Value of positron emission tomography scan in stage III cutaneous melanoma: a systematic review and meta-analysis

The objective of this study was to review the collective experience and utility of FDG-PET scans (FDG-PET) in the detection of systemic metastases in patients with stage III melanoma.

A systematic search for relevant studies published between 1990 and 2012 was performed. We included English language studies that evaluated melanoma patients with stage III disease, with at least 10 patients per study, and collected statistical data to assess FDG-PET utility in the detection of distant metastases. The SIGN tool was used to evaluate methodological quality and a meta-analysis was performed using Stata statistical software to quantify the clinical utility of FDG-PET.

The systematic search yielded 9 studies eligible for inclusion in quantitative analyses with a total of 623 patients. The overall sensitivity of FDG-PET in detecting systemic metastases was 89.42% (95% CI: 65.07-97.46), and specificity was 88.78% (95% CI: 77.04-94.91). The pooled positive likelihood ratio was 7.97 (95% CI: 3.58-17.71) and the negative likelihood ratio was 0.12 (95% CI: 0.03-0.47). The area under the summary receiver operating curve (SROC) was 0.94 (95% CI: 0.92-0.96) and the diagnostic odds ratio (DOR) was 66.84 (95% CI: 10.66-418.89). A change in stage and/or management was noted in 22% (126/573) of patients when FDG-PET was utilized.

Our findings indicate that FDG-PET may be useful in detecting distant metastases in patients with stage III melanoma. For this highly selected group of patients, FDG-PET has a high sensitivity, specificity and performance, frequently leading to a change in treatment plan.