Prognostic value of metabolic tumor volume measured by ¹⁸F- fluorodeoxyglucose positron emission tomography in patients with esophageal carcinoma

Purpose: The aim of this study was to evaluate the prognostic value of metabolic tumor volume (MTV) measured by ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) in patients with esophageal carcinoma. Methods: We retrospectively reviewed 151 patients with pathologically proven esophageal carcinoma (146 squamous cell carcinomas and 5 adenocarcinomas) who underwent pretreatment ¹⁸F-FDG PET. MTV and maximum standardized uptake value (SUVmax) for the primary tumors were measured by ¹⁸F-FDG PET. The prognostic significance of MTV, SUVmax, and other clinicopathological variables was assessed by Cox proportional hazards regression analysis. To further evaluate and compare the predictive performance of PET parameters, MTV and SUVmax, time-dependent receiver operating characteristic curve (ROC) analysis was used. Results: In the univariate analysis, age, American Joint Committee on Cancer (AJCC) stage, tumor-node-metastasis (TNM) factors, MTV, and SUVmax of primary tumor were significant predictors of survival. On multivariate analysis adjusted for age, sex, and treatment modality, independent predictive factors associated with decreased overall survival were T stage [hazard ratio (HR) 4.325, P = 0.006], M stage (HR 2.009, P = 0.007), and MTV (HR 1.013, P = 0.021). SUVmax was not a significant factor (HR 0.97, P = 0.061). On time-dependent ROC analysis, MTV showed good predictive performance for overall survival consistently better than SUVmax. Conclusion: MTV, a volumetric parameter of ¹⁸F-FDG PET, is an important independent prognostic factor for survival and a better predictor of survival than SUVmax for the primary tumor in patients with esophageal carcinoma.