Objective: The management of metastatic melanoma remains challenging with only modest response rates to chemotherapy but the need to identify the best re-staging techniques remains paramount. This study evaluates our early experience in the use of FDG PET-CT in the assessment of early response to chemotherapy in metastatic melanoma.
Methods: FDG PET-CT was performed at baseline and following two or three cycles of combination or single agent chemotherapy in seven patients. Response was assessed visually as complete, partial metabolic response or progressive disease.
Results: There was intense FDG uptake in all metastases at baseline. Following two to three cycles of chemotherapy, there was a complete metabolic response (CMR) in one patient, partial metabolic response (PMR) in two patients and progressive metabolic disease (PMD) in the remaining three patients. Survival was 679 days in the single patient with a CMR, median of 206 and 129 days in the patients with PMR and PMD respectively.
Conclusion: This pilot study demonstrates the potential use of FDG PET as a biomarker in early response assessment to chemotherapy in metastatic melanoma. PET-CT already plays in integral role in staging high risk melanoma patients and it may also have a promising role in assessing response to current and novel therapies. Further larger studies examining specific therapies and optimal timing are required.