6-[F-18]Fluoro-<scp>l</scp>-Dihydroxyphenylalanine Positron Emission Tomography Is Superior to Conventional Imaging with 123I-Metaiodobenzylguanidine Scintigraphy, Computer Tomography, and Magnetic Resonance Imaging in Localizing Tumors Causing Catecholamine Excess

Context: Catecholamine excess is rare, but symptoms may be life threatening.Objective: The objective of the study was to investigate the sensitivity of 6-[F-18]fluoro-L-dihydroxyphenylalanine positron emission tomography (F-18-DOPAPET), compared with I-123-metaiodobenzylguanidine (I-123-MIBG) scintigraphy and computer tomography (CT)/magnetic resonance imaging (MRI) for tumor localization in patients with catecholamine excess.Design and Setting: All consecutive patients with catecholamine excess visiting the University Medical Center Groningen, Groningen, The Netherlands, between March 2003 and January 2008 were eligible.Patients: Forty-eight patients were included. The final diagnosis was pheochromocytoma in 40, adrenal hyperplasia in two, paraganglioma in two, ganglioneuroma in one, and unknown in three.Main Outcome Measures: Sensitivities and discordancy between F-18-DOPA PET, I-123-MIBG, and CT or MRI were analyzed for individual patients and lesions. Metanephrines and 3-methoxytyramine in plasma and urine and uptake of F-18-DOPA with PET were measured to determine the whole-body metabolic burden and correlated with biochemical tumor activity. The gold standard was a composite reference standard.Results: F-18-DOPA PET showed lesions in 43 patients, I-123-MIBG in 31, and CT/MRI in 32. Patient-based sensitivity for F-18-DOPA PET, I-123-MIBG, and CT/MRI was 90, 65, and 67% (P Conclusion: To localize tumors causing catecholamine excess, F-18-DOPA PET is superior to I-123-MIBG scintigraphy and CT/MRI. (J Clin Endocrinol Metab 94: 3922-3930, 2009)