Efficacy of the smaller target volume for stage III non-small cell lung cancer treated with intensity-modulated radiotherapy

Abstract

The present study reports the local recurrence, distant metastasis, progression-free survival, overall survival and radiation toxicity between two arms of stage III non-small cell lung cancer (NSCLC) treated with intensity-modulated radiotherapy (IMRT); one arm with clinical target volume (CTV) and the other without CTV. The two arms of local recurrence, distant metastasis, progression-free survival, overall survival, grade 3-4 radiation esophagitis and hematological toxicity had no statistical significance. However, the grade 3-4 radiation pneumonia rate of the group without CTV was significantly decreased. This supports the concept that stage III NSCLC treated with IMRT, which omitted CTV, can reduce the occurrence of radiation pneumonia. The aim of the present study was to analyze the feasibility of the smaller target volume for stage III NSCLC treated with IMRT. Data from 105 patients with stage III NSCLC who were hospitalized and received IMRT between January 1, 2008 and November 30, 2012 were retrospectively analyzed. A total of 55 cases were irradiated with target volume without CTV and 50 cases were irradiated with CTV. Dose prescription was 100% PTV at 54-63 Gy/27-35 F/5.4-7 weeks. The two arms of the patient characteristics and treatment deliveries had no statistical significance. The two arms of the patients were compared for local recurrence, distant metastasis, progression-free survival, overall survival and radiation-related toxicity. In the arms without and with CTV, the local relapse and distant metastases rates were 32.7 and 32.0% (P=1.000) and 56.4 and 48.0% (P=0.946), respectively. The median progression-free survival time for the two arms was 9 months (P=0.619). The 1-, 2- and 3-year survival rates of the arms without and with CTV were 74.5, 43.6 and 23.6%, and 70.0, 46.0 and 20.0% (P=0.956), respectively. In the two arms, grade 3-4 radiation esophagitis and hematological toxicity had no statistical significance. However, in the arm without CTV, grade 3-4 radiation pneumonia was only 5.5%, compared with 18.0% in the arm with CTV (P=0.044). In conclusion, the smaller target volume for stage III NSCLC treated with IMRT was feasible.