Malignant melanoma: staging with whole-body positron emission tomography and 2-[F-18]-fluoro-2-deoxy-D-glucose.

PURPOSE: To evaluate whole-body positron emission tomography (PET) with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) in the detection of metastasis from melanoma.

MATERIALS AND

METHODS

Whole-body PET was performed in 33 patients with either known metastatic or newly diagnosed melanoma. Patients with suspected metastases also underwent computed tomography, magnetic resonance imaging, or both. Diagnoses were confirmed with histologic examination or with at least one imaging modality in addition to PET. Blinded interpretations of PET scans were performed.

RESULTS

Forty of 53 lesions evaluated proved to be melanoma metastases. Whole-body PET correctly depicted 37 sites of metastases. Three cutaneous metastases (< 3 mm) were missed. PET correctly excluded malignancy in 10 cases where suspicious lesions were found with conventional cross-sectional imaging modalities but later ruled out with fine-needle biopsy. In six patients, PET depicted new metastases. The sensitivity for the detection of malignant lesions was 92%; the specificity for reading the PET images without clinical information was 77% and with clinical information was 100%.

CONCLUSIONS

These results suggest that whole-body FDG PET is an effective imaging modality to screen for metastases from malignant melanoma.