The ⁶⁸ Ga-prostate-specific membrane antigen ( ⁶⁸ Ga-PSMA) has been recently developed to be used, as a ligand, in positron emission tomography/computed tomography (PET/CT) prostate cancer imaging, to detect prostate disease. The main objective of this review was to collect data and findings from other studies and articles to assess, theoretically, if ⁶⁸ GA-PSMA PET/CT is a more appropriate prostate cancer diagnostic technique in comparison with others available such as CT, ¹⁸ F-fluoro-2-deoxyglucose PET/CT, or ¹⁸ F-fluoromethylcholine ( ¹⁸ F-choline) PET/CT. For that purpose, PubMed, the online scientific articles' database, was consulted where the keywords "PSMA" and "PET" were used to find relevant articles. The clinicaltrials.gov, clinical trials' database, was also consulted where the keywords " ⁶⁸ Ga-PSMA" and "prostate" were used to search clinical trials. Based on the reviewed scientific literature, several studies were conducted to assess and compare the ⁶⁸ Ga-PSMA PET/CT detection rate in prostate cancer with other available techniques. One of those studies, conducted by Giesel et al., concluded, within study sample, that 75% of patients with lymph nodes detected by ⁶⁸ Ga-PSMA PET/CT would have not been identified using other conventional morphological criteria based techniques. In Eiber et al.'s study, ⁶⁸ Ga-PSMA PET detected prostatic disease findings in 67% of patients with prostate-specific antigen levels <1 ng/mL, when compared with choline-based PET that presented detection rates between 19% and 36%. In Bluemel et al.'s study, ⁶⁸ Ga-PSMA identified positive prostatic disease in 43.8% of the patients with negative findings in F-choline PET/CT. Findings from this review demonstrate that ⁶⁸ Ga-PSMA PET/C is more effective in detecting metastases, lymph nodes, and recurrent prostate cancer when compared to ¹⁸ F-choline-based PET/CT and CT. ⁶⁸ Ga-PSMA PET/CT presents also more imaging contrast and can be more cost-effective. ⁶⁸ Ga-PSMA has already been subjected to first-in-human trials, and it is now being tested in Phase II and III trials.

In this paper, we present an original radiocirculographic method for investigates of cerebral blood flow, which has proven to be very useful, simple, and efficient for studies of brain hemodynamics. Physical considerations on injected radioactive tracer in cardiovascular system, allowed us to state a relationship for the blood flux, F, valued as the amount of fluid-blood that traverses a vascular segment in unit time. All these theoretical facts, along with a host of remarkable clinical results, are presented in a doctoral thesis entitled "The cerebral Hemodynamics in Essential Hypertension and Arteriosclerosis" of the eminent doctor Ioan Mures,an, who died in 1984, at only 50 years old. Using tracers marked with radioactive chrome ⁵¹ Cr and iodine ¹³¹ I, it was studied, for patients with various vascular diseases the blood circulation in other territories as an echo of cerebral blood flow. Outstanding results, relating to physiology, diagnosis, and therapy of some diseases, have been obtained. Through intensive collaborations, this method has been operationalized at the University Clinics of Cluj. Here, thousands of patients have been investigated, obtaining quantifiable information which highlighted the patient's condition by emergent and incident blood flows in the global circulatory process and related to other vascular segments.

The aim of this study was to determine the role of antithyroglobulin antibody (ATA) serum as a marker of successful I-131 ablation therapy in differentiated thyroid cancer (DTC) patients with low serum thyroglobulin (Tg). A retrospective study was conducted on 60 patients (10 males and 50 females). All patients underwent posttotal thyroidectomy and received 2.96 to 3 GBq I-131 ablation. Subjects were divided into two groups with succesful and unsuccessful I-131 ablation therapies. The data of age, gender, histopathologic type, tumor size, and metastasis were collected. Preablation serum Tg and ATA level (Tg1 and ATA1) 6-12 months after ablation (Tg2 and ATA2) were measured. The success of ablation therapy was evaluated by diagnostic whole body scan (DxWBS) 6-12 months after ablation. There were no significant differences in age, gender, type of histopathology, tumor size, and nodal metastasis between the two groups. ATA2 ≤30 kIU/L were found in 23 (62.2%) subjects with successful ablation therapy, and ATA2 >30 kIU/L in 16 (69.6%) subjects belonged to the unsuccessful group (P = 0.017). Changes between ATA1 and ATA2 levels did not differ significantly in both the groups (P = 0.062). Tg1 <10 mg/L was found in 26 (57.8%) subjects with successful therapy (P = 0.037). Multivariate analysis showed ATA2 and Tg1 as the independent factors for the success of ablation therapy (P = 0.007 and 0.015). Adjusted odds ratio of postablation ATA was 5.379 [95% confidence interval (CI) 1.590 to 18.203] and preablation Tg was 5.822 (95% CI 1.418 to 23.902). ATA levels at 6-12 months after ablation, by considering the preablation Tg levels, is a useful marker to determine successful ablation therapy in WDTC patients with low serum Tg. Changes in serum ATA levels, although not statistically significant, can provide additional information about the course of the disease.

The aim of this retrospective study is to evaluate the clinical impact and efficacy of fluorodeoxyglucose (FDG) positron emission tomography–computed tomography (PET/CT) on management decisions for patients suffering from clinically operable non–small-cell lung cancer (NSCLC). A retrospective review of 186 potentially operable NSCLC patients who underwent whole-body PET/CT examination in 2012 was performed. The patients were further analyzed via the electronic patient record (ePR) system for relevant findings. Overall change in management was assigned if a patient avoided unnecessary surgery due to disease upstaging or if a patient underwent further neoadjuvant treatment or investigation before the curative surgery. Of all 186 subjects, 65 (34.9%) became inoperable after PET/CT due to disease upstaging. The remaining 121 (65.1%) of patients remained operable after PET/CT examination. Nineteen out of 121 potentially operable patients did not receive curative surgery eventually, as 11 patients had poor clinical condition and 8 patients refused surgery. One hundred two out of 186 (54.8%) patients received curative operation following PET/CT. Among these 102 individuals, 97 patients (95%) proceeded to surgery without further neoadjuvant treatment or other investigatory procedures. Of the remaining 5 patients, 4 (3.9%) received neoadjuvant treatment and 1 (1.0%) had further investigation after PET/CT. Seventy of the 186 (37.6%) patients underwent changes in management plans after PET/CT study. Out of the 186 individuals, a subgroup of 141 (75.8%) patients underwent dedicated CT thorax before PET/CT examination. Forty-seven (33.3%) patients had avoided futile surgery due to disease upstaging. Fifty-one of the 141 (36.2%) patients underwent changes in management plans after PET/CT. PET/CT had great clinical impact, with significant reduction of futile curative surgery.

Prostate cancer is the most common noncutaneous cancer in males. Men of African origin are at a significantly higher risk as reflected in the higher incidence and mortality rates in this racial group. Metastases incidence increases parallel to serum levels of prostate-specific antigen (PSA), contributing significantly to morbidity and mortality. Staging of the disease involves bone scans, which are sensitive in detecting skeletal metastases. Suggestions that these scans may be omitted in some situations in patients with low prostate specific antigen levels have drawn attention to the matter. In this case-control study, using radiology and pathology records, a registry of prostate cancer patients recorded as being of dark-skinned ethnicity was obtained. Images were presented to image reviewers blinded to the PSA level, to determine the presence of skeletal metastases. The risk factor for the outcome of interest (skeletal metastases) was PSA level above 20 ng/mL. The reliability of image reporting was also assessed. Of the 122 patients, skeletal metastases were present in 50 (41%) while these were absent in 72 (59%). The prevalence of metastases among the high PSA group was 55.9% [95% confidence interval (CI) 44.1–67.7%] and among the normal/low PSA group was 22.2% (95% CI 11.1–33.3%). The odds ratio (OR) for skeletal metastases in the exposed (high PSA) group was 4.4 (95% CI, 2.01–9.78.) Intraobserver agreement on image interpretation was 88.5% with a Kappa statistic of 0.76. A relatively higher prevalence of skeletal metastasis is seen in regional dark-skinned African males with prostate cancer at both low and high prostate specific antigen levels. Bone scanning in this population should therefore, be considered even at PSA levels below 20 ng/mL.

The aim of this study was to investigate the prognostic significance of standardized uptake value (SUV) on 18 fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma (NPC). Thirty-four patients who have histologically proven NPC and underwent ¹⁸F-FDG PET/CT were included in this study. After ¹⁸F-FDG PET/CT, all the patients received radiation therapy and 32 of them received concomitant weekly chemotherapy. The maximum SUV (SUV_max) at the primary tumor and the SUV_maxof the highest neck nodes were determined. The SUV_max-T ranged from 5.00 to 30.80 (mean: 15.37 ± 6.10) and there was no difference between SUV_max-T values for early and late stages (P = 0.99). The SUV_max-N ranged from 3.10 to 23.80 (mean: 13.23 ± 5.76). There was no correlation between SUV_max-T and SUV_max-N (r = 0.111, P = 0.532). There was no difference between the SUV_max-T and the positivity of neck lymph nodes (P = 0.169). The ability of SUV_maks-N to predict stage was obtained by a receiver operating characteristic (ROC) analysis. The area under the curve is 0.856 and the best cut-off value is 7.88. There was a good correlation between SUV_max-N and stage. While the mean SUV_max-T for the alive patients was slightly lower than that for the dead (14.65 ± 5.58 vs. 20.30 ± 7.92, P = 0.061), the difference between the groups was not statistically significant. Furthermore, there was no statistically significant difference for SUV_max-N between these two groups (P: 0.494). Cox-regression analysis showed that an increase in SUV_max-T and SUV_max-N was associated with death risk (relative risk [RR]: 1.13, P = 0.078 and RR: 1.052, P = 0.456, respectively). SUV_max-T and SUV_max-N were independent prognostic factors for survival in NPC patients. This will help the clinicians in choosing suitable candidates for more aggressive treatment modalities.

The purpose of the study is to find out the overall incidence of superscan among different type of cancers, causes of superscan and its relationship with other parameters such as age, sex, duration of disease, and serum alkaline phosphatase (ALP) levels. This was a retro-prospective study. Records of all previous bone scans and reported patients of superscan were re-evaluated retrospectively. Patients who were diagnosed as having superscan in the preceding 3 years with confirmed histopathological diagnosis were included in the retrospective group. In the prospective group, all the patients who were reported to have superscan appearance over the past 2 years of prospective period were included. Total of 6027 bone scans were examined in a 5-year period and out of which 80 cases were diagnosed as superscan. The overall incidence of superscan in different type of cancers was 1.3% (80/6027). Prostate cancer (46/80) was the most common cause of superscan appearance followed by breast cancer (10/80). Out of 6027 patients referred for bone scan, 307 patients had prostate cancer on histopathological examination. Out of 307 patients with prostate cancer, 46 had superscan appearance. Incidence of superscan in prostate cancer was 14.98% (46/307), and 71.73% (33/46) prostate cancer patients with superscan had Gleason score of 8 and above 8 with mean serum prostate-specific antigen level was 178.42 ng/ml in symptomatic patients and 122 ng/ml in asymptomatic patients. Out of all patients with superscan, 71 patients (88.7%) had elevated serum ALP levels. Overall incidence of superscan in our study was 1.3% in different type of cancer patients, and the most common cause of superscan appearance was prostate cancer. Incidence of superscan appearance in prostatic cancer patients was 14.98%.

^99mTc-tetrofosmin (^99mTc-TF) is a single-photon emission computed tomography tracer that has been used for brain tumor imaging. The aim of the study was to assess if ^99mTc-TF uptake by glioblastoma cells correlates with their response to temozolomide (TMZ). We investigated the correlation of TMZ antitumor effect with the ^99mTc-TF uptake in two glioblastoma cell lines. The U251MG cell line is sensitive to TMZ, whereas T98G is resistant. Viability and proliferation of the cells were examined by trypan blue exclusion assay and xCELLigence system. Cell cycle was analyzed with flow cytometry. The radioactivity in the cellular lysate was measured with a gamma scintillation counter. TMZ induced G₂/M cell cycle arrest in U251MG cells, whereas there was no effect on cell cycle in T98G cells. Lower ^99mTc-TF uptake was observed in U251MG cells that were exposed to TMZ compared to control (P = 0.0159). No significant difference in respect to ^99mTc-TF uptake was found in T98G cells when exposed to TMZ compared to control (P = 0.8). With ^99mTc-TF, it was possible to distinguish between TMZ-sensitive and resistant glioblastoma cells within 6 h of treatment initiation. Thus, ^99mTc-TF uptake may consist a novel approach to assess an early response of glioblastoma to chemotherapy and deserves further investigation.

The goal of this study was to identify associations between positron emission tomography/computed tomography (PET/CT) maximum standardized uptake value (SUVmax) in patients presenting with head and neck squamous cell carcinoma (SCC) with tumor site, size, histologic differentiation, smoking, and diabetes. Charts of patients with oropharyngeal and laryngeal SCC who underwent ¹⁸F-fluorodeoxyglucose PET/CT scans were reviewed between May 2007 and August 2013. Statistical analyses included modeling log-transformed SUVmax values by tumor site, size, histologic differentiation, smoking status, and diabetes using unadjusted linear regressions. Differences were considered statistically significant for P< 0.05. A total of 111 patients (54 with oropharynx and 57 with larynx cancers) were included, 83 men and 28 women with an average age of 57.5 years old. There was a significantly higher pack-year smoking history (P = 0.005) in the larynx cancer group. While tumor T-stage was found to be significantly different (P < 0.0001), there was no difference in tumor size between the two groups: 3.16 cm and 3.58 cm in the oropharynx and larynx, respectively (P = 0.55). In the oropharynx cohort, SUVmax was associated with both tumor size (P = 0.0001) and stage (P < 0.0002). Interestingly, SUVmax differed by tumor differentiation in the larynx (P = 0.04) but not the oropharynx (P = 0.71). Finally, there was no significant difference in SUVmax relative to diabetes and smoking status. PET/CT SUVmax correlated with both tumor size and stage in oropharyngeal cancer patients, and it correlated only with tumor differentiation but not the size or stage in the larynx. There were no significant differences in SUVmax by diabetes or smoking status.

Case report describing the finding of central pontine myelinolysis (CPM) using combined fluorine-18 ( ¹⁸ F)-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). The patient was a known alcoholic who, during admission was under treatment for hyponatremia, showed a significant decline in both motor and cognitive function. Combined ¹⁸ F-FDG PET/CT showed localized FDG uptake in the pons, consistent with the finding of CPM observed on magnetic resonance imaging (MRI). CPM is a demyelinating lesion of the pons, resulting in several neurological symptoms. The exact cause of CPM is not clear, but a strong relations between loss of myelin and osmotic stress exists, especially during rapid correction of hyponatremia. The osmotic stress is thought to induce disruption of the blood-brain barrier, allowing access for inflammatory mediators in extravascular brain tissue, which most likely attracts glial cells of the brain, attracts macrophages and activates astocytes. We suggest that metabolism in these activated cells could be responsible for the localized FDG uptake during active CPM.

A case of a 7-month-old white female who was referred for 18F-fluorodeoxyglucose (FDG) Positron emission tomography/computed tomography (PET/CT) initial evaluation of a lytic skull lesion with presumed diagnosis of Langerhans cell histiocytosis is described. Incidentally, she was found to have hypermetabolic nodules in the soft tissues of her anterior thighs.

Three cases of metabolic bone disease in the setting of metastatic neuroendocrine tumor (NET) are illustrated with associated etiopathologies.  One of these cases harbored mixed lesions in the form of vertebral metastasis (biopsy proven) while the other skeletal lesions were caused due to metabolic bone disease related to multiple parathyroid adenomas. While the metastatic lesion was positive on 68Ga-DOTATATE positron emission tomography-computed tomography (PET-CT), the lesions of metabolic bone disease were negative and the 18F-fluoride PET-CT demonstrated the features of metabolic bone scan. Similar picture of metabolic bone disease [18-sodium fluoride (18NaF)/68Ga-DOTATATE mismatch] was documented in the other two patients, while fluorodeoxyglucose (FDG)-PET-CT was variably positive, primarily showing tracer uptake in the metabolic skeletal lesions of the patient with hypersecretion of parathyroid hormone-related protein (PTHrP) by the underlying tumor. Discordance between 18NaF PET-CT and 68Ga-DOTATATE PET-CT serves as a good marker for identification of metabolic bone disease and diagnosing such a clinical entity. In a patient of NET with metabolic bone disease and hypercalcemia, thus, two causes need to be considered: (i) Coexisting parathyroid adenoma in multiple endocrine neoplasia type I (MEN-I) syndrome and (ii) humoral hypercalcemia of malignancy (HHM) related to hypersecretion of PTHrP by the tumor. The correct diagnosis of metabolic bone disease in metastatic NET can alter the management substantially. Interestingly, peptide receptor radionuclide therapy (PRRT) can emerge as a very promising treatment modality in patients of metabolic bone disease caused by HHM in the setting of NET.

Kikuchi-Fujimoto disease (KFD) is a benign but self-limiting disorder. However, KFD is often misdiagnosed as a malignant disease. Although 18F-fludeoxyglucose (FDG) uptake on dual-time-point imaging (DTPI) positron emission tomography (PET)/computed tomography (CT) is useful in distinguishing malignant from benign disease, the latter sometimes mimics malignancy on DTPI PET/CT, resulting in a misdiagnosis. Here, we describe the case of a 30-year-old woman who complained of cervical lymphadenopathy. PET showed increased FDG uptake in multiple lymph nodes, with a maximum standardized uptake value (SUVmax) of 19.0 in the early phase to 21.8 in the late phase. A biopsy was performed, and pathological examination revealed KFD. KFD with FDG uptake in lymph nodes on DTPI PET/CT is rare and difficult to be distinguished from a malignant disease.

Erdheim–Chester disease (ECD) is a rare, non-Langerhans histiocytic disorder. The most common manifestations consist of polyostotic sclerotic lesions with the majority of cases also demonstrating soft tissue involvement of the sinuses, retroperitoneum, large vessels, heart, lungs, and central nervous system. Nuclear medicine can play an important role in assessing the extent of the disease with bone scintigraphy and fluorodeoxyglucose (FDG)-positron emission tomography (PET). We present the case of a middle-aged female who initially presented with tooth pain. She subsequently underwent imaging including plain film, bone scan, computed tomography (CT), magnetic resonance imaging (MRI), and FDG-PET/CT, which showed characteristic bony involvement. Biopsy results confirmed the diagnosis of ECD.

Pulmonary hypertension significantly changes biventricular anatomy and physiology, frequently evolving to clinical deterioration and right ventricular failure. The case of a woman developing atrial arrhythmias complicating dipyridamole stress in concomitance with scintigraphic “D-shaped” left ventricle is briefly reported. Although rare, our finding may suggest that nonselective vasodilators should be used with caution in this clinical setting.

The occurrence of left bundle branch block (LBBB) in electrocardiogram during exercise testing is a relatively rare finding. The incidence of LBBB during exercise testing ranges from 0.5% to 1.1%. The mechanism of exercise-induced LBBB (EI-LBBB) is poorly understood, but ischemia is a proposed etiology. Stress myocardial perfusion imaging (MPI) can be useful in patients with EI-LBBB to rule out coronary artery disease. Adenosine vasodilator stress is the preferred mode of stress in patients with LBBB for performing stress-MPI. Here we present an interesting case of adenosine-induced LBBB during stress-MPI in a 67-year-old female patient with normal coronary angiography.

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography-computed tomography is a standard diagnostic imaging tool in many types of cancer. Its physiological in vivo distribution includes the brain, liver, heart, kidneys, and urinary tract at 1 h after tracer injection. Skeletal muscle is known to show variable amounts of ¹⁸F-FDG uptake because it has a relatively high-glucose metabolism. We report a case of a 20-year-old patient with gross ¹⁸F-FDG uptake involving multiple muscle groups and its likely correlation to potassium chloride infusion before ¹⁸F-FDG injection.