Effectiveness of positron emission tomography for the detection of melanoma metastases

Objective The purpose of this study was to determine the sensitivity, specificity, and clinical utility of F-18 2-fluoro-2-deoxy-D-glucose (FDG) total-body positron emission tomography (PET) scanning for the detection of metastases in patients with malignant melanoma. Summary Background Data Recent preliminary reports suggest that PET using FDG may be more sensitive and specific for detection of metastatic melanoma than standard radiologic imaging studies using computed tomography (CT). PET technology is showing utility in the detection of metastatic tumors from multiple primary sites including breast, lung, lymphoma, and melanoma. However, little information is available concerning the general utility, sensitivity, and specificity of PET scanning of patients with metastatic melanoma. Methods One hundred three PET scans done on 76 nonrandomized patients having AJCC stage II to IV melanoma were prospec tively evaluated. Patients were derived from two groups. Group 1 (63 patients) had PET, CT (chest and abdomen), and magnetic resonance imaging (MRI; brain) scans as a part of staging requirements for immunotherapy protocols. Group 2 (13 nonprotocol patients) had PET, CT, and MRI scans as in group 1, but for clinical evaluation only. PET scans were done using 12 to 20 mCi of FDG given intravenously. Results of PET scans were compared to CT scans and biopsy or cytology results.