18F-FDOPA PET/CT for neuroendocrine tumors in multiple endocrine neoplasia type 1.

OBJECTIVE: The aim of this study was to evaluate the efficacy of 6-18F-fluoro-L-3,4-dihydroxyphenylalanine (18F-FDOPA) positron emission tomography/computed tomography (PET/CT) in the identification of primary and metastatic NETs in patients with multiple endocrine neoplasia type 1 (MEN1). DESIGN: This prospective MEN1 cohort study evaluated 16 genetically confirmed patients with MEN1. Inpatient subjects were imaged using CT, magnetic resonance imaging (MRI), 68Ga-DOTATATE PET/CT, and 18F-FDOPA PET/CT. A composite reference test combining up to 3 years of historical imaging and a multidisciplinary evaluation was used against the index test. Lesion-, patient-, and site-based analyses were performed. SETTING: The NIH Clinical Center was the setting for this study. PATIENTS: Patients with germline MEN1 variants confirmed to have MEN1 were included in the study. RESULTS: A total of 134 lesions were identified after review of CT, MRI, and 68Ga-DOTATATE PET/CT. 18F-FDOPA PET/CT detected 17% (23/134, 95% CI: 8.2-27.1). Of the total study participants, 50% (8/16) of the patients had 18F-FDOPA PET/CT uptake in primary and metastatic sites with overlapping 68Ga-DOTATATE PET/CT uptake and localization on CT and MRI. Region-based analysis showed that 18F-FDOPA PET/CT had the highest avidity for lung (4/12, 33%) and pancreatic (8/38, 21%) NETs. CONCLUSION: 18F-FDOPA PET/CT has low efficacy overall in detecting MEN1-related NETs. CLINICAL TRIAL REGISTRATION: https://clinicalstudies.info.nih.gov/protocoldetails.aspx?id=000344-DK&&query=, identifier NCT04969926.