OBJECTIVE: The aim of this retrospective multicenter study was to evaluate the clinical and prognostic impact of 18F-FDG-PET/CT in the restaging process of cutaneous melanoma (CM) after surgery in patients with suspected distant recurrent disease or suspected metastatic progression disease.
MATERIALS AND METHODS: 74 patients surgically treated for CM underwent 18F-FDG-PET/CT for suspicious of distant recurrent disease or suspected metastatic progression disease. The diagnostic accuracy of visually interpreted 18F-FDG-PET/CT was obtained by considering histology (n=21 patients), other diagnostic imaging modalities performed within 2 months from PET/CT (CT in 52/74 patients and Whole Body MRI in 18/74 patients) and clinical follow-up (n=74 patients) for at least 24 months containing al clinical and diagnostic information useful for PET performance assessment and outcome. Progression-free survival (PFS) and overall survival (OS) were assessed by using Kaplan-Meier method. The risk of progression (Hazard Ratio-HR) was computed by Cox regression analysis.
RESULTS: Suspicious of recurrent CM was confirmed in 24/27 patients with a positive 18F-FDG-PET/CT scan. Overall, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG-PET/CT were 82%, 93%, 88%, 89%, and 89%, with area under the curve being 0.87 (95%IC 0.78-0.97; p<0.05). 18F-FDG-PET/CT findings significantly influenced the therapeutic management in 18 patients (modifying therapy in 10 patients; guiding surgery in 8 patients). After 2 years of follow-up, PFS was significantly longer in patients with a negative vs. a positive 18F-FDG-PET/CT scan (90% vs 46%, p<0.05; Figure 1). Moreover, a negative study was associated with a significantly longer OS than a positive one (76% vs 39% after 2 years, p<0.05; Figure 2). In addition, a positive 18F-FDG-PET/CT scan was associated with an increased risk of disease progression (HR=8.2; p<0.05).
CONCLUSION: 18F-FDG-PET/CT showed a valuable diagnostic performance in patients with suspicious of recurrent CM. This imaging modality might have an important prognostic value in predicting the survival outcomes, assessing the risk of disease progression, and guiding treatment decision making.