Prognostic Value of Metabolic Parameters Measured By 18F-FDG PET/CT In Patients With Metastatic Cutaneous Malignant Melanoma

Abstract

Purpose: The purpose of this study was to investigate the prognostic relevance of metabolic parameters measured using 18F-FDG PET/CT in patients with metastatic cutaneous malignant melanoma (CMM).Materials and Methods: The prognostic impact of whole-body metabolic tumor volume (wMTV), whole-body tumor lesion glycolysis (wTLG), maximum standardized uptake value (SUVmax) and mean standardized uptake value (SUVmean) was evaluated in 42 metastatic CMM patients who underwent 18F-FDG PET/CT. The metabolic parameters were dichotomized by optimal cutoff values using time-dependent receiver operating characteristic (ROC) curves. In addition, univariate and multivariate analyses of the metabolic parameters were performed using the Kaplan-Meier method and Cox proportional hazards models.Results: The optimal cutoff values for disease-free survival (DFS) were 4.63 for SUVmax, 3.31 for SUVmean, 8.22 cm3 for wMTV, and 18.22 for wTLG. The optimal cutoff values for melanoma-specific survival (MSS) were 4.77 for SUVmax, 3.31 for SUVmean, 22.32 cm3 for wMTV, and 51.37 for wTLG. Thirty-two (72%) of the 42 patients experienced recurrence during the follow-up period, and 21 patients (50%) died from the disease. In univariate analysis, SUVmax greater than 4.63 (p= 0.025) and SUVmean greater than 3.31 (p= 0.011) affected DFS, while SUVmax greater than 4.77 (p= 0.039), wMTV greater than 22.32 (p= 0.023) and wMTV greater than 51.37 (p= 0.016) affected MSS. In multivariate analysis after adjustment for the effects of clinical parameters, SUVmax was the best predictive factor for DFS (p = 0.016), and SUVmax, wMTV and wTLG were the best predictive factors for MSS (p = 0.023, p = 0.018, and p = 0.007).Conclusions: SUVmax appears to be a strong independent prognostic factor for recurrence in metastatic CMM, and SUVmax, wMTV and wTLG were found to be the best predictive markers for melanoma-specific death.