The role of pretreatment FDG-PET in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

Purpose: Pretreatment with 2- [ 18F] fluorodeoxyglucose positron emission tomography ( 18F-FDG-PET) was evaluated as a predictor of local failure-free survival (LFFS), disease-free survival (DFS), and overall survival (OS) in patients with nonkeratinizing nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT) alone or concurrently with chemotherapy (CCRT). Patients and Methods: Seventy-five M0 NPC patients who received FDG-PET before treatment were analyzed. The primary tumor FDG uptake was measured as the maximum standardized uptake value (SUVmax). The LFFS, DFS, and OS were calculated by the Kaplan-Meier method, and the differences were evaluated on log-rank test. The prognostic significance was assessed by univariate and multivariate analyses. Results: Eighteen patients received IMRT alone and 57 received CCRT. The mean SUVmax was significantly higher in 12 patients with locoregional or distant failure than in those without failure (p <0.001). On multivariate analysis, the SUVmax was the only significant variable for 5-year LFFS (p = 0.017) and DFS (p = 0.000) but not for OS (p = 0.065). Conclusion: SUVmax is a potential independent prognostic predictor of clinical outcomes in patients with nasopharyngeal carcinoma treated with IMRT alone or with CCRT. A high 18F-FDG uptake (SUVmax >5) indicates poor outcome in patients with NPC.