RecruitingEarly Phase 1Drug trial18F-MFBG PET/CT in the Evaluation of Neural Crest TumorThe aim of this study is to evaluate the diagnostic performance and tumor burden of 18F-metafluorobenzylguanidine (18F-MFBG) positron emission tomography (PET) in patients with neuroendocrine tumors mainly in pheochromocytoma and paraganglioma (PPGL) and neuroblastoma (NB).