Gross tumor volume is the prognostic factor for squamous cell esophageal cancer patients treated with definitive radiotherapy.

Abstract

To investigate whether gross tumor volume (GTV) defined on radiotherapy planning scans a prognostic factor for esophageal squamous cell carcinoma (ESCC) patients treated with definitive radiotherapy. From 2008 to 2011, 187 ESCC patients who were treated with definitive radio(chemo)therapy were analyzed retrospectively. Tumor volumes such as GTV, gross tumor volume of primary esophageal cancer (GTV-P), and gross tumor volume of metastases lymph nodes (GTV-N) were computed by Philips Healthcare radiation therapy planning system (Pinnacle 8.0). Kaplan-Meier cumulative probability and Cox proportional hazards regression models were used to assess the effect of the clinical factors along with tumor volume on progression-free survival (PFS) and overall survival (OS). In the univariate analysis, fraction dose, TNM stage, total radiation dose, GTV, GTV-P, and GTV-N were all significantly associated with both OS and PFS (P<0.05). While in multivariate analysis, GTV and fraction dose were significantly associated with both OS and PFS (adjusted P<0.05) with adjustment for age, sex, smoking status, chemotherapy, fraction dose, GTV, and radiation dose. GTV may serve as a good prognostic factor for ESCC patients treated with definitive radiotherapy. Larger prospective studies are needed to validate these findings.