Prognostic value of midtreatment FDG‐PET in oropharyngeal cancer

Abstract

Abstract Background Prognostic metabolic imaging indices are needed for risk stratification for patients with locally advanced oropharyngeal cancer. Methods We retrospectively examined pretreatment and midtreatment fluorodeoxyglucose‐positron emission tomography (FDG‐PET) parameters in patients with locally advanced oropharyngeal cancer who were treated with definitive chemoradiation. Results A total of 74 patients were evaluated. Pretreatment metabolic tumor volume (MTV) using threshold of 50% standardized uptake value (SUV) maximum (MTV 50% ) was associated with progression‐free survival (PFS; p = .003; hazard ratio [HR] = 1.57 per 10 cc; 95% confidence interval [CI] = 1.17–2.11) and overall survival (OS; p = .01; HR = 1.36 per 10 cc; 95% CI = 1.07–1.74). Midtreatment MTV using a threshold of SUV 2.0 (MTV 2.0 ) was associated with PFS ( p < .001; HR = 1.24 per 10 cc; 95% CI = 1.10–1.39) and OS ( p = .009; HR = 1.21 per 10 cc; 95% CI = 1.05–1.39). Nodal total lesion glycolysis (TLG) velocity >5% decrease/week was associated with improved PFS ( p = .04; HR = 0.37; 95% CI = 0.15–0.95). Conclusion Metabolic response during chemoradiation is associated with survival in locally advanced oropharyngeal cancer and may aid with risk‐adapting treatment. © 2016 Wiley Periodicals, Inc. Head Neck 38: First–1478, 2016