Clinical value of 6-[^sup 18^F]fluoro-3,4-dihydroxy-L-phenylalanine positron emission tomography/computed tomography ([^sup 18^F]FDOPA PET/CT) with contrast-enhancement and without carbidopa premediaction in patients with insulinoma

Objectives: Insulinoma is a very rare disease and since the operative enucleation of the tumor provides a permanent cure in the most of the cases, a high sensitivity for the imaging method is paramount to the successful treatment. The objective of this study was to determine the clinical value of [18F]FDOPA PET/CT with contrast enhancement and without carbidopa premedication in patients with insulinoma. Methods: In this retrospective study, 26 consecutive patients, who were referred to our PET/CT center for the detection of clinically suspected insulinoma, were included. All [18F]FDOPA PET/CT examinations were performed with contrast enhancement and without carbidopa premedication in a one-stop shop fashion. Results: In 10 of 26 patients (8 women, 2 men; mean age=53 years; age range=30-94 years) a detected lesion was confirmed histologically as insulinoma (gold standard). In none of the remaining16 patients, insulinoma could be detected through [18F]FDOPA PET/CT or other imaging techniques (i.e. MRI, EUS). [18F]FDOPA PET detected the tumor in four of ten patients with histologically verified insulinoma, while contrast enhanced CT detected the tumor in five of ten, respectively. Overall [18F]FDOPA PET/CT with contrast enhancement and without carbidopa premedication was able to detect the insulinoma in seven of ten patients (70%). Conclusion: Based on our data, [18F]FDOPA PET/CT with contrast enhancement and without carbidopa premedication as a "one-stop diagnostic modality" is a viable option for insulinoma detection.