The relative prognostic utility of standardized uptake value, gross tumor volume, and metabolic tumor volume in oropharyngeal cancer patients treated with platinum based concurrent chemoradiation with a pre-treatment [18F] fluorodeoxyglucose positron emission tomography scan

ObjectivesThis study compared the relative prognostic utility of the Gross Tumor Volume (GTV), maximum Standardized Uptake Value (SUVmax), and Metabolic Tumor Volume (MTV) in a uniform cohort of oropharyngeal squamous cell carcinoma (OPSCC) patients treated with platinum-based concurrent chemoradiation therapy (CCRT).Methods and materialsOne-hundred OPSCC with a pretreatment [(18)F] fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) were treated with CCRT. Kaplan-Meier curves and Cox proportional hazard models were generated.ResultsWhen dichotomized by the median, a smaller MTV correlated with improved 5year locoregional control (LRC) (98.0% versus 87.0%, p=0.049), freedom from distant metastasis (FDM) (91.7% versus 65.0%, p=0.005), progression-free survival (PFS) (80.3% versus 56.7%, p=0.015), and overall survival (OS) (84.1% versus 57.8%, p=0.008), whereas a smaller GTV correlated with improved PFS (80.3% versus 57.4%, p=0.040) and OS (82.1% versus 60.1%, p=0.025). SUVmax failed to correlate with any outcome. On multivariate analysis, when adjusted for GTV, T-stage, and N-stage a smaller MTV remained independently correlated with improved FDM, PFS, and OS. GTV failed to reach significance in the multivariate model.ConclusionsA smaller MTV correlates with improved LRC, FDM, PFS, and OS in OPSCC patients undergoing platinum-based CCRT