Whole-body F-18-fluoro-2-deoxyglucose positron emission tomography/computed tomography imaging in the follow-up of metastatic uveal melanoma.

Metastasis has been reported in the follow-up of up to 50% of uveal melanoma patients. Established oncological diagnostic modalities in tumor follow-up so far have limited sensitivity and specificity. The diagnostic value of combined positron emission tomography (PET)/computed tomography (CT) scans in the follow-up of patients with metastatic uveal melanoma was assessed. Eleven patients with successfully treated and one patient with suspected uveal melanoma underwent combined PET/CT scan. The indication for PET/CT scan was heterogenous and ranged from suspected metastatic choroidal melanoma in conventional imaging (n=3) to exclusion of further organ involvement before local therapy of liver metastases (n=5) and restaging after local or systemic therapy of metastases (n=4). PET/CT scan showed vital metastases from uveal melanoma in all patients (n=12). Ten patients showed vital hepatic metastases (83%), five osseous (42%), four lymphatic (33%), two pulmonary (17%), one adrenal (8%) and one had muscular metastases (8%). Six patients showed multiple organ involvement (50%). In addition, PET/CT scan correctly identified a primary intraocular tumor and ruled out pulmonary metastatic involvement with suspicious intrapulmonary findings in a CT scan and chest X-ray in two patients. It could also confirm an equivocal intrahepatic finding in an MRI scan as a vital metastasis. PET/CT scan is a very sensitive and specific tool for the detection and localization of metastatic disease in patients with uveal melanoma, assessing both anatomical morphology and cell metabolism in one single examination. With novel therapeutic approaches in evolution, PET/CT scanning can be of great importance for therapy planning and monitoring.