (MI), clinical features of MI patients with Q-waves limited only to V7-9 leads has not been fully elucidated. The synthesized 18-lead ECG (Nihon Kohden), which has been developed recently, estimates V7-9 leads waveforms from the standard 12-lead ECG, without placing ECG leads on the back. We sought to evaluate the usefulness of posterior leads derived from the 18-lead ECG in the diagnosis of posterior MI. Methods: Myocardial SPECT was retrospectively analysed in prior non-anterior MI patients (n=218). The extent and severity score in the inferior or lateral area were analysed using a 17-segment model. The relation between these SPECT score parameters and Q-waves in the V7-9 leads was analysed using an 18-lead ECG. Patients with prior anterior MI, history of coronary artery bypass grafting, right or left bundle branch block, right or left ventricular hypertrophy, Wolff-Parkinson-White syndrome, a cardiac device implantation such as pacemaker or cardiac resynchronization therapy, were excluded. Results: Among 218 patients, Q-waves were solely limited to V7-9 leads in 15 patients (7%). No Q-wave in the inferior leads or high R-wave in the V1 lead was observed in these patients. Extent score in the lateral area was greater in 15 patients with Q-waves in V7-9 leads (2.2±1.9 vs 1.1±1.5; p=0.005) than in 203 patients without such findings, while extent score in the inferior area was similar (1.2±1.4 vs 2.0±1.7; p=NS). Severity score in the lateral area was also greater in patients with Q-waves in V7-9 leads (6.5±7.7 vs 2.2±3.8; p=0.05) than in those without, while extent score in the inferior area was similar (2.1±2.2 vs 3.0±4.0; p=NS). Among 15 patients with Q-waves limited to V7-9 leads, coronary angiography showed LCX lesion in 12 patients while distal RCA lesion in 3 patients. Conclusion: Even if a standard 12-lead ECG is masked to detect abnormal findings, the 18-lead ECG analysis reveals Q-waves in V7-9 leads, which is regarded as a simple indicator for posterior MI.


   P060: Effectiveness of Manual Modification Compared to Automatic Extraction in Myocardial Perfusion Imaging Top


Masamichi Imai*1, Y Kosaka1, M Tachi1, K Mori1, H Maruno1

1Department of Radiology, Toranomon Hospital, Tokyo, Japan

Background/Aims: Stress myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) is useful for risk stratification of seriously cardiac events. Now several software packages to analyse including the quantitative perfusion SPECT (QPS),[1] cardioREPO,[2] and Heart Risk View are available, which contain unique algorithm for automatic epi/endocardial extraction of each software. However, the automatic extraction sometimes does not work well in clinical cases with abnormal SPECT findings, in which we need to modify the segmentation manually. The modification affects uptake scores such as summed stress score (SSS) to estimate the prognosis of cardiac events. The purpose of this study is to investigate the difference of each automatic extraction and the influence of the manual modification. Methods: We reviewed 59 patients who underwent stress MPI using Tl-201, with SSS between 5 and 13 under the regular protocol in our institute. Their data were reprocessed with automatic extraction using QPS, adding manual modifications by less-experienced technologist and experienced technologist. Whereas automatic extraction was also performed using cardioREPO and Heart Risk View software. In parallel, an expert radiologist gave visual scoring without any quantitative results from software. Then we compared each SSS and summed rest score (SRS) between those automatic extractions, modifications, and visual scoring by correlation analysis. Results: SSS with the manual modification by the experienced technologist had the highest correlation to visual scoring SSS (R=0.76). SSS with automatic extraction (R=0.55) was lower than SSS with the manual modification even by the less-experienced technologist (R=0.68). Of automatic extractions, cardioREPO had the highest correlation, however was inferior to the manual modification by the experienced technologist. Regarding SRS, there was the same tendency as SSS. Conclusion: Manual modification is recommended to provide appropriate cardiac SPECT images to a clinician.

References

  1. Germano G, Kavanagh PB, Waechter P, Areeda J, Van Kriekinge S, Sharir T, et al. A new algorithm for the quantitation of myocardial perfusion SPECT. I: Technical principles and reproducibility. J Nucl Med 2000;41:712-9.
  2. Lomsky M, Richter J, Johansson L, El-Ali H, Aström K, Ljungberg M, et al. A new automated method for analysis of gated-SPECT images based on a three-dimensional heart shaped model. Clin Physiol Funct Imaging 2005;25:234-40.



   P062: Myocardial Perfusion Images in Patients with Three Vessel Coronary Artery Disease: Comparison with Visual and Software Program Assessment Top


Keiko Koyama*1, K Takahashi1, T Ogura1, M Kanou1, K Mehara1, T Ino1

1Gunma Prefectural Cardiovascular Center, Maebashi, Japan

Background/Aims: Evaluation of ischaemia has been increasing its value in diagnosis and prognosis especially for patients with severe coronary artery disease such as multi vessel disease. It is difficult to exactly detect lesions in patients with balanced ischaemia in myocardial perfusion images(MPI). Recently software program using Artificial Neural Network (ANN) based on many characteristics from Japanese data base has been provided to assist interpretation of MPI. We compared visual assessment with two versions of software program assessments, old version based on European data base and new one based on Japanese data base, in MPI of patients with three vessel disease. Methods: Ten patients with three vessel disease diagnosed by coronary angiography were enrolled in this study. All of them underwent MPI. Stress and rest SPECT studies were performed. In visual assessment, two expert physicians in nuclear medicine detected myocardial abnormality. SPECT data were also analysed by software programs. Results: The age of the patients ranged from 50 to 70 years old. All patients had at least 90% stenosis in 2 vessels and ischaemic lesion. Four cases showed total occlusion vessels and myocardial damage. In this study, 80% of the patients had ischaemic lesion in apical and inferior wall and 60% of them in septal and lateral wall. In visual assessment, lesions were interpreted more severe than in software programs. In new version program, ischaemic area was clearer than old one. In cases of small heart, new version program could detect apex lesions well. About apex or anterior lesions, some cases showed different results of segmentation in visual assessment and software program assessment. Conclusion: There will be possibility of software program to support interpretation in MPI of patients with three vessel diseases. It needs to pay attention to variation of coronary artery distribution and sensitivity of software program.


   P063: A New Insight into Myocardial Washout Rate of iodine-123-β-Methyl Iodophenyl-Pentadecanoic Acid: As a Crucial Index for Diagnosing Triglyceride Deposit Cardiomyovasculopathy Top


Hideyuki Miyauchi*1, O Hashimoto1, N Mori1, T Limori2, K Sawada3, Y I Kuwabara1, K I Hirano4, Y Kobayashi1

1Chiba University, 2Department of Radiology, 3Department of Radiology, Chiba University Hospital, Chiba, 4Department of Cardiology, Osaka University, Osaka, Japan

Background/Aims: Triglyceride deposit cardiomyovasculopathy (TGCV) is a novel clinical entity found in Japanese patients waiting for heart transplant. TGCV is characterized by the accumulation of triglyceride into the myocardium and coronary artery. Diagnosing TGCV is often difficult because the patients are generally treated as coronary artery disease, heart failure or cardiomyopathy. In addition, plasma triglyceride level is not directly associated with TGCV. Remarkably reduced washout rate (WOR) of iodine-123-β-methyl iodophenyl-pentadecanoic acid (BMIPP) is useful for the diagnosis and it is one of the major diagnostic criteria for TGCV. However, executing additional delayed image is burdensome in some institutes, and WOR is sometimes substituted by reduced accumulation BMIPP in the early image. Therefore, we evaluated the usefulness of early BMIPP indices by comparing to the WOR of BMIPP in diagnosing TGCV. Methods: We executed early and delayed cardiac BMIPP imaging in 129 patients with cardiac disease to calculate WOR, and they were applied to diagnostic criteria for TGCV. In addition, early BMIPP indices, the heart to mediastinum ratio (H/M) of BMIPP and the relative accumulation of BMIPP to Tl (BM/Tl) were also calculated. Results: Among 129 patients, 59 received the definitive diagnosis of TGCV. The diagnostic values of the BMIPP indices were evaluated by ROC analysis. Area under the curve of H/M and BM/Tl were 0.53 and 0.75, respectively. The optimal diagnostic cut-off values of the H/M and BM/Tl were 2.50 (sensitivity = 52.5%, specificity = 56.3%) and 0.934 (sensitivity = 66.5%, specificity = 83.2%), respectively. Conclusion: For diagnosis of TGCV, early BMIPP indices cannot replace the WOR although BM/Tl uptake ratio might be useful in some extent. In any case, BMIPP scintigraphy has to be performed for patients with idiopathic coronary artery disease, heart failure and cardiomyopathy.


   P064: Comparison of Diagnostic Accuracy of Myocardial Perfusion Imaging Between Visual Assessment and Artificial Neural Networks Based Diagnostic System in Both Cadmium-Zinc-Telluride Camera and Standard Anger Camera Top


Takayuki Morishima*1, S Hida2, T Saito, K Hirose2, Y Igarashi2, T Hatano2, T Chikamori2

1Migita Hospital/Tokyo Medical University, Hachioji, 2Department of Cardiology, Tokyo Medical University, Tokyo, Japan

Background/Aims: Although an artificial neural network (ANN)-based diagnostic system is reported to have good diagnostic accuracy in the myocardial perfusion imaging using the Anger cameras,[1] the applicability of the ANN-based diagnostic system for cadmium-zinc-telluride (CZT) camera remain to be elucidated. Methods: The study group comprised of 84 consecutive patients who underwent a 1 day 99mTc-sestamibi stress/rest myocardial perfusion imaging (370 MBq for stress, 740 MBq for rest) and performed data acquisition with both a conventional Anger camera and CZT camera (Discovery NM530c). Myocardial perfusion was assessed by each coronary territory using a 17-segment model visually, and summed scores were analysed. The perfusion abnormality at stress SPECT derived by the ANN-based diagnostic system was determined using cardioREPO®. Results: Among 252 coronary territories visually evaluated, 102 territories showed normal findings, 54 fixed defects (FD), 95 reversible defects (RD), and 1 reverse redistributions (RR) in a standard Anger camera. By contrast, 91 territories showed normal findings, 61 FD, 67 RD and 33 RR in a CZT camera. On the Anger camera, the ANN-based analysis showed less area under the ROC curves (AUC) than summed stress score (SSS) (LAD: 0.57 vs. 0.76, p<0.05, RCA: 0.75 vs. 0.87, p=NS, LCx: 0.65 vs. 0.84, p<0.05). On the other hand, on the CZT camera, the ANN-based analysis showed equivalent AUC compared with SSS (LAD: 0.75 vs. 0.71, RCA: 0.81 vs. 0.78, LCx: 0.78 vs. 0.76, respectively; all p=NS). Conclusion: These results indicate that ANN-based diagnostic analysis may be useful as the auxiliary diagnostic tool even in CZT camera system.

References

  1. Nakajima K, Kudo T, Nakata T, Kiso K, Kasai T, Taniguchi Y, et al. Diagnostic accuracy of an artificial neural network compared with statistical quantitation of myocardial perfusion images: A Japanese multicenter study. Eur J Nucl Med Mol Imaging 2017;44:2280-9.



   P065: Stress-Induced Left Ventricular Diastolic Dysfunction Assessed by Quantitative Gated Myocardial Perfusion Single Photon Emission Computed Tomography as a Determinant of Coronary Artery Disease Severity Top


Christian Michael Pawhay*1, T Nakajima1

1Saitama Cardiovascular and Respiratory Center, Kumagaya City, Japan

Background/Aims: The aim of this study was to evaluate the utility of stress-induced left ventricular (LV) diastolic dysfunction assessed by 99mTc-tetrofosmin gated single photon emission computed tomography (SPECT) in determining the presence and extent of coronary artery disease (CAD). Methods: Two hundred and one patients (135 men; mean age 70y) who underwent a one-day adenosine stress-rest 99mTc-tetrofosmin myocardial perfusion imaging with subsequent coronary anatomy evaluation by invasive or computed coronary angiography were included. The summed difference score (SDS) was calculated for each patient. Peak filling rate (PFR), 1/3 mean filling rate (MFR/3) and time to PFR (TTPFR) after stress and at rest were derived from standard 16-frame gated SPECT images, and the percent stress-to-rest difference of these parameters were determined to describe stress-induced diastolic dysfunction. Results: In the overall population, the mean SDS was 5±4, while mean PFR at rest and after stress were 2.1±0.6 end-diastolic volumes (EDV)/s and 2.0±0.7 EDV/s, respectively. The mean rest and stress MFR/3 were 1.2±0.4 EDV/s and 1.1±0.4 EDV/s respectively, while the mean TTPFR was 248±121ms at rest and 261±115ms after stress. There is a significant correlation (p<0.05) between the presence and extent of CAD and both myocardial SDS and more altered diastolic function parameters. Furthermore, there was trend of increasing extent of CAD and worsening stress-induced LV diastolic dysfunction described as decreasing percent stress-to-rest difference in PFR and MFR/3 and increasing TTPF. The independent diastolic function determinants of the presence and extent of CAD in this study are the percent stress-to-rest TTPF difference (p=0.006) and the stress TTPF value (p=0.006). Other significant determinants noted are myocardial SDS (p=0.002), resting ejection fraction (p=0.001), indexed resting end-systolic volume (p=0.007) and indexed end-diastolic volume at stress (p=0.009). Conclusion: This study shows that stress-induced LV diastolic dysfunction assessed by gated SPECT aids in the detection of the presence and extent of CAD.


   P066: Does Aspirin Modify Gastric Wall Sestamibi uptake in Patients Taking a Proton Pump Inhibitor? Top


D Rose*1, B Robinson2, Z King1, S Kannan1, J Lee1

1The Prince Charles Hospital, Chermside, Queensland, 2Department of Nuclear Medicine, Royal Brisbane and Women’s Hospital, Brisbane, Australia

Background/Aims: Gastric wall sestamibi uptake is a source of artefacts on myocardial perfusion imaging (MPI) and has been associated with proton-pump inhibitor (PPI) therapy. PPI treatment predictably increases serum gastrin, a hormone known to induce expression of the COX-2 isoenzyme and prostaglandin synthesis in the gastric mucosa. Prostaglandin effects including mucosal hyperplasia and increased blood flow are plausible mechanisms for increased sestamibi uptake. Thus, it was hypothesised that concurrent use of aspirin, an irreversible inhibitor of COX-2, might reduce the effect of PPIs on gastric wall sestamibi uptake. Methods: We reviewed medical records and images of 319 consecutive patients undergoing MPI Between July 1 and September 30, 2015, for clinically significant gastric wall sestamibi uptake (greater than myocardium), PPI use, and aspirin use. We estimated the relative risk (RR) for significant gastric wall uptake associated with PPI use stratified according to aspirin use. (Approved by TPCH HREC.) Results: Significant gastric wall sestamibi uptake was seen in 55/135 (41%) of patients taking a PPI versus 32/184 (17%) not taking a PPI for a RR of 2.3. The RR due to PPI use stratified by aspirin use was:



Conclusion: There was evidence of an association between PPI use and clinically significant gastric wall sestamibi uptake (RR 2.3). The effect of PPIs was stronger in the absence of concurrent aspirin use (RR 3.8) but weak or non-existent in the subgroup taking aspirin. Therefore, aspirin may inhibit the increased gastric uptake on MPI studies due to PPI therapy in keeping with mediation by the gastrin-COX-2-prostaglandin pathway. Our study raises the possibility that short-term use of aspirin or a selective COX-2 inhibitor may improve image quality in patients taking a PPI.


   P067: Performance Evaluation of a Myocardial Perfusion Analysis Software with the Artificial Neural Network in Stress Myocardial Perfusion Scintigraphy Top


Takayuki Sada*1, H Miyauchi2, T Iimori1, K Sawada1, T Umezawa1, Y Masuda1, Y Kuwabara2, T Uno3, Y Kobayashi2

1Chiba University Hospital, Departments of 2Cardiovascular Medicine and 3Diagnostic Radiology and Radiation Oncology, Chiba University Graduate School of Medicine, Chiba, Japan

Background/Aims: Myocardial perfusion analysis software has been widely used for the detection of ischaemic heart disease and evaluation of prognostic. in myocardial nuclear medicine. A newly released myocardial perfusion analysis software, cardioREPO (cREPO: FUJIFILM RI Pharma, Tokyo, Japan; with EXINI Diagnostics, Lund, Sweden), has an artificial neural network. Recently, its usefulness of ischaemia evaluation in myocardial perfusion single photon emission computed tomography (SPECT) has been reported. However, the diagnosis accuracy of cREPO in each coronary artery branch areas has not yet reported. The purpose of this study was to evaluate for the diagnostics concordance rate of cREPO and the quantitative perfusion SPECT (QPS) using the 17-segment detect score in myocardial perfusion SPECT in each coronary artery branch areas. Methods: (1) The retrospective survey of a125 participants who had undergone 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI) scintigraphy were conducted. The image data of 99mTc-MIBI stress myocardial perfusion SPECT were analysed with cREPO and QPS, and summed defect scores in each coronary artery branch areas (summed DS) were calculated. (2) The receiver operating characteristic (ROC) analysis were performed for cREPO and QPS based on the diagnosis data from cardiac catheterization. Results: The summed DS of cREPO and QPS were significantly concordant in each branch areas (RCA: rs=0.07, LAD: rs=0.66, LCx: rs=0.57). There were no significant differences between area under the curve values of cREPO and that of QPS (p>0.05). Conclusion: It was suggested that cREPO is useful to evaluate ischaemia in each coronary branch areas as well as QPS.

Disclosure of Interest: H Miyauchi Conflict with: FUJIFILM RI Pharma; T Iimori Conflict with: FUJIFILM RI Pharma; K Sawada Conflict with: FUJIFILM RI Pharma; Y Kuwabara Conflict with: FUJIFILM RI Pharma; Y Kobayashi Conflict with: FUJIFILM RI Pharma, Tokyo, Japan.


   P068: Relationships between Electrical and Mechanical Dyssynchrony in Patients with Right Bundle Branch Block Top


Saara Sillanmäki*1, S Aapro2, J Lipponen3, M Tarvainen3, T Laitinen1, M Hedman4, T Laitinen1

1Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, 2University of Eastern Finland, Kuopio, 3Department of Applied Physics, University of Eastern Finland, 4Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland

Background/Aims: Right bundle branch block (RBBB) can cause electrical dyssynchrony but it´s association to mechanical dyssynchrony is not as thoroughly understood. In this study, we characterized electrical and mechanical dyssynchrony and analysed their relationships in RBBB patients as well as in healthy controls. Methods: We analysed data of 994 patients who underwent myocardial perfusion imaging (MPI) SPECT. Thirty patients fulfilled criteria for RBBB (Surawicz et al. 2009) and twenty-four for controls. 12-lead-ECGs recorded along with MPIs were transformed to vector electrocardiography (VECG) for characterizing electrical activation. Left ventricular (LV) mechanical dyssynchrony was analysed by using MPI phase analysis method. MPI parameters representing mechanical dyssynchrony were phase analysis bandwidth (phaseBW), standard deviation and Entropy%. Results: 43% of RBBB patients had LV-mechanical dyssynchrony. ECG/VECG parameters that were significantly different between RBBB patients with and without mechanical dyssynchrony were QRS/T angle (105° vs. 59°, p=0.018) and QRS-angle in sagittal plane (QRSsag;-56° vs. 26°, p=0.049). In multivariate analysis, independent predictors for mechanical dyssynchrony were QRS duration (QRSd) and QRSsag. Together these two parameters explained 40% of the variation in phaseBW. The optimal cut-off value for predicting mechanical dyssynchrony was 144 ms for QRSd with the sensitivity of 67% and the specificity of 80%. For QRSsag the cut-off value was 49° with the sensitivity of 73% and the specificity of 77%. Conclusion: Almost half of the RBBB patients have LV mechanical dyssynchrony analysed with MPI phase analysis. RBBB patients with mechanical dyssynchrony had wider QRS/T angle and more negative QRSsag compared to controls and RBBB patients with more synchronous LV contraction. This finding may have clinical value when evaluating patients for cardiac resynchronizing therapy.

Disclosure of Interest: S Sillanmäki Conflict with: Educational support from GE Healthcare.


   P069: Cardiac Uptake in Skeletal Scintigraphy with 99mTc-HDP at Sunderby Hospital, northern Sweden 2012–2016, a Retrospective Study of 1000 Patients: A Potential Biomarker for ATTR Cardiomyopathy? Top


Torbjörn Sundström*1, G Eriksson1, P Lindqvist2, B Pilebro3

1Diagnostic Radiology, 2Department of Surgical and Perioperative Sciences, Clinical Physiology, 3Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden

Background/Aims: Amyloidosis is a heterogeneous group of diseases characterized by localised or systemic deposition of insoluble extracellular fibrillary proteins into organs and tissues. Several types of amyloid can infiltrate the heart which can result in restrictive cardiomyopathy, heart failure and even cardiac arrhythmias. Scintigraphy is a non-invasive method that has been shown to facilitate early diagnosis of cardiac amyloidosis, hereditary or wild type (wt) ATTR. Since wt ATTR, formerly designated as senile systemic amyloidosis (SSA), is normally found in elderly males matching the ages found in prostate cancer patients referred to bone scan, we wanted to investigate the incidence of cardiac uptake in patients examined with 99mTc-HDP and frequency of contemporary atrial fibrillation, hypertension and heart failure. Methods: A total of 1000 patients during 2012-2016 referred to skeletal scintigraphy with 99mTc-HDP were consecutive included in this retrospective study. Data were obtained from referral and journals for both men and women in accordance with the approved ethical application. Data of diagnosed hypertension, heart failure or atrial fibrillation were collected. For tables and statistics, Excel 10 was used. p-values <0.05 was considered statistically significant. All patients received intravenous injection 550MBq of 99mTc-HPD. 3 hours after the injection, the entire body was scanned with anterior and posterior planar imaging. All scans were visually graded by an experienced radiologist with nuclear medicine according to Perugini et al.[1] Results: Cardiac uptake were seen in 1.6% of the patients, predominant in elderly men. In a subgroup of men over 80 years of age 8.9% had cardiac uptake. The presence of atrial fibrillation and heart failure was statistically significantly higher in both men and women with cardiac uptake, p <0.001, even after age correction. No significant association with hypertension was seen. Conclusion: Cardiac uptake of 99mTc-HDP in clinical routine is associated with a higher frequency of atrial fibrillation and heart failure compared to age matched controls. Thus,99mTc-HDP can be proposed as a potential biomarker for ATTR.

References

  1. Perugini E, Guidalotti PL, Salvi F, Cooke RM, Pettinato C, Riva L, et al. Noninvasive etiologic diagnosis of cardiac amyloidosis using 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid scintigraphy. J Am Coll Cardiol 2005;46:1076-84.



   P071: Patient and Clinical Correlates of a Negative 99mTc Sestamibi stress Scan-Advancing the Cause of the Stress Only Protocol Top


Alla Turlakow*1, H Xiao1, T Chen1

1Western Health, Melbourne, Australia

Background/Aims: Efforts continue in decreasing radiation to patients from radiographic investigations. The 99mTc-sestamibi stress scan, if performed as a 2 part study requires two separate radiotracer injections and a prolonged period in the laboratory. The stress only protocol, followed by a resting study if abnormal or equivocal, is an established alternative and has advantages in substantially reducing radiation burden, test time, cost and improving patient throughput. Some centres however prefer the two-part protocol in all patients for both clinical and logistic reasons. The aim of this study was to determine if certain pretest clinical characteristics correlated with absence of ischaemia on 99mTc-sestamibi stress scan, so that selected patients could be pre-emptively allocated to stress-only protocol thereby minimising disruption to department scheduling. Methods: We conducted a retrospective review of 158 consecutive patients who undertook 99mTc-sestamibi stress scans in our department. Patient and clinical characteristics of age, sex, coronary risk factor (CRF) status, prior myocardial infarction, prior ischaemic heart disease, left ventricular dysfunction, type of stress undertaken and admission status were correlated to the patient’s myocardial perfusion scan result. Results: Of 158 patients, 42 (27%) had a positive and 116 (73%) a negative 99mTc-sestamibi scan for ischaemia. Negative scans correlated with fewer CRFs (2.1:2.7 p<0.01), a non-diabetic state (p<0.05), normal left ventricular function (p< 0.001) and patients were more likely to be female (p<0.05). There was no significant correlation with age, history of myocardial infarction or ischaemic heart disease, absence or specific CRFs excluding diabetes, need for pharmacologic stress and inpatient status. Conclusion: Certain clinical and patient characteristics correlate significantly with absence of myocardial ischaemia, and could be used pre-emptively to individually prescribe stress only 99mTc-sestamibi stress protocols to low risk patients, specifically to spare them an unnecessary radiation and temporal burden.


   P072: Normal Values of Cardiac Mechanical Synchrony Parameters in Korean Population using Gated Myocardial Perfusion Single-Photon Emission Computed Tomography Top


Kyoung Sook Won*1, B I Song1, H W Kim1, B W Kim1

1Keimyung University Dongsan Medical Center, Daegu, Republic of Korea

Background/Aims: The aim of this study was to evaluate the normal values of cardiac mechanical synchrony parameters in Korean population using one day low dose rest/high dose stress with adenosine gated myocardial perfusion SPECT. Methods: A total of 78 healthy controls consisted with 36 men and 42 women were retrospectively enrolled in the study. The healthy control was defined as people with low pretest likelihood of coronary artery disease, no abnormal finding in gated myocardial perfusion SPECT using one day low dose rest/high dose stress with adenosine, and QRS interval less than 120ms in electrocardiogram. For quantification of cardiac mechanical synchrony parameters, phase standard deviation (PSD), and phase histogram bandwidth (PHB) were measured on both rest and stress phases. Comparison of the normal values was performed by t-test. This study was approved from institutional review board. Results: PSD were 14.4 ± 2.5˚ (rest) and 15.2 ± 3.4˚ (stress) in male and 10.2 ± 1.9˚ (rest) and 11.3 ± 2.1˚ (stress) in female, PHB were 40.3 ± 4.5˚ (rest) and 47.2 ± 5.3˚ (stress) in male and 35.9 ± 4.8˚ (rest) and 40.6 ± 6.1˚ (stress) in female. Significant difference was noted in PSD between men and women both stress and rest and in PHB of the men between stress and rest. Conclusion: The normal values of cardiac mechanical synchrony parameters in Korean population showed significant difference in PSD between men and women on both stress and rest and in PHB of the men between stress and rest. Thus, centers using GMPS should have its normal database for men and women and stress and rest, respectively.


   P073: Validation of Left Ventricular Ejection Fraction with the IQ•Single-Photon Emission Computed Tomography System in Small-Heart Patients Top


Hiroto Yoneyama*1, T Shibutani2, M Onoguchi2, T Konishi1, K Okuda3, S Matsuo4, K Nakajima4, S Kinuya4

1Department of Radiological Technology, Kanazawa University Hospital, 2Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 4Department of Nuclear Medicine, Kanazawa University Hospital, Kanazawa, 3Department of Physics, Kanazawa Medical University, Kahoku, Japan

Background/Aims: The IQ•SPECT system, which is equipped with multifocal collimators (SMARTZOOM) and uses ordered-subset conjugate gradient minimization as the reconstruction algorithm, reduces the acquisition time of myocardial perfusion imaging compared with conventional SPECT systems equipped with low-energy high-resolution collimators. We compared the IQ•SPECT system with a conventional SPECT system for estimating left ventricular ejection fraction (LVEF) in patients with a small heart (end-systolic volume < 20 mL). Methods: The study consisted of 98 consecutive patients who underwent a 1 day stress-rest myocardial perfusion imaging study with a 99mTc-labeled agent for preoperative risk assessment. Data were reconstructed using filtered back projection for conventional SPECT and ordered-subset conjugate gradient minimization for IQ•SPECT. End-systolic volume, end-diastolic volume, and LVEF were calculated using quantitative gated SPECT (QGS) and cardio REPO software. We compared the LVEF from gated myocardial perfusion SPECT to that from echocardiographic measurements. Results: End-diastolic volume, end-systolic volume, and LVEF as obtained from conventional SPECT, IQ•SPECT, and echocardiography showed a good to excellent correlation regardless of whether they were calculated using QGS or using cardio REPO. Although LVEF calculated using QGS significantly differed between conventional SPECT and IQ•SPECT (65.4%±13.8% vs. 68.4%±15.2%, p=0.0002), LVEF calculated using cardio REPO did not (69.5%±10.6% vs. 69.5%±11.0%). Likewise, although LVEF calculated using QGS significantly differed between conventional SPECT and IQ•SPECT (75±9.6 vs. 79.5±8.3, p=0.0005), LVEF calculated using cardio REPO did not (72.3%±9% vs. 74.3%±8.3%). Conclusion: In small-heart patients, the difference in LVEF between IQ•SPECT and conventional SPECT was less when calculated using cardio REPO than when calculated using QGS.


   P074: 18F-Fludeoxyglucose Positron Emission Tomography in Diagnosing Cardiac Sarcoidosis: Variability of the Interpretation and Translation of Evidence for Low Carbohydrate dietary Preparation Top


V Atterton-Evans1, James Turner*2, T Robertson1, A Vivanti1,3

1Department of Nutrition and Dietetics and 2Diagnostic Radiology, The Princess Alexandra Hospital, Queensland Health, Woolloongabba, 3School of Human Movement and Nutrition Sciences, University of Queensland, St Lucia, Queensland, Australia

Background/Aims: ‘Low carbohydrate’ diets are recommended to suppress cardiac glucose uptake and enhance image interpretation of 18F-FDG PET scans when diagnosing cardiac sarcoidosis. A review was undertaken to identify low carbohydrate dietary prescriptions within the cardiac sarcoidosis literature. Methods: A critical review of human studies in any language was undertaken using MEDLINE and PubMed databases until April 2017. Search terms included: Fluorodeoxyglucose F18; Myocardium OR Cardiac; diet OR carb* OR fat; sarcoidosis. Results: Four studies were identified, all rated as NHMRC quality level III-3 to IV. One study described dietary preparation quantitatively (<5g carbohydrate/meal) and qualitatively (“egg, tofu, grilled chicken with stir-fried vegetables”).[1] One study described preparation qualitatively, listing permitted (e.g. non-processed poultry, fish, meat, eggs) and prohibited foods (e.g. sugar, pasta, bread, starchy vegetables, fruit, milk, candy, sauces, alcohol).[2] Intervention groups followed the same dietary preparation for differing lengths of time, with no comparison to high carbohydrate preparations. Two studies provided minimal dietary details; one described a “carbohydrate-restricted, fat-and protein-allowed diet for at least 12 hours”[3] and another described a “fat meal: cheese, egg, etc, no carbohydrates before a 12 hour fast”.[4] In the four studies, dietary preparation protocols included: diet and fasting for 6, 12 or 18 hours and low carbohydrate diet for 1 meal, 12 hours, 24 hours or 72 hours. While prohibited foods were confirmed as high carbohydrate, no studies described carbohydrate as a proportion of energy. Conclusion: Despite published studies recommending low carbohydrate diets prior to 18F-FDG PET scans for diagnosing cardiac sarcoidosis, preparation advice and protocols greatly varied. Stronger study designs to determine a quantitative definition of a low carbohydrate diet are required to translate into clinical dietetic prescription and practice.

References

  1. Manabe O, Yoshinaga K, Ohira H, Masuda A, Sato T, Tsujino I, et al. The effects of 18-h fasting with low-carbohydrate diet preparation on suppressed physiological myocardial (18)F-fluorodeoxyglucose (FDG) uptake and possible minimal effects of unfractionated heparin use in patients with suspected cardiac involvement sarcoidosis. J Nucl Cardiol 2016;23:244-52.
  2. Lu Y, Grant C, Xie K, Sweiss NJ. Suppression of myocardial 18F-FDG uptake through prolonged high-fat, high-protein, and very-low-carbohydrate diet before FDG-PET/CT for evaluation of patients with suspected cardiac sarcoidosis. Clin Nucl Med 2017;42:88-94.
  3. Scholtens AM, Verberne HJ, Budde RP, Lam MG. Additional heparin preadministration improves cardiac glucose metabolism suppression over low-carbohydrate diet alone in ¹8F-FDG PET imaging. J Nucl Med 2016;57:568-73.
  4. Ambrosini V, Zompatori M, Fasano L, Nanni C, Nava S, Rubello D, et al. (18)F-FDG PET/CT for the assessment of disease extension and activity in patients with sarcoidosis: Results of a preliminary prospective study. Clin Nucl Med 2013;38:e171-7.



   P075: 18F-Fludeoxyglucose Uptake by Untreated Fresh Autologous Pericardial Valve at Pulmonary Position: Positron Emission Tomography/Computed Tomography Valuation at Mid Term Top


Amitabh Arya*1, S Pande2, G Sankar1, P Tewari3, S K Agarwal2, N Soni4, S Kumar4

Departments of 1Nuclear Medicine, 2CVTS, 3Anaesthesiology and 4Radiology, SGPGIMS, Lucknow, Uttar Pradesh, India

Background/Aims: Pericardium is most commonly used material for creating a cardiac valve. Commercially available bioprosthetic valve utilises treated xenogenic tissue. Autologous pericardial tissue is also in use for this purpose albeit treatment with gluteraldhyde. When untreated, it has the advantage of having living cells while creating the cardiac valve. However, there is no information if the property of living tissue at operation continues in years to follow when untreated pericardium is used as material for construction of cardiac valve. Methods: Pericardium was used to construct a competent pulmonary valve in patients of tetralogy of fallot requiring enlargement of pulmonary annulus. Between 2006 and 2012, 78 patients required reconstruction of pulmonary valve. Of these, 19 patients with more than 3 years of follow-up who consented for the study were included. The study was cleared by the ethics committee. All the patients underwent 18FDG PET scan following overnight fasting. Uptake of FDG by pericardial valve leaflet, native aortic and pulmonary valve leaflet is calculated. Uptake for LV and RV myocardium is also calculated. RV function is assessed by right ventricle fractional area shortening (RVFAC) in 2 D echocardiography. RVFAC of <35% is considered RV dysfunction. Results: Median age was 14 years (9-37 years) and 16 were male. Follow-up is for median 4 years (3 – 9). FDG uptake is observed in pericardial valve leaflet. Uptake show significant strong correlation with the native aortic leaflet (p=0.0001, AUC= 0.861) and native pulmonary leaflet in some cases (p=0.0001, AUC=0.844). RVFAC correlated with ratio of RV and LV FDG uptake (p=0.049). Conclusion: At midterm follow-up, pericardium to create pulmonary valve, has confirmed uptake of glucose. This was similar to the native aortic valve uptake. Uptake of glucose confirms living tissue, though its characterisation is not possible in the scope of study.


   P077: Assessment of Left Ventricular Remodelling and Angiogenesis in Ischaemic-Reperfused Rat Hearts Protected by Dodecafluoropentane Oxygen-Carrier Top


Zhonglin Liu*1, C Barber1

1University of Arizona, Tucson, United States

Background/Aims: We have previously demonstrated that NVX108, an oxygenated nano-emulsion of dodecafluoropentane (DDFP), can limit acute myocardial infarct (MI). It was unclear whether excess oxygen generation by DDFP delivery might have a negative impact on infarct repair. This study used SPECT to determine the effects of NVX108 on postinfarct left ventricular (LV) remodelling and angiogenesis in an ischaemic-reperfused (I/R) rat heart model. Methods: I/R rat hearts prepared by ligation of the left coronary artery (LCA) for 45-min followed by reperfusion were treated by intravenous injection of NVX108 (0.6 mL/kg) (n=8) or saline as control (n=6) 15-min after LCA-ligation. High-resolution SPECT studies were performed over 16 weeks. 99mTc-sestamibi (MIBI) was used to assess myocardial perfusion and LV dilation. 99mTc-3P4-(Arg-Gly-Asp)2 (99mTc-3P4-RGD2, RGD) was used to assess αvβ3 integrin expression associated with angiogenesis. After the final imaging session, the rats were sacrificed for postmortem analyses of myocardial RGD uptake and histopathological changes. Results: MIBI images showed LV defects in all hearts. The defects in the control hearts enlarged significantly from 1 week to 16 weeks (31.8±3.5% of LV vs. 39.7±4.8%, p<0.05), whereas those in the NVX108-treated hearts did not (25.7±2.1% vs. 27.7±3.6%, p>0.05). LV cavity size on MIBI tomography indicated that the LV dilated by a factor of 1.29±0.06 over 16 weeks in the controls and 1.05±0.04 in the NVX108-treated hearts (p<0.05). Angiogenesis in the infarcted myocardium was most active at 1-week and still detectable at 16-week; there was no difference in the RGD activity (%ID/g) between the controls and NVX108-protected hearts (0.14±0.01 vs. 0.13 ±0.01%, p>0.05). Autoradiography confirmed increased RGD uptake in the LV ischaemic areas-at-risk. Conclusion: Significant attenuation of post-infarct LV remodelling, as assessed by MIBI imaging, was achieved with administration of NVX108 as an oxygen carrier after an I/R incident. It appears that NVX108 limits adverse LV enlargement, while not showing inhibition of post-MI angiogenesis.


   P079: Comparison of 99mTc-Haxamethylpropyleneamine Oxime-Labelled Leukocytes -Labeled Leukocyte Single-Photon Emission Computed Tomography-Computed Tomography and Echocardiographic Results in Infective Endocarditis Top


Magdalena Kostkiewicz*1, K Holcman1, W Szot1, A Lesniak-Sobelga1, P Podolec1

1Department of Nuclear Medicine, Jagiellonian University Collegium Medicum, Krakow, Poland

Background/Aims: Infective endocarditis (IE) is one of the most common life-threatening infection syndromes, with remaining high mortality. Establishing diagnosis is a clinical challenge. Single photon emission tomography (SPECT) and computed tomography (CT) with 99mTc-haxamethylpropyleneamine oxime-labelled leukocytes (99mTc-HMPAO) has recently been introduced as a novel diagnostic tool in patients with suspected IE. The aim of this study was to evaluate 99mTc-HMPAO SPECT/CT and to compare with echocardiographic study. Methods: The study group included 40 consecutive adults with suspected IE, based on standard medical diagnostic process. Patients underwent transthoracic and transoesophageal echocardiography (TTE and TEE) for assessment of lesions typical for IE. Subsequently all patients had 99mTc HMPAO SPECT/CT. Scans were evaluated for presence and location of increased radioactivity foci, which correspond to the accumulation of the radiolabelled leukocytes in inflammatory lesions. The patients were followed up for 6 months, which included outpatient visits and TTE. Results: For IE diagnosis, 99mTc-HMPAO SPECT/CT was characterised by 93% sensitivity, 88% sensitivity, 96% negative predictive value,81% positive predictive value. There is statistically significant correlation between TEE and scintigraphic results. Extracardiac foci of increased radioactivity were observed in 47.5% of patients, with most common location in digestive system. Conclusion: In patients with suspected IE, 99mTc-HMPAO SPECT/CT provides information about localisation and range of infection. 99mTc-HMPAO SPECT/CT and echocardiography are complementary modalities in diagnosing IE, 99mTc-HMPAO SPECT/CT can distinguish patients with IE and other systemic infections.


   P080: 99mTechnetium Pyrophosphate in Cardiac Amyloidosis an Alternative for Patients Not Considered Suitable for Biopsy Top


Zoey-Jo Murphy*1, S Weerasooriya1

1Townsville Hospital and Health Service, Townsville, Australia

Background/Aims: Cardiac amyloidosis is an infiltrative condition increasingly recognised as an important cause of diastolic heart failure and arrhythmias. The two main subtypes of this condition include Immunoglobin light-chain amyloidosis (AL) and Transthyretin-related amyloidosis (ATTR) characterised by extracellular deposition of misfolded proteins, thus forming deposits in the heart resulting in myocardial dysfunction. Differentiating AL from ATTR type is imperative for patient’s prognosis and management. This case series aims to demonstrate how nuclear medicine can be used as a diagnostic tool in the diagnoses of ATTR in patients not suitable/considered for cardiac biopsy. Methods: Literature review was undertaken to demonstrate the validity of using 99mTechnetium pyrophosphate (99mTc-PYP) in the diagnosis of ATTR amyloid. In our case series, 99mTc-PYP was administered to patients who were suspected of having ATTR amyloid and scanned 1 hour post injection. Semiquantitative and quantitative analysis was calculated through both visual scores and heart to contralateral ratio as per the protocol by Bokhari et al, Circ Imaging 2013. Definitive diagnosis was correlated on clinical findings, ECG, echocardiography, cardiac MRI when available and other relevant findings (eg. serum electrophoresis/fat pad biopsy). Results: Five subjects over a 12 month period were referred for cardiac amyloid scanning with 99mTc-PYP. Three out of the five patients had a negative study for ATTR cardiac amyloid. The two out of five that were positive for ATTR cardiac amyloid demonstrated a visual score of 3 and Heart: Contralateral ratio of >1.5% alongside highly suggestive clinical history/ECG/Echo +/-CMR findings. Conclusion: Nuclear medicine 99mTc-PYP scintigraphy is a simple and widely available tool in the diagnoses of ATTR cardiac amyloidosis. 99mTc-PYP may be considered as an alternative method to differentiate ATTR from AL cardiac amyloidosis in patients not considered for cardiac biopsy.


   Gastrointestinal/Hepatobiliary Top



   P081: Unraveling a Decade-Long Case of Chronic Obscure Gastrointestinal Bleeding with 99mTc-Red Blood Cell Scintigraphy Top


Bridget Nancy Coote*1, E E Ongkeko1

1St. Luke’s Medical Center-Global City, Taguig City, Philippines

Background/Aims: Representing 5% of approximately all cases of gastrointestinal bleeds, obscure gastrointestinal bleeding (OGIB) is defined as chronic occult or overt bleeding from the gastrointestinal tract that remains unexplained by standard upper and lower endoscopic and radiological gastrointestinal investigations. Causes of OGIB can range from vascular, neoplastic, inflammatory, and extraluminal etiologies. Endoscopic evaluation remains the cornerstone of the diagnosis and management of OGIB. However, for patients who are bleeding profusely or are hemodynamically unstable, this may pose a challenge. Arteriography or nuclear scintigraphy may therefore be considered in these situations. This case report details the case of a patient with a 10-year history of chronic OGIB that was eventually resolved with the aid of 99mTc-red blood cell (RBC) scintigraphy. Methods: A 65-year-old male with a 10-year history of OGIB presented at the emergency department (ED) due to acute episodes of mixed hematochezia and melena. Multiple and varied previous work-ups for bleeding episodes over the years were unsuccessful in determining the etiology. He was referred to our department for RBC scintigraphy. Results: Scintigraphic examination done at the time of initial presentation was inconclusive. A month later, patient sought follow-up due to recurrence of OGIB. Repeat RBC scintigraphy demonstrated evidence of bleeding in the jejunal segments, which on oral enteroscopy revealed an ulcerated mass in the mid-distal jejunum. Resection and histopathologic examination of the mass confirmed a diagnosis of a gastrointestinal stromal tumour (GIST). Conclusion: RBC scintigraphy is a quick, simple, and non-invasive procedure that requires no specific patient preparation, making it useful in situations where endoscopy may not be immediately feasible or tolerated by the patient. It is a sensitive test that also enables continuous monitoring of the entire GI tract for up to 24 hours, thus increasing the likelihood of detection over other techniques that are limited to a single time point.


   P082: Correlation between Preoperative Gastric Emptying Scintigraphy and Clinical Outcome after Bariatric Surgery Top


Sana Hava*1, TA Ho1, A Gish1, S Dadparvar1

1Diagnostic Radiology-Department of Nuclear Medicine, Temple University Hospital, Philadelphia, United States

Background/Aims: As morbid obesity continues to rise, more patients are turning to bariatric surgery for weight-loss. These surgeries, however, may potentially result in long-term motility disorders. This retrospective study assessed the value of gastric emptying scintigraphy prior to surgery with patient’s post-surgical clinical outcome. Methods: Pre-operative gastric emptying studies for 101 patients (96 females, 5 males, mean age 44.7 years) were analysed. Five patients who underwent gastric scintigraphy after surgery and 1 patient with a non-diagnostic pre-op study were excluded. The results of pre-operative gastric scintigraphy were reviewed on 95 patients. Patients underwent either laparoscopic sleeve gastrectomy (77) or Roux-En-Y gastric bypass (24). The average post-operative clinical follow-up was 3 months after surgery. Results: Of the 95 patients who were analysed, 71 had normal and 24 had abnormal pre-op gastric emptying scintigraphy. Of the 71 patients with normal pre-op results, 46 (64.8%) were asymptomatic and 25 (35.2%) were symptomatic after surgery. Of the 24 patients with delayed pre-op results, 13 (54.2%) were asymptomatic and 11 (45.8%) were symptomatic post-op. There was no significant difference between pre-op gastric emptying results and post-surgical adverse clinical outcomes (p=ns). 76 patients underwent sleeve gastrectomy. Of the 62 patients with normal pre-op gastric emptying results, 41 (66.1%) were asymptomatic, and 21 (33.9%) were symptomatic after surgery. Of the 14 patients with delayed pre-op results, 8 (57.1%) were asymptomatic and 6 (42.9%) were symptomatic post op. Nineteen patients underwent Roux-en-Y gastric bypass. Of the 9 patients with normal pre-op gastric emptying, 5 (55.6%) were asymptomatic, and 4 (44.4%) were symptomatic after surgery. Of the 10 patients with delayed pre-op results, 5 (50%) were asymptomatic, and 5 (50%) were symptomatic post op. There was no significant correlation between pre-op gastric emptying study results, surgery type, and post-surgical clinical outcome (p=ns). Conclusion: Pre-operative gastric emptying study was not a strong predictor of clinical outcome in bariatric surgery. There was no significant association between pre-op gastric emptying and surgery type. We recommend a larger sample size representing each surgery type and longer range of follow-up to predict patient’s outcome.


   P083: 25-hydroxyvitamin-D Serum Levels in Patients with Idiopathic Inflammatory Bowel Disease. Correlation with Disease Severity Top


D Kittou1, C Tsigalou2, A Strataki1, A Tsartsarakis1, A Pistola1, S Boundi1, M Lambropoulou3, K Chatzipanagiotou1, V Xanthis1, G Kouklakis4, Athanasios Zissimopoulos*1

1Democritus University of Thrace, 2Laboratory of Biopathology-Immunology, Democritus University of Thrace, 3Laboratory of Histology-Embryology, Democritus University of Thrace, 4A’ Pathological Clinic, Democritus University of Thrace, Alexandroupolis, Greece

Background/Aims: Idiopathic bowel disease includes immune system diseases of unknown origin. The pathogenesis involves a complex between genetic, environmental, and immunologic factors. In the present study, we examine the vitamin D serum values of patients with IBD and its relation with the severity of the disease. Methods: 125 patients (78 men and 47 women), aged from 28 to 68 (average 54 +/-6), were examined in a 3 years period. 87 had IBD in several stages-48 with ulcerative colitis (25 men, 23 women) group A, 39 with Crohn’s disease (23 men, 16 women) group B and 38 (30 men, 8 women), with general gastrointestinal diseases group C. Patients originated from clinics of University Hospital of Evros. The evaluation of vitamin D levels was made at the University Nuclear Medicine Department by using the radioimmunoassay method with kits Dia-Sorin Italy. Statistical analysis was performed by the x2-test (student test) and statistical significance was considered for p<0.05. Results: 82% of group A patients had low values of vitamin D (deficiency), 12% showed insufficiency and 6% had sufficiency serum vitamin D levels (p <0.05). In group B 83% had deficiency, 15% had insufficiency and 2% had sufficiency vitamin D levels (p <0.05). It should be noted that in both groups A and B patients with severe diseases had a very low 25-hydroxyvitamin-D levels (p <0.05). In group C patients had lower rates compared to those of groups A and B, where 57% showed a deficiency, 32% showed insufficiency and 11% showed sufficiency (p <0.05). Conclusion: The evaluation of serum vitamin D in patients with IBD is useful in patients monitoring. The very low values of 25-hydroxyvitamin-D are associated with disease severity. Further studies are required for any possible improvement of patient status after vitamin D substitution.


   P084: Evaluation of Sonographically Suggested Cases of Hepatic Hemangioma by 99mTc-Red Blood Cell Scintigraphy Top


Nafisa Sayeed*1

1BSMMU, Dhaka, Bangladesh

Background/Aims: Hemangioma is the most common benign hepatic tumour and second most common neoplasm of the liver, following intrahepatic metastases. They are most common in people in their third to fifth decade of life. Women, especially with a history of multiparity, are affected more often than men. The female-to-male ratio is 4:1 to 6:1. The course of hemangioma is usually uncomplicated, differentiation from other lesions, such as metastases, is essential to avoid unnecessary or risky examination and treatment. Ultrasonogram is sensitive but not specific for evaluating hepatic hemangioma. Using CT, there is some evidence that metastatic lesions and hepatoma may have an appearance similar to that of hemangioma. Methods: An observational descriptive cross-sectional study, made on 110 sonographically suggested hepatic hemangioma cases in National Institute of Nuclear Medicine and Allied Sciences (NINMAS) were studied. Hepatic hemangioma with tumour size <2cm and pregnant women were excluded from this study. Results: In this study, it was revealed that among 110 sonographically suggested hepatic hemangioma cases, 66 cases were true positive for hepatic hemangioma done by 99mTc-RBC scintigraphy. There was a significant difference between 2 different age in RBC scan positive cases of hepatic hemangioma (p<0.001). Among the patients with <50 years, total 52 (69%) patients were true positive for hepatic hemangioma whereas among the patients with ≥50 years, total 14 (40%) patients were true positive for hepatic hemangioma. There was significant association between <50 years and hepatic hemangioma (p<0.001). Conclusion: Hepatic hemangioma is the most common benign tumour with a clinical diagnosis of a significant importance. Diagnosis of hepatic hemangioma is sometimes difficult by means of ultrasound. 99mTc-RBC scintigraphy is very sensitive and specific imaging modality for this kind of lesion.


   P085: Solitary Ischaemic Necrosis of the Liver: Role and Imaging Characteristics of 18F-FDG PET/CT in a Rare Diagnostic Problem Top


Robbe Waterschoot*1, F Laloo2, I Goethals1

Departments of 1Nuclear Medicine and 2Radiology and Medical Imaging, University Hospital Ghent, Ghent, Belgium

Background/Aims: The liver has a unique dual blood supply-75% portal venous, 25% hepatic arterial-which makes ischaemic liver necrosis a rare finding. When observed, pre-existing conditions resulting in impaired blood flow should be excluded. We present a case illustrating the supportive role of multimodal imaging in diagnosis. Methods: Only a limited number of cases regarding solitary ischaemic liver necrosis have been published. Existing case reports were reviewed, supplemented by literature, regarding the pathophysiology of ischaemic liver disease. Results: A 52-year-old woman was transferred to Ghent university hospital after newly diagnosed infarction of liver segments 5 and 6, with concurrent occlusion of the celiac trunk and superior mesenteric artery. She suffered from chronic abdominal pain, inadequately responsive to drug treatment and resulting in total weight loss of 20 kilograms. Relevant history included heavy smoking, gastritis treated with proton-pump inhibitors and cholecystitis treated with antibiotics. Abdominal palpation showed no rebound tenderness. Laboratory results showed severely impaired liver function tests, marked inflammation and thrombocytosis. The urgent nature of this case initiated multiple investigations. Normal coronarography and repeat ECG made atherosclerotic and arrhythmogenic etiology highly unlikely. Autoimmune and infectious serology were normal. MRI scan confirmed stable liver necrosis. 18F-FDG PET/CT excluded large-vessel vasculitis and underlying neoplasm as thromboembolic origin, yet revealed low-grade cholecystitis, confirmed by cholecystectomy. Liver biopsy confirmed ischaemia and necrosis. After elaborate genetic testing, essential thrombocytosis was presumed the most likely diagnosis. Right hepatectomy was planned and prophylactic heparin was continued. Unfortunately, prior to surgery new thrombosis resulted in extensive acute mesenteric ischaemia and the patient’s death. Conclusion: Solitary ischaemic liver necrosis is rare and rapid diagnosis of the underlying problem is mandatory. This case illustrates the supportive role of whole body 18F-FDG PET/CT in the diagnostic approach of life-threatening ischaemic liver necrosis excluding underlying pathology such as vasculitis and malignancy-related hypercoagulability.


   P086: Evaluation of the Effect of Percutaneous Transhepatic Portal Embolization Using 99mTc-galactosyl Human Serum Albumin SPECT/CT for Assessment of Hepatic Function Top


Yuka Yamamoto*1, T Sanomura1, H Okuda1, T Norikane1, Y Nishiyama1

1Kagawa University, Kita-Gun, Japan

Background/Aims: 99mTc-galactosyl human serum albumin (99mTc-GSA) measures the total amount of asialoglycoprotein receptor within a subject’s liver. The purpose of this study was to evaluate the effect of percutaneous transhepatic portal embolization (PTPE) to induce compensatory hypertrophy of the remnant lobe using 99mTc-GSA SPECT/CT for assessment of hepatic function. Methods: This study was approved by our institutional ethics review board. 99mTc-GSA SPECT/CT was performed before and 2 weeks after PTPE of the right portal vein in 9 patients. The liver uptake ratio (LUR) which reflects the amount of asialoglycoprotein receptor and liver volume (LV) using 99mTc-GSA SPECT/CT data were calculated separately in the right and left lobes, as well as in the whole liver. Correlations between the LUR and LV values and the result of conventional test of the hepatic functional reserve, i. e., the indocyanine green retention rate at 15 minutes after administration (ICG15) were analysed. Results: The proportion of the non-embolized lobe (left lobe) LV to the total LV slightly increased after PTPE (p=0.085) and the proportion of the right lobe LV to the total LV slightly decreased after PTPE (p=0.085). After PTPE, the proportion of the right LUR to the total LUR significantly decreased (p<0.04) and the proportion of the left LUR to the total LUR significantly increased (p<0.04). The total LUR correlated particularly well with ICG15 (p<0.001). Conclusion: 99mTc-GSA SPECT/CT showed that PTPE induces a shift in hepatic function from the embolised part to the non-embolised part of the liver.


   Musculoskeletal Top



   P087: The Bone Scan Pattern of Two Concomitant Rare Diseases in a Paediatric Patient Top


Mehrosadat Alavi*1, S Mortazavi2

1Ionizing and Non-Ionizing Radiation Protection Research Center, 2Department of Nuclear Medicine, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran

Background/Aims: Sturge-Weber syndrome is a rare, sporadic neurocutaneous syndrome, characterized by leptomeningeal angiomatosis and an ipsilateral facial cutaneous vascular malformation. Ewing’s sarcoma is a rare malignant tumour of the foot, very rarely occurring in the talus bone. Methods: The patient is a 15–year-old girl, with a background of Sturge-Weber syndrome who presented with Ewing’s sarcoma of the left talus bone. Whole body bone scan showed tumoural involvement of the left talus bone extending to the left lower tibia, left ankle soft tissue involvement, and right humeral head metastasis. High diffuse radiotracer uptake of right skull half was also noted, which was confirmed as leptomeningeal angiomatosis on brain MRI. Results: Weber syndrome, in which angiosarcoma and malignant peripheral nerve sheet tumour have been demonstrated to be coinciding.[1],[2] Existence of added risk of malignancies in patients with Sturge-Weber syndrome warrants further investigations and researches. Conclusion: It is a report of a case with concomitant two rare diseases.

References

  1. Purkait R, Samanta T, Sinhamahapatra T, Chatterjee M. Overlap of sturge-weber syndrome and Klippel-Trenaunay syndrome. Indian J Dermatol 2011;56:755-7.
  2. Baskerville PA, Ackroyd JS, Browse NL. The etiology of the Klippel-Trenaunay syndrome. Ann Surg 1985;202:624-7.



   P088: Enhanced Diagnostic Performance of Three Phase Bone Single-Photon Emission Computed Tomography for Osteomyelitis by Addition of Blood Pool Single-Photon Emission Computed Tomography Top


Yun Young Choi*1, S J Lee1, K S Won2

1Department of Nuclear Medicine, Hanyang University Medical Center, Seoul, 2Department of Nuclear Medicine, Keimyung University Dongsan Medical Center, Daegu, Republic of Korea

Background/Aims: Bone scan is a highly sensitive modality for detection of osteomyelitis, however it has lower specificity. The purpose of this study was to investigate if addition of blood pool SPECT/CT could enhance the diagnostic performance of osteomyelitis (OM), compared to the conventional method using three phase bone scan (TPBS) with bone SPECT/CT. Methods: Twenty-one patients with suspected OM were enrolled, retrospectively, including patients who had history of old bone fracture (n=6), previous soft tissue inflammation (n=3), rheumatoid arthritis (n=2), diabetic foot (n=2), and no other relevant history of inflammation (n=8). TPBS, blood pool SPECT/CT and bone SPECT/CT were performed sequentially after a single injection of 99mTc-MDP. The results were confirmed by surgery or clinical follow-up over 6 months. Results: OM was diagnosed in 11 of 21 patients (52.4%)-9 patients surgically, and 2 patients clinically. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 81.8%, 50%, 64.3% 71.4%, and 66.7% for TPBS; 90.9%, 80%, 83.3% 88.9%, and 85.7% for combined TPBS and bone SPECT/CT (conventional method); and 90.9%, 90%, 90.9%, 90%, and 90.5% for combined conventional method and blood pool SPECT/CT. In eight patients without any relevant history of inflammation, both TPBS alone and blood pool SPECT/CT alone showed high sensitivity (100%, respectively), while the specificity was higher in blood pool SPECT/CT alone (100%), compared to TPBS alone (specificity 50%). Conclusion: Addition of blood pool SPECT/CT could enhance the diagnostic accuracy and specificity of osteomyelitis, compared to conventional imaging methods using TPBS or combined TPBS and bone SPECT/CT, providing accurate anatomic information for the location of increased blood pool activity on CT images.


   P089: Bone Single-Photon Emission Computed Tomography in Diagnostics of Vertebral Diseases Top


Jan Lepej*1,2, I Marin3, J Betnatova3, L Hredzakova3, M Seabrook2

1Clinic of Nuclear Medicine, Institute of Nuclear and Molecular Medicine, 2Faculty of Medicine, University of P. J. Safarik, 3Institute of Nuclear and Molecular Medicine, Kosice, Slovakia

Background/Aims: Whole body scintigraphy (WBS) is the diagnostic method most commonly used in nuclear medicine. There is an increased interest in the literature for the use of tomography in the diagnosis of vertebropathies. Retrospective analysis comparing the advantages of SPECT/CT over WBS in the diagnosis of vertebropathies. Methods: Using the gamma camera Phillips Bright View, 20% of the 2127 WBS performed 73% (1565) of the orthopaedic indication in 2015. SPECT/CT was added in 6% of cases. In detail, were analysed 87 patients 39M and 48F (64.1±12.5). From 2 to 18 vertebrae were evaluated in all patients by two independent observers. Results: In assessing the most serious pathology, the agreement between WBS and SPECT/CT was 35.2%. The most common disagreement 12x (54.5%) was between facet joint arthrosis (FJA) and spondylosteophytes (SPO). FJA was diagnosed in 9 patients with SPECT/CT, as compared with 18 unclear findings on WBS. The diagnosis of SPO was identical in 6 and specified in 23 cases. SPECT/CT revealed 18.6% more pathologic findings than WBS (increased sensitivity). Of 645 vertebrates, SPO were present on CT in 50.1% (323 cases). Their incidence was increased with the age of patients. Of these, there were only 28.2% scintigraphically active and the incidence only minimally correlated with age. Conclusion: SPECT/CT contributes to a marked increase in the sensitivity and specificity of skeleton scintigraphy in the diagnosis of pathological spine changes. A positive finding on the spine SPECT/CT shows the activity of the pathological process and the higher clinical severity of FJA and SPO, which cannot be detected by CT itself. Its wider use has the benefit of indicating and evaluating targeted vertebropathic treatment.


   P090: Axillary Lymph Node Assessment on 18F Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Rheumatoid Arthritis Patients Treated with Biologic Therapies Top


Thuy Trang Dam*1,2, K Okamura1, T Nakajima1, H Chikuda1, Y Tsushima1

1Gunma University Graduate School of Medicine, Maebashi, 2Department of Radiology, Bach Mai Hospital, Hanoi, Viet Nam, Japan

Background/Aims: Lymphadenopathy is a common extra-articular manifestation in rheumatoid arthritis (RA). We employed positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) administration for assessing lymph node (LN) inflammation in RA patients treated with biologic therapies. We aimed to evaluate the correlation between the FDG uptake parameters of axillary LN and those of the arm joints as well as the disease activity before and after biologic treatment. Methods: Sixty-seven patients with RA were assessed. 18F-FDG PET and clinical evaluations were performed at baseline and 6 months after the treatment. Quantitative parameters including maximum standardized uptake value (SUVmax), metabolic active volume (MAV), and total lesion glycolysis (TLG) were used for the FDG uptake. Clinical evaluations include the serum markers and the disease activity scores (DAS28 and DAS28-CRP). The D represents the differences of each parameter before and after treatment. Results: Significant correlations were observed between the FDG uptake parameters (DSUVmax and DTLG) of the axillary LN and those of the arm (elbow + wrist) joints (r=0.524, p<0.001; r=0.424, p<0.001, respectively). There were also positive correlations between the DSUV, DMAV, and DTLG of the axillary LN and the DDAS28 (r=0.412, p=0.001; r=0.315, p=0.009; r=0.370, p=0.002), DDAS28-CRP (r=0.455, p<0.001; r=0.370, p=0.002; r=0.438, p<0.001), respectively. Conclusion: The FDG uptake of the axillary LN may reflect the inflammatory activity of the elbow and wrist joints and correlate with the therapeutic response to the biologic treatment of RA.


   P091: Positron Emission Tomography/Magnetic Resonance Imaging Fusion Demonstrates Hamstring Peritendonitis in Untreated Patients with Polymyalgia Rheumatica Top


C Owen1, A Poon2, Sze Ting Lee*2,3, L P Yap3, R Zwar3, C McMenamin1, A Kemp1, D Liew1, A M Scott2,3,4,5, R Buchanan1,3

1Department of Rheumatology, Departments of 2Molecular Imaging and Therapy, 3Tumour Targeting Laboratory, Olivia Newton-John Cancer and Research Institute, 4Department of Medicine, The University of Melbourne, 5School of Cancer Medicine, La Trobe University, Melbourne, Australia

Background/Aims: To characterise 18F-fluorodeoxyglucose (18F-FDG) uptake on whole body positron emission tomography/computed tomography (PET/CT) in polymyalgia rheumatica (PMR), and identify its precise anatomic correlate using magnetic resonance imaging (MRI). Methods: Patients with newly diagnosed PMR according to the 2012 EULAR/ACR classification criteria were prospectively recruited. Participants with giant cell arteritis were excluded. A whole body 18F-FDG PET/CT scan was performed in all untreated patients. Qualitative and semi-quantitative (standardised uptake value maximum [SUVmax]) scoring of abnormal 18F-FDG uptake was undertaken. MRI of the pelvis, knee and, wrist and hand was performed in three representative patients with anatomical correlation of FDG avid sites carried out using Medview fusion software. Results: Twenty-two patients with PMR were recruited. Mean age was 68.3±6.3 years and 13/22 were male. On whole body PET/CT, 18F-FDG uptake adjacent to the ischial tuberosities was observed in twenty-one participants (95.4%), and recorded the highest mean SUVmax value (3.6±1.7). A high frequency of posteromedial knee (61.9%) and, wrist and/or hand involvement (66.7%) was also appreciated. MRI pelvis revealed high T2 signal surrounding the proximal hamstring tendon origins of both semimembranosus and the conjoint tendon of semitendinosus and biceps femoris. At the knee, peritendonitis at the distal insertion of semimembranosus was observed. PET/MRI fusion at the pelvis and knee confirmed semimembranosus peritendonitis as the anatomical correlate of 18F-FDG uptake adjacent to the ischial tuberosities and of posteromedial knee structures. Conclusion: Hamstring peritendonitis is a common and distinctive manifestation of PMR on whole body PET/CT.


   P093: Comparison of Diagnostic Capability About Different types of Bone Metastases between Positron Emission Tomography/Computed Tomography and Whole Body Bone Scan Top


Rong Fu Wang*1, A H Zhu1

1Department of Nuclear Medicine, Peking University First Hospital, Beijing, China

Background/Aims: The purpose of this study is to analyse the value of 18F-FDG PET/CT and 99mTc-MDP whole-body bone scan to diagnose different types of bone metastases. Methods: Twenty-six patients with bone metastases underwent 18F-FDG PET/CT and whole-body bone scan were enrolled in this study. The diagnostic ability between 18F-FDG PET/CT and 99mTc-MDP SPECT whole-body bone scan for bone metastases were analysed. The diagnostic sensitivities for different types of metastatic tumours of bone were compared between PET/CT and whole-body bone scan. Results: Among 135 lesions which were detected by PET/CT and whole-body bone scan, 121 lesions were clinically confirmed to be metastases and 14 lesions were benign. The statistical difference of diagnostic efficiencies between PET/CT and whole-body bone scan is significant (p<0.05). The sensitivities for the diagnosis of osteolytic, osteoblastic, mixed and normal bone structure metastatic tumours diagnosed by PET/CT and whole-body bone scan were 95% (35/40) and 90% (36/40), 100% (25/25) and 72% (18/25), respectively. Conclusion: The diagnostic value of PET/CT for bone metastases is obviously better than that of whole body bone scan. For different types of bone metastases, the diagnostic capability is different between PET/CT and whole body bone scan. It is necessary to be rational selection of PET/CT and whole body bone scan in staging of primary neoplasms.


   P094: Lumbar Spine and Hip Bone Mineral Densities of Healthy Filipino Adults Aged 20–39 Years Top


Bridget Nancy Coote*1, G Goco1

1Department of Nuclear Medicine and PET Center, St. Luke’s Medical Center-Global City, Taguig City, Philippines

Background/Aims: Bone Mineral Density (BMD) measurements are utilised in the diagnosis of osteoporosis and low bone mass, and are indicators of bone health. The Philippines has a rapidly aging population and it is anticipated that osteoporosis will be a major health issue in the future. Peak bone mass is achieved by age 18 to 25 and a current assessment of the BMDs of young Filipino adults may be beneficial to clinicians as a baseline reference for the possible trend of bone health. This study aims to present lumbar spine and hip BMD measurements of Filipinos aged 20 to 39 years old. Methods: Subjects included 105 healthy young adults who underwent Dual Energy X-ray Absorptiometry (DXA) from 2011 to 2016 at St. Luke’s Medical Center. BMD measurements of lumbar spine and femoral necks were obtained using the GE Lunar DXA machine. Mean and standard deviations (SD) of measurements were determined. Results: Mean age of patients is 31.5 years. Fifty-seven percent of subjects belong to the 30-39 year age group. Results of BMD measurements were grouped according to sex and decade. Mean BMDs of females aged 20-29 are as follows: spine 1.092g/m2 (SD 0.143), left femoral neck (LFN) 0.853g/m2 (SD 0.085), and right femoral neck (RFN) 0.856g/m2 (SD 0.086). For females aged 30-39: spine 1.124g/m2 (SD 0.112), LFN 0.848g/m2 (SD 0.108), and RFN 0.854g/m2 (SD 0.113). For males aged 20-29: spine 1.159g/m2 (SD 0.195), LFN 0.976g/m2 (SD 0.195), and RFN 0.977g/m2 (SD 0.183). Lastly, for males aged 30-39 are: spine 1.129g/m2 (SD 0.115), LFN 0.869g/m2 (SD 0.159), and RFN 0.891g/m2 (SD 0.186). Of the 105 patients, 95 had BMDs within normal while 10 were below the expected range. Conclusion: Majority of subjects have BMDs that are within normal based on World Health Organization (WHO) and International Society for Clinical Densitometry (ISCD) standards.


   P095: Relationship between Normal Thyroid Hormone Profile and Bone Mineral Density Among Healthy Euthyroid Subjects Top


S Haider*1

1Centre for Nuclear Medicine, Lahore, Pakistan

Background/Aims: Thyroid illness such as hyperthyroidism affect the bone mineral density and prone such patients to osteoporotic fractures. The normal range of thyroid profile with upper and lower limits could affect the bone mineral density with estimation of fracture risks. Such individuals may adopt measures for their bone health such as bone strengthening exercises, calcium and vitamin D supplements. Methods: The study was approved by the ethical committee of the Institution. Euthyroid subjects with normal thyroid hormone profile were enrolled in the study, having no systemic illnesses. Each subject underwent DXA scan of Lumbar Spine (L1-L4) & Hip regions. Bone mineral density values (BMD) were calculated and risk estimation of fractures were estimated on the basis of T-score with WHO classification. Pearson correlation (r-value) with statistical significance (p<0.05) between serum thyroid hormone profile estimated by radioimmunoassay (TSH-Normal 0.3-5 mIU/L) & DXA derived BMD values were calculated. Results: A total of 93 subjects of both sexes, at or above 50 years of age were enrolled in the study. Total Lumbar Spine, individual vertebrae & Femoral neck BMD values with TSH showed positive correlation (r=0.22, p=0.0341), L1 (r=0.19, p=0.0681), L2 (r=0.23, p=0.0266), L3 (r=0.18, p=0.0843), L4 (r=0.22, p=0.0341) & Femoral neck (r=0.25, p=0.0157). Conclusion: Normal thyroid hormone profile does not affect the bone metabolism. However, TSH values in lower limit of normal range can affect the bone mineral density and appropriate bone strengthening measures are necessary to prevent osteopenia and osteoporosis.


   P096: Atypical Femoral Fracture: An Incidental Finding. The Role of Bone Mineral Density Scans & Three Phase Bone Scintigraphy Top


Chloe Madiona*1, G Roff1, K Pathmaraj1, A M Scott1,2,3,4

1Department of Molecular Imaging and Therapy, Austin Health, 2Olivia Newton-John Cancer Research Institute, Austin Health, Heidelberg, 3School of Cancer Medicine, La Trobe University, 4Department of Medicine, The University of Melbourne, Melbourne, Australia

Background/Aims: Atypical femoral fracture (AFF) is rare and can be complete or incomplete, often bilateral and initially involves the lateral femoral cortex.[1] There appears to be increased risk of AFF in patients on anti-resorptive therapy.[2] We describe an incidental finding of AFF in a 63 year old male patient. His bone mineral density was being monitored due to prolonged glucocorticoid therapy for rheumatoid arthritis. In June 2013, he was diagnosed with osteoporosis and underwent anti-resorptive therapy. Methods: In July 2017, the patient had Dual Energy X-Ray Aborptiometry (DXA) scans of the lumbar spine and proximal femur, and a Single Energy Femur Scan (SEFS), on the Hologic Horizon DXA system. A nuclear medicine bone scan (BS) was performed 9 days later on the Symbia T16 SPECT/CT gamma camera. Following 723MBq intravenous injection of 99mTc-MDP dynamic imaging commenced over the proximal femora. Blood pool static images were acquired over the distal femora, then delayed static images over the lumbar spine, femora and knees. SPECT/CT was performed over both the femurs. Results: The SEFS demonstrated slight focal thickening on the left lateral femoral cortex. In the BS, early imaging showed normal perfusion in the thighs, with small focus of mildly increased early blood pool activity in the right mid-to-distal thigh. Delayed imaging showed local increase in tracer uptake in the proximal left and mid-right femurs localising to the lateral cortex. The scan findings were consistent with bilateral healing lateral cortical femoral fractures. Conclusion: Our case illustrates the complementary use of DXA and BS in obtaining a definite diagnosis of AFF. The increased sensitivity and specificity of the BS confirmed bilateral incomplete AFF in our patient. It potentially has a role in AFF screening for patients on long-term anti-resorptive therapies, especially symptomatic patients with subtle abnormalities in the SEFS.

References

  1. Toro G, Ojeda-Thies C, Calabrò G, Toro G, Moretti A, Guerra GM, et al. Management of atypical femoral fracture: A scoping review and comprehensive algorithm. BMC Musculoskelet Disord 2016;17:227.
  2. Donnelly E, Saleh A, Unnanuntana A, Lane JM. Atypical femoral fractures: Epidemiology, etiology, and patient management. Curr Opin Support Palliat Care 2012;6:348-54.



   Asian Nuclear Medicine Board Examinees Top



   P097: Is Low-dose Radioiodine Ablation Sufficient for Low to Intermediate Risk Differentiated Thyroid Cancer Patients? (Endocrinology) Top


Kun Zheng*1,2, T Zhang1,2, Y Lin1,2

1Peking Union Medical College Hospital, 2Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, China

Background/Aims: This study aimed to evaluate the effectiveness of low-dose RAI ablation in low to intermediate risk patients and target the factors associated with unsuccessful ablation. Methods: This is a single-center, retrospective study approved by Institutional Review Board of the Peking Union Medical College Hospital. Low to intermediate risk DTC patients underwent RAI ablation within 6 months after thyroidectomy from July 2010 to December 2016 were selected. Successful ablation was determined as proposed by the ATA guidelines. Factors as age, sex, tumour size, capsule invasion, pathological type, numbers and regions of metastatic lymph nodes, TNM stage, BRAF gene, TSH stimulation methods were analysed. T-test and logistic regression were used for statistical analysis. Results: A total of 737 patients (Male 213, Female 524) were enrolled. The mean age was 39 years. There were 35 low-risk and 702 intermediate-risk patients. 581 patients (26 low-risk, 512 intermediate-risk) have responses evaluated by October 2017. In the low-risk group, 96.2%(25) showed excellent responses (ER), 3.8%(1) indeterminate responses (IR). In the intermediate-risk group, 82.0%(420) ER, 1.8%(9) biochemical incomplete response(BIR), 3.3%(17) structural incomplete response (SIR) and 12.9%(66) IR. 43 patients (intermediate risk 40, low risk 3) were given a subsequent dose. Among them 55.8%(24) ER, 14.0%(6) BIR, 16.3%(7) SIR, and 14.0%(6) IR. Much residual thyroid tissues and many metastatic lymph nodes were significant factor related to unsuccessful ablation. Conclusion: Low-dose RAI ablation is sufficient for low-risk and majority of intermediate-risk patients. For patients with much residual thyroid and/or many metastatic lymph nodes, regular follow-up is essential and additional low-dose ablation may be needed. Smaller subgrouping may be required for further optimal dosing in future studies.


   P098: Copper Sulfide-loaded Microspheres for Breast Cancer Theranostics (Nuclear Medicine Innovation) Top


Shaoli Song*1, Q Liu1, P Liu1, G Huang2

1Department of Nuclear Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, 2Shanghai Key Laboratory for Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai, China

Background/Aims: Compared to conventional cancer treatment, combination therapy based on well-designed nanoscale platforms may offer an opportunity for eradication of tumours and reduce recurrence and metastasis. Methods: In this study, we prepared the multifunctional microspheres loading 131I-labelled hollow copper sulfide nanoparticles and paclitaxel (131I-HCuSNPs-MS-PTX) for imaging and therapeutics of orthopic W256/B breast tumour in rats. Results: 18F-fluordeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging detected that the expansion of the tumour volume was delayed (p<0.05) following intra-tumoural (i. t.) injection with 131I-HCuSNPs-MS-PTX plus near-infrared (NIR) irradiation. The immunohistochemical analysis further confirmed the anti-tumour effect. The single photon emission computed tomography (SPECT)/photoacoustic imaging mediated by 131I-HCuSNPs-MS-PTX demonstrated that microspheres were mainly distributed in the tumours with a relatively low distribution in other organs. Conclusion: Our results revealed that 131I-HCuSNPs-MS-PTX offered combined photothermal, chemo-and radio-therapies, eliminating tumours at a relatively low dose, as well as SPECT/CT and photoacoustic imaging to monitor distribution of the injected agents non-invasively. The copper sulfide-loaded microspheres, 131I-HCuSNPs-MS-PTX, can serve as a versatile theranostic agent in breast cancer orthotopic model.


   P099: Positron Emission Tomography Response Assessment in Patients with Radioactive Iodine-Refractory Thyroid Cancer after Apatinib Treatment, a Novel Tyrosine Kinase Inhibitor of Phase II Study (Endocrinology) Top


Chen Wang*1, X Zhang1, Y Lin1

1Department of Nuclear Medicine, Peking Union Medical College Hospital, Beijing, China

Background/Aims: Till now, there have been few specific markers for radioactive iodine-refractory differentiated thyroid cancer (RAIR-DTC) after tyrosine kinase inhibitor (TKI) therapy. This work aimed at using PET/CT technique to early identify the response and predict the prognosis of RAIR-DTC treated with apatinib, a novel TKI targeting VEGFR-2. Methods: Twenty patients with RAIR-DTC were sequentially enrolled to receive oral apatinib (750 or 500 mg qd). 18F-fluorodeoxyglucose (18FDG) and 68Ga-NOTA-PRGD2 PET/CT were conducted, and standardised uptake value (SUV), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were evaluated by two nuclear medicine physicians. Tumour response were evaluated by RECIST 1.1 criteria every two cycles. Results: 16/20 (80%) patients achieved partial response (PR) and 4/20 (20%) had stable disease (SD) after apatinib therapy. Six progression-free survival (PFS) events occurred, and the median PFS had not been reached. Strong correlations were achieved between the best change in sum of diameter of target lesions (ΔCT%) and 18FDG PET/CT index at 1-cycle treatment (ΔMTV% [p=0.0019], ΔTLG% [p=0.0021] and ΔSUVmax% [p=0.0443]). Significant difference in PFS was observed between patients with a ΔMTV% <-45% and ≥-45% (9.3 [95%CI,7.0-11.6] months vs. not reached; p=0.0019), as well as between patients with a ΔTLG% <-80% and ≥-80% (9.5 [95%CI,6.8-12.2] months vs. not reached; p=0.0065). Totally, 10/11 patients presented decrease in SUVmax in 68Ga-NOTA-PRGD2 PET/CT after 2 cycles of apatinib therapy, showing PR of the best response, while the one presenting increase in SUVmax only had SD of the best response. When a cut-off value of target/background ratio at-20% was used, two PFS curves showed significant difference (p=0.0016). Conclusion: Early assessment by 18FDG and 68Ga-NOTA-PRGD2 PET/CT were effective in prediction and evaluation of RAIR-DTC treated with apatinib.


   P100: Higher Amyloid Deposition in the Striatum in VEOAD: A Preliminary Positron Emission Tomography/Computed Tomography and Positron Emission Tomography/Magnetic Resonance Imaging study (Neuroscience) Top


Liping Fu*1, C Wei2, J Zhang1, B Xu1

1Chinese PLA General Hospital, 2Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China

Background/Aims: It is assumed that the abnormal amyloid-β deposition is an initiating event in Alzheimer’s disease (AD). We evaluated the Pittsburgh compound-B-PET images of very early onset AD (VEOAD), sporadic late onset AD (LOAD) and cognitively normal elder controls (NC) to find whether a different amyloid deposit pattern existed among groups. Methods: 11C-PIB PET/CT or PET/MRI images of 5 VEOAD patients (M: F=1:4, age range: 36-43 years, 39.0±3.4), 10 LOAD patients (M: F=4:6, age range: 62-75 years, 67.2±4.0) and 10 NC subjects (M: F=6:4, age range: 60-72 years, 66.4±3.2) with definite clinical diagnosis and complete neuropsychological tests were reviewed. All subjects received 11C-PIB injection intravenously (4.44-5.55MBq/kg) 40 minutes prior to data acquisition, including 3 VEOAD at a PET/CT (Biograph 64, Siemens, Germany) and 22 subjects at a PET/MRI scanner (Biograph mMR, Siemens, Germany). Regions of interest were drawn over cortex, the striatum and cerebellar gray matter (CGM) in CT or MRI and their PIB-PET images manually. The CGM was chosen as the reference region for standardised uptake value ratio (SUVR) measurement. One way ANOVA analysis was used to assess the differences of ages, MMSE scores and SUVRs of cortical and striatum among 3 groups. Results: VEOAD patients were younger than LOAD and NC subjects (F=70.02, p<0.05). Both the two AD groups’ MMSE scores were significantly worse than NC (F=43.77, p<0.05). No significant difference in cortical 11C-PIB retention were observed between VEOAD and LOAD patients, but were great higher than that of NC (F=50.61, p<0.01). Significant higher SUVR of striatum was observed in VEOAD than LOAD and NC. In addition, the SUVR of striatum in LOAD was also higher than NC (F=28.93, p< 0.01). Conclusion: Extensive higher striatal amyloid deposition as PIB-PET detected in VEOAD, along with diffused cortical deposition, which might be associated with their early-onset symptoms.


   P101: Positron Emission Tomography Using a Gastrin Releasing Peptide Receptor Antagonist 68Ga-RM26 in Healthy Volunteers and Prostate Cancer Patients (Molecular Imaging) Top


Jingjing Zhang*1, G Niu2, X Fan3, L Lang2, G Hou1, H Wu4, F Li1, Z Zhu1, X Chen2

1Department of Nuclear Medicine, Peking Union Medical College Hospital, 4Department of Pathology, Peking Union Medical College Hospital, Beijing, 2Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 3Department of Urology, China

Background/Aims: This study was designed to study the safety, biodistribution, radiation dosimetry of a gastrin releasing peptide receptor (GRPR) antagonist positron emission tomography (PET) tracer, 68Ga-RM26, to assess its clinical diagnostic value in prostate cancer patients, and to perform a direct comparison between GRPR antagonist 68Ga-RM26 and agonist 68Ga-BBN. Methods: This study was approved by the Institutional Review Board of Peking Union Medical College Hospital. Five healthy volunteers were enrolled to validate the safety of 68Ga-RM26 and calculate dosimetry. A total of 28 patients with prostate cancer were recruited with written informed consent. All the cancer patients underwent PET/CT scans at 15-30 min after intravenous injection of 1.85 MBq (0.05 mCi) per kilogram body weight of 68Ga-RM26. Among them, 22 patients accepted 68Ga-BBN PET/CT for comparison within 1 week. GRPR immunohistochemical staining of tumour samples was performed. Results: The administration of 68Ga-M26 was well tolerated by all subjects with no adverse symptoms being noticed or reported during the whole procedure and 2 weeks follow up. The total effective dose equivalent (EDE) and effective dose (ED) were 0.0912±0.0140 and 0.0657±0.0124 mSv/MBq, respectively. In the 17 patients with newly diagnosed prostate cancer, 68Ga-RM26 PET/CT showed positive prostate-confined findings in 15 tumours with maximum standard uptake value (SUVmax) of 6.49±2.37. Compared with 68Ga-RM26 PET/CT, GRPR agonist 68Ga-BBN PET/CT detected less primary lesions and lymph node metastases as well as lower tracer accumulation. There was a significant positive correlation between SUV derived from 68Ga-RM26 PET and the expression level of GRPR (p <0.001). Conclusion: This study indicates the safety and significant efficiency of GRPR antagonist 68Ga-RM26. 68Ga-RM26 PET/CT would have remarkable value in detecting both primary prostate cancer and metastasis. 68Ga-RM26 is also expected to be better than GRPR agonist as an imaging marker to evaluate GRPR expression in prostate cancer.


   P102: Value of Dual Phase 99mTc-MIBI Scintigraphy and corRelation of 99mTc-MIBI Scintigraphy Findings with Parathyroid Hormone Values in Secondary Hyperparathyroidism Patients (Endocrinology) Top


Leilei Yuan*1, J Yang1

1Department of Nuclear Medicine, Beijing Friendship Hospital, Beijing, China

Background/Aims: Surgical intervention in the form of parathyroidectomy is generally only considered in severe secondary hyperparathyroidism (SHPT). However, correct location of the parathyroid glands before parathyroidectomy is a challenge. The first purpose of this study is to compare the diagnostic value of early and delayed phase 99mTc-sestamibi SPECT/CT in the detection of parathyroid tissue. The second purpose is to compare the findings of parathyroid scintigraphy with serum concentration of parathyroid hormone, and plasma calcium with positive parathyroid scan in secondary hyperparathyroidism patients. Methods: Forty-two patients with SHPT on hemodialysis were evaluated preoperatively with dual phase 99mTc-sestamibi SPECT/CT parathyroid scintigraphy to locate parathyroid tissue prior to parathyroidectomy. The concentration of parathyroid hormone, plasma calcium in serum of these patients was monitored. The scintigraphic findings were graded from 1 to 5 according to the uptake degree of the avid lesion subjectively. The accuracy of 99mTc-sestamibi early and delayed phase SPECT/CT scintigraphy were determined and compared. The correlation of PTH and plasma calcium with positive parathyroid scan were analysed. Results: The sensitivity, specificity, and accuracy of early and delayed phase per lesion was 72.8%, 79%, and 74.4%; 76%, 74.4%, and 75.6%. The sensitivity, specificity, and accuracy of dual phase was 80.8%, 74.4%, and 79.1%. Early phase 99mTc-sestamibi SPECT/CT was able to detect 2.16 parathyroid glands (PTGs), while delayed phase 99mTc-sestamibi SPECT/CT was able to detect 2.26 PTGs per study. The average value of PTH and plasma were 550.24±125.14 pg/ml (Grade 4), 787.84±194.78 pg/ml (Grade 5), and 2.24±0.07 mmol/L (Grade 4), 2.67±0.32 mmol/L (Grade 5). The average value of PTH and plasma were significantly higher in patients with higher grade of scintigraphic findings. Pearson Correlation Coefficient showed moderate relationship of PTH and plasma calcium (r=0.621, p<0.001). Conclusion: Our study indicates that dual phase 99mTc-MIBI SPECT/CT should be performed preoperatively in order to detect all PTGs without increase of radiation dose. Scintigraphy of parathyroid glands and the value of PTH, calcium in serum should be incorporated into the test algorithm for SHPT patients on hemodialysis.


   P103: Dopamine Transporter Imaging and Metabolic Network Expression in Patients with Idiopathic REM Sleep Behaviour Disorder and Parkinson’s Disease (Neuroscience) Top


Zhemin Huang*1, P Wu1, H Yu2, C Zuo1, Y Guan1

1PET Center, 2Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China

Background/Aims: Idiopathic rapid-eye-movement sleep behaviour disorder (IRBD) is regarded as the prodromal stage of Parkinson’s disease (PD) characterised by nigrostriatal dopamine loss and a unique metabolic brain network (PDRP). This study aimed to investigate the abnormalities in striatal dopamine transporter (DAT) distribution and PDRP activity as well as the correlations between the two measures in the same IRBD patients with comparison to PD using a dual tracer imaging design. Methods: Age-matched 37 IRBD patients, 86 PD and 15 control subjects performed concurrent PET scans with 11C-N-2-carbomethoxy-3-(4-fluorophenyl)-tropane (CFT) to quantify striatal DAT binding and 18F-fluorodeoxyglucose (FDG) to quantify PDRP expression. Results: IRBD patients were divided into two subgroups: with normal (RBD-N) or abnormal (RBD-AB) DAT binding. Relative to the controls, significantly decreased DAT binding was present in all patient groups except for IRBD-N. By contrast, significant increase in PDRP expression was present in all patient groups. There’re trends of decrease in DAT binding in the striatum and increase in PDRP expression from IRBD-N to advanced PD. Significant but weak correlations were observed between PDRP expression and DAT binding in all three parts of the striatum in PD. Stronger correlations were observed in the putamen in IRBD-AB. No significant correlation was found in IRBD-N. Conclusion: IRBD patients presented an intermediate state in striatal DAT distribution and PDRP activity between PD and normal controls. The modest correlations between dopaminergic dysfunction and abnormal PDRP expression in both IRBD and PD suggest differences in network activity can’t be explained solely by nigrostriatal dopaminergic denervation.


   P104: Functional Dyspepsia: Impaired Intra-Gastric Distribution or Impaired Gastric Emptying: An Attempted Evaluation by Nuclear Scintigraphy (Gastrointestinal) Top


Vishal Agarwal*1

1House of Diagnostics, India

Background/Aim: Functional Dyspepsia (FD) is a heterogeneous disorder and is a diagnosis of exclusion. By definition, presence of symptoms originating in the gastro-duodenal region in the absence of any identifiable cause-should explain the condition. Some patients have delayed gastric emptying, but overall, there seems to be little relation between rate of emptying and symptoms. This study is an attempt to find the cause of symptoms of FD. Methods: We examined 18 patients, having symptoms of bloating and epigastric discomfort and 8 volunteers. All of them were served 99mTc-DTPA mixed food. Then, they were asked to stand upright in front of gamma camera, and imaged for 1 minute over the area of upper abdomen, every 10 minutes, for a total of 90 minutes. Then, the images were divided into upper 1/3 (proximal) and lower 2/3 (distal) gastric portions and the time-activity curves (TAC) were obtained for upper 1/3rd, lower 2/3rd and total stomach region. Results: TAC of total stomach region between patients and volunteers was not significantly different in its information but TAC of distal stomach region (lower 2/3rd) was. In the volunteers, food remained predominantly in the proximal half and then moved towards the distal half. However, in the patient sub-group, food moved quickly from the fundus to the antrum and showed stasis of food for longer duration (in antrum). Conclusion: Our study indicates that the primary cause of FD is the intra-gastric maldistribution of food (stasis in the distal stomach and antrum) rather than the abnormal gastric emptying.


   P105: Uncommon bone Metastasis from Thyroid Cancer (Endocrinology) Top


Yustia Tuti*1, A R Dewi1

1Dharmais Cancer Centre Hospital, Jakarta, Indonesia

Background/Aims: Metastasis thyroid carcinomas mainly include cervical lymph nodes, lung and bone. Vertebrae, femur, skull, pelvis and clavicle were the most common sites of metastases. Bone metastasis in the phalanx is rare site. Methods: We will discuss a rare case from the patient with phalanx metastasis from thyroid cancer with clinical course, imaging, pathological findings, and treatment. Results: In December 2016, a 40 years old female was referred to have second 131I therapy for follicular variant papillary thyroid cancer. She previously underwent total thyroidectomy followed by 131I ablation on September 2012 and also craniotomy for brain metastasis on November 2016. She complained of tenderness and swelling in her 4th phalanx. She was given 150 mCi of 131I therapy. On post-therapy, the whole body scan revealed pathological uptake on left 4th phalanx, parietal, ribs, pelvic and femur. X-Ray on her left hand showed lytic lesion on 4th phalanx, which was amputated. The histopathological result showed metastasis from follicular variant of papillary thyroid cancer. Conclusion: Even though metastatic spread to phalanx are rare, any pathological uptake in that area should be carefully evaluated.


   P106: Prevalence of Vertebral Fracture in Low Bone Mass Detected by Vertebral Fracture Assessment (Musculoskeletal) Top


Waralee Teeyasoontranon*1, M Ekmahachai1

1Department of Radiology, Division of Nuclear Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand

Background/Aims: Vertebral fracture assessment (VFA) is the useful technique to assess vertebral fracture. Detection of unnoticed vertebral fracture in low bone mass leads to changing of diagnosis and treatment decision. This study aims to determine the prevalence of unnoticed vertebral fracture in low bone mass patients by using VFA. Methods: Sixty-Five low bone mass patients (5 males, 60 females, mean age 64 years, range 44-81 years) diagnosed by BMD, T-scores between-1.0 and-2.5, and underwent VFA study using Hologic Discovery A (S/N 82938) at Division of Nuclear Medicine, Maharaj Nakorn Chiang Mai Hospital between January 2015 and June 2017 were enrolled. The patients had never been diagnosed vertebral fracture or had history of fragility fracture. VFA was done in supine position from T4 to L4. Vertebral fractures were defined by the two experienced radiologists in a consensus reading using combination of Genant semi-quantitative (SQ) approach and quantitative morphometry. Prevalence of vertebral fracture was calculated in percentage and an inter-observer agreement was determined using Kappa score. Results: Ninety-three percent of T4-L4 vertebrae and 98% of T7–L4 vertebrae were adequately visualized. Vertebral fractures were detected in 14 of 65 patients (21.5%, 1 male and 13 females). The inter-observer agreement between two experienced radiologists was excellent (Kappa score = 0.92). Conclusion: The additional VFA at the time of BMD study should be the standard investigation in low bone mass patients. VFA detected unnoticed vertebral fractures in 21.5% of low bone mass patients, which changes the diagnosis and treatment decision in this group of patients.


   P107: Is 18F Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography a Potent Tool to Restage and Prognosticate Patients with Cervical Carcinoma? A Future Argument (Oncology) Top


Tarun Kumar Jain*1, A Bhattacharya1, R K Basher1, H Singh1, V Jain2, B R Mittal1

Departments of 1Nuclear Medicine and 2Obstetrics and Gynecology, Post Graduate Institute of Medical Education and Research, Chandigarh, India

Background/Aim: To analyse the efficacy of integrated 18F-DG PET/CT in treated cervical carcinoma patients. Methods: A retrospective analysis of histopathologically confirmed patients with carcinoma cervix (n=193; age-range 32-82 years; mean-age 51.4 years) was done. All patients were treated either in combination or alone with surgery, radiotherapy or chemotherapy and referred for FDG PET/CT on the basis of clinical and imaging suspicion of residual or recurrent disease and for post-therapy monitoring. Histopathological examination and clinical or imaging follow-up (minimum18 months) were taken as gold standard. Result: Of the total 193 patients, PET/CT detected abnormal FDG uptake in 113 patients. Uptake at primary site was detected in 56/193 (29.01%) patients and only metastatic sites in 64/193 (33.1%) patients. Out of 56 patients with primary lesions, 28 had additional regional lymph nodes and 25 had additional distant lesions. In PET/CT, 11 patients were also suspected for metachronous primaries and confirmed on histopathology (lung-4, pharynx-2 breast-2, lymphoma-2 and rectum-1). We found that for residual/recurrence detection, FDG PET/CT has the sensitivity, specificity, PPV, NPV and accuracy 89.38%, 65%, 78.29%, 81.25% and 80% respectively. On ROC curve analysis, lesions with SUVmax>4.4 in PET/CT had sensitivity and specificity 78.8% and 83.7% respectively for being pathological. In the survival analysis, positive FDG PET/CT patients has significantly high risk of patient death [hazard ratio =5.95 (p <0.0001; 95%CI 3.43-10.3) and patients with SUVmax >4.4 was significantly associated with higher patient death [HR=6.45 (p<0.0001; 95%CI 3.77-10.99)]. Conclusion: We concluded that 18F-FDG PET/CT is accurate for detection of suspected residual/recurrent disease in cervical cancer patients and it also provides the valuable information for survival so patient management can be improved.


   P108: Fixed dose of Radioactive Iodine in the Therapy of Hyperthyroidism-what is Outcome and Factors Affecting it: Experience at Our Institute (Endocrinology) Top


S H Nohario*1, N A Laghari1, S S Iqbal1

1Nuclear Institute of Medicine and Radiotherapy, Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan

Background/Aim: Radioactive iodine therapy (RAI) for hyperthyroidism is safe and definitive, although post-treatment hypothyroidism and the need for life-long thyroxine are to be expected. Fixed dose radioactive iodine is increasing popular, but the responses may vary and the optimal dose of radioactive iodine for hyperthyroidism is still debated. The aim of this study is to evaluate the outcome of radioactive iodine therapy in patients with hyperthyroidism, using a standard dose and explore the outcome and the factors influencing it. Methods: A prospective study was conducted in hyperthyroid patients, who are referred to nuclear medicine department for the RAI therapies. We studied 207 patients with hyperthyroidism treated between June 2010 and June 2015 with a standard dose of 550MBq 131I. Patients were classified as Graves’ disease, toxic multinodular goiter or intermediate aetiology. Anti-thyroid drugs were routinely stopped at least one week before radioiodine therapy. Results: Graves’ disease was the most common cause of hyperthyroidism. One year after RAI treatment, 185 patients were hypothyroid, 13 patients were euthyroid, and 6 had required a further dose of 131I. Patients with Graves’ disease were more likely to become hypothyroid than dose with toxic multi nodular goiter (97% vs. 87%) and less likely to become euthyroid (4% vs. 15%). Patients with a small goiter were more likely to be successfully treated by a single dose than those with large goiter (99% vs. 76%). Anti-thyroid treatment was taken by most of the patients. Patients with prior anti-thyroid treatment for many years were associated with increased failure rate compared to those who had anti-thyroid treatment for fewer periods (20% vs. 3%). High free T4 level at initial presentation was associated with an increased failure rate. Conclusion: A single fixed dose of radioactive iodine is a simple, safe, and highly effective in treating hyperthyroidism. The aetiology, goiter size, high basal free thyroxine concentration, prior anti-thyroid treatment for long periods all are associated with higher chance of failure and have significant effect on outcome. Higher radioiodine doses may be considered to improve the cure rate.


   P109: Sensitivity and Accuracy for Localization of Parathyroid Gland (Endocrinology) Top


Peerawan Chochai*1, P Parklug1

1Faculty of Medicine, Vajira Hospital, Bangkok, Thailand

Background/Aim: Purpose of this study is to evaluate sensitivity, specificity, accuracy, positive predictive value, negative predictive value of parathyroid scan (single isotope double-phase technique, dual isotope subtraction technique, SPECT/CT scan, combined 2 techniques of double-phase technique and dual isotope subtraction technique, and combined 3 techniques of double-phase technique, dual isotope subtraction technique, SPECT/CT scan) in patients with hyperparathyroidism, histologic analysis as the reference of standard. Sensitivity, specificity, and accuracy of dual isotope subtraction technique combined SPECT/CT scan, and combined 3 techniques were compared. Methods: Sixty-three consecutive patients had parathyroid scan before surgery for hyperparathyroidism. Analysis consisted of single isotope double-phase technique, dual isotope subtraction technique, SPECT/CT scan, and combined 3 techniques were retrospective review. Each review was scored from 1(definitely negative) to 4 (definitely positive) for location and certainty of focus by 2 readers. Pathological report was as the standard. Sensitivity, specificity, accuracy, positive predictive value, negative predictive values were determined for each method. Results: Of the 156 parathyroid lesions, 8 lesions were parathyroid adenoma, 148 lesions were parathyroid hyperplasia. Reading combined 3 techniques had the most sensitivity (65.97%) and accurate (70.51%); however, it was not significantly more sensitivity and accurate than reading by combined 2 techniques of double-phase technique and dual isotope subtraction technique (p >0.05). Reading all images was significantly less sensitivity in the detection of lesions with weight less than 600 mg. Conclusion: The combined 3 techniques has the most sensitivity and accurate; however, reviewing dual isotope subtraction technique combined SPECT/CT scan, and combined 3 techniques has not significant difference in sensitivity, specificity and accuracy.


   P110: Quantitative 4D-MSPECT Stress Radionuclide Myocardial Perfusion Imaging Predicts Significant Coronary Artery Stenosis (Cardiology) Top


Tarit Taerakul*1

1Department of Radiology, Nuclear Medicine Unit, College of Medicine, Rajavithi Hospital, Rangsit University, Pathum Thani, Thailand

Background/Aim: Stress radionuclide myocardial perfusion imaging is one of the initial evaluation methods of coronary artery disease. Nuclear medicine physicians usually use qualitative analysis method to interpret result. However, quantitative analysis has better reproducibility of measurements and equal diagnostic accuracy of visual observers. In this study, we used quantitative method of 4D-MSPECT software to evaluate ability to predict coronary artery stenosis. Methods: 122 patients who suspected coronary artery disease were done myocardial perfusion scan and followed by cardiac catheterisation. Perfusion severity scores of 3 coronary arteries and left ventricular ejection fraction (LVEF) values from 4D-MPECT software were analyzed with to predict significant coronary artery stenosis and factor association. Results: Higher perfusion severity score of 3 coronary arteries had more significant coronary artery stenosis. Significant coronary artery stenosis had higher mean difference of severity scores of myocardial perfusion, wall motion, wall thickening and LVEF than controls in all 3 coronary arteries (p<0.05) except in wall motion severity score of left circumflex artery (p=0.479). Conclusion: Severity scores of stress radionuclide myocardial perfusion imaging and LVEF from 4D-MSPECT software can predict significant coronary artery stenosis of all 3 main coronary arteries and higher perfusion severity score had higher change for significant coronary artery stenosis.


   P111: Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Response Velocity Metrics following Postlung Stereotactic Ablative Radiotherapy (Molecular Imaging) Top


S Gawde*1, S Parekh1, S Vangipuram2, B S Ajaikumar3

1Department of Nuclear Medicine and PET/CT, HCG Apex Cancer Centre 2Department of Radiation Oncology, HCG Apex Cancer Centre, Mumbai, Maharashtra, 3Department of Radiation Oncology, HCG Cancer Center, Bengaluru, Karnataka, India

Background: FDG PET/CT is a well-established cancer imaging tool for diagnosis, staging and response assessment. It is also well known that, post chemotherapy or radiotherapy, metabolic response precedes morphologic response which is based on size criteria. However, earliest time needed for the maximum metabolic response post radiosurgery has never been assessed. Present study evaluates the metabolic regression velocity post SBRT with serial FDG PET/CT scans in patients with oligo solitary lung or mediastinal metastases. Methods: 5 patients with oligometastatic lung tumours (primaries: colorectal cancer-2, breast-2 and head and neck cancer-1) were planned for SBRT by deep inspiratory breath hold technique using active breath controller & risk fractionated protocol. Doses delivered were in the range of 110-116 Gy BED. All patients underwent diagnostic pre-and post-treatment PET/CT scans. Post-SBRT PET/CT scans were timed serially at 48 hours, 7 days, 30 days and 60 days post-treatment. PET/CT scans were reviewed in order to determine the pre-and post-treatment maximum standardized uptake value (SUVmax) of the lesion, including “complete resolution” of FDG-avidity. Corresponding morphologic variations of the target lesions were studied on the CT images. Results: All the 5 patients showed serial regression in metabolic activity, with maximum regression in metabolic activity occurring at 1week post SBRT. The observed metabolic regression was between 40-54% (median 50%) at 48 hours and 67-82% (median 80%) at 1 week post-SBRT. During the evaluation period, there was no significant change in size of the lesion. After 1 week of SBRT, there was no further decrease in metabolic activity, most probably due to initiation of inflammation. Conclusion: In cases of recurrent solitary lung or mediastinal metastases, the metabolic response precedes morphologic response, with maximum response seen at 1 week post-SBRT. This is the first study reported in literature which looked in the metabolic regression velocity.


   P112: Assessment of Small Hearts for Perfusion Defects in Comparison with General Population Using Myocardial Perfusion Scintigraphy (Cardiology) Top


Muhammad Iqbal*1, M B Imran1, M S Afzal1, M S Akhtar1

1Department of Nuclear Medicine, Pinum Cancer Hospital, Faisalabad, Pakistan

Background/Aims: Myocardial perfusion Scintigraphy (MPS) is a sensitive non-invasive imaging modality to assess myocardium for perfusion defects in known or suspected cases of coronary artery diseases (CAD). Its sensitivity may get compromised in certain patients like in patients with small hearts. The aim of this study was to assess small hearts for perfusion defects and compare results with general population. Methods: A total of 1000 MPS (combined set of Rest+Stress) images acquired by dual head SPECT/CT Hawkeye gamma camera were retrospectively analysed and categorized into two groups as general population i.e. ESV>15ml and subjects with small hearts i.e. ESV≤15ml. Each group was further categorised as normal, reversible perfusion defect and fixed perfusion defects. Cases of dilated cardiomyopathy/post-nitrate rest studies were excluded from the study. Results: Out of total 1000 patients, 350 (35%) met criteria for small hearts and 580 (58%) for general population while 70 (7%) patients were excluded from the study. Irrespective of the risk factors, in the category of patient with small hearts, 310 patients (88.6%) showed normal perfusion and 40 patients (11.4%) showed reversible ischaemic defects while no patient showed fixed perfusion defect. In category of general population 240 patients (41%) showed normal perfusion, 180 patients (31%) showed reversible ischaemic defects and 160 patients (28%) showed fixed perfusion defects. Conclusion: Number of perfusion defects differs to a significant level in both categories. Low percentage of perfusion defects in small hearts may be because scintillation detectors are not able to pick small perfusion defects in small hearts due to inherent low spatial resolution. Secondly total phase analysis (combined full cycle systole/diastole images) of MPS images is usually done, which may hinder diagnosis of small perfusion defects in patient with small hearts. We think this problem may resolve with the use of solid state detectors with high spatial resolution and may also be overcome by single diastolic phase analysis of MPS images.


   P113: Concordance among Single-Photon Emission Computed Tomography/Computed Tomography, Perioperative Neoprobe Sentinel Localisation and Patent Blue Dye Technique for Mapping Hidden Sentinel Nodes in Early Stage Breast Cancer Patients (Oncology) Top


Maimoona Siddique*1, A Hassan2, M K Nawaz1, H Bashir2

1Department of Nuclear Medicine, Pakistan Kidney and Liver Institute, 2Department of Nuclear Medicine, Shaukat Khaunum Memorial Cancer Hospital and RC, Lahore, Pakistan

Background/Aim: Compare the detection efficacy of SPECT/CT vs. Patent Blue Dye (PBD) technique for sentinel Lymph Node (SLN) detection in breast cancer patients. Methods: Prospectively, 1024 early stage (tumours <3cm) breast cancer patients with impalpable lymph nodes who underwent SLN mapping using radioisotope and PBD techniques between April, 2015 and March 2017 were studied. Cases who underwent SPECT/CT due to non-visualisation of SLN/equivocal findings on PS (n=134) followed by perioperative detection of hot node counts were included. Blue stained nodes were surgically removed and subjected to frozen section histopathological analysis. The histopathology results of SLNs detected by both techniques were compared for diagnostic value assessments. Results: Total 134 females underwent SPECT/CT and PBD injection for SLN on PS. Median age is 47 years. 49 (36.6%) T1, 85 (63.4%) T2. 131/134 (97.8%) had positive SLN detected by isotope and/or PBD technique. Six cases having no detectable radioactivity in the axilla had SLN identified only by PBD staining (blue-only) while none of the cases was only identified by isotopic detection, illustrating failure rates of 6.7% (9/134) and 2.2% (3/134) respectively. 26/134 had negative SPECT/CT lymphoscintigraphy but later neoprobe detected hot nodes in 20 cases. Therefore, the contribution of PBD to metastatic nodes identification was relevant for only 4.5%(6/134) patients. On subsequent axillary nodal dissection of three false negative cases on both isotope and PBD technique, all had nodal metastatic disease. The positive predictive value (PPV) of SLNs detected by isotope and PBD techniques were found to be 30.4% and 29% respectively. Conclusion: Role of PBD to reduce the false-negative rate of SLN mapping is limited to the rare cases in which no radioactivity is detectable in the axilla by SPECT/CT and/or Neoprobe detection (<5%). When a radioisotope mapping has localized SLN, the use of PBD should be limited.


   P114: The Utility of Tungsten Apron for γ-ray Protection (Physics) Top


Hiroshi Wakabayashi*1, H Yoneyama1, J Taki1, A Inaki1, D Kayano1, N Akatani1, S Watanabe1, T Yamase1, T Hiromasa1, A Toratani1, H Mori1, A Takata1, S Matsuo1, K Nakajima1, S Kinuya1

1Kanazawa University Hospital, Kanazawa, Japan

Background/Aims: The selection of efficient shielding materials for radiation protection is important to protect medical staff in the field of nuclear medicine. Metallic materials having a high atomic number and high density shield γ-rays. In clinical settings, easily available aprons are made by lead but they are too thin to shield γ-rays. The aim of this study was to investigate shielding effects of a commercially available tungsten apron using a γ camera. Methods: Attachable tungsten shields (TSs) in a commercial tungsten apron (Chiyoda Technol Corp.) are set on the surface-ray source (GPA-09A, Toshiba). A lead apron (HAGOROMO 0.35 mmPb, Maeda) is used to cover the upper half of the surface source as an additional protector. 99mTc and 131I are used as sources. A gamma camera (Symbia T6, Siemens) with low-energy/high-resolution and high-energy general-purpose collimators is used for 99mTc and 131I imaging, respectively. Circular regions of interest (ROIs) are set in the shielded and non-shielded areas. The mean count density per pixel of each ROI was analysed. Results: Mean counts of 99mTc were 201±12 in non-shielded area, 28±6 in the area shielded with 1 TS, 3±1 in that shielded with 2 TSs, 2±1 in that shielded with 3 TSs, and 1±1 in that shielded with 4 TSs. Additionally, the corresponding mean counts of 131I were 71±8, 53±7, 46±6, and 38±6, respectively. The linear attenuation coefficient (μL) of the tungsten shield is calculated from the rate of attenuation. Mean μL values were 1.3±0.1 for 99mTc and 0.1±0.006 for 131I. Conclusion: We demonstrated efficient shielding effects of the tungsten apron using a γ camera. The tungsten apron is promising shielding materials to protect medical staff in the field of nuclear medicine.


   P115: Utility of Delayed-phase 11C Methionine Positron Emission Tomography in the Evaluation of Focal Brain Tumours (Oncology) Top


K Takanami*1, K Takase1

1Department of Diagnostic Radiology, Tohoku University Hospital, Sendai, Japan

Background/Aims: 11C-methionine (MET) PET is used for the evaluation of brain tumours. The purpose of this study is to determine whether additional delayed-phase scan at MET PET study can improve the diagnostic accuracy in high-grade malignant brain tumours. Methods: This retrospective study included 21 patients who underwent MET PET and subsequently underwent brain tumour resection. At the PET studies, early-and delayed-images were scanned at 20-30 and 30-40 minutes after the administration of MET, respectively. MET uptake (SUVmax) in the focal brain tumours and background (contralateral site) and the lesion-to-background SUVmax ratio (SUVratio) on the early-and delayed-images were obtained. Retention index of MET uptake (delayed-SUVratio/early-SUVratio) were calculated. High-grade malignant tumours were defined based on the pathological findings (grade 3 or 4 on WHO classification). Mann-Whitney test was used for comparing the results between the high-grade tumours and the others. p-value <0.05 was set as a statistically significance. Receiver-operating characteristic (ROC) analysis was performed. Results: The 21 lesions consisted of 13 high-grade malignant tumours and 8 low-grade-/non-malignant tumours. Median of the early-SUVmax, delayed-SUVmax, early-SUVratio, delayed-SUVratio, and retention index were 4.17, 4.07, 2.63, 2.31, and 0.90 for the high-grade malignant tumours, and 2.58, 2.51, 1.72, 1.77, and 1.03 for the low-grade-/non-malignant tumours, respectively. There was a significant difference in each factor between the two groups (p<0.05), especially in the retention index (p<0.01). Area under the curve by ROC analysis was 0.78 for early-SUVmax, 0.78 for delayed-SUVmax, 0.84 for early-SUVratio, 0.78 for delayed-SUVratio, 0.87 for retention index. Sensitivity and specificity for detecting high-grade malignant tumours was 92.3% and 87.5% using a cutoff retention index of <1, respectively. Conclusion: Additional delayed-phase MET PET may improve the diagnostic accuracy in high-grade malignant brain tumours.


   P116: Usefulness of 18F Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Health Screening: Comparative Study with Korea Central Cancer Registry (Oncology) Top


Young Hwan Kim*1, H S Chang1, S J Kim1, Y Chang2, S Ryu2

1Department of Nuclear Medicine, Center for Cohort Studies, 2Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea

Background/Aims: The usefulness of PET/CT in patients is well known. In addition, studies on the usefulness of PETCT for healthy examinees have been conducted to some extent. Therefore, we investigated the usefulness of PET/CT for healthy examinees through cancer patients enrolled in Korea Central Cancer Registry (KCCR). Methods: The subjects were 236 registered at KCCR within one year after PET/CT examination was performed between 2010 and 2014 at the Total Healthcare Center of Kangbuk Samsung Hospital. The investigators were grouped by age and analyzed by which method the cancer was diagnosed. Results: Among 236 cancer patients, 88 were negative for PET/CT, but negative for other tests. On the other hand, there were 43 patients who were not diagnosed as having PETCT but were diagnosed as cancer by another test. Conclusion: It is expected that PET/CT can play a role in health checkups such as cancer diagnosis. Since PET/CT, which has recently reduced radiation exposure, has become available, it has become more likely to be used for health promotion. In the future, if only high price problems are solved, more use may be possible.


   P117: Clinical Significance of Measurement of Serum Anti-thyroglobulin Antibodies in the follow up of Differentiated Thyroid Carcinoma (Endocrinology) Top


Kahkashan B Mir*1, A Ammar1, S Fatima1, S Butt1, Muhammad Faheem1

1Atomic Energy Commission Hospital-Nuclear Medicine, Oncology and Radiotherapy Institute, Islamabad, Pakistan

Background/Aim: Despite the excellent prognosis, recurrence rate of differentiated thyroid carcinoma (DTC) is 20-40%. That’s why long-term follow-up with sensitive tests is needed. Serum thyroglobulin (Tg) has an established role as a tumor marker of relapse. Tg measurement is important for follow-up after surgery in patients with DTC and for detection of persistent or recurrent thyroid cancer but in the presence of anti-Tg autoantibody (TgAb) a negative Tg result is most likely false-negative. So, recent guidelines recommend assessing TgAb, with simultaneously measurement of serum Tg, every 6-12 months after surgery. Complete elimination of follicular cells by total thyroidectomy followed by remnant ablation should lead to cessation of antigenic stimuli and a progressive decline in TgAb concentration, resulting in complete TgAb disappearance but persistence of TgAb after treatment, or increasing TgAb concentration indicates persistent or recurrent DTC. Methods: Retrospective study was done on 258 patients and the criteria of the study were collection of data of patients with DTC who have undergone total thyroidectomy along with I-131 ablation. Serial assessment of Tg and TgAb level was done in those patients. Conclusion and results were extracted after comparison of ATG level with available imaging modalities i. e. WBS, ultrasound, CXR, bone scintigraphy, CT and MRI. and response to therapy. Results: 221 patients (75.8%) out of total 290 patients was female while rest of 70 (75.8%) were males. 193 (66.5%) out of the total patients had papillary carcinoma, while the rest of 98 (33.5%) had follicular carcinoma. Total patients with increased TgAb of >20 were 67 (23.1%), of which 19 (28.3%) patients had increased Tg and increased TgAb, while 49 (73.1%) patients with normal Tg and increased TgAb. Out of these 49 (73.1%) patients, 14 (28.58%) patients had ablated thyroid tissue, 16 (32.66%) patients had residual thyroid tissue, and 19 (38.76%) patients had residual thyroid tissue with metastasis. Conclusion: TgAb is also a tumour marker, rising when tumour is present and falling when it has been destroyed. There is a statistically significant correlation between the complete disappearance of thyroid tissue and the presence of thyroid antibodies, supporting the concept that continued antibody production depends on the persistence of autoantigen, so serial measurement of TgAb levels in the follow-up of patients with differentiated thyroid cancer is as important as the measurement of Tg level.


   P118: Radioiodine Therapy in Hyperfunctioning Metastatic Thyroid Cancer: A Case Report (Endocrinology) Top


Alvita Dewi Siswoyo*1, Johan S Masjhur2

1Department Cipto Mangunkusumo, 2Nuclear Medicine Division of Radiology, National General Hospital, Jakarta, Indonesia

Background/Aims: Thyrotoxicosis resulting hyperfunctioning metastatic thyroid cancer is extremely rare. It presents a therapeutic challenge, as both the metastatic cancer and thyrotoxicosis need to be treated. Methods: We report a 54 year old female patient diagnosed as papillary thyroid carcinoma with multiple bones and lungs metastases. She had symptoms of thyrotoxicosis during her thyroid hormone withdrawal as a preparation of second radioiodine (RAI) therapy. Clinical examination revealed tachycardia, tremors, and weight loss. Pre-treatment with high doses of anti-thyroid drugs and beta blocker were given and continued during the RAI therapy to avoid complications due to release of excessive thyroid hormones by the hyperfunctioning metastatic lesions. Results: The patient was treated with 150 mCi 131I without any significant side effects. After the 131I therapy, her thyrotoxicosis subsequently decreased, then anti-thyroid drug was discontinued. When patient became hypothyroid, she received L-T4 100 mcg daily to suppress her Thyroid Stimulating Hormone levels. At six months follow-up, there was significant reduction of Thyroglobulin and uptake of radioiodine scan in her multiple metastatic lesions which was appropriate with her clinical symptoms and other imaging modality results. Conclusion: Good response of this patient may due to high affinity of RAI to hyperfunctioning metastatic thyroid cancer. RAI treatment with anti-thyroid drug is the treatment of choice for hyperfunctioning metastatic thyroid cancer.


   P119: Iodine Concentration Calculated by Dual-energy Computed Tomography as a Functional Parameter to Evaluate Thyroid Metabolism in Patients with Hyperthyroidism (Endocrinology) Top


Binh Duong Duc*1, T Nakajima1, H Otake, T Higuchi2, Y Tsushima2

1Vinmec International Hospital, Ha Noi, Vietnam, 2Department of Diagnostic Radiology and Nuclear Medicine, Graduate School of Medicine, Gunma University, Maebashi, Japan

Background/Aims: Thyroid function in patients with Graves’ disease is usually evaluated by thyroid scintigraphy with radioactive iodine. Recently, dual-energy CT (DECT) with two different energy X-rays can calculate iodine concentrations and can be applied for iodine measurements in thyroid glands. This study aimed to assess the potential use of DECT for the functional assessment of the thyroid gland. Methods: Thirteen patients with Grave’s disease treated at our hospital from May to September 2015 were included in this retrospective study. Before treatments, all subjects had undergone both iodine scintigraphy [3 and 24 hours after oral administration of 123I (20 µCi)] and non-enhanced DECT. The region of interests (ROIs) were placed in both lobes of the thyroid glands, and CT values (HU: Hounsfield unit) and iodine concentrations (mg/mL) calculated from DECT images were measured. The correlation between CT values and iodine concentrations from DECT in the thyroid gland was evaluated and then the iodine concentrations were compared with radioactive iodine uptake ratios by thyroid scintigraphy. Results: Mean (±SD) 123I uptake increased from 46.3±22.2% (range 11.1–80.1) at 3 hours, to 66.5±15.2% (range 40–86.1) at 24 hours (p<0.01). CT values ranged from 34.5 to 98.7 HU (mean 67.8±18.6), while the iodine concentrations calculated with DECT ranged from 0.0 to 1.3 mg/mL (mean 0.5±0.4). A moderate positive correlation between CT values and the calculated iodine concentrations in the thyroid gland was seen (R=0.429, p<0.05). A significant negative correlation between 123I uptake at 3h and iodine concentration by DECT were seen (R= −0.680, p<0.05), although no correlation was observed between 123I uptake at 3 h and CT values (p=0.087). No correlation was observed between 123I uptake at 24h and CT values (p=0.153) or that between 123I uptake at 24h and iodine concentration by DECT (p=0.073). Conclusion: The negative correlation of 123I uptake at 3h with iodine concentration evaluated by DECT was better than that observed with simple CT value. DECT may have a potential role in the evaluation of iodine turnover in hyperthyroid patients.


   P120: To Assess the Effect of Hypothyroidism on Kidneys by Renal Scintigraphy (Renal) Top


Ayesha Ammar-Bokhari*1, M A Saeed1, S Fatima1, K Mir1, S Butt1, M Faheem1

1NORI, Islamabad, Pakistan

Background/Aim: The present study is planned to see the hypothyroid effects on renal function using GFR value as a marker of renal function. To study the effect of hypothyroidism on renal function using camera based GFR assessment method. Methods: Total number of 58 patients were included in the study. Out of 58 patients, 53 patients were thyroid carcinoma in whom hypothyroidism was due to discontinuation of thyroxine (51 patients) or injection of recombinant TSH (2 patients). Remaining 5 hypothyroid patients were post-radioactive iodine treatment for hyperthyroidism. Renal function tests (urea/creatinine) and serum electrolytes followed by 99mTc-DTPA renal scan for GFR assessment (GATES’ method) were carried out in all subjects twice during the study-one study during hypothyroid state (TSH > 30mIu/ml) and other during euthyroid state (TSH between 0.4 to 4 IU/ml). In addition, renal function was assessed with creatinine clearance in those subjects who showed raised creatinine values in either of study (hypothyroid or euthyroid state). Results: The results of Student’s t-test showed significant difference in renal function (urea, creatinine, creatinine clearance, GFR values) in euthyroid state and hypothyroid state (p <0.05). In the case of creatinine, the paired t-test reveal the mean 1.014±0.428, with standard error of 0.669 within 95% confidence interval, for creatinine clearance 80.11±14.12 with standard error of 1.94 within 95% confidence interval, for urea the mean 28±12.13 with standard error of 1.607 within 95% confidence intervals and for GFR for individual kidney is 38.056±8.56 with standard error of 1.3717 within 95% confidence interval. Conclusion: Hypothyroidism, irrespective of the cause, impairs renal function to a significant level and hence needs to be prevented and corrected as early as possible.


   P121: The Effect of Calcification on Pineal Function as Measured by FDG Uptake (Other) Top


Russell Kosik*1

1Tenth People’s Hospital, Shanghai, China

Background/Aim: Pineal gland calcification is often dismissed as a clinically insignificant phenomenon on CT examination of the head. However, previous research has identified multiple possible associations including malignancy, migraines, and intracerebral hemorrhage. Yet, no association between pineal calcification and function has been identified, namely pineal hormone levels are not affected by the presence of calcification. While numerous studies have examined pineal function using secreted hormones as a proxy for function, no prior studies have looked at FDG avidity as a measure of pineal function. We hypothesise that FDG avidity will decrease with the presence and amount of calcification. Methods: In this study, we examine how the presence and degree of pineal calcification affects pineal FDG avidity as determined by obtaining an SUVmax from a region of interest circumscribing the pineal gland. We will examine 500 PET/CT examinations that include the pineal gland. The presence or absence of pineal calcification will be determined. For those glands that are calcified, both the volume of calcification as well as the density of calcification as measured by Hounsfield Units (HU) will be determined. Results: The student’s t-test will be used to examine for statistically significant differences in FDG avidity between calcified and non-calcified pineal glands. Similarly, statistical analysis will be performed to determine if and how FDG avidity changes as the volume and density of pineal calcification increases. Conclusion: In this study, we aim to determine how pineal function, as measured by FDG uptake, is affected by the presence of calcification.


   P123: 99mTc-PSMA I+S Single-Photon Emission Computed Tomography/Computed Tomography Imaging in the Diagnosis of Prostate Cancer in Myanmar (Oncology) Top


Kyin Myint*1

1PERFECT Molecular Imaging and Therapy Center, Yangon, Myanmar

Background/Aim: Prostate cancer is fourth most common malignancy worldwide, and third in Myanmar. Currently, serum PSA is the tumour marker of choice with highest positive predictive value in prostate carcinoma. Regarding staging of the disease, ultrasonography, CT, MRI and 99mTc-MDP SPECT/CT bone scintigraphy are choices of investigations currently practicing. Because of the evidence-based, promising success of 68Ga-PSMA PET/CT imaging in the diagnosis of prostate cancer worldwide, we have to run 99mTc-PSMA I+S imaging in Myanmar with the available facilities (SPECT/CT). Methods: Ten patients with castrate resistant metastatic prostate cancer were imaged with 20mCi of 99mTc-PSMA SPECT/CT during three months period, from October 2017 to January 2018. We compared scan results with serum PSA level and 68Ga-PSMA PET/CT imaging abroad. Results: No abnormal radiotracer uptake is seen at normal serum PSA level and multiple skeletal and soft tissue uptakes are seen with raised serum PSA level. Though 68Ga-PSMA PET/CT imaging has good quality image, it is comparable to 99mTc-PSMA SPECT/CT. It could provide prognosis of the disease and lead to treatment modality. Conclusion: This pilot study is the stepping stone of theranostics in Myanmar. Myanmar is one of the developing countries and people could not afford costly high-tech imaging techniques for diagnosis. 99mTc-PSMA imaging for prostate cancer diagnosis is non-invasive, cost-effective, and provides an additional boon to our health-care system. This project will benefit both public and private sector hospitals and more importantly for the people of Myanmar.


   P124: Early Outcome of Fixed Dose Radioiodine Therapy in Hyperthyroid Patients (Endocrinology) Top


Jasmine Ara Haque*1, H A Rahman1, S Sharmin1

1National Institute of Nuclear Medicine and Allied Sciences, Dhaka, Bangladesh

Background/Aims: Early outcome of fixed radioiodine therapy is significantly reduced morbidity in hyperthyroid patients. Methods: 31 patients (M: F 9:22, age 19-60 years, mean 40 years) with hyperthyroidism treated in the year of 2016 with the dose of 8mCi to 15mCi. Patients were classified as Graves’ disease, toxic multinodular goiter, diffuse toxic goiter. Antithyroid drugs were stopped at least 3 days before radioiodine therapy. Results: Three months after radioiodine therapy, 3 (9.6%) patients were hypothyroid, 11 (35.48%) patients were euthyroid and remaining 17 (54.92%) patients were hyperthyroid. Patients having Graves’ disease were developed more euthyroid (50%) than those who had toxic nodular goiter (18.18%) and diffuse toxic goitre (37.5%). Conclusion: Early outcome in hyperthyroid patients was significantly affected by aetiology, severity of hyperthyroidism as well as goitre volume.


   P125: Tumour Marker Guided Positron Emission Tomography in Breast Cancer Recurrence (Oncology) Top


Borzou Rashidi*1

1Department of Nuclear Imaging, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Islamic Republic of Iran

Background/Aim: Early diagnosis and accurate restaging of recurrent breast cancer is important to the selection of the most appropriate therapeutic strategy, mainly by identifying patients with limited disease who could benefit from curative treatment. Methods: Integrated positron emission tomography/computed tomography (PET/CT), which combines anatomic and metabolic imaging information, has been shown to further improve diagnostic accuracy and clinical management of patients through accurate localisation of functional data on high-resolution anatomic CT imaging. Results: Although the utilisation of new therapeutic protocols aimed at reducing the recurrence risk is defined, the diagnostic approach for early detection remains to be clarifies. Conclusion: We aim to provide an overview of recently published reports on the use of tumour markers in breast cancer patients as a guide for 18F-Fluorodeoxyglucose PET/CT.


   P126: Brain Perfusion Single Photon Emission Computed Tomography in Patients with Attention-deficit/Hyperactivity Disorder using 99mTc-ECD: A Report of Three Cases and Review of the Literature (Neuroscience) Top


Mina Taghizadeh Asl*1, F Yousefi2, R Nemati3, M Assadi2

1Department of Nuclear Medicine, Kasra Hospital, Tehran, 2The Persian Gulf Nuclear Medicine Research Center, Bushehr University of Medical Sciences, 3Department of Neurology, Bushehr Medical University Hospital, Bushehr University of Medical Sciences, Bushehr, Islamic Republic of Iran

Background/Aim: Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent developmental disorder in children. The main symptom of the disorder is inattention, hyperactivity, and impulsivity, and is among the most prevalent of childhood disorders. Only a limited number of studies have investigated cerebral metabolism or perfusion in these patients. Therefore, such indices are not fully understood yet. Methods: In this study, three cases of ADHD underwent brain perfusion SPECT to evaluate cerebral perfusion. Results: All three patients showed abnormal cerebral perfusion on brain SPECT but normal MRI. Patient 1 was a 5 year old girl with ADHD. The SPECT showed moderate frontal hypoperfusion and bilateral inferior temporal hypoperfusion. The second patient was a 14 years old girl with ADHD. The SPECT showed generalized diffuse cortical hypoperfusion, more prominently on the superior pre-frontal cortex and also moderate hypo perfusion of cerebellar hemispheres. Patient 3 was a 7 year old girl with ADHD. The SPECT showed mild hypoperfusion of the right parietal-temporal region and sub-cortical structures. Conclusion: The study showed the frontal lobe is a key structure in ADHD that another area of the brain may contribute to the disease with various severity.


   P127: 188Re-Lipoidol TARE in Inoperable Primary Liver Tumours-Institutional Experience from a Quarternary Care Centre in South India (Radionuclide Therapy) Top


Shagos Gopalan Nair Santhamma*1, Firuz1, A Rabindranath1, R Brijesh2, K S Babu1, A Maliakkal1, P Prabhakaran1

1Aster Medcity, Kochi, 2Department of Radiodiagnosis and Interventional Radiology, Aster Medcity, Kochi, Kerala, India

Background/Aim: Hepatocellular carcinoma has increasing incidence in developing countries. Chemoembolisation, radiofrequency ablation and transarterial radioembolisation (TARE) are few non-surgical modalities in non-resectable liver tumours. 188Rhenium-Lipioidol TARE is a new therapeutic alternative to Yttrium-SIRsphere in inoperable liver tumours. The aim is to assess feasibility and evaluate outcomes of 188Re-Lipioidol TARE in unresectable primary liver tumours. Methods: 35 patients of inoperable primary liver tumours underwent 188Re-Lipioidol TARE during a period of 18 months. Pre-therapy triple phase CT angiogram done and tumour volume calculated using CT-based software. Pre-therapy lung shunt calculated in 5 patients. Administered doses of 188Re-Lipioidol varied from 1 mCi/ml up to 3 mCi/ml. TARE was done by an interventional radiologist after super-selective cannulation of feeding artery through a femoral approach. Post-therapy imaging was done after 24 hours in all patients. Response evaluation was based on contrast CT or MRI after 6 weeks, performance score, AFP levels and time to progress. Results: 14.3% showed good response, 28.57% stable disease, 11.4% partial response. Progressive disease was seen in 22.8%, time to progress varied from 4 to 10 months. Longest response duration was 14 months. No significant pulmonary toxicity was observed. Conclusion: 188Re-Lipioidol TARE is cost-effective, well-tolerated, effective palliative therapeutic modality in inoperable primary liver tumours.


   P128: A Comparison of the Diagnostic Accuracy of MRI and 99mTc-Ubiqucidin Single-Photon Emission Computed Tomography/Computed Tomography in Suspected Postoperative Spinal Infection (Infection/Inflammation) Top


Shazia Fatima*1, S T Butt1, M A Saeed1, N Ahmed1, K B Mir1, F Hussain2, R N Miller3

1Nuclear Medicine, Oncology and Radiotherapy Institute, Islamabad, 2Nuclear Medicine Centre, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, 3Nuclear Medicine Section, International Atomic Energy Agency, Vienna, Austria

Background/Aim: The diagnosis and localisation of post-operative spinal infection remains a challenge for physicians, as change in morphological feature after surgery renders MRI interpretation challenging. 99mTc-Ubiqucidin has shown promising role in musculoskeletal infections, however, its role in diagnosing post-operative spinal infections has not been fully explored. The purpose of this study was to evaluate the diagnostic value of 99mTc-labelled Ubiquicidin SPECT/CT scan and magnetic resonance imaging (MRI) in diagnosing post-operative spinal infection. Methods: From December 2013 to November 2017 patients with a clinical suspicion of infection in patients having prior spinal surgery, were included if 99mTc-Ubiquicidin SPECT/CT and MRI of the spine were performed within a 2-week time span. Imaging results were compared to histopathology, culture and final clinical diagnosis and follow-up data were collected. Results: Thirty-eight patients were included, of whom 23 patients were diagnosed with active infection. MRI showed an overall sensitivity of 66.67% and specificity of 85%. Diagnostic accuracy was 76.32%. 99mTc-SPECT/CT showed a sensitivity of 72.22 % and specificity of 90%. While diagnostic accuracy was 81.58%. Inter-observer agreement was better with SPECT/CT compared with MRI as well. Conclusion: As compared to MRI, 99mTc-Ubiquicidin SPECT/CT has superior diagnostic value for detecting post-operative spinal infections.


   P129: GI Bleeding Scintigraphy (Gastrointestinal) Top


Khalid Al-Busa’idi*1

1Royal Hospital, Muscat, Oman

Background/Aim: Gastro-intestinal (GI) bleeding scintigraphy is a useful non-invasive diagnostic procedure, used in acute cases of GI bleeding in order to localize the site of the bleeding, stratify the risk in patients with GI bleeding and try to assist in planning for other procedures or surgeries. Although it is more used in lower GI bleedings, GI bleeding scintigraphy can detect both upper and lower causes of GI bleeding and plays a complementary role to endoscopy and angiography. Methods: 99mTc-Sulfur colloid and 99mTc-RBC are the two radiotracers used for this study, with the latter being used more nowadays for its characteristic of remaining in the intravascular space for up to 24 hours. Results: GI bleeding scintigraphy has many advantages over the other diagnostic procedures, like: being non-invasive, having high sensitivity with low radiation dose, not requiring specific preparation and having the ability of scanning for long time which enables the detection of intermittent and slow bleedings. False positive cases can be seen when radiotracer accumulation is seen in the extra-vascular space; and such issues can be solved by acquiring extra images or by using SPECT/CT. Conclusion: Gastrointestinal bleeding scintigraphy is an important and very useful tool for diagnosis, localization and risk stratification of acute GI bleeding cases; with many advantages over the other diagnostic procedures. More studies are needed to answer the queries regarding the use of SPECT and SPECT/CT in the GI bleeding scintigraphy.


   P130: The Utility of 18F-Sodium Fluoride Positron Emission Tomography/Computed Tomography for Skeletal Staging in the Morbidly Obese Patients (Oncology) Top


Muhammad Sharjeel Usmani*1, F Marafi1, E Abdul-Redha1, F Al-Kandari1

1Department of Nuclear Medicine, Kuwait Cancer Control Center, Kuwait

Background: Optimising diagnostic imaging may be challenging in obese patients. The quality of conventional bone scintigraphy can be poor in the morbidly obese due to a combination of factors including high background soft tissue activity. In comparison, Sodium Fluoride (18F-NaF PET/CT) has a better target to background ratio attributed to rapid single-pass extraction and fast clearance from the soft tissues. The aim of the present study is to assess the diagnostic efficacy of 18F-NaF PET/CT in the evaluation of bone metastases in morbidly obese cancer patients. Methods: Two hundred and twelve morbidly obese patients (BMI 45±5.1 Kg/m2 and mean age, 57 years; range 32-81 years) with BMI > 40 kg/m2 referred for sodium fluoride (NaF) PET/CT for osseous staging of malignancy were retrospectively analyzed. All patients underwent PET/CT scan by injecting 2.2 MBq/kg (0.06 mCi/kg) of 18F-NaF. Results: 18F-NaF PET/CT was definitely benign in 145, possibly benign in 3; equivocal in 4; possibly malignant in 13 and definitely malignant in 47 patients. The sensitivity, specificity, PPV, NPV and accuracy of 18F-NaF PET/CT were 93.1%, 96.1%, 90%, 97.3% and 95.2% respectively (95% CI). Conclusions: The results of the present study indicate that 18F-NaF PET/CT retains its high diagnostic accuracy in morbidly obese patients and by inference can be a preferred functional modality in these patients.


   P131: Evaluating the Assessment of Vertebral Fractures with Bone Mineral Density in the Diagnosis of Osteoporosis; Reporting Initial Findings (Muscoloskeletal) Top


Roffat P Hussain1, A Ahmed1, T Mehmood2

1Karachi Institute of Radiotherapy and Nuclear Medicine, 2Jinnah Postgraduate Medical Center, Karachi, Pakistan

Background/Aim: The Dual Energy X-ray Absorptiometry (DXA) is a gold standard for the assessment of the bone mineral density and is also the only validated technology that uses the BMD input for the WHO fracture risk assessment algorithm, FRAX. Identification of previously unrecognized vertebral fractures with VFA, have the tendency to change diagnostic classification, fracture risk assessment and decisions regarding treatment with alteration of management of the patient with reduction of morbidities. The rational of this cross-sectional study was to look into the problems and report the advantage of VFA with BMD (as reported by others) in our current settings and offer an algorithm for the assessment of osteoporosis. Reported here are the initial findings of the study. Methods: Acquisitions for the BMD and VFA was done and reported with standard Hologic reference database for Caucasian males/females. After the routine BMD, VFA was performed after positioning the patient in the right lateral position. Following the acquisitions, machine software will be used to generate the BMD as well the VFA report and a comprehensive report stating the bone mineral condition as well as vertebral fracture assessment is made and reported. This study uses descriptive statistics only. Quantitative data includes age, expressed as mean ± standard deviation (SD). Frequencies and percentages are being calculated for qualitative data such as gender and findings of osteopenia or osteoporosis (Yes/No). The subgroup comparisons are based on students t-test with a P value of 0.0 5 as cut-off. Results: In process; to be concluded when presented. Conclusion: In process; to be concluded when presented.


   Asian School of Nuclear Medicine Posters Top



   P132: Inflammatory and Microcalcified Imaging for Monitoring Atherosclerotic Plaques (Cardiology) Top


Hui Tan*1, J Zhou1, Y Hu1, J Xiao1, D Cheng1, H Shi1

1Zhongshan Hospital, Fudan University, Shanghai, China

Background/Aims: To identify availability of inflammatory and microcalcified molecular probe in detecting atherosclerotic plaques. Moreover, to study whether the combination of both molecular probe imaging could assess the vulnerability of atherosclerotic plaques. Methods: The ApoE-/-mice were selected to establish atherosclerotic plaques model through feeding with high fat and high cholesterol (HFC) diet, while the C57BL/6J mice feeding with chow diet were selected as control. Mice body weight, the weight of abdominal adipose, serum lipids and serum inflamed and calcific cytokines were investigated, when the mice have been fed for 12 weeks, 20 weeks and 33 weeks. After that, imaging related experiments were performed, included BSGI imaging, micro-SPECT/CT imaging and micro-PET imaging. After imaging aorta vascular of these mice were used for histopathological analysis. Fianally, the correlation between imaging results and histopathological analysis were conducted, to further match and confirm imaging results. Results: The ApoE-/-mice were with higher body weight than the C57 BL/6J mice both at 12 weeks and at 33 weeks. The weight of abdominal adipose of ApoE-/-mice at 12 weeks, 20 weeks and 33 weeks were lighter than those of C57BL/6J mice. The levels of serum lipids (TC, TG and LDL) in ApoE-/-mice were significantly higher than in C57BL/6J mice at different weeks. Inversely, the levels of serum HDL of ApoE-/-mice was lower than C57BL/6J mice. Compared with C57BL/6J mice, the levels of TNF-α, IL-1β, CRP and Runx-2 in ApoE-/-mice were higher, but only some with statistically difference. Based on micro-SPECT/CT and BSGI imaging, the results showed that the radioactivity signal of aortic plaque in ApoE-/-mice was gradually increased with HFC feeding, while the aorta in C57BL/6J mouse fed normal feed displayed no radioactive concentration. In addition, we isolated aorta to perform microcalcified 18F-NaF PET in vitro imaging. In addition, the results showed that 18F-NaF micro-PET gradually increased in ApoE-/-mice with feeding time moving forward, significantly higher than that of C57BL/6J mice. The aortic plaque showed C57BL/6J mice displayed no radioactive concentration in aorta. Conclusion: This study demonstrated inflammatory and microcalcified molecular probe imaging could dynamically monitor AS plaques.


   P133: Dynamic Evaluation of Glucose Metabolism in Rats with Acute Myocardial Infarction, Using Positron Emission Tomography/Computed Tomography Imaging with 18F Fluorodeoxyglucose (Cardiology) Top


Su Hang*1, X Zhang1, Q Wang1, Y Zhang1, T Mou1

1Department of Nuclear Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China

Background/Aims: Micro PET/CT imaging of 18F-fluorodeoxyglucose (18F-FDG) was performed on acute myocardial infarction (AMI) models of rats, at different time points and different dietary state (fasted/non-fasted), to evaluate the metabolic changes of myocardium and brain after AMI. Methods: SD rats (n=12) were anesthetized with isoflurane. The ligation of left anterior descending (LAD) coronary artery was performed. MicroPET/CT imaging of 18F-FDG was acquired at different time points (pre-operation, day 1, day 3, day 7, week 4 and week 8 after operation) and different dietary states (fasted/non-fasted). Region of interests (ROIs) was drawn in myocardium (MI center, peri-infarction area and remote area), brain and liver. Standardised uptake values (SUVs) (SUVmean and SUVmax) were calculated. After the PET/CT imaging at week 8, rats were executed. Ex-vivo histopathological analysis was performed. All animal studies were performed under a protocol approved by the Beijing Administration Office of Laboratory Animal (BAOLA). Results: In non-fasted state, MI center showed the lowest radioactive uptake, while remote area showed the highest uptake. SUVs in MI center were gradually reduced from day 1 to week 8, indicated the severity of MI was gradually increased with time. In the meantime, SUVs in peri-infarction and remote area didn’t change significantly. In fasted state, since day 7 after surgery, the peri-infarction area exhibited highest uptake. SUVs in peri-infarction area were significantly higher than that in MI center (F=17.037?p=0.001<0.05). In fasted state, SUVs in brain was significantly higher than that in non-fasted state (p=0.001<0.05). HE staining and Masson staining studies confirmed that, there was myocardial infarction and myocardial fibrosis formation in MI area. Conclusion: 18F-FDG PET/CT imging could be used to evaluate the myocardial viability (in non-fasted state) and the inflammatory reaction (in fasted state) in AMI models of rats. Brain glucose metabolism of rats in fasted state is significantly higher than non-fasted state, which has clinic meanings for the further study.


   P134: Association Between Glycemic Control and Presence of Myocardial Ischaemia among Filipino Patients with Type 2 Diabetes Mellitus Using Stress Myocardial Perfusion Scintigraphy (Cardiology) Top


Henry G Canizares*1,2, A Sampana3, M Ogbac1, J Obaldo1

1Heart Center, 3Philippine Heart Center, Quezon, 2Department of Internal Medicine, Vicente Sotto Memorial Medical Center, Cebu, Philippines

Background/Aims: Coronary Artery Disease (CAD) is the leading cause of mortality among type 2 diabetic patients. Several studies evaluated glycemic control and MPS results with good correlation. In the Philippines, data concerning this matter is non-existent, hence this study. Methods: This study was approved by PHC IERB. Retrospective cohort study of selected Filipino type 2 diabetic patients without previous cardiac events who underwent stress or pharmacologic stress MPS (Tl-201 or Tc99m Sestamibi) over an 18-month period at the Philippine Heart Center. Patients were group into adequate glycemic control (HBA1c <7.0%) and inadequate glycemic control (HBA1c >7.0%). Association of myocardial ischaemia and risk of having significant CAD were computed using Pearson linear correlation analysis and logistic regression analysis based on summed stress score (SSS). Results: A total of 206 diabetic subjects-114 (HBA1c <7.0%) and 92 (HBA1c >7.0%), were included in the study. Male subjects dominate the population at 75%. Ischaemia on ECG were prominent among the 2nd group (p=0.018). LVEF values were significantly lower in the latter group (p=<0.001). The distribution in the degree of myocardial ischaemia was significantly higher in the inadequate glycemic control group; with values of 46.7% (43/92) for insignificant, 16.3% (15/92) for mildly abnormal and 37% (34/92) for moderate to severely abnormal (p=<0.001). It also had direct moderate association to abnormal MPS results (r=0.3279; p=<0.0001) and relative risk for having significant CAD of 4.27 (95%CI 2.32-7.85, p=<0.001) than their counterpart. Factoring the duration of inadequate glycemic control to >10 years, showed increased in relative risk to 7.26 (95% CI 2.1-25). Conclusion: The study shows that Filipino patients with Type 2 diabetes with inadequate glycemic control have varying degrees of abnormal myocardial ischaemia, direct moderate association to abnormal MPS results, and increase relative risk for having significant CAD as seen on stress MPS.


   P135: Role of Phase Analysis by Gated Myocardial Perfusion SPECT in Patient Selection and Site of Lead Placement in Cardiac Resynchronisation Therapy (CRT) (Cardiology) Top


Sadaf Butt*1, M Saadullah2, S Fatima1, N Marwat1, A Ammar1, K Mir1, A Saeed1, M Faheem1

1Aech-Nori, Islamabad, 2Department of Nuclear Medicine, NWGH, Peshawar, Pakistan

Background/Aims: Cardiac resynchronization therapy (CRT) is currently recommended in patients with wide QRS complex (≥120 ms), heart failure symptoms, and depressed left ventricular (LV) function (ejection fraction ≤ 35%) despite optimal medical therapy. CRT can improve symptoms, LV function, heart failure hospitalizations, and overall mortality. However, it is observed that a substantial group of patients who received CRT according to these selection criteria do not respond favourably to CRT. Methods: We selected 18 CHF patients already booked for CRT under Institute’s selection criteria. All patients underwent presurgery detailed clinical assessment followed by baseline 99mTc myocardial perfusion SPECT. CRT was done irrespective of results of myocardial perfusion scan. A follow up myocardial perfusion scan and clinical assessment was done after 6 months. Criteria for labelling improved clinical response was defined. Results: Phase analysis was carried out in 18 CHF patients having CRT. Based on pre-defined criteria; response was assessed at 6 month intervals. 66% were classified as responders and 34% were non-responders. It was also seen that SD (68.3±20.2 vs. 32.2±15, p<0.001) and HBW (178±70 vs. 112±55, p<0.001) were significantly higher in responders as compared to non-responders. The optimal cutoff values of SD (54°) and PHB (142°) for predicting CRT response were derived by receiver operating characteristic curve analysis. With these optimal cutoff values, phase analysis showed sensitivity/specificity values of 68% and 70%, respectively, in predicting clinical response to CRT. Regional mechanical activation was quantified. A 17-segment model is used to quantify the phase polar map, the mean phase of regions were compared. 78% patients had concordant lead placement while 22% patients had discordant lead placement. At 6 month follow-up, patients with a concordant LV lead position showed significant improvement in LVEF and reduction in LVESV (p<0.05), whereas with a discordant LV lead position showed no significant improvement. Conclusion: Phase analysis by gated myocardial perfusion SPECT is an evolving technique for measuring LV mechanical dyssynchrony. SD and HBW parameters measured by phase analysis were shown to predict response to CRT. It was found useful in identifying site of latest mechanical activation.


   P136: Reducing the Small-heart Effect in Paediatric Gated Myocardial Perfusion Single-photon Emission Computed Tomography (Cardiology) Top


Hiroto Yoneyama*1, T Shibutani2, M Onoguchi2, T Konishi1, K Okuda3, S Matsuo4, K Nakajima4, S Kinuya4

Departments of 1Radiological Technology and 4Nuclear Medicine, Kanazawa University Hospital, 2Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, 3Department of Physics, Kanazawa Medical University, Kahoku, Japan

Background/Aims: We compared two reconstruction algorisms and two cardiac functional evaluation software programs in terms of their accuracy for estimating ejection fraction (EF) of small hearts (SH). Methods: The study group consisted of 66 paediatric patients. Data were reconstructed using a filtered back projection (FBP) method without the resolution correction (RC) and an iterative method based on an ordered subset expectation maximization (OSEM) algorithm with the RC. EF was evaluated using two software programs of quantitative gated single-photon emission computed tomography (SPECT) (QGS) and cardioREPO. We compared the EF of gated myocardial perfusion SPECT to echocardiographic measurement (Echo). Results: Forty-eight of 66 patients had an end-systolic volume <20 mL which was used as the criterion for being included in the SH group, and the SH effect led to an overestimation of EF. While significant differences were observed between Echo (66.9±5%) and QGS-FBP without RC (76.9±8.4%, p<0.0001), QGS-OSEM with RC (76.6±8.6%, p<0.0001), and cardioREPO-FBP without RC (72.1±10%, p=0.0011), no significant difference was observed between Echo and cardioREPO-OSEM with RC (67.4±6.1%) in SH group. Conclusion: In paediatric gated myocardial perfusion SPECT, the SH effect can be significantly reduced when an OSEM algorithm is used with RC in combination with the specific cardioREPO algorithm.


   P137: The Utility of Cross-calibration for Heart-to-mediastinum Ratio Using Planar Image Created from IQ-Single Photon Emission Computed Tomography System (Cardiology) Top


Takayuki Shibutani*1, M Onoguchi, H Yoneyama2, T Konishi2, K Okuda3, S Matsuo4, K Nakajima4, S Kinuya4

1Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Departments of 2Radiological Technology and 4Nuclear Medicine, Kanazawa University Hospital, 3Department of Physics, Kanazawa Medical University, Kanazawa, Japan

Background/Aims: Myocardial sympathetic nervous scintigraphy with 123I-labeled meta-iodobenzylguanidine (MIBG) uses a planar image to measure heart-to-mediastinum ratio (HMR). However, planar images are not available from IQ-SPECT with SMARTZOOM collimator (SZC) due to its multi-focal collimation. Since we created the planar-equivalent (IQ-planar) images from the IQ-SPECT transverse image, the aim of this study was to demonstrate the utility of the new method for calculating HMR. Methods: The planar image with low-medium energy general-purpose collimator (LMEGP) and IQ-SPECT image with SZC were acquired with the four calibration phantoms filled with 123I-MIBG solution. The IQ-SPECT image reconstruction used ordered subset conjugate gradient minimizer method, and transverse images with attenuation and scatter corrections (ACSC) and without ACSC (NC) were obtained. Multi-planar reconstruction and ray-summation processing were applied to create the IQ-planar images with NC and ACSC. Linear regression between the measured HMR from the planar image and the mathematically calculated HMR was used to calibrate HMR to standardised values. We used the smartMIBG software for semiautomatic region setting. Both planar and IQ-SPECT images were obtained in 19 patients to compare the relationship between the HMR values before and after cross-calibration. Results: Scatterplots and linear regression lines between planar and IQ-planar HMRs before and after cross-calibration showed systematic differences both NC and ACSC conditions. The planar and IQ-planar HMR values with NC and ACSC were 2.65±0.68, 3.84±1.24 and 3.97±1.47 before cross-calibration, 2.90±0.78, 3.16±0.81 and 2.98±0.97 after cross-calibration, respectively. The IQ-planar HMR with NC and ACSC was significantly higher compared with that of the conventional planar image (p<0.001). However, the IQ-planar HMR with NC and ACSC after cross-calibration was similar to standardised HMR calculated by planar image. Conclusion: The IQ-planar HMR using the new method could be used with the conventional planar HMR.

References

  1. Nakajima K, Matsubara K, Ishikawa T, Motomura N, Maeda R, Akhter N, et al. Correction of iodine-123-labeled meta-iodobenzylguanidine uptake with multi-window methods for standardization of the heart-to-mediastinum ratio. J Nucl Cardiol 2007;14:843-51.
  2. Okuda K, Nakajima K, Hosoya T, Ishikawa T, Konishi T, Matsubara K, et al. Semi-automated algorithm for calculating heart-to-mediastinum ratio in cardiac iodine-123 MIBG imaging. J Nucl Cardiol 2011;18:82-9.



   P138: Serial Change of Rat’s Cardiac Function along with Growing (Cardiology) Top


Tomo Hiromasa*1, J Taki1, H Wakabayashi1, A Inaki1, S Kinuya1

1Kanazawa University Hospital, Kanazawa, Japan

Background/Aims: There are few studies that evaluate normal rat’s myocardial perfusion and ventricular function in the process of growing using in-vivo imaging. The purpose of the study was to evaluate cardiac perfusion and function serially in the growing rats by SPECT/CT for small animals and Quantitative Gated SPECT (QGS; Cedars-Sinai) software using 99mTc-sestamibi. For cardiac volume measurement, phantom study was also performed. Methods: Using cardiac phantom with 179.8μL of inner cavity, we measured ventricular volume with SPECT/CT and QGS software. We performed gated SPECT/CT in 6 rats every week from 8 to 28 weeks after their birth. Left ventricular functional parameters were calculated by QGS software. Results: The ventricular phantom volume was calculated as 168μL by QGS software. The weight of the rats increased week by week from 8 to 16 weeks, and the increase rate became low from 16 to 28 weeks. The heart rates did not change significantly over time. The left ventricular end-diastolic volume (EDV) and stroke volume (SV) increased over time in a linear fashion. The ejection fraction (EF) showed some fluctuation but no tendency of change over time with an average of 49.5±9.21%. EDV, ESV and SV showed the strong positive correlation with weight. The EF showed weak correlation with the weight, but showed rather constant value in over 400g in weight. There is no correlation between each functional parameters and heart rate. Conclusion: We analysed the rat cardiac functional parameters in every week from 8 to 28 weeks after their birth using 99mTc-sestamibi gated SPECT/CT with QGS software. EDV, ESV, SV showed high positive correlation with the weight, but EF showed rather constant value over time.


   P139: Lower Annual Cardiac Events in Diabetics with a Normal Exercise Gated Myocardial Perfusion Imaging and a Functional Capacity ≥7METS on Treadmill (Cardiology) Top


Nosheen Fatima*1,2, M U Zaman1,2

1Radiology, Aga Khan University Hospital, 2Department of Nuclear Cardiology, Karachi Institute of Heart Dise