Impact of fluorodihydroxyphenylalanine-18F positron emission tomography on management of adult patients with documented or occult digestive endocrine tumors.

Abstract

Fluorodihydroxyphenylalanine-(18F) (FDOPA) positron emission tomography (PET) is a recent imaging modality used to localize endocrine tumors. This study was conducted to evaluate the impact of FDOPA-PET on the management of patients referred for carcinoid or noncarcinoid digestive tumors and the clinical relevance of the treatment decisions based on this examination. Between March 2002 and December 2006, 101 FDOPA-PET examinations were performed in 78 adult patients for follow-up of histologically documented carcinoid tumor of the ileum (23 patients) or noncarcinoid digestive tumor (26 patients) or to screen for occult digestive endocrine tumors (29 patients). More than one FDOPA-PET examination was performed in 12 patients. The impact of FDOPA PET was evaluated on a per-patient basis by means of a questionnaire completed by the referring physician, and the relevance of the treatment decision was assessed on the basis of follow-up data. The survey response rate was 91% (71 of 78). The overall impact rate of FDOPA-PET on patient management was 25% (18 of 71). The greatest impact was observed for carcinoid tumors (50%: 11 of 22) and was clinically relevant in every case, followed by occult endocrine tumors (16%: four of 25), and was clinically relevant in three of the four cases, and noncarcinoid tumors (13%: 3 of 22), clinically relevant in only one case. FDOPA-PET appears to be a major tool for the management of carcinoid tumors with excellent diagnostic performances and induced relevant changes in patient management. FDOPA-PET was less sensitive and less useful for the management of noncarcinoid tumors.