Comparison of 18F-Fluoro-L-DOPA, 18F-Fluoro-Deoxyglucose, and 18F-Fluorodopamine PET and 123I-MIBG Scintigraphy in the Localization of Pheochromocytoma and Paraganglioma

Context: Besides 123I-metaiodobenzylguanidine (MIBG), positron emission tomography (PET) agents are available for the localization of paraganglioma (PGL), including 18F-3,4-dihydroxyphenylalanine (DOPA), 18F-fluoro-2-deoxy-d-glucose (18F-FDG), and 18F-fluorodopamine (18F-FDA). Objective: The objective of the study was to establish the optimal approach to the functional imaging of PGL and examine the link between genotype-specific tumor biology and imaging. Design: This was a prospective observational study. Intervention: There were no interventions. Patients: Fifty-two patients (28 males, 24 females, aged 46.8 \ub1 14.2 yr): 20 with nonmetastatic PGL (11 adrenal), 28 with metastatic PGL (13 adrenal), and four in whom PGL was ruled out; 22 PGLs were of the succinate dehydrogenase subunit B (SDHB) genotype. Main Outcome Measures: Sensitivity of 18F-DOPA, 18F-FDG, and 18F-FDA PET, 123I-MIBG scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI) for the localization of PGL were measured. Results: Sensitivities for localizing nonmetastatic PGL were 100% for CT and/or MRI, 81% for 18F-DOPA PET, 88% for 18F-FDG PET/CT, 78% for 18F-FDA PET/CT, and 78% for 123I-MIBG scintigraphy. For metastatic PGL, sensitivity in reference to CT/MRI was 45% for 18F-DOPA PET, 74% for 18F-FDG PET/CT, 76% for 18F-FDA PET/CT, and 57% for 123I-MIBG scintigraphy. In patients with SDHB metastatic PGL, 18F-FDA and 18F-FDG have a higher sensitivity (82 and 83%) than 123I-MIBG (57%) and 18F-DOPA (20%). Conclusions: 18F-FDA PET/CT is the preferred technique for the localization of the primary PGL and to rule out metastases. Second best, equal alternatives are 18F-DOPA PET and 123I-MIBG scintigraphy. For patients with known metastatic PGL, we recommend 18F-FDA PET in patients with an unknown genotype, 18F-FDG or 18F-FDA PET in SDHB mutation carriers, and 18F-DOPA or 18F-FDA PET in non-SDHB patients