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ABSTRACTS
Year : 2020  |  Volume : 19  |  Issue : 4  |  Page : 457-476

Abstracts 15Th International Conference On Radiopharmaceutical Therapy (ICRT2020) December 5-6, 2020


Date of Web Publication25-Dec-2020

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DOI: 10.4103/1450-1147.304777

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How to cite this article:
. Abstracts 15Th International Conference On Radiopharmaceutical Therapy (ICRT2020) December 5-6, 2020. World J Nucl Med 2020;19:457-76

How to cite this URL:
. Abstracts 15Th International Conference On Radiopharmaceutical Therapy (ICRT2020) December 5-6, 2020. World J Nucl Med [serial online] 2020 [cited 2021 Jan 21];19:457-76. Available from: http://www.wjnm.org/text.asp?2020/19/4/457/304777


   Theragnostics Top


99mTC-Prostate-Specific Membrane Antigen Single-Photon Emission Computed Tomography/Computed Tomography, an Evaluation of the Method Including Comparison with Methylene Diphosphonate Single-Photon Emission Computed Tomography/Computed Tomography

Marcel Baehr, Bernd Kuhn, Knut Liepe

Department of Nuclear Medicine, GH Klinikum Frankfurt (Oder), Frankfurt, Germany

Background: When PSMA-PET/CT and whole-body MRI are not available, current guidelines recommend CT imaging plus bone scan for prostate cancer staging of nodal and distant metastasis. Although 99mTc-PSMA SPECT/CT (PSMA-SPECT/CT) is thought to be a valuable alternative, its method is not standardized, yet. Methods: In 67 patients PSMA SPECT/CT using 512 to 757 MBq 99mTc-PSMA-API and MDP-SPECT/CT using 502 to 566 MBq of 99mTc-MDP were performed. Routinely PSMA SPECT/CT includes whole-body scan after 1 hour and SPECT/CT after 4 to 6 hours. In three patients, repetitive SPECT/CTs were performed between 1 and 6 hours. Results: In PSMA SPECT/CT, variation of administered activity showed no significantly different changes in SUVlbm (SUV). Target-tobackground ratio (T/B) was higher in lymph nodes than bone lesions. T/B increased over time from 1 to 6 hours. PSMA SPECT/CT detected more lesions than whole-body scan, especially in body trunk. In extremities, no lesions were missed. PSMA SPECT/CT showed significantly higher T/B than MDP SPECT/CT. Mean effective doses were 7,8 mSv for PSMA SPECT/CT, 5,1 mSv for MDP SPECT/CT and usually 15 mSv for diagnostic CT. Conclusion: In PSMA SPECT/CT contrast was high and steadily increased within six hours after administration. With respect to patient comfort, imaging after 3 to 5 hours is optimal. Whole-body scan with SPECT/CT of body trunk facilitates detection of smallest lesions in body trunk without missing metastasis in extremities. PSMA SPECT/CT is favored against bone scan plus CT concerning radiation exposure, patient comfort and contrast in bone and lymph node metastases.


   Prostate Top


99mTC-Prostate-Specific Membrane Antigen Single-Photon Emission Computed Tomography/Computed Tomography is a Valuable Alternative to 68Ga-Prostate-Specific Membrane Antigen-Positron Emission Tomography-Computed Tomography in Prostate Cancer Patients

Knut Liepe, Marcel Baehr, Bernd Kuhn

Department of Nuclear Medicine, GH Hospital Frankfurt (Oder), Frankfurt, Germany

Background: In patients (pts) with prostate cancer 99mTc-PSMA-SPECT/CT might be a viable option when, 68Ga-PSMA PET/CT is accessible due to availability or costs of the device or radiopharmaceuticals. Methods: 99mTc-PSMA-SPECT/CTs were performed using 634 ± 68 MBq of 99mTc-PSMA-API in biochemical recurrence of prostate cancer (n=78 patients), primary staging of prostate cancer especially before local radiotherapy (n=32 patients) and in association with. 177Lu-PSMA therapy (n=5 patients). 36 patients received 99mTc-PSMA-SPECT/CT and 99mTc-MDP-SPECT/CT within one month. Results: Mean age of patients was 72±8 years, PSA level ranged from 0.04 to 1050.00 ng/ml, and mean PSA-doubling-time (PSA-DT) from 1.5 to 45.4 months. In patients with a Gleason-score ≥ 4+4=8, 72% (26/36 patients) had positive findings in 99mTc-PSMASPECT/CT. In primary staging prostate cancer was detected in 100%. Additional lymph node metastases (LNM) were found in 16% compared to MRI or CT, which leads to up-staging of these patients. In patients with biochemical recurrence 55% have positive findings. The smallest positive LNM and bone metastases were each 4 mm, which is sufficient for diagnostic. Here, the lowest PSA was 0.14 ng/ml. In patients with negative results, the lowest PSA-DT was 5.9 months. The comparison of 99mTc-PSMA-SPECT/CT and 99mTc-MDPSPECT/CT revealed concordant findings in 92% (33/36 patients). The three discordant patients presented one a false positive finding in bone scan after local radiotherapy and two bone metastases, which were underestimated in 99mTc-PSMA-SPECT/CT. Conclusion: 99mTc-PSMA-SPECT/CT is a very useful alternative to PSMA PET/CT in primary staging, biochemical recurrence and to control effect of 177Lu-PSMA therapy. In primary diagnostic 99mTc-PSMA-SPECT/CT is recommended especially in high-risk prostate cancer due to higher probability of lymph node and bone metastases. In biochemical recurrence, patients with a PSA-DT > 5.9 months have not shown a pathologic finding, whereas positive lymph nodes were even detected in PSA 0,14 ng/ml. Although bone metastases were underestimated in 2 patients, future studies will show, if 99mTc-PSMA-SPECT/CT may substitute CT plus 99mTc-MDP-SPECT/CT in the primary staging of high-risk prostate cancer.


   Pain Top


A Long-Term Study of Radiosynovectomy in Patients with Knee Replacement and Chronic Synovitis

Knut Liepe, Marcel Baehr

Department of Nuclear Medicine, GH Klinikum Frankfurt (Oder), Frankfurt, Germany

Background: After knee replacement (TKR), therapy-resistant, persistent synovitis is a common problem which causes effusion, pain, and leads to loosing. It has been hypothesized that radiosynovectomy (RSO) is useful in these patients. Methods: A cohort of 55 patients with 57 TRK and persistent synovitis underwent 182 ± 9 MBq of Y-90-citrate. The number of RSOs in single patients ranged from one to four. A bone scan before and three months after every RSO was performed. Long-term follow-up ranged from 0.8 to 7.6 years with a mean of 23.2 months. For qualitative analysis, an established four steps scoring was used. For quantification, the uptake was determined within the Tc 99m MDP scintigraphy blood pool phase before and after therapy. Results: Long-term response was in 27% with excellent, 24% good, 30% weak and 20% no response. The duration of response was 12.0 ± 12.0 months (maximum 54 months). In patients with repeated treatment, the effect after the first therapy was lesser than in patients who received a single treatment in total. However, three months after the last RSO, patients with repeated treatment showed a similar effectiveness than single treated patients. At the end of long-term follow-up, patients with repeated RSOs had a higher effectiveness at similar duration response. In bone scan 65% of patients showed a reduction of uptake. When comparing subjective and objective response 78% of patients showed a concordance in both, symptoms and scintigraphy. Pilot histological analysis revealed that the synovitis is triggered by small plastic particles. Conclusion: We propose RSO as a therapeutic option of first choice in patients with TKR and persistent synovitis in order to improve the patients' satisfaction and decrease the number of revisions. Repeated treatment leads to a stronger long-time response.


   Thyroid Top


A Quantitative Comparison of I-131 and I-123 Scatter Corrected Single-Photon Emission Computed Tomography/Computed TomographyImages Using a Custom- Made Neck-Thyroid phantom With Thyroid Remnants

Konstantinos Michael1,2, Anastasia Hadjiconstanti3, Elena Ttofi4,5, Demetris Kaolis6, Yiannis Roussakis7, Maria Lyra3, Savvas Frangos8, Ioannis Iakovou9, Yiannis Parpottas3

Departments of 1Medical Physics and 2Mechanical Engineering, Bank of Cyprus Oncology Center, Frederick University, 3Frederick Research Center, Frederick University, Departments of 4Computer Science and 5Medical Physics, German Oncology Centre, Frederick University, 6Department of Medical Physics, Nicosia General Hospital, 8Department of Nuclear Medicine, Bank of Cyprus Oncology Center, Nicosia, 7Department of Medical Physics, German Oncology Centre, Limassol, Cyprus, 9Department of Nuclear Medicine, AHEPA Academic Hospital, Thessaloniki, Greece

Background: Postsurgical SPECT/CT thyroid imaging with I-131 or I-123 is performed to evaluate the disease, localize and estimate sizes of remnants, before radioiodine therapy. This study assessed quantitatively the quality of I-131 and I-123 SPECT/CT images using a custom-made phantom with small sizes of thyroid remnants. Materials and Methods: The used neck-thyroid phantom enclosed 1.5 and 3 mL sizes of thyroid remnants. Activity could be injected in the remnants and the background area. Scatter corrected SPECT/CT images were acquired following the clinical protocols for (a) various administered I-131 and I-123 activities within the remnants to study the modality response and the counting rate, and (b) different I-131 and I-123 remnant-to-background activity ratios to calculate the contrastto-noise (CNR) and signal-to-noise (SNR) and decide the image quality. Results: The total counts in each remnant per administered I-131 and I-123 activity showed a linear response of the modality. The counting rate for the I-123 acquisitions was much higher than the I-131 ones. Both SNR and CNR values were higher for the I-123 acquisitions that the I-131 ones. While, in all cases, the ratio of the SNR values between I-123 and I-131 acquisitions was almost constant, the corresponding ratio of CNR values was increased for higher background and for the smallest remnant. Conclusions: In postsurgical SPECT/CT thyroid imaging, the image quality of I-123 is superior than the I-131 ones. Acknowledgments: This study was co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research and Innovation Foundation (Project: EXCELLENCE/1216/0088).


   Theragnostics Top


Association between Clinical, Metabolic and Volumetric Parameters with Positron Emission Tomography-Computed Tomography 18F-FDG and 68Ga-RGD as a Predictor of Progression in Breast Cancer

Filiberto Lemus Ramírez, F Osvaldo García Pérez, Joel Eduardo Vargas Ahumada, Edgar Valentin Gómez Argumosa

Instituto Nacional de Cancerología, Medicina Nuclear, Mexico

Introduction: PET / CT with 18 FDG has become an indispensable tool for the management of this neoplasm and there is evidence that some metabolic parameters such as SUVmax or TLG have prognostic value as they are closely related to biological markers of aggressiveness. Angiogenesis is among the biological processes capable of studying molecular imaging, such as 68Ga-RGD (Arg-Gly-Asp), which assesses the presence of αvβ3 integrins in the cell membrane and which is highly expressed in both endothelial cells Neovascular as in tumor cells, including breast cáncer. Materials and Methods: The study is an ambispective cohort type, the inclusion criteria were patients over 18 years of age, diagnosed with breast cancer, who underwent PET with 18F-FDG and 68Ga-RGD, before treatment and with an interval of not more than 4 weeks between each one. Metabolic and volumetric parameters were measured for both radiotracers, both for primary tumor and for lymph nodes. For 18F-FDG: SUVmax, TLG and MTV; for 68Ga-RGD: SUVmax, MVD (tumour microvessel density) and TLM (Total lesion microvessels). A multivariate analysis was performed with the clinical variables of interest, in addition to the metabolic and volumetric parameters obtained in the PET studies, the multivariate analysis was using a log-logistic regression (STATA 15). Results: A total of 28 patients were studied, during follow-up 7 (25%) presented progression. No statistically significant differences between the means and standard deviations between the values studied for 18F-FDG and 68Ga-RGD were identified using a student's T test. Likewise, a cut-off point was not identified in the value of the parameters studied to predict progression. The results obtained in the multivariate analysis are summarized in the table. Conclusion: As the value of each parameter increases one point, the risk of progress increases. And it can be seen more significant for SUVmax RGD measured in axillary lymph node, followed by SUVmax FDG in axillary lymph node. So we have significant potential to use 68Ga-RGD PET / CT during staging as a good predictor of recurrence risk, and we confirm the role of FDG as a good predictor of recurrence.


   Thyroid Top


Brain Metastasis from Differentiated Thyroid Cancer: Diagnosis and Treatment - One Case Report

Tamara Geliashvili1, Valery Krylov1, Tatyana Berezovskaya2, Danil Gogolin3, Mikhail Sigov4, Yana Dayneko2

A. Tsyb Medical Radiological Research Center – Branch of the National Medical Research Radiological Center, Ministry of Health of the Russian Federation, Obninsk, Russia

Background: Brain metastases from differentiated thyroid cancer (DTC) are rare. DTC patients with brain metastases have poor prognosis. Diagnosis and treatment of these patients should be individualized. Methods: We report diagnostic and treatment options of a 68-year-old man DTC with single brain metastasis combined with single soft tissues metastasis, multiple lungs and bones metastases. The patient underwent a comprehensive examination including post-therapeutic (after radioactive iodine, 131I (RAI) therapy) SPET/CT, 18F-FDG PET/CT and whole-body MRI with diffusion-weighted imaging (WB-MRI with DWI). At the time of reporting (October 2020) the patient has received combined treatment for metastatic disease included three RAI therapy courses (cumulative 131I activity 13 GBq), external beam radiation therapy for the bone (32 Gy) and soft tissues metastases (22.5 Gy) and proton beam therapy for brain metastasis (4 GyE, 11 fractions). Due to the disease progression RAI therapy was canceled and prescribed target therapy by tyrosine kinase inhibitor. Results: Brain metastasis visualized as 131I, 18F-FDG and DWI positive lesion in the left temporal lobe. FDG-positive metastases showed poor response to RAI therapy regardless of the 131I uptake degree. During further disease progression we observed a partial response is maintained only in metastases on which external radiation therapy was performed including in single brain metastasis. Conclusion: In cases of concomitant existence of brain metastasis and extracranial multiple lesions local treatment on brain lesion is recommended as soon as possible regardless of its 131I uptake. Proton radiation therapy is one of the brain metastasis local treatment options for such patients.


   Theragnostics Top



   Thyroid Top



   Cancer Top


Comparison of 68Ga-Prostate-Specific Membrane Antigen, 68Ga-Dotatate and 18F-FDG in Metastatic Radioiodine Refractory Hurthle Cell Variant of Follicular Thyroid Carcinoma: A Case Report

Bawinile Hadebe1, Nozipho Nyakale2, Joseph Kabunda1, Lerwine Harry1

1Department of Nuclear Medicine, University of KwaZulu Natal, Durban, 2Department of Nuclear Medicine, Sefako Magkatho Health Sciences University, Ga-Rankuwa, South Africa

Background: Hurthle cell carcinomas (HCCs) are rare differentiated thyroid neoplasms of follicular cell origin which have a greater tendency to metastasise to distant sites and a higher mortality rate. The majority of HCCs are refractory to radioiodine therapy and are difficult to treat as they also respond poorly to chemoradiotherapy. Molecular therapies such as tyrosine kinase inhibitors can be used with some success however they are limited by high cost and side effect profile. Some radioiodine refractory (RAIR) thyroid cancers demonstrate prostate specific membrane antigen (PSMA) expression and radionuclide therapy with 177Lutetium PSMA has been used as treatment in this setting. 177Lu-labelled somatostatin analogues have also been used with mixed results likely due to variable somatostatin receptor-2 expression. Case Presentation: We present a case of a 51 year old female with metastatic RAIR, Hurthle cell variant of follicular thyroid cancer which showed poor Gallium-68 (Ga-68) PSMA avidity but high SSTR-2 expression on 68Ga-DOTATATE PET/CT. Uptake with 68Ga-DOTATATE PET/CT was similar to that of 18F-FDG PET/CT which makes peptide receptor radionuclide therapy (PRRNT) with 177Lu-DOTATATE a therapeutic option for this patient. The patient subsequently received targeted radionuclide therapy with 177Lu-DOTATATE, and the scan performed after the first cycle of 177Lu-DOTATATE demonstrated significant uptake and retention in most of the lesions. Conclusion: This case report demonstrates the poorer radioiodine and PSMA avidity of Hurthle cell thyroid carcinoma in comparison to 68Ga-DOTATATE and emphasises 177Lu-DOTATATE as appropriate choice of ligand to be considered for radionuclide therapy in this histological subtype of thyroid cancer.


   Theragnostics Top


Comparison of 68Ga-Prostate-Specific Membrane Antigen-11 versus 18F-FDG Positron Emission Tomography-Computed Tomography in Nonprostate Tumors

Joel Vargas, F Osvaldo García, Filiberto Lemus, Quetzali Pitalúa, Eleazar Ignacio

Instituto Nacional de Cancerología, Medicina Nuclear, Mexico

Background of the Study: 18F-FDG PET/CT has rapidly become a widely used imaging modality for evaluating a variety of malignancies. PET/CT with 68Ga-PSMA11 (prostate-specific membrane antigen) is highly useful for disease staging and detection of recurrent prostate cancer. PSMA expression has been reported in a variety number of malignant tumors. Given the success and the increasing number of case reports on PSMA uptake, our objective was to evaluate the avidity of PSMA in non-prostatic malignancies and compare the diagnostic accuracy with 18FFDG PET/CT. Objective: Compare the metabolic parameters of 18F-FDG PET/CT and volumetric parameters obtained with 68Ga-PSMA-11 PET/CT in non-prostatic malignancies. Materials and Methods: A total of 50 patients with non-prostate tumors underwent 68Ga-PSMA-11 and 18F-FDG PET/CT within 21 days; gastrointestinal tract (n=3), breast (n=2), liver (n=13), thyroid (n=10), urological (n=16), skin and soft tissues (n=6) tumors were included. The quantification of SUVmax, MTV, TLG, PSMA-TV (PSMA-derived tumor volume) and TL-PSMA (total lesion PSMA) was evaluated in each of them with the corresponding radiotracer. All tumors were correlated with histopathology. Results: Of the total patients, 50.9% were women and 49.1% men. The average age was 57.2 ± 14.8 years. Regarding the histopathological diagnosis, the most frequent were: 25.4% clear cell renal carcinomas, 24.4% hepatocarcinomas well, moderately and poorly differentiated and 17.6% papillary thyroid carcinoma. To establish if there were statistically significant differences between the volumetric and metabolic parameters, a one-way analysis of variance (ANOVA) was calculated, statistically significant values were found in malignancies such as hepatocarcinoma and clear cell carcinoma. Levene's test was performed in the group with a diagnosis of hepatocarcinoma to establish equality of variances, finding that the group with a moderately differentiated diagnosis of hepatocarcinoma was the group that presented statistically significant differences in SUVmax values (p 0.03). Conclusions: 68Ga-PSMA PET/CT showed higher values statistically significant in volumetric and metabolic parameters when compared with 18F-FDG PET/CT in clear cell renal carcinomas and hepatocarcinomas specially in moderately differentiated group. The expression of PSMA in a variety of non-prostatic malignancies, gives us the potential theragnostic application and as an alternative imaging modality for staging and restaging in tumor types where FDG PET/CT imaging has low diagnostic accuracy.


   Cancer Top


Comparison of Compensation Biologically Effective Dose(s) by Changing the Planned biologically Effective Dose of Either Normal Tissue or Tumor or Balancing Both

Mst. Sarmin Sultana, Md. Masud Parvej, Nazneen Sultana, Md. Abul Hasnat, Samiul Alim, Md. Monjur Ahasan

Bangladesh Atomic Energy Commission, Institute of Nuclear Medical Physics, Savar, Bangladesh

During radiotherapy of a cancer patient, unnecessary prolongation of treatment time is strictly averted and it is very good practice to aim to avoid interruption of the treatment schedule. But practically, schedule gap occurs due to various reasons such as patient's illness, machine disturbance, etc. In such situation, treatment planning team including radiation oncologist and medical physicist work together to handle this problem. The unscheduled treatment gap can be compensated by adding extra fractions (previously practiced) or managing gap without adding extra fraction. This work deals with the second one where various techniques were used to manage gap using biologically effective dose (BED) calculation formula. A nominal 5 week schedule beginning on Sunday was prescribed as 50 Gy/25 fraction/32 days. As the patient was too unwell, last five fractions were missed. These missed fractions can be managed either changing tumor BED keeping normal tissue BED unchanged or vice versa. If tumor BED is changed and normal tissue BED remain unchanged, the unscheduled five fraction can be delivered in three ways- i) in consecutive five days excluding weekend (total treatment time 39 days) where tumor BED decreases by 11.2% ii) in consecutive 5 days including weekend (total treatment time is 37 days) where tumor BED decreases by 8% and iii) in three days with two fractions in same day at alternative days (time interval between two fractions is > 6 hours) where tumor BED decreases by 4.8%. If tumor BED remain unchanged and normal tissue BED is changed (total treatment time is 37 days), the normal tissue BED will be increased by 9.4% and dose per fraction will be 2.62 Gy. Another approach may be compensating both tumor BED and normal tissue BED. However which technique will be applied will depend on radiation oncologist considering patient condition.


   Other Top


Comparison of the Efficacy between Periareolar and Peritumoral Injection for Sentinel Lymph Node Detection in Breast Cancer Patients

Margarida Rodrigues, Felix Schmidt, Roy Moncayo, Irene Virgolini

Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria

Introduction: Breast cancer is the most often diagnosed malignant tumour in women worldwide. The assessment of the regional lymph nodes is an essential factor to notice a potential tumour spread into the lymphatic system and furthermore to plan the following therapeutical approach. Sentinel lymph node (SLN) scintigraphy aims to mark the first few lymph nodes into which the tumour drains before these SLN become excised and histopathologically examined. Aim: To compare the efficacy of periareolar and peritumoral injections for SLN detection in breast cancer patients. Materials and Methods: Anonymised data of 231 female patients investigated with SLN scintigraphy for breast cancer were retrospectively evaluated. All patients underwent planar (anteriror) and SPECT/CT (360°, low dose CT) imaging of thorax 1 h after injection of 30 MBq Tc-99m human serum albumin nanocolloids (injection volume: 0,2- 1,0 ml). Tracer application was periareolar in 117 patients and peritumoral (ultrasound-guided) in 114 patients. Tracer application was performed 18-24 h before breast surgery and SLN biopsy. Results: SLN detection rate was 95,73 % in the periareolar group and 86,84 % in the peritumoral group. Histopathologic confirmed false negative rate in the periareolar group A was 0 % while in the peritumoral group B it was 12,12 %. Conclusion: The periareolar injection showed to be more sensitive for SLN mapping and for avoiding false negative results as compared with the peritumoral application. For routine investigation the periareolar injection should be applied in as much as the method is easier to carry out than the peritumoral procedure.


   Prrt Top


Efficacy and Safety of Peptide Receptor Radionuclide Therapy in Metastatic Neuroendocrine Tumour: Malaysian Single Institution Retrospective Analysis

Teik-Hin Tan1, Yee-Lian NG2, Haniff Shazwan Muhammad Sarwan Selvam2, Ew-Jun Chen2, Farhan Yusof2, Tim-Roy Lai2, Joey Chan2

1Department of Nuclear Medicine, Sunway University, 2Department of Nuclear Medicine, Sunway Medical Centre, Selangor, Malaysia

Background: PRRT has been recommended as a treatment option in metastatic SSTR+ve GEP-NETs, thoracic-NETs, and pheochromocytomas/paragangliomas. Methods: Seven-three NET patients who received either 177Lu-DOTA-TATE or 90Y-DOTA-TOC in a single institution in Malaysia from Mar 2018 to Mar 2020 were evaluated for treatment outcome. Patients were either local or from South-East Asia and East Asia countries. Progression was determined by RECIST 1.1. Toxicities were assessed using CTCAE. Results: Sixty patients are from GEP-NET; 6 thoracic-NET; 5 paraganglioma/ pheochromocytomas and 2 unknown primary. Most NETs are G1 (19.2%) and G2 (60.3%). Twenty-nine (39.7%) of patients received >2 medical therapy + liver directed therapy prior PRRT. Thirtynine (53.4%) patients received 2-4 cycles of PRRT; whereas 34.2% received >4 cycles. Twelve (16.4%) patients received either 1 or 2 courses of PRCRT. Nearly 1/3 patients received alternating 177Lu-/90Y-PRRT. Objective response rate (ORR) in all NETs patients was 47.0%, whereas disease control rate (DCR) was 83.3%. In GEP-NETs, 55.6% patients achieved ORR and 88.9% achieved DCR. With regards to adverse effect, only one patient developed Grade 3 bicytopaenia who required transfusion and thrombopoietin. No renal toxicity was identified including 4 patients initially presented with Stage 2 and 3 CKD. One patient developed Grade 3 liver toxicity but recovered after symptomatic treatment. Three (4.1%) patients developed transient vomiting during radiopharmaceutical infusion. Conclusion: In this small cohort, PRRT demonstrates high ORR and DCR in these parts of Asian population. PRRT is well-tolerated. In the follow-up period, rare incidence of Grade 3/4 haematological toxicity and no renal toxicity are observed.


   Theragnostics Top


Evaluation of The Biochemical Response Post 14.8 Gbq of 177Lu Marked with a New Molecule (ipsma) in Patients with Castration Resistant Prostate Cancer

Filiberto Lemus Ramírez, F Osvaldo García Pérez, Joel Eduardo Vargas Ahumada, Quetzali Pitalua Cortes, Eleazar Ignacio Alvarez

Instituto Nacional de Cancerología, Medicina Nuclear, Mexico

Introduction: 177Lu-PSMA is an emergent therapy in patients with castration-resistant metastatic prostate cancer, unlike other radiopharmaceuticals, this can condition a serum reduction of biomarkers, without hematotoxicity and offer pain control. 177Lu-iPSMA, obtained with radiochemical purities of 99%, showed specific in vitro and in vivo recognition for PSMA in prostate cancer cells and high LNCaP-tumor uptake (11 ± 2% ID/g at 24 h). The results obtained warrant further studies to evaluate the therapeutic efficacy of 177Lu-iPSMA. Material and Methods: Seventeen patients were included, with metastatic prostate cancer resistant to symptomatic and progressive castration previously treated with second generation antiandrogens, taxane-based chemotherapy or 223Radio and with metastatic lesions with 68Ga-PSMA uptake above or equal to liver activity. The biochemical behavior after 2 cycles of 177Lu-iPSMA was analyzed every 6-8 weeks, 2 weeks after the second dose. Serum values of prostate specific antigen, pre and post therapy blood cytometry where evaluated. Results: 16 of 17 (94%) patients had some type of response (mean reduction 50%). For leukocytes, platelets and hemoglobin at evaluation none of the values were found below the minimum values to apply therapy. All patients report an improvement in pain. Conclusion: 177Lu-iPSMA is an efficient and safe therapeutic alternative for the management of patients with castration-resistant prostate cancer. The administration of at least two doses allows reducing APE values by more than 50%. Prospective studies are needed to evaluate mean progression-free survival.


   Cancer Top


Importance of Adaptive Radiotherapy in Head and Neck Cancer

Samiul Alim1, Md. Masud Parvej1, Md. Abul Hasnat1, Mst.Sarmin Sultana1, Nazneen Sultana1, Md. Jakir Hosen1, Md. Khirul Islam1,2, M Monjur Ahasan1,2

Departments of 1Radiotherapy and 2Nuclear Medicine, Institute of Nuclear Medical Physics (BAEC), Baipayl, Bangladesh

Radiotherapy is noble approach of cancer treatment. But we can observe in the half way of treatment significant change the shape of tumor. Many sources have reported volume reductions in the primary target, nodal volumes, and parotid glands over treatment, which may result in unintended dosimetric changes affecting the side effect profile and even efficacy of the treatment. Adaptive radiotherapy (ART) is an exciting treatment paradigm that has been developed to directly adjust for these changes. ART is the process of re-planning patients based on structural and spatial changes occurring over treatment, with the intent of reducing overdosage of sensitive structures such as the parotids, improving dose homogeneity, and preserving coverage of the target. Adaptive radiotherapy (ART) is a novel approach to correct for daily tumor and normal tissue variations through online or offline by CBCT, or CT guided modification of tumor volumes and plans.


   COVID 19 Top


Initial Experience of Technical Aspects of Nuclear Medicine in COVID Times

Meena Negi, Vandana Kumar Dhingra, Leesa Thakur

Department of Nuclear Medicine, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India

Background: Handling unsealed radiation in Nuclear Medicine inherently calls for special precautions, additionally the COVID pandemic in 2020 has led to more challenges in Clinical Nuclear Medicine. Aim and Objectives: To describe the initial experience during handling of patients in the initial months of COVID-19 pandemic. Methodology: Technical aspects Nuclear Medicine procedures in the initial months of COVID pandemic were studied, they were divided into three groups: i Personnel related, ii. Patient related iii. General aspects. Results: During this period, no staff were infected with COVID 19. A total of 109 patients were included in the study i. Personnel Related aspects: The resident doctors and technical staff worked on rotation basis. All working technical staff and residents wore Personal protection equipment including gloves, mask and face shield for the entire duration of patient handling. Staff not directly handling patients wore face mask, face shield and gloves all the time. Hand hygiene/hand sanitization procedures and social distancing was maintained all the time in working hours. ii. Patient related: During imaging, plastic sheets were used on patient's couch. Technical Staff who wore PPE kit during injection and later maintained 1-1.5 m social distancing with patients and spent minimum time near to the patients. iii. General Aspects: Reports were dispatched in a non-contact method mostly online and gave the reports with proper hand sanitization and face shielding whenever manual. Staff used separate pen for this work. Workplace was sanitized with hypochlorite solution at the end of each day. Most common scans performed were renogram, bone, cardiac and thyroid scan. Auxiliary staff were trained for collection of radioactive consignments in non-contact mode. We did 109 total scans in 5 months of COVID 19 period. Conclusion: COVID 19 still has no medication till date. Nuclear Medicine Department working must ensure precaution in all aspects all the time especially during the COVID pandemic. We need to learn better ways to protect ourselves from the disease while not compromising on patient care.


   Cancer Top


Inmunotherapy Adverse Events Diagnosis with 18FDG Positron Emission Tomography-Computed Tomography

Lucrecia Solari, Martin Rettore, Mariela Agolti

Centro de Medicina Nuclear Clinica Modelo, Argentina

Background: immunotherapy is an increased useful therapy in oncology. Adverse effects are different from those seen with other therapies, they can be diagnosed through 18 FDG PET CT, and this is very important in life-threatening effects to start treatments. We describe our incidence and findings for 16 months. Methods: we have made 56 18FDG PET CT from 31st March 2019 to 1st August 2020 to patients treated with Immunotherapy: the treatments were ordered for Lung Cancer in 20 patients, renal cancer in 14 patients, melanoma in 15 patients, pancreatic cancer in 3 patients, 4 head and neck cancer. Results: We found possible IrAE in 9 patients: 1 increased uptake in Hipophysis, without clear symptoms,3 patients with findings possibly related to Colitis, however, one of them was discharged for he was under oral treatment for Type II Diabetes, 2 Patients with increased uptake in Thyroid, without clear Hyperthiroidsm symptoms 2 findings compatible with pneumonitis, and 2 with sarcoidosis like adenitis. The incidence of our findings was 16 %. Conclusion: When reporting 18 FDG PET CT in immunotherapy evaluation, to look after IrAE is very important for findings, and every nuclear medicine physician should have a checklist for some of these undesirable effects that may be life-threatening and once diagnosed they can be correctly treated.


   Theragnostics Top


International Patient Travel Consideration Post Radio Receptor Therapy - US Experience

Ayse Kendi1, Thorvardur Halfdanarson2, Boris Naraev3, David Mercer4, James Underwood1, Josh Mailman5

3Department of Medical Oncology, Banner M.D. Anderson, Arizona, 4 os Alamos National Laboratory, New Mexico, Departments of 1Radiology and 2Medical Oncology, Mayo Clinic, 5NorCal CarciNET Community, USA

Introduction: PRRT has been used for the treatment of advanced somatostatin receptor positive gastroenteropancreatic neuroendocrine tumors. Most commonly used forms of PRRT are Lutetium 177 labeled DOTATATE (Lutathera, Advanced Accelerator Applications, a Novartis company) which was recently approved by U.S. Food and Drug Administration (FDA) and Yttrium 90 labeled DOTATATE. In our experience, it is not uncommon for patients recently treated with PRRT to be stopped by United States Customs and Border Protection (CBP) officers while traveling, due to the detection of residual radiation activity. We would like to present results of an online public survey about patient experience with travel after PRRT. Methods: An online public survey performed by one of our authors (JAM) regarding patient experience at the US ports of entry and high security areas after PRRT. Results: 54 episodes of treatment-related travel delays reported in the survey. Time from radiation detection to final security clearance was less than 30 min in 17% of cases (9 events), 30-60 min - in 22% (12 events), 1-2 hrs - in 37% (20 events), more than 2 hrs - in 24% (13 events). Majority of patients (44 pts, or 81%) reported being treated with Lu177, 15% (8 pts) - with Y90, 4% (2 pts) - with combination of Lu177 and Y90. Conclusion: Traveling while undergoing PRRT should be discussed with the patient by the clinical care team and nuclear medicine/nuclear radiology team prior to treatment to avoid any unwanted surprises. Patients can arrange their schedules accordingly if they are well informed about this process ahead of time.


   Dosimetry Top


Investigation of Dose Confirmation by Comparing the Monitor Unit of Resultant Treatment Plan and of Manual Input

Nazneen Sultana, Masud Parvej, Sarmin Sultana, Abul Hasnat, Samiul Alim, Monjur Ahasan

Bangladesh Atomic Energy Commission, Institute of Nuclear Medical Physics, Savar, Bangladesh

Radiotherapy is a well established method for cancer treatment all over the world. In this institute there is a dual photon energy (6MV and 15 MV) CLINAC-iX machine which also provide all the electron beam of 6MeV to 18MeV with Eclipse 13.7 TPS software where used AAA for dose calculation. The main purpose of absorbed dose measure is to determine the extend of both the tumours and normal tissues are affected by the given radiation beam. All types of radiation therapy machine only accept the command of monitor unit (MU) which will be the resultant of all factors calculated by the dedicated algorithm. In radiotherapy MU is a measurement of ionisation occurring in a treatment beam within the gantry head of the machine. Now we want to compare the MU of radiation between planned one and manually input one for both 6 MV and 15 MV photon energy. In this comparison here used the same machine, chamber, phantom and geometrical setup, so all types of factors will be same but the resultant charge can be vary. Using this concept to compare these two resultant for investigate the accuracy. When a treatment plan have been done every time got a fixed MU for each field. For this investigation first of all CT simulation have been done for both water and solid phantom then fired radiation beam basis on that plan on both phantom. Besides these fired radiation beam on both phantom input manually the equal monitor unit. For this study there used a FC65-P chamber, field size 10×10 cm2 , SSD 90 cm, depth 10 cm. Here used 100 MU dose and took reading for both solid and water phantom both energies for this experiment. For water phantom resultant charge of treatment plan and manual input are 17.40 nC and 17.40 nC for 6 MV; and 20.71 nC and 20.72 nC for 15 MV respectively. For solid phantom resultant charge of treatment plan and manual input are 17.00 nC and 17.01 nC for 6 MV; and 19.87 nC and 19.88 nC for 15 MV respectively. After comparing the resultant charge maximum difference between these reading is 0.05%. The reason behind this change may be the geometrical position. As the CT simulation bore and treatment couch are different so during set up position may be changed a little bit. From this investigation it can be said that the delivered dose is equivalent to planned dose as the error is in acceptable range for CLINACiX machine which used in Institute of Nuclear Medical Physics.


   Protection Top


Lead Equivalent Test for Radiography Room to Ensure the Radiation Protection

Md Masud Parvej1, Myat Mon Aye2, Sam Paul3, Asmaliza Hashim4

1Bangladesh Atomic Energy Commission, Institute of Nuclear Medical Physics, Savar, Bangladesh, 2Department of Nuclear Technology, Division of Atomic Energy, Myanmar (Burma), 3Department of Radiology, Port Moresby General Hospital, Port Moresby, Papua New Guinea, 4Radiation Safety and Health Division, Malaysian Nuclear Agency, Selangor, Malaysia

Introduction: For radiation safety according to NCRP reference, Lead shielding wall of at least 2 mm thickness or equivalent of any material like concrete is required to ensure the protective equipment in hospital and radiation areas are complied which is expensive all over wall. Objective: To find out the equivalent of 2 mm Lead thickness of wall to ensure that requirement of radiation protection. Methods: To test and verify the integrity of the shielding thickness in term of Lead equivalent for radiation room and Lead shielding wall, Americum-241 (T1/2 = 432.17 y, 7.4 GBq) radioactive sealed source is used because of its energy (60 KeV) is within the energy range of X-ray (1100 KeV) of radiography room. Test procedure was based on comparison of the penetration of radiation from Am-241 on the protective barriers under test (wall, door etc) with the calibration curve of attenuation coefficient vs thickness of pure Lead sheets. The Lead equivalent measurements for the X-ray rooms and the diagnostic radiology room were carried out at positions such as walls, doors, Lead glass and weak point such as doorknobs, electrical sockets-switches, Lead glass frame, pipelines and door slits. Results: The value [ln(I/I0)] of calibration curve was 6.53 for 2 mm Lead thickness where count rate was 53 μR/h from 40 cm. Then results showed that radiation rooms almost meet the needs the equivalent of 2 mm Lead thickness. But, those weak points were less equivalent of 2 mm which may contribute to higher radiation exposure to human. Conclusion: By taking into account that the primary beam is not directed towards the wall with the weak points, then the results are thus acceptable.


   Theragnostics Top


Making Precision Personalised Radiotargetted Therapy Affordable!

Daya Hazra1, Padmamalika Khanna Nee Hazra2, Sandeep Agarwal3

1Department of Nuclear Medicine, Boston Medical Centre, 2Department of Chemistry, St. John's College, 3Purushottamdas Savitridevi Cancer Care Research Centre, Surgery, Agra, Uttar Pradesh, India

Background: Inspired by Richard Baum 's review last year Looking Backwards Moving Forward - 20 years of Radio Therapy at Bad Berka, in order to make radiotargetted therapy affordable , we indicate some avenues to achieve this. Methods: 1) To obviate where possible high cost of imported targeting biomoieties by radiolabelling histological supravital nucleophilic dyes (reminiscent of Paul Ehrlich:Richard Baum's initial picture) already used in outpatient settings for cancer delineation 2)To reduce nontarget reticuloendothelial uptake of immunoglobulin homing agents 3) Use pancarcinoma targets ranging from cytokeratin 8-18 targetted by us using Bjorklund's M3 monoclonal to Andrew Scott's Fibroblast Associated Peptide FAP (used in Richard Baum's Peptide Targetted RadioTherapy PTRT) 4) Pretargetting 5) Localised external irradiation analogous to hyperthermia of target lesions. Results: 1) It is possible to label Toluidine Blue (tolonium chloride) in vitro with diverse agents which can be imaging beta /positron /gamma emitters or therapy beta /alpha emitters , some constituting theragnostic pairs. 2) Cold nonspecific immunoglobulins significantly reduce wasteful reticuloendothelial system uptake of radiolabelled /unlabelled /toxin labelled therapeutic anticancer immunoglobulins. 3) Cytokeratin 8-18 can be targeted in a variety of tumours and like other such pancarcinoma targets can be investigated for pretargetting, 4) Localised irradiation though effective is limited in the anatomically feasible targets. Conclusions: Hopefully these represent methods to reduce costs in theragnostic targeting that need further development.


   Thyroid Top


Mibi Spect as First Line Diagnostic of Hypofunctioning Thyroid Nodules – A Long-Term Study

Marcel Baehr, Knut Liepe

Department of Nuclear Medicine, GH Klinikum Frankfurt (Oder), Frankfurt, Germany

Background: 99mTc-MIBI SPECT (MIBI SPECT) can exclude malignancy in hypofunctioning thyroid nodules. However, current guidelines do not integrate MIBI SPECT and recommend fine-needle biopsy (FNB) instead. We suggest MIBI SPECT with additional FNB of MIBI positive nodules as safe and effective assessment of hypofunctioning thyroid nodules. Methods: In 769 patients with hypofunctioning nodules was performed SPECT using 400 MBq ± 40 MBq of MIBI 120 min p.i. Additional FNB was performed in high-risk nodules and MIBI positive nodules. Long-term follow-up ranged from 14 to 70 months (mean 31.7 months). Results: MIBI SPECT was positive in 73 patients. The following surgery showed 17 malign and 24 benign neoplasia. In follow-up, MIBI negative patients revealed malignancy in 0.6% due to 2-4 mm papillary carcinoma. MIBI SPECT showed sensitivity of 82%, specificity of 95%, negative predictive value (NPV) of 99% and positive predictive value of 29%. Conclusion: With a NPV of 99%, MIBI SPECT is suitable for excluding malignancy of hypofunctioning thyroid nodules. In 696 MIBI SPECT negative patients three papillary carcinoma <5 mm have been missed due to physical resolution properties of SPECT. We suggest MIBI SPECT as first line screening tool in low to intermediate risk thyroid nodules and multinodous goiter. MIBI negativity instantly excludes malignancy and following ultrasound control is sufficient. An assessment of hypofunctioning thyroid nodules with MIBI SPECT first, followed by selective FNB will effectively reduce the frequency of thyroidectomies.


   Other Top



   Theragnostics Top


New Quantitative Nuclear Functional Imaging Data in Nets Theragnostic Approach

Cati Raluca Stolniceanu1, Irena Grierosu1, Mihai Gutu1, Doina Azoicai2, Teodor Ionescu1, Wael Jalloul1, Christina Ungureanu3, Cristina Preda3, Milovan Matovic4, Cipriana Stefanescu1

1Department of Biophysics and Medical Physics, “Grigore T. Popa” University of Medicine and Pharmacy, 2“Grigore T. Popa” University of Medicine and Pharmacy, Discipline of Primary Health Care and Epidemiology, 3Endocrinology Clinic, “St. Spiridon” Hospital, Iasi, Romania, 4Center for Nuclear Medicine, Clinical Center Kragujevac, Kragujevac, Serbia

Background: In neuroendocrine tumors (NETs) theragnostic, somatostatin receptor imaging represents gold standard in NETs management algorithm. Our study aims to establish new quantitative functional parameters, within the theragnostic approach of NETs patients. Methods: We analyzed, over a 12-month period, 43 patients, histologically proven NETs. Study design (a gamma camera Siemens e cam Dual Head, LEAP collimator, appropriate software): whole body scintigraphy (matrix 256x1024, 6 cm/min bed movement) and SPECT (128x128 matrix, 132 images), the images being acquired 3 hours after administration of 99mTc-HYNIC-Tyr3-Octreotide. Regions of interest (ROIs) for each hot pathological area were defined, the uptake was quantified (counts/pixel) and the ROI obtaining values was corrected. Three uptake indices were calculated (I1=tumor/liver, I2=tumor/spleen, I3=tumor/lung) and their values, uptake kinetics and the tumor heterogeneity graphs were compared before and after the applied corrections. Statistical correlations were calculated to evaluate the differences between the corrected and uncorrected pathological quantitative uptake indices. Results: Spearman's correlation was run to assess the relationship between the corrected and uncorrected pathological quantitative uptake indices, Spearman's Rank correlation coefficient (rs) being used to summaries the strength and direction of a relationship between our variables. For I1 and cI1 - rs value was 0.88, for I2 and cI2 - rs was 0.87, respectively 0.9 for I3 and cI3, the interpretation showing a strong positive correlation between corrected and uncorrected parameters. Conclusions Corrected uptake kinetics indices next to the tumor heterogeneity graphs can describe more precise the radiotracer biodistribution, representing an important nuclear functional imaging feature in NETs theragnostic approach.


   Thyroid Top


Normal Reference Value for Thyroid Uptake of Technetium-99m Pertechnetate for the Bangladeshi Population

HM Mohaymen Munna1, Md. Masud Parvej2, Farzana Ferdous1, Golam Abu Zakaria1

1Department of Medical Physics and Biomedical Engineering, Gono University, Savar, Dhaka, 2Bangladesh Atomic Energy Commission, Institute of Nuclear Medical Physics, Savar, Bangladesh

Changes in normal thyroid values for iodine have been reported in different geographical areas. These changes have been linked to geographical and chronological fluctuations in dietary iodine intake in different populations. Bangladesh is a country with mixed ethnicity, they intake iodine by table salt. Bangladeshi authorities have never publish their reference values, nor have local reference values been established. Participants who were considered to be euthyroid used to complete all requirements with thyroid pathologies, as well as those with renal or heart disease. The study consists of 30 participants (Males) and performed at the Institute of Nuclear Medicine and Allied Sciences (INMAS), Cumilla. The age of the participants ranges from 15 years to 58 years. In the experimental process first, blood is drawn for thyroid hormone assessment. Participants are then given 100 MBq of Technetium-99m per technetate intravenously and their percentage thyroid uptake is recorded after 20 minutes. In the study, thyroid-stimulation hormone (TSH), tri-iodothyronine (T3) and thyroxine (T4) levels found to be 1.24 mIU/L, 1.69 nmol/L and 88.97 nmol/L respectively. Normal reference uptake value for 99mTc pertechnetate for the population under study ranges between 0.66% and 3.88%. these results show deviation from the reference values have used by INMAS, Cumilla, Bangladesh.


   COVID 19 Top


Oncology Patients at COVID Hospital in Novi Sad (Military Hospital)

Milan Bozinovic

Military Hospital, COVID Hospital, Novi Sad, Serbia

Introduction: Numerous comorbidities are present in patients with covid19. Oncological diseases are no exception. The aim of this study was to determine whether there are patients in the Covid Hospital in Novi Sad (Military Hospital) who have had / previously been treated for a malignant disease. Patients and Methods: Retrospective analysis included all 202 case histories of patients who were covid19 positive and who were treated at Covid Hospital in Novi Sad (Military Hospital). Results: Of the 202 patients treated at Covid Hospital, 13 (6.44%) of them had malignancy. The malignancies that were present in patients were: uterine cancer 3 (23.08%), thyroid cancer 3 (23.08%), breast cancer 2 (15.38%), prostate cancer 2 (15.38%) and other cancers 3 (23.08%). Discussion: The main comorbidities in patients at the Covid Hospital in Novi Sad (Military Hospital) were hypertension, diabetes, and obstructive pulmonary disease. Malignant diseases were also present in 13 patients (6.44%). All patients with malignant diseases had completed oncological treatment. The relatively wide range of malignancies that patients have required additional monitoring and analysis. Conclusion: During the hospitalization of patients with covid19, special attention must be paid to patients with malignant diseases.


   Dosimetry Top



   Theragnostics Top


Predicting Specific Outcome in Dosimetry-Based Treatment for Graves' Disease

Paul Gape, Jan Taprogge, Lily Peake, Iain Murray, Glenn Flux

Department of Radioisotope Physics, The Royal Marsden NHS Foundation Trust, Sutton, UK

Introduction: Predicting Specific Outcome in Dosimetry-Based Treatment for Graves' Disease Background In 131I-NaI (radioiodine, RAI) therapy for the treatment of hyperthyroidism there is a lack of consensus between professional societies on the desired outcome of the therapy (euthyroidism or hypothyroidism) and on the optimal methodology to achieve the outcome (from empirical activities to personalised absorbed dose calculation). Methods: Analysis was performed on data from a prospective study of 284 patients with Graves' disease who were administered radioiodine calculated to deliver an absorbed dose of 60Gy to the thyroid.[1] Multivariate logistic regression was carried out to determine prognostic covariates and produce a model to give probability of outcome. Outcomes investigated were cure of hyperthyroidism (including euthyroid and hypothyroidism), euthyroidism, and hypothyroidism. Outcome was assessed at 12 months post administration. Receiver operating characteristics (ROC) curves were produced and model performance was assessed using area under the curve (AUC). Results: The AUC of the predictive model exceeded 70% for each outcome. Thyroid volume and percentage uptake in a 131I-NaI tracer study were identified as being predictive of cure of hyperthyroidism. Volume and effective half-life of the tracer were predictive of euthyroidism, and effective half-life and tracer uptake were predictive of hypothyroidism. Conclusions: This work allows us to determine which patient specific factors are significant predictors of response when dose is constrained. We produce models that allow for patient specific predictions of euthyroid and hypothyroid outcome following RAI therapy at 60 Gy.


   Reference Top


  1. Nguyen BJ, Burt A, Baldassarre RL, Smitaman E, Morshedi M, Kao S, et al. The prognostic and diagnostic value of 18F-FDG PET/CT for assessment of symptomatic osteoarthritis. Nucl Med Commun 2018;39:699-706.



   Thyroid Top


Presence of Residual Thyroid Tissue after Thyroidectomy in Differentiated Thyroid Cancer Patients and the Limitation of Using Thyroglobulin Level as a Prognostic Indicator for First Radioactive Iodine Ablation Therapy

Damayanthi Nanayakkara1, Sanooz Raheem2, Nawaz Saumya1, Piumi Herath1

1Nuclear Medicine Unit, Faculty of Medicine, University of Peradeniya, Peradeniya, 2Department of Clinical Sciences, Faculty of Health-Care Sciences, Eastern University, Chenkalady, Sri Lanka

Background: Serum Thyroglobulin (sTg) predicts the functioning residual thyroid tissues or metastasis in differentiated thyroid cancer (DTC) after surgery. False low value of sTg is caused by interferences of thyroglobulin antibodies and a lack of established reference ranges for cured patients with thyroid remnants. This study describes the presence of functioning residual thyroid tissue in DTC after total or near total thyroidectomy with the level of stimulated Tg before first RAI ablation. Methodology: A retrospective study of 56 DTC patients referred for first RAI therapy for residual ablation and metastases evaluation was carried out using thyroid cancer 2019 database at Nuclear Medicine Unit, University of Peradeniya. Thyroxin was withheld for 4-6 weeks and serum TSH and Tg were assessed prior to 30 mCi of RAI administration. A post-therapy whole body scan was performed with an additional neck image. Stimulated sTg of <1 ng/ml (RIA method) is considered as successful ablation and patients were categorized having <1 ng/ml or >1 ng/ml sTg level. Results: Residual thyroid tissue was noted in 91.0% (N= 51) of the study population. The stimulated sTg level was <1 ng/ml in 30.4% (N=17) and >1 ng/ml in 69.6% (N=39) of the participants. Residual thyroid uptake was seen among 88.24% (N=15) of <1 ng/ml sTg and 92.31% (N=36) of >1 ng/ml sTg. The presence of residual thyroid tissue didn't have statistical difference (P= 0.623) between these two groups i.e. sTg levels <1 ng/ml and >1 ng/ml. Conclusion: Considerable number of patients had functioning residual thyroid tissues even though sTg level was <1 ng/ml. Thus, irrespective of initial sTg level suggest offering activity of 30mCi RAI for residual ablation to all DTC patients.


   Thyroid Top


Prolonged Remission in Anaplastic Thyroid Cancer with Personalised Multimodality Therapy

Nat Patrick Lenzo1, Tee Sin Lim2, Sanjay Mukhedkar3, Dean Lisewski4

2Nuclear Medicine Unit, Faculty of Medicine, University of Peradeniya, Notre Dame University, Fremantle, 1GenesisCare, 3Oncology West, 4Perth Thyroid Clinic, Australia

Background: Anaplastic thyroid cancer is a rare but highly aggressive cancer that is usually seen in elderly patients. This cancer has limited treatment options and a dismal prognosis. Chemotherapy has a limited role in this condition. New approaches to therapy are required to improve the poor outcomes traditionally seen in patients who present with this cancer. Methods: A multimodality approach was utilised in 2 consecutive patients. Prior to treatment imaging with CT, FDG PET and PSMA PET was performed If debulking surgery could be attempted this was performed followed by focal radiotherapy in combination with nivoluvamab immunotherapy and then followed by alpha emitter radioligand therapy with Actinium-225 PSMA, again together with immunotherapy. Following these initial therapies both patients were commenced on the multikinase inhibitor lenvatanib. Serial monitoring with CT, FDG PET and PSMA PET together with clinical review was performed to monitor treatment response. Results: The first patient presented with locally advanced disease and pulmonary metastases. Following the above treatment strategy the patient has been in remission for 18 months. The second patient with inoperable locally advanced disease and stridor had resolution of disease and is in remission 6 months following diagnosis. Conclusion: We have developed a multimodality personalised approach to management of advanced anaplastic thyroid cancer that appears to have potential efficacy and may alter the natural progression of this usually aggressive and rapidly terminal cancer. This approach should be studied further in a clinical trial format.


   COVID 19 Top



   Prrt Top



   Cancer Top


Peptide Receptor Radionuclide Therapy in Neuroendocrine Patients during Sars-cov2 Pandemia: The Experience of European Institute of Oncology

Chiara Maria Grana1, Paola Anna Rocca1, Marzia Colandrea1, Laura Gilardi1, Silvia Lidia Fracassi1, Laura Lavinia Travaini1, Mahila Esmeralda Ferrari2, Nicola Fazio3, Emilio Bertani4, Guido Bonomo5

Departments of 1Nuclear Medicine, 2Health Physics, 3NET Medical Oncology, 4General Surgery and 5Interventional Radiology, IRCCS European Institute of Oncology, Milan, Italy

Background: Oncological patients are at higher risk of being affected by COVID-19, with an increased risk of severe illness and mortality; however, at the same time, it is important to go on with assistance and treatments. In an Italian recently published multicenter study, 45.5% of centers reported a delay at the beginning of PRRT for new candidates, and a delay in 15% in those patients who had already started PRRT, as a consequence of COVID-19. Methods: The aim of this study was to understand if SARS-CoV2 infection has modified the clinical management of NEN patients in neuroendocrine tumor board, with particular attention to PRRT administration. Results: The activity of IEO neuroendocrine tumor board never stopped. Since February 20th to the end of May, we performed 22 cycles of PRRT (either in clinical practice or in clinical trials), without any delay. Only one patient coming from the South of Italy could not travel during the lockdown period, so this patient received PRRT near at home. Moreover, a patient coming from abroad arrived in Milano and could receive PRRT on time. Conclusions: The results of our experience demonstrate that as far as PRRT is concerned, those centers with more experience and with a dedicated nuclear medicine performing PRRT like in our Institute, they are able to adapt to the new organisations imposed by the extraordinary situation. However, the network of our neuroendocrine multidisciplinary tumor board was able to provide continuity in care without withdrawing PRRT.


   Protection Top


Radiation Dose Assessment around Patients in SPECT (single Photon Emission Computed Tomography) Units Diethylene Triamine Pentaacetic Acid Renogram and Bone Scan

Bahalul Hasan1, Md. Selim Reza2, Md. Masud Parvej3, Nupur Karmaker1, Hasin Anupama Azhari1, Golam Abu Zakaria1

1Department of Medical Physics and Biomedical Engineering, Gono University, 2Bangladesh Atomic Energy Commission, Institute of Nuclear Medicine and Allied Sciences, Dhaka, 3Bangladesh Atomic Energy Commission, Institute of Nuclear Medical Physics, Savar, Bangladesh

Introduction: SPECT is one of the imaging modalities to diagnosis the tumor or cancer where ionizing radiation is emitted from patient who is injected radioisotope. To define the safe area for radiation protection is essential for occupational workers of nuclear medicine. Methods: For this study, all data of 26 male patients (Age: 2-69 y; Avg: 30.8 y) of DTPA Renogram and 26 male patients (Age: 29-71 y; Avg: 52.69 y) of Bone scan, who are injected 99mTc of 5mCi and 20mCi respectively, are collected via SPECT at in INMAS, Dhaka Medical, Dhaka in 2019. The dose rates were measured pragmatically by using a survey meter around radioactive injected patients in different points as radius from SPECT head. Results: This study observed that during contact with radioactive patient the occupational exposure increases but significantly decreases by increasing distance as well the dose rate reduces greatly with respect to time. Inside of 0.25 m radius, inside of 1.25 m radius and outside of 1.25 m radius of SPECT heads, the maximum dose rate measured 12.63 μSv/h, 1.47 μSv/h and 0.82 μSv/h respectively for DTPA renogram scan and 35.10 μSv/h, 1.90 μSv/h and 0.63 μSv/h respectively for bone scan. For console, corridor and outside of the room, the maximum dose rate was 0.36 μSv/h. Therefore, these areas would be defined as uncontrolled, controlled, supervised and public area respectively according to their limits. Conclusion: The occupational worker of SPECT should carry TLD batch and wear Lead shield aprons during radioactive injected patient handling. They should remain at a distance more than 1 m from the patient.


   Thyroid Top


Radioiodine Therapy Outcome in Differentiated Thyroid Carcinoma: The Impact of Pre-Ablation Thyrotropin Level

Ismaheel Lawal1, Nozipho Nyakale2, Lerwine Harry3, Kgomotso Mokoala1, Neo Mokgoro1, Mike Sathekge1

1Department of Nuclear Medicine, University of Pretoria, Pretoria, 2Department of Nuclear Medicine, Sefako Makgatho Health Sciences University, Ga-Rankuwa, 3Department of Nuclear Medicine, University of Kwa-Zulu Natal, Durban, South Africa

Objectives: Radioiodine ablation (RAIT) is administered in the post-thyroidectomy setting for complete extirpation of thyroid tissue thereby improving the utility of thyroglobulin as a tumour marker. When used as adjuvant therapy, RAIT may also improve disease control rate in differentiated thyroid cancer (DTC). The malignant follicular cells do not trap iodine to the same as extent as the normal thyroid cells. Elevated serum thyroid-stimulating hormone (TSH) level is, therefore, necessary to achieve significant uptake of radioactive iodine in the remnant thyroid tissue to achieve successful ablation. A cut-off value of 30 μIU/mL is commonly use; a decision without strong support from the literature. We aimed to determine if higher serum TSH levels will result in better rate of complete ablation of DTC using I-131 following initial thyroidectomy. Methods: A total of 132 Patients (female=94, male=38; mean age=47 years) with low- to intermediate-risk differentiated thyroid cancer treated with I-131 were divided into four treatment groups based on pre-ablation serum TSH levels. They were followed-up at 6-12 months post-treatment with stimulated serum thyroglobulin level, anti-thyroglobulin antibodies, clinical examination and diagnostic whole-body scan with radioactive iodine I-123 to determine early response. Treatment outcome was classified according to the four response-to-therapy categories recommended by the American Thyroid Association. Results: Seventy-eight patients had papillary thyroid carcinoma while 54 had follicular carcinoma. A positive correlation was found between pre-ablation serum TSH level and successful ablation (p<0.001); Excellent response was seen in 66.7% of patients with TSH level >90 μIU/mL, 72.2% in the group with TSH level of 60 to 89 μIU/ml, 48.5% when TSH was 30 to 59 μIU/mL and 26.7% when TSH was <30 μIU/mL. In a multivariate analysis done to determine the predictors of excellent response to therapy, only pre-ablative TSH level was found to be an independent predictor of successful ablation, Odds ratio = 1.754 (95% CI was 1.190-2.586, p=0.005). Conclusions: In patients with low- to intermediate-risk differentiated thyroid carcinoma treated with radioiodine therapy post thyroidectomy, higher pre-ablative serum TSH predicts better rate of complete ablation of remnant thyroid tissue.


   Theragnostics Top


Radiopharmaceuticals Therapy in Saudi; Current and Future

Mohammed Al Qahtani1, Mohammed Al Rowaily2

Departments of 1Cyclotron and Radiopharmaceutical and 2Radiology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia

Until quite recently, radiopharmaceuticals, both in the diagnostic and the therapeutic fields, have been confined to a very limited number of major hospitals in Saudi Arabia. Radiopharmaceuticals for Therapy in particular introduced in the early 80's, mainly Iodine-131. However, in the last decade, medical teams have started to unlock the huge potential of these compounds. The increasing demands for the therapeutic radiopharmaceuticals on many applications make it unavoidable to start the use of these compounds in several specialized hospitals which in turn improve the healthcare system in the county. Radioactive Iodine-131 is the most used radiotracer since early 80's and now it is used in at least 15% of the nuclear medicine departments around the country. Several other therapeutic radiotracer have been introduced in only one major hospital which is King Faisal Specialist Hospital and Research Center and that include so far Y-90, Lu-177 DOTATATE/TOC and Lu-177 PSMA, Ra-223, Sr-89 Chloride and Sm-153 EDTMP and on planning phase is the introduction of Re-186 radiotracer. The future plan is to have most needed radiopharmaceuticals for therapy available in the major hospitals that design to host state of the art nuclear radiopharmacy.


   Pain Top


Radiosynoviorthesis of Painful Synovitis of Elbow Due To Systemic Arthritis

Ioannis Iakovou1, Evanthia Giannoula1, Dimitrios Kotrotsios1, Asterios Kalaitzoglou2, Konstantinos Michailos2, Fotini Spyroglou1, Emanouil Papanastasiou1

Departments of 1Second Academic Nuclear Medicine and 2Third Academic Nuclear Medicine, Academic General Hospital of Thessaloniki “AHEPA,” Aristotle University of Thessaloniki, Thessaloniki, Greece

Aim/Introduction: Rheumatoid and psoriatic arthritis (RA) are chronic, progressive, disorders, characterized by synovial inflammation of the joint. Radiosynoviorthesis (RSV) has been adopted as a therapeutic option. The objective of this study was to retrospectively evaluate the long term efficacy of RSV in patients with systemic (rheumatoid or psoriatic) arthritis of the elbow joint. Materials and Methods: Thirty six patients with 37 painful despite pharmacotherapy elbow joints (28 females, 67+-3 years old) enrolled the study. They were intraarticularly injected with 2mci of 169Er citrate under x-ray guidance. In the pretherapeutic bone scan, all joints presented a positive blood pool image, indicative for active local synovitis. Joint functional status and pain were assessed by a visual analog scale (VAS) of ten steps: 1 - lack of any impairment to 10 - total disability just before (less than a week), a month and a year after treatment. Results: Thirty three in 36 patients (34 in 37 joints >90%) responded to therapy reporting a pronounced improvement in their manual activities as documented by the decrease of the mean VAS score prior to treatment from 8,4+- 1,5 to 2,6+-1,8 (p<0,05) 12 months after RSV. Conclusion: RSV is a highly effective procedure in elbow's systemic arthritis active synovitis.


   Thyroid Top


Role of 99mtc-Galacto-Rgd2 S Emission Computed Tomography/Computed Tomography in Identifying Metastatic Differentiated Thyroid Carcinoma after Thyroidectomy and Radioactive Iodine Therapy

Rencong Liu1, Qinfeng Xu2, Jun Wang1, Yue Huang1, Shaohua Li1, Lele Zhang1, Feng Wang1

1Department of Nuclear Medicine, Nanjing First Hospital, Nanjing Medical University, 2Department of Nuclear Medicine, Drum Hospital, Nanjing University, Nanjing, China

Background: We investigated the clinical role of 99mTc-Galacto-RGD2 SPECT/CT in high-risk differentiated thyroid carcinoma (DTC) after thyroidectomy and radioactive iodine (RAI) therapy. Methods: Thirty-six patients with high-risk DTC (20 males, 16 females; mean age: 59.9 ± 16.6 y) who had undergone thyroidectomy and RAI therapy were consecutively enrolled in this study. All patients underwent 99mTc-Galacto-RGD2 SPECT/CT and diagnostic 131I whole-body scanning 6 months after the last RAI treatment. A region of interest (ROI) was drawn and the ratio of tumor/non-target (T/NT) was calculated. Per-patient and per-lesion analysis was performed to evaluate the diagnostic efficacy. The final diagnosis was confirmed by histopathology and follow-up. Integrin αvβ3, CD31, and Ki-67 expression in the tumor were also analyzed for evaluation of angiogenesis and proliferation. Results: Out of 36 patients, twenty-two had metastatic disease. By per-patient analysis, the area under the curve of 99mTc-Galacto-RGD2 SPECT/CT was significantly higher than that of 131I whole-body scan and morphological imaging (including CT and ultrasonography) (P=0.0034 and 0.0006). For per-lesion analysis, 99mTcGalacto-RGD2 SPECT/CT identified 67 metastatic lymph nodes in 14 patients, 12 lung metastases in four patients, and 12 bone metastases in six patients; its sensitivity was significantly higher than that of 131I whole-body scan in detection of lymphatic (90.54% vs. 55.41%, P=0.0124) and bone metastasis (92.31% vs. 30.77%, P=0.046). The tumor-to-normal ratios of metastatic lesions increased with the increase in DTC stage. Conclusion: 99mTc-Galacto-RGD2 SPECT/CT has high sensitivity in the detection of remote metastasis in high-risk DTC and further contribute to evaluation of tumor angiogenesis.


   Thyroid Top



   Cancer Top


Sirt5 Is Critical For Differentiated Thyroid Cancer Tumor Growth and 131i Therapeutic Sensitivity

Liang Shi1, Zhenhua Sun2, Qinqin You1, Shaohua Li1, Rencong Liu1, Xiaochen Yao1, Xiaowei Tang1, Qiong Jia3, Feng Wang1

Departments of 1Nuclear Medicine and 3Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 2Department of Thyroid and Breast Surgery, Affiliated Hospital of Jiangsu University, Zhenjiang, China

Background: 131I Radioiodine treatment is a key adjuvant therapy for patients with differentiated thyroid cancer (DTC). Sublethal radiation damage can be repairedwhen tumor cells are in the condition of enough nutrition and energy. SIRT5 is a member of the sirtuin family, which can sense nutrient requirements to maintain cellular survival under limited nutritional conditions. The role of SIRT5 in 131I radioiodine therapy for DTC patients is poorly understood. Methods: The levels of SIRT5 immunohistochemistry (IHC) analyses were performed on 67 paraffin-embedded DTC tissues and matched peritumoral tissues. SIRT5 overexpression in BCPAP cells were used to examine the role of SIRT5 in tumor cell proliferation, glycolysis and apoptosis by cck-8, 18F-FDG uptake test, ATP production, lactate release, matabolic flux analyze, flow cytometry, and apoptotic protein expression. Cell proliferation and apoptosis were also detected in BCPAP cells co-cultured with SIRT5 inhibitor GW5074 and/or 131I. The mechanisms underlying the adjuvant sensitization effect of SIRT5 inhibition in 131I treatment of DTC was also analyzed using molecular techniques. Results: SIRT5 protein levels in DTC cells were higher than those in benign cells. SIRT5 overexpression promoted BCPAP cells proliferation, glycolysis and apoptosis. 131I combined SIRT5 inhibitor treatment had higher apoptosis, lower proliferation and glycolysis status than 131I alone. Mechanistically, SIRT5 targeted pyruvate kinase M2 (PKM2)-mediated glycolysis pathway and alter DTC 131I therapeutic response. Conclusion: Thus, our findings provide insight into the role of SIRT5/PKM2 axis in 131I therapy for DTC and suggest that combination 13II and targeting SIRT5 protein therapy may represent a new strategy for DTC.


   Other Top


Single-Photon Emission Computed Tomography/Computed Tomography Imaging With 99mTc-Prostate-Specific Membrane Antigen in Patients with Prostate Cancer

Sonya Sergieva1, Kamen Nedev2, Zahary Zahariev3, Radoslav Mangaldjiev4

Departments of 1Nuclear Medicine and 4Medical Oncology, Sofia Cancer Center, 2Department of Radiotherapy, City Clinic Oncology Center, 3Department of Radiotherapy, Uni Hospital, Sofia, Bulgaria

Introduction: Prostate-specific membrane antigen (PSMA) is a cell surface glycoprotein with a large extracellular domain with overexpression of the prostatic tumor cells. A lot of small molecules of PSMA ligands or inhibitors binding to active site of PSMA were developed. 99mTc-PSMA-T4 is a new radiopharmaceutical (Polatom) for imaging of loco-regional metastases and/or local relapse in patients with prostate cancer. The purpose of this work was to evaluate clinical application of SPECT-CT imaging with 99mTc-PSMA-T4 in patients with recurrent prostate cancer. Patients and Methods: Thirty-six patients with prostate cancer, aged 60-84 years with biochemical relapse of PSA (ranged from 0.03 to 62 ng/ml) were included Three patients were studied after tru-cut biopsy, hormonal and cytoreductive radiotherapy and 33 patients out of 36 – after radical treatment (total prostatectomy or definitive radiotherapy of the tumor). All of them underwent whole-body imaging examinations with subsequent target SPECT-CT studies of the pelvis, abdomen and/or chest, 1–3 hrs post i.v. administration of 99mTc-PSMA-T4. The average activity dose was 6.3 MBq/kg in a man of 70 kg. Double-head SPECTCT gamma camera with low dose CT scanning (Symbia T2, Siemens) was used. The images were interpreted based on all other clinical and radiological data. Follow-up could be conducted in 11/36 patients during that period. Results: Normal biodistribution of the radiopharmaceutical with high activity background was observed in the liver, spleen, kidneys, lacrimal and salivary glands, bowels and urinary bladder. Positive imaging for local relapse in the prostate bad was imaged in 21 patients, lymph node metastases – in 16 cases, bone lesions – in 10 cases, pulmonary metastases – in 2 cases, hepatic lesions were visualised in one of them and in another - adrenal suprarenal metastasis with intensive tracer uptake significant for overexpression of PSMA. There was suspicious for local recurrences in 4 patients with negative MRT studies who were followed-up. In 3 cases, previously treated bone metastases were partially negative without tracer uptake, only some progressive bone lesions were positive. Five patientC were with negative results. Sensitivity was 84,37% (27/32), specificity – 100% (4/4) and accuracy – 86,11% (31/36). Conclusion: In conclusion SPECT-CT imaging with 99mTc-PSMA could be applied in patients with prostate cancer for the diagnosis of recurrent disease in order to determine personalized treatment for each individual patient. Specific uptake of this tracer, depicted by SPECT-CT images has clinical importance of identifying and assessment PSMA expression before consideration of Radio Ligand Therapy (RLT) with 177Lu-PSMA. SPECT-CT imaging with 99mTc-PSMA is promising and reliable nuclear medicine approach to monitor therapeutic effect after treatment – to detect progressive/active lesions or to report full/ partial response.


   Thyroid Top


Sternal Bone Metastases from Differentiated Thyroid Carcinoma: A Single Institutional Experience

Zeenat Jabin1, Jasmin Ferdous1, Farhana Haque1, Mohammed Abdus Sattar2, Zakir Ullah Rasha3, Kazi Saiful Islam3, Fatima Begum1

1Thyroid Division, University of Notre Dame Australia on National Institute of Nuclear Medicine and Allied Sciences, 2Department of Otolaryngology and Head, Neck Surgery, Bangabandhu Sheikh Mujib Medical University, 3Department of Thoracic Surgery, National Institute of Diseases of the Chest and Hospital, Dhaka, Bangladesh

Background: The incidence of distant metastases from differentiated thyroid cancer (DTC) is not too high. Sternum, manubrium, clavicles are close to neck area and loco-regional hematogenous spread are often unstoppable. Our experience with few cases of DTC with metastases to the sternum are demonstrated here. Materials and Methods: DTC patients referred to National Institute of Nuclear Medicine & Allied Sciences (NINMAS) with complaints of hard to firm, bony swelling in upper chest area or known positive lesion(s) in sternal area pre or post radioiodine therapy (RAIT) were explored. Nine female patients of 55-60 (56 7.2) years with a median follow up time of 32 months were included. Results: Most frequent histological type of DTC among sternal metastases patients was Follicular thyroid carcinoma (FTC) 57%, rest 43% was Follicular Variant Papillary thyroid carcinoma (FVPTC). Bony metastases was present in 42.8% patients at the time of initial diagnosis. Serum Tg level was invariably high, ranging from 27 to >300 ng/dl (110 142). Patients received personalized and often alternative therapeutic approach. External beam radiotherapy (EBRT), surgical excision of sternum along with EBRT followed by adjuvant RAIT was successful in 72% patients with an asymptomatic follow up for 3 2 years. Palliative treatment was offered to 28%. One neglected patient developed hemiplegia with further enlargement of sternal lesion. Sternectomy of one patient with Proline mesh covering showed very good response. Conclusion: Management of DTC with sternal metastases seems extremely challenging. Multidisciplinary team approach is the key to achieve satisfactory prognosis in a tertiary hospital.


   Dosimetry Top



   Prrt Top


The Benefit of Early versus Delayed Dual Point Imaging in Neuroendocrine Tumors of the Abdomen Using 68Ga-Dotanoc Positron Emission Tomography/Computed Tomography

Trisha Govender, Masha Mahara

Nuclear Medicine Imaging and Therapy Centres of Excellence, Umhlanga, South Africa

Background: Neuroendocrine tumors (NETs) constitute a heterogeneous group of tumors that frequently express cell membrane-specific peptide receptors, such as somatostatin receptors (SSTRs), and of which gastroenteropancreatic (GEP), carcinoid, and pancreatic islet cell tumors exhibit the highest expression of SSTRs. Aims and Objectives: To assess the benefit of dual point imaging in neuroendocrine tumour (NET) of the abdomen using 68GalliumDotanoc PET/CT. Methods: 30 patients with confirmed NET of the abdomen were retrospectively assessed. The mean age was 59 with 15 males, 15 females. Histological profile (Duodenal-4, Gastric-5, Pancreas-2, Colon-1, Stomach-2, Small Bowel-5, Ovarian-1, Cervix-1, Appendix-1, Midgut-2, Liver-1, Paraganglioma-2, Lung-2, Mediastinal-1. Mean Chromogranin A level of 271.2 All had 68Gallium Dotanoc imaging. The appropriate 68Gallium synthesis was done, using an onsite 68Gallium generator synthesis unit (Trasis all in one system) with Ga68 generator supplied by Ithemba labs. The dose of 68Gallium-Dotanoc peptides used ranged between 3-5mCi. Images were acquired using a GE PET Discovery IQ, 5 ring PET/CT scanner. Early image acquisition time averaged 40 minutes post-injection and delayed images were acquired between 70 to 90 minutes post-injection. The outcome was determined by the calculation of the SUVmax on early vs delayed imaging as well as visually for new lesions which were noticed on the delayed images. SUV (g/ml with referenced to lean body mass) was calculated using Q-Clear Technology. Results: In 30 cases (12) 40 % of patients had abnormalities detected on imaging. Of the 12 patients, early imaging showed 33% areas of suspicious activity, 100% of lesions were detected on delayed imaging. On the delayed imaging: 13.33% were new lesions, 3.33% were residual tumor. The delayed imaging further confirmed 43.33% suspicious areas as a physiological/ inflammatory processes. Conclusion: In our small study, we have shown that there is a benefit for performing early and delayed imaging on NET of the abdomen. The benefit is shown with new lesions being seen and to assist in distinguishing inflammation from tumour tissue.


   Other Top



   Theragnostics Top


The Effect on In situ Inhibition of Nep and/or Ace on Tumor Targeting of A Technetium-99m Labeled Biodegradable Neurotensin (7-13) Based Radiotracer

Panagiotis Kanellopoulos1, Berthold A Nock1, Eric P Krenning2, Theodosia Maina1

1Molecular Radiopharmacy, INRASTES, NCSR “Demokritos”, Athens, Greece, 2Cyclotron Rotterdam BV, Erasmus MC, 3015 CE Rotterdam, The Netherlands

Background: Neurotensin subtype 1 receptor (NTS1R) is overexpressed in various malignancies, such as lung, colon, breast and pancreatic cancer. In this work, we investigated the capability of technetium-99m labeled DT1 ([N4-Gly7]NT (7-13)) to target different malignancies in association with its stability in the blood stream. [99mTc]Tc-DT1, like neurotensin, is fast degraded by NEP and ACE. Accordingly, the use of NEP (e.g. phosphoramidon (PA)/Entresto) and/or ACE (e.g. lisinopril (Lis)) inhibitors can increase its stability and tumor targeting capabilities. Methods: In this study, NTS1R-positive colon adenocarcinoma WiDr and pancreatic adenocarcinoma AsPC-1 cell-lines were used. The cell-association was assessed at 37oC after 1 h incubation. The stability of the tracer was examined, 5 min post injection (pi) in healthy mice. Biodistribution was performed 4 h pi in male SCID mice bearing subcutaneous WiDr/AsPC-1 xenografts. The radiopeptide was administered intravenously in animals treated or not with Lis and/or PA/Entresto. Results: [99mTc]Tc-DT1 displayed high cell uptake both in WiDr (10.1±2.3%) and AsPC-1 (15.2±2.6%) cells, with the bulk of the radioactivity found internalized. In peripheral mouse blood the analog was degraded (1.8±0.8% intact), but applying the combination of Lis + PA/Entresto it remained intact up to 72.3±3.2%. A drastic increase in tumor targeting was observed in mice treated with the combination of Lis + PA/Entresto (9.60±3.62/7.05±0.8%IA/g for WiDr/AsPC-1 tumors) vs. untreated controls (≈1%IA/g). Conclusion: As previously suggested, the performance of biodegradable peptidic radiotracers, such as [99mTc]Tc-DT1, can be greatly improved with the use of key-peptidase inhibitors.


   Dosimetry Top


The Possibility for The Dosimetry of 177Lu-PSMA Therapy in Prostrate Patients Using Less Imaging Acquisition Time Points

Feng Wang, Zhi Yang

Nuclear Medicine Unit, Faculty of Medicine, University of Peradeniya, Peking University Cancer Hospital, Beijing, China

Objective: This research is to assess the possibility for dosimetry of 177Lu-PSMA therapy in prostrate patients using less acquisition time points. Methods: The first treatment cycles of patients who had received several cycles of 177Lu-PSMA therapy were chose for study. Renal and tumor absorbed dose were normally calculated as golden standard data using SPECT imaging at 0.5, 3, 20, 44 and 68 h post injection, and two alternative protocols to estimate the residence time of kidneys and tumors using less time points were explored. Protocol 1: The residence time of kidneys and tumors derived from the formulaτ= (At/A0)*2*t/ln2, where At was the activity at the t time (0.5, 3, 20, 44 and 68 h). Protocol 2: The residence times of kidney and tumors were calculated from the 6 different groups of two times points (3,20), (3,44), (3,68) (20,44) (20,68) (44,68), respectively. Results: Totally 43 cycles were analysed. For protocol 1, it got lest deviations (10.8 %) from the golden standard data using 68 h data in kidney dosimetry estimation, while got the 10.94 % deviation in tumor dosimetry estimation using 68 h data. For protocol 2, the (20,68) group data got the lest variation in kidney and tumor absorbed dose estimated (7.34%, 6.68%) compared with golden standard data. Conclusion: It is possible to determine the absorbed dose of kidney and tumor in the treatment of 177Lu-PSMA patients using less times points acquisition, to allow routine personalized dosimetry when it is impractical to make multiple time point data acquisition.


   Dosimetry Top



   Prostate Top



   Theragnostics Top


Treatment Response and Safety of 177Lu-Prostate-Specific Membrane Antigen-617 Radiolig and Therapy in Metastatic Castration Resistant Prostate Cancer: Uruguayan Experience

Gerardo dos Santos1, Juan Carlos Hermida2, Enzo Silvera2, Mónica Rodriguez3, Mariella Terán4, Wilson Golomar5, Fátima Coppe2, Henia Balter3, Eugenia de Marco2, Omar Alonso3

1Department of Nuclear Medicine, CUDIM, 3CUDIM, Montevideo, 4Facultad de Química, 5Instituto Nacional del Cáncer, Uruguay

Background: The aim of this study was to evaluate treatment response and safety of radioligand therapy (RLT) with 177Lu-PSMA-617 in metastatic castration-resistant prostate cancer patients (mCRPC). Methods: Between October/2017 and October/2020 seventeen patients (mean age 67.3 years, range 50-79 years; median PSA level 100 ng/ml, range 6-1000 ng/ml) with mCRPC underwent 68Ga-PSMA-11 PET/CT and 177Lu-PSMA therapy. We evaluated clinical response (by pain relief and use of analgesics), therapy response (by PSA and PSMA-PET-Progression-criteria), adverse events (CTCAE version 4.03) and dosimetry. Results: All patients received 1 to 5 doses of 177Lu-PSMA-617 (mean activity 7.1 GBq/cycle) every 6-8 weeks (1 cycle n=1, 2 cycles n=2, 3 cycles n=12, 4 cycles n=1 and 5 cycles n=1). Eleven patients (70.6%) completed three cycles of therapy. PSMA-avid metastatic lesions were seen in the following sites: bone (all patients), lymph nodes (n=11), liver (n=2), lung (n=2) and adrenal glands (n=1). Twelve patients (70,6%) showed pain relief and reduction in the use of analgesics. Concerning PSA response five patients showed biochemical response, 3 patients stable disease and 7 patients progressive disease. 7/15 patients (46.6%) showed any PSA decline. We documented xerostomia (n=2), nausea (n=3), fatigue (n=5), thrombocytopenia (n=2) and pain relief (n=8). There was no hepatotoxicity and nephrotoxicity documented. The safety of 177Lu-PSMA-617 for non target tissues was confirmed showing mean absorbed doses (Gy) below the recommended ones in critical organs. 68Ga-PSMA-11 PET/CT images showed disease progression (n=9) and partial remission (n=5). During the observation period seven patients (41%) died. Conclusion: RLT is a safe and well tolerated therapeutic option for patients with mCRPC.


   Thyroid Top


Unusual Sites of Metastases from Differentiated Thyroid Carcinoma: A Case Series

Jasmin Ferdous1, Zeenat Jabin, Papia Akhter2, Urnas Islam1, Rahima Perveen1, Fatima Begum1

1Department of Nuclear Medicine, Thyroid Division, Bangladesh Atomic Energy Commission, Savar, 2Department of Nuclear Medicine, Thyroid Division, NINMAS, Dhaka, Bangladesh

Background: During long term follow up period 6-20% patients with differentiated Thyroid carcinoma (DTC) develop distance metastases. Unusual metastasis from DTC is very rare (<1%). Objective: The objective of the study is to report three cases of patients with DTC with unusual distant metastases. METHODS: Metastatic sites from DTC are usually identified by clinical evaluation, performing whole body scans (WBS) with stimulated serum thyroglobulin (Tg) level, Ultrasound, CT scan and histopathology. Results: Among the reported cases, two were female and one was male and the mean age was 65 years. Histopathology report (HPR) of these reported cases were follicular variant papillary carcinoma, papillary carcinoma and follicular carcinoma having metastases in right lobe of liver, roof of the nasal cavity including right ethmoidal sinus and left side of the upper gum respectively. Patient with liver metastases was evaluated at time of diagnosis by ultrasound imaging. The median time interval between the first diagnosis and metastases of the other two cases was 05 years. Metastasis in upper gum was clinically visible lesion. CT scan revealed metastases in the roof of nasal cavity. In WBS findings of these cases only liver metastasis showed iodine avidity. All metastatic sites were confirmed by histopathology. Gum metastasis was excised and other two cases refused to do operation. Tg levels in all cases were >300 ng/ml with absence Tg antibody. Conclusion: Individualized and patient specific management approach in unusual site metastases from DTC seems to be beneficial with the supports of multidisciplinary team.


   Thyroid Top


Validation of a Neck-Thyroid Phantom with Small Sizes of Thyroid Remnants Using I-131 and I-123

Anastasia Hadjiconstanti1, Konstantinos Michael2,3, Demetris Kaolis4, Theodoros Leontiou5, Antonios Lontos1, George Demosthenous6, Savvas Frangos7, Yiannis Parpottas8

1Frederick Research Centre, Departments of 2Medical Physics and 3Mechanical Engineering, Bank of Cyprus Oncology Center, Frederick University, 4Department of Medical Physics, Nicosia General Hospital, 5Department of Mechanical Engineering, Frederick Research Centre, Frederick University, 6Department of Mechanical Engineering, Frederick University, 7Department of Nuclear Medicine Bank of Cyprus Oncology Centre, 8Frederick Research Centre, Frederick University, Nicosia, Cyprus

Background: Anthropomorphic phantoms are widely used in nuclear medicine for quality assurance and optimization of imaging techniques without exposing patients to radiation. They can be used in postsurgical SPECT/CT thyroid imaging to provide information about the presence and sizes of remnants and then to accurately determine the therapeutic doses for ablation. This study aims to validate a custom-made neck-thyroid phantom with thyroid remnants for SPECT/CT imaging. Materials and Methods: For the validation, the custom-made and a commercial phantom were used. The custom-made phantom consists of a hollow neck which encloses a trachea, an oesophagus, a cervical spine, and a removable section with two hollow cavities of 1.5 and 3 mL to simulate thyroid remnants. The RS542 commercial consists of a solid neck and a removable thyroid gland which was modified to enclose same sizes of remnants, at the same clinically relevance position, as in the custom-made phantom. SPECT/CT acquisitions were performed using various activities of I131 and I-123 in both phantoms. The SPECT sensitivity (counts/(sec×activity)) for each remnant were measured. Results: The counts in each remnant showed a linear correlation with activity in both phantoms. The measured sensitivity was comparable among the two phantoms in the whole range of activities. Conclusions: This custom-made phantom with small sizes of thyroid remnants, that can also simulate background activities, can be used to evaluate postsurgical thyroid SPECT/CT imaging. Acknowledgments: This study was cofunded by the European Regional Development Fund and the Republic of Cyprus through the Research and Innovation Foundation (Project: EXCELLENCE/1216/0088).


   Theragnostics Top


Value of 18F-FDG PET/CT in Patients with Gastroenteropancreatic Neuroendocrine Tumors Treated with Second Peptide Receptor Radionuclide Therapy Cycle

Margarida Rodrigues, Kevin Winkler, Anna Svirydenka

Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria

Aim/Introduction: 18F-FDG PET/CT has been used increasingly for evaluation of neuroendocrine tumors (NET). Peptide receptor radionuclide therapy (PRRT) has been recognized as one of the most promising therapies against NET. We evaluated the value of 18FFDG PET/CT in gastroenteropancreatic (GEP) NET patients treated with second 177Lu-DOTATATE PRRT cycle. Furthermore we investigated whether changes in 18F-FDG-uptake correlated with disease course. Materials and Methods: 40 patients with progressive GEP NET who underwent 2 PRRT cycles and combined 68Ga-DOTA-TOC and 18F-FDG PET/CT investigations (before PRRT, 3 months after completion of first PRRT cycle and every 6-9 months thereafter) were retrospectively evaluated. Results: At baseline, 33 patients (82.5%) were FDG-negative and 7 patients (17.5%) FDG-positive. After second PRRT cycle, 26 patients (65.0%) were FDG-negative and 14 (35.0%) FDG-positive. 2 patients (5.0%) were in partial remission, 21 (52.5%) in stable disease and 17 (42.5%) in progressive disease. Median time to progression was 19 months (11-47 months). Median overall survival (OS) was 122 months (30 days-123 months). OS was significantly higher (p=0.033) in 18F-FDG-negative than in 18F-FDG-positive patients (122.10 versus 48.00 months, respectively). Patients with 18F-FDG-negative after second PRRT cycle were still alive with partial remission or stable disease at end of study while 18F-FDG-positive patients (including 4/7 patients who changed from 18F-FDG-negative into 18F-FDG-positive) deceased under stable or progressive disease. Conclusions: 18F-FDG PET-negative patients after 2 PRRT cycle had longer OS and progression free survival than 18F-FDG PET-positive patients. 18F-FDG PET/CT contributes to management and evaluation of prognosis of GEP NET patients.


   COVID 19 Top


Ventilation Perfusion Lung Scan in Pregnant Patient During Covid-19

Kerry Jewell, Sze Ting Lee

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

The COVID-19 pandemic has affected many aspects of nuclear medicine, including reduction in referrals for ventilation perfusion (V/Q) lung scans.[1] COVID-19 is associated with a hypercoagulable state, commonly with increased D-dimer and fibrinogen.[2] Pregnancy is also associated with a prothrombotic state resulting in pulmonary embolism which is estimated to affect around 1 in 1600 pregnancies.[3] We report a case of a 31 year old female of 24 weeks gestation who presented with dyspnoea, dry cough and fatigue, on a background of a COVID-positive swab seven days prior due to a positive household contact. Given her worsening symptoms and pregnant status, a SPECT VQ scan was arranged to exclude pulmonary embolism (PE) as a contributor to her symptoms. This demonstrated multiple bilateral perfusion mismatches consistent with pulmonary embolism, and a concurrent low dose CT demonstrated the presence of underlying COVID lung changes in areas which did not demonstrate perfusion mismatches, consistent with the presence of dual pathology. She was treated with anti-coagulation for her pulmonary embolism and supportive care for COVID. She was discharged two days later and long term anticoagulation was continued until 6 weeks post-partum. We conclude that it is safe to perform ventilation perfusion lung scans in COVID patients as clinically indicated, but the appropriate use of personal protective equipment (PPE) needs to be employed to minimise the risk of transmission to nuclear medicine personnel.


   References Top


  1. Freudenberg LS, Paez D, Giammarile F, Cerci J, Modiselle M, Pascual TN, et al. Global impact of COVID-19 on nuclear medicine departments: An international survey in April 2020. J Nucl Med. 2020;61:1278-83.
  2. Panigada M, Bottino N, Tagliabue P, Grasselli G, Novembrino C, Chantarangkul V, et al. Hypercoagulability of COVID-19 patients in intensive care unit: A report of thromboelastography findings and other parameters of hemostasis. J Thromb Haemost 2020;18:1738-42.
  3. Marik PE, Plaete LA. Venous thromboembolic disease and pregnancy. N Engl J Med 2008;359:2025-33.



   Thyroid Top


Visual Evaluation of Two Scatter Correction Methods on I-131 and I-123 Single-Photon Emission Computed Tomography/Computed Tomography Images Using A Neck-Thyroid Phantom with Small Sizes of Thyroid Remnants

Anastasia Hadjiconstanti1, Savvas Frangos2, Konstantinos Michael3,4, Yiannis Parpottas5

1Frederick Research Centre, Departments of 3Medical Physics and 4Mechanical Engineering, Bank of Cyprus Oncology Center, Frederick University, 5Frederick Research Centre, Frederick University, Nicosia, Cyprus, 2Department of Nuclear Medicine, AHEPA Academic Hospital, Aristotle University, Thessaloniki, Greece

Background: Diagnostic postsurgical SPECT/CT imaging is important to provide information on the actual presence and sizes of thyroid remnants, before radioiodine therapy. In this study, two scatter correction methods, the dual energy window (DEW) and the triple energy window (TEW), were visually evaluated on I-131 and I-123 SPECT/CT images. Materials and Methods: Acquisitions were performed using a neck-thyroid phantom with two thyroid remnants of 1.5 and 3 mL. Activity could be injected in the remnants and the background area. Two experienced nuclear medicine physicians were visually evaluated the images. In the first part, scatter corrected I-131 and I-123 SPECT/CT images were evaluated (a) for various remnants' activities and (b) with and without different background activities. In the second part, the DEW and TEW images were evaluated for I-131 and I-123, separately. Results: The I-123 improved image quality compared to I-131 with and without background, as expected. Both scatter correction methods improved image quality on I-131 and I-123 images. However, the evaluation showed that this improvement is more profound when applying the TEW method. Conclusion: In this study, we evaluated the diagnostic postsurgical SPECT/CT imaging. The image quality of the I-123 images is superior than the I-131 ones, as well as the image quality of the TEW images than the DEW ones for both I-131 and I-123. Acknowledgments: This study was co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research and Innovation Foundation (Project: EXCELLENCE/1216/0088).


   Theragnostics Top


Voxel-Wise Prediction of Post-Therapy Dosimetry for 177lu-Prostate-Specific Membrane Antigen I and T Therapy

Song Xue1, Andrei Gafita2, Kuangyu Shi3

1Department of Nuclear Medicine, University of Bern, Bern, Switzerland, Departments of 2Nuclear Medicine and 3Informatics, Technical University of Munich, Munich, Germany

PSMA-directed radioligand therapy (RLT) has become one of the effective treatment options for metastatic castration-resistant prostate cancer (mCRPC). However, individual treatment planning is still not feasible. In this study, we propose the approach for voxel-wise prediction of post-therapy dosimetry via generative adversarial networks (GANs) from pre-therapy positron emission tomography (PET) images. 23 patients with mCRPC treated with 177Lu-PSMA I&T RLT and 11 patients treated with 177Lu-PSMA-617 were retrospectively included in this study. Only those cycles with pre-therapy PET imaging before the treatment and at least 3 post-therapeutic SPECT/CT dosimetry imaging were selected. Totally 48 treatment cycles from 177Lu-PSMA I&T and 11 cycles from 177Lu-PSMA-617 were considered for this proof-of-concept study. 3D RLT DoseGAN were developed with a 3D U-net generator and a convolutional neural network (CNN) based discriminator. The proposed 3D RLT Dose GANs achieved the voxel-wise normalized root mean squared error (NRMSE) of 3.8±0.7% (mean±std.) and PSNR of 28.5±1.6 on 177Lu-PSMA I&T. As for PSMA-617, it achieves 2.1±0.8% NRMSE and PSNR of 34.0±3.8 on 18F dataset, and 1.8±0.85% NRMSE and PSNR of 35.0±2.5 on 68Ga dataset. Furthermore, clinical assessment with coronal maximum intensity projection (MIP) and dose-volume histogram (DVH) also confirmed that our proposed model achieved similar performance on examples from these two datasets in terms of image quality. Our experimental results demonstrate the potential of artificial intelligence to estimate voxel-wise post-therapy dosimetry, it may provide a practical solution to improve the dosimetry-guided treatment planning for RLT.




 

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