Prognostic value of volume-based positron emission tomography/computed tomography in patients with nasopharyngeal carcinoma treated with concurrent chemoradiotherapy

Objectives. The aim of this study was to evaluate the prognostic value of volume-based metabolic parameters measured by 1₈ F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) in patients with nasopharyngeal carcinoma (NPC). Methods. Forty-four NPC patients who underwent ¹⁸F-FDG PET/CT for initial staging work-up before concurrent chemoradiotherapy (CCRT) were retrospectively evaluated. Maximum standardized uptake value (SUV), mean SUV, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumors were measured. The prognostic significance and predictive performance of these parameters were assessed by Cox proportional hazards regression analysis and time-dependent receiver operating characteristics (ROC) curve analysis. Results. Multivariate analysis showed that American Joint Committee on Cancer stage 7th edition (hazard ratio [HR], 1.525; 95% confidence interval [CI], 1.062 to 2.188; P=0.022), and TLG (HR, 7.799; 95% CI, 2.622 to 23.198; P≤ 0.001) were independent predictive factors associated with decreased disease-free survival (DFS). Time-dependent ROC curve analysis indicated that TLG was a better predictor of DFS than MTV (P=0.008). Conclusion. The TLG of the primary tumor was a significant independent metabolic prognostic factor of DFS in patients with NPC treated with CCRT.