Abstract:
Objective To explore the effects of tumor volume on long-time effi cacy of stage Ⅲ non-small cell lung cancer (NSCLC) after three dimensional conformal radiotherapy (3D-CRT). Methods From August 2000 to December 2004, 72 patients, 29 cases were in ⅢA and 43 cases in ⅢB stage. 32 cases were treated with radiotherapy alone, while 40 cases with concurrent or sequential radiotherapy and chemotherapy. 28 cases were treated with conventional radiotherapy (CRT) and later-course 3D-CRT, while 44 cases with 3D-CRT. The median equivalent dose was 6 625 cGy(5 000-7 800 cGy). DVH was used for assessing GTV, CTV and PTV.Standard of RTOG Radiation was used for evaluating induced esophagitis and pneumonitis. Results 69 cases were followed up for 5 years and rate was 95.8%. After radiotherapy, there were 14 cases of CR, 42 cases of PR, and 16 cases of SD. Overall survival rate and median survival time of 1 year, 3 years, and 5 years was 45.8%, 15.3%, 10.5% and 10.2 months, respectively. All patients were divided into two groups according to GTV median (155 cm3). Only the incidence of >grade 2 radiation induced pneumonitis in group of GTV>155 cm3 was higher than that in group of GTV≤155 cm3 (P<0.05), while there was no significant difference in gender, age, T, N, TNM, biologic equipotent dose, radiation style, chemotherapy and radiation esophagitis between two groups. Overall survival rate and median survival time of 1 year, 3 years and 5 years of patients with GTV≤155 cm3 and >155 cm3 were 61.1%, 19.4%, 16.2%, 17 months and 30.6%, 11.1%, 4.2%, 9 months respectively(χ2=5.16, P=0.023). CTV and PTV were divided into two groups according to median, and there was signifi cant difference in survival rate (P<0.05). With univariate analysis of all prognosis, GTV, CTV, PTV, and immediate effect were related with prognostic survival (P<0.05). Multivariable analysis indicated GTV and immediate effect were independent prognostic factors. Conclusion GTV was one important prognostic factor for stage III NSCLC after 3D-CRT, and immediate effect was another prognostic factor.