FDG volumetric parameters and survival outcomes after definitive chemoradiotherapy in patients with recurrent head and neck squamous cell carcinoma

OBJECTIVE. The purpose of this study was to establish the predictive value of ¹⁸F-FDG parameters for overall survival in biopsy-proven recurrent head and neck squamous cell cancer (HNSCC) patients after definitive chemoradiotherapy. MATERIALS AND METHODS. We conducted a retrospective study including 34 patients with HNSCC who had biopsy-proven recurrence between April 2004 and March 2012 and underwent FDG PET/CT at our institution at the time of recurrence. Maximum standardized uptake value (SUV_max), peak SUV (SUV_peak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured. The primary outcome measure was overall survival. ROC analysis, univariate and multivariate Cox regression models, and Kaplan-Meir survival curves were performed. RESULTS. In univariate analyses, human papillomavirus (HPV) status (p = 0.04), primary site recurrence of MTV (p = 0.03), metastasis of MTV (p = 0.02), metastasis of TLG (p = 0.02), total MTV (p = 0.002), and total TLG (p = 0.04) were significantly associated with overall survival outcome. Total MTV remained as significant independent prognostic factor when adjusted for all other covariates except for primary site recurrence SUV_max and SUV_peak and lymph node SUV_max and SUV_peak. There was a significant difference in time to survival between patients with total MTV above and below the 50th percentile (Mantel-Cox log-rank test, p = 0.05 and Gehan-Breslow-Wilcoxon test, p = 0.03) and the optimum threshold of 16.8 mL (Mantel-Cox log-rank test, p = 0.01 and Gehan-Breslow-Wilcoxon test, p = 0.01; hazard ratio [HR], 0.25). CONCLUSION. FDG PET/CT-based total MTV and clinical HPV status may be significant prognostic markers for overall survival of patients with recurrent HNSCC after definitive chemoradiotherapy.