Impact of tumor local factors on radiotherapy in non-small cell lung cancer

Objective To evaluate the impact of tumor local factors on radiotherapy in non-small cell lung cancer(NSCLC). Methods From Jan.2000 to Jun.2002, 75 stageⅠ～Ⅲb NSCLC patients who received definitive radiotherapy were analyzed retrospectively. Thirty-nine patients treated by conventional radiotherapy and 36 by three dimensional radiotherapy with 60-70?Gy/30-35F/6-7w. The tumor diameter and volume were measured on CT scans. The impact of related prognostic factors on survival was evaluated by univariate and multivariate analysis. The treatment outcome was analyzed by prognostic index model. Results The complete response (CR)was 33.3%(25/75), partial response was 52.0%(39/75)and median survival time was 13.8 months. The 1.0-,1.5-year survival rates were 54.7% and 27.5%, respectively. Smaller tumor diameter and volume, earlier T stage, shorter overall treatment time and milder acute radiation pneumonitis were favorable factors for survival when analyzed by univariate and multivariate. Prognostic index was higher sensitivity for predicting treatment outcome. Conclusions Tumor diameter, tumor volume, T stage, overall treatment time,milder acute radiation-induced pneumonitis are likely to be independent prognostic factors. Prognostic index model may well raise the predictive value of multivariate analysis for NSCLC treated by radiotherapy.