Purpose: To assess the effect of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) on the treatment of patients with cutaneous malignant melanoma.
Materials and methods: We retrospectively reviewed the medical records of 38 patients with newly diagnosed (n = 25) and recurrent (n = 13) cutaneous melanoma who were referred for evaluation with FDG PET imaging at our institution. We compared the PET findings with computed tomography (CT), which was available in 21 (55%) patients, and tabulated the changes in the diagnostic evaluation and therapeutic management that were prompted by PET during a follow-up period of 10 to 36 months.
Results: Compared with PET, the extent of disease was underestimated by CT in 5 (13%) patients. Planned surgical resection of metastases was canceled in two of these patients. In another patient, surveillance PET detected an unsuspected hypermetabolic abdominal mass that was noted on a subsequent CT to arise from the small bowel. The mass was found to be jejunal metastatic melanoma at the time of resection. Overall, PET influenced surgical management in 3 (8%) patients, but it did not affect the wait-and-watch strategy or decision to initiate immunotherapy in the others.
Conclusions: FDG PET contributes important information not provided by CT and has a substantial effect on the clinical management of patients with malignant melanoma.