Prognostic factors for survival in stage III non-small-cell lung cancer treated with definitive radiation therapy: Impact of tumor volume

Purpose: To investigate the impact of tumor volume on overall survival in patients with Stage III non-small-cell lung cancer (NSCLC) treated with definitive radiation therapy (RT). Methods and Materials: Between May 1997 and February 2003, 71 patients with Stage III NSCLC were treated with radiation therapy of 60 Gy or more. The total target dose was between 60 and 77 Gy (average, 66.3 Gy). Chemotherapy was used in 45 cases. The primary tumor and nodal volume were identified in pretreatment computed tomography scans. Univariate and multivariate analyses were used to evaluate the impact of tumor volume on survival after RT. Results: The overall 2-year survival rate was 23%, with a median survival time of 14 months. The median survival times were 10 months and 19 months with large primary tumor volume more than median volume and smaller primary tumor volume, respectively. At a univariate analysis, the total tumor volume (TTV) (p < 0.0003) and the primary tumor volume (p < 0.00008) were significant and the nodal volume was not. At multivariate analyses, both the TTV and the primary tumor volume were significant prognostic factors. Conclusion: The primary tumor volume as well as TTV is a significant prognostic factor on survival in patients with Stage III NSCLC treated with RT and should be recorded in clinical results when the survivals are compared among clinical studies