Intraindividual comparison of 18F‐FDOPA and 68Ga‐DOTATOC PET/CT detection rate for metastatic assessment in patients with ileal neuroendocrine tumours

Introduction In patients with ileal neuroendocrine tumours (ileal NETs), head‐to‐head evaluation of diagnostic performances of 68Ga‐DOTA‐peptides and 18F‐fluorodihydroxyphenylalanine (18F‐FDOPA) positron emission tomography/computed tomography (PET/CT) has been performed in only few small patients’ cohorts. The aim of this retrospective study was to compare 68Ga‐DOTATOC and 18F‐FDOPA PET/CT for metastatic disease assessment in a homogeneous large series of patients with well‐differentiated ileal NETs. Methods All patients with ileal NETs who underwent both 18F‐FDOPA and 68Ga‐DOTATOC PET/CT within a 3‐month period and no therapeutic change between the two studies were retrospectively included. The detection rates of both modalities were calculated using per‐patient, per‐region and per‐lesion analyses. Results Forty one patients with ileal NETs were evaluated. 18F‐FDOPA and 68Ga‐DOTATOC showed similar detection rates according to per‐patient (97% for both) and per‐region analyses (94% for 18F‐FDOPA vs 88% for 68Ga‐DOTATOC, P = .35). For a total of 605 positive lesions, 458 (76%) were detected by both modalities, 122 (20%) exclusively by 18F‐FDOPA PET/CT, and 25 (4%) by 68Ga‐DOTATOC PET/CT only. In a per‐lesion analysis, 18F‐FDOPA PET/CT performed better than 68Ga‐DOTATOC PET/CT (overall detection rates of 96% vs 80%; P