Role of [68Ga]DOTANOC PET/computed tomography and [131I]MIBG scintigraphy in the management of patients with pheochromocytoma and paraganglioma: a prospective study.

Abstract

The primary aim of study was to compare role of iodine-131 (I-131)-labeled metaiodobenzylguanidine ([I]MIBG) and gallium-68 (Ga-68)-labeled DOTA-l-Nal3-octreotide ([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. We performed [Ga]DOTANOC PET/CT and [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. [I]MIBG detected 41 lesions in 34 patients and [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 ([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). [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.