Purpose of the Study: To study quality control parameters of routinely prepared positron emission tomography (PET) radiopharmaceuticals. Materials and Methods: Three PET radiopharmaceuticals fluorine-18 fluorodeoxyglucose (F-18 FDG), N-13 ammonia (N-13 NH ₃ ), and Ga-68 DOTATATE (n = 25 each), prepared by standardized protocols were used. The radionuclide purity, radiochemical purity, residual solvents, pH, endotoxins, and sterility of these radiopharmaceuticals were determined. Results: The physical half-life of radionuclide in radiopharmaceuticals, determined by both graphical and formula method, demonstrated purity of radionuclides used. pH of all PET radiopharmaceuticals used was in the range of 5-6.5. No microbial growth was observed in radiopharmaceutical preparations. The residual solvents, chemical impurity, and pyrogens were within the permissible limits. Conclusions: All three PET radiopharmaceuticals were safe for intravenous administration.

Aim: The aim of this study is to evaluate the role of ⁶⁸ Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) scan for the detection of bone metastases in pediatric neuroendocrine tumors (NETs) and to compare it with CT scan. Materials and Methods: A total of 30 patients (18 were males and 12 were females; age range: 1-18 years; mean age 7.6 years) with histologically confirmed NETs referred to our department were retrospectively analyzed. All patients underwent ⁶⁸ Ga-DOTATATE PET/CT scan at the time of diagnosis for primary staging. Contrast enhanced CT (CECT) performed at the time of PET scan acquisition was used for comparison with PET data. Imaging results were analyzed on a per-patient and on a per-lesion basis. Clinical follow-up of all patients and repeat PET/CT imaging ( n = 10) was taken as the reference standard. Results: Out of the 30 patients, 17 had no evidence of bone metastases on any imaging modality or on clinical follow-up while the rest of 13 patients showed evidence of bone metastases (nine showing positivity both on ⁶⁸ Ga-DOTATATE PET and CT scan while four showing positivity only on ⁶⁸ Ga-DOTATATE PET). Compared with CT scan, ⁶⁸ Ga-DOTATATE PET detected bone metastases at a significantly higher rate ( P = 0.0039). On a per lesion analysis, out of a total of 225 lesions detected by ⁶⁸ Ga-DOTATATE PET, only 84 lesions could be detected by CT scan. Conclusion: ⁶⁸ Ga-DOTATATE PET/CT scan is more useful than CECT scan for the early detection of bone metastases in pediatric NETs.

Purpose: The primary aim of study was to compare role of iodine-131 (I-131)-labeled metaiodobenzylguanidine ([ ¹³¹ I]MIBG) and gallium-68 (Ga-68)-labeled DOTA-l-Nal3-octreotide ([ ⁶⁸ Ga]DOTANOC) PET/computed tomography (CT) in patients with pheochromocytoma (PCC) and paraganglioma (PGL), subsequent follow-up to see management. The secondary aim was to see association of germline mutation in histopathologically proven patients. Procedures: We performed [ ⁶⁸ Ga]DOTANOC PET/CT and [ ¹³¹ I]MIBG in 106 patients (61 men; age: 38.5 ± 16.2 years) of known or suspected PCC/PGL. Following scans, 16 histopathologically proven patients were screened for germline mutations. Results: [ ¹³¹ I]MIBG detected 41 lesions in 34 patients and [ ⁶⁸ Ga]DOTANOC PET/CT detected more than 79 lesions in 55 patients. The mean duration of follow-up was 20.6 ± 16.5 months. Management following scans: surgery in 35 patients (positive histopathology in 34 patients, negative in 1 patient); lutecium-177 (Lu-177)-labeled DOTA-0-Tyr-3 octreotate ([ ¹⁷⁷ Lu]DOTATATE) therapy in 2 patients; chemotherapy in 1 patient; conservative therapy in 34 patients; no therapy in 17 patients; 2 patients have died and 3 were lost to follow-up. Among 12 previously operated, 2 patients showed metastatic disease and 1 showed residual disease. Out of 16 patients who underwent genotypic analysis (15 operated), 8 were positive for germline mutations. Mutations were seen in SDHB , RET , VHL , MDH2 and SDHA genes, including two germline mutations in two patients. Deletion was observed in one patient in SDHB gene and substitution in all other mutations. Four novel mutations in MDH2 (c.1005G>C, c.916G>A, c.580G>A) and SDHB (c.378_380delAAT) were observed (SRA accession: PRJNA551457). Conclusions: [ ⁶⁸ Ga]DOTANOC PET/CT should be considered as a first-line investigation in PCC/PGL especially at high risk of metastasis and screening of persons with familial syndrome.