Prognostic value of pretreatment 18F-FDG PET/CT in patients with primary malignant melanoma / 中华核医学与分子影像杂志

ABSTRACT

Objective:To assess the prognostic value of pretreatment 18F-FDG PET/CT metabolic parameters in patients with primary melanoma. Methods:A retrospective analysis comprised of 35 patients (21 males, 14 females, age 35-85 years; from January 2014 to August 2019; Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School) who were newly-diagnosed primary melanoma with preoperative 18F-FDG PET/CT was conducted. 18F-FDG PET/CT metabolic parameters including SUV max, SUV mean, peak of SUV (SUV peak) were obtained. Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of primary focus were measured automatically using the threshold of 40%SUV max. The optimal thresholds of PET parameters were obtained by using ROC curve analysis. The associations between melanoma-specific survival (MSS), progression-free survival (PFS) and PET/CT metabolic parameters were assessed using Kaplan-Meier method and Cox proportional hazards model. Results:The median follow-up was 15.4 months, and 20 patients showed disease progression and 7 died. The cut-off values for SUV max, SUV mean, SUV peak, MTV and TLG were 3.95, 2.45, 2.65, 3.60 cm 3 and 14.85 g, respectively (AUCs 0.742, 0.790, 0.728, 0.655, 0.693; P values 0.016, 0.004, 0.022, 0.121, 0.053). Kaplan-Meier method and log-rank test showed that SUV max, SUV mean, SUV peak, MTV and TLG were predictors of PFS ( χ2 values 4.06-8.35, all P<0.05). Multivariate analysis showed that MTV (hazard ratio ( HR)=3.09, 95% CI 1.08-8.86, P=0.036) and TLG ( HR=3.36, 95% CI 1.11-10.14, P=0.031) were significant predictors of PFS but not for MSS ( HR=5.14, P=0.080). Conclusions:SUV max, SUV mean and SUV peak of primary focus may help for predicting PFS of patients with primary melanoma. MTV and TLG of primary focus may be the best to predict PFS of primary melanoma.