Clinical use of positron emission tomography in the management of cutaneous melanoma

Cutaneous melanoma is the seventh most common newly diagnosed cancer among Americans. It frequently metastasizes and is difficult to treat. Accurate disease staging is important for optimizing therapy and selecting appropriate patients for experimental trials. Positron emission computed tomography (PET) using ¹⁸F-fluorodeoxyglucose (FDG) has been studied extensively since 1991 and shows great promise in the detection of metastatic cutaneous melanoma. Cumulative data from the last 13 years is reviewed in this article and suggest that FDG-PET is the modality of choice for evaluating patients who fit into one of four categories: 1) individuals with a high risk for distant metastases based on extent of locoregional disease, 2) patients with findings that are suspicious for distant metastases, 3) individuals with known distant tumor deposits who still stand to benefit from customized therapies if new lesions are discovered or treated lesions regress, and 4) patients at high risk for systemic relapse who are considering aggressive medical therapy. Despite the overall superiority of FDG-PET in the detection of melanoma metastases, limitations exist with respect to detection of small lung nodules and brain metastases, which are better evaluated by computed tomography and magnetic resonance imaging, respectively.