Introduction: The aim of this study was to perform a systematic review of the literature to evaluate the accuracy of FDG-PET in staging and restaging of cutaneous melanoma.
Methods: Systematic methods were used to identify, select, and evaluate the methodologic quality of the studies as well as to summarize the overall findings of sensitivity and specificity. The search strategy consisted of identifying studies published between 2000 and 2006. Inclusion criteria were studies that evaluated the diagnostic performance of FDG-PET in staging/restaging of cutaneous melanoma. The results were compared and pooled with a meta-analysis published previously that included studies published until 1999. The meta-analysis included 95% confidence intervals (CI) of sensitivity, specificity, likelihood-ratio (LR), and diagnostic-odds-ratio (DOR).
Results: The quantitative meta-analysis included 24 studies that were analysed in two groups: eight studies were included only in the regional staging analysis (group I), 13 studies were included only in the detection of distant metastases analysis (group II), and three studies were included in both analyses. Compliance with the methodologic-quality criteria was acceptable. We analysed the results of data presented in patients, lesions, basins, lymph-nodes, areas, and scans. Regarding the performance of FDG-PET in the detection of metastases, the pooled studies presented homogeneity for the negative-LR (0.15; 95% CI, 0.10-0.22) when analyzing lesions. When analyzing scans, there was global homogeneity for specificity (0.86; 95% CI, 0.77-0.92), positive-LR (5.86; 95% CI, 3.64-9.43), and DOR (37.89; 95% CI, 15.80-90.86). The pooled studies presented heterogeneity for the other items analysed. Regarding the detection of regional metastases, when analyzing lymph-nodes there was global homogeneity for specificity (0.99; 95% CI, 0.97-0.99; P = 0.101). The meta-regression evidenced that the variable that most influenced the DOR of the different studies and that can explain the heterogeneity was the year of publication; this may be related to the evolution of PET technology and an improvement of sensitivity/specificity.
Conclusion: FDG-PET is not useful in the evaluation of regional metastases, as it does not detect microscopic disease. However, FDG-PET could be useful in the detection of distant metastases, and could suggest its utility in the management of patients with cutaneous melanoma.