ABSTRACT
Objective To investigate the incidence of radiation?induced lung injury ( RILI ) in patients with locally advanced non?small cell lung cancer ( LA?NSCLC ) after involved?field intensity?modulated radiotherapy ( IMRT) and concurrent chemotherapy, and to figure out the predictive factors for RILI. Methods Two hundred and fifty?six patients with stage Ⅲ NSCLC who were treated without surgery in our hospital from January 2007 to December 2011 were enrolled as subjects. All patients received involved?field IMRT with a median dose of 60 Gy ( 50?70 Gy) in 30 fractions. In all patients, 109 patients (42.6%) received concurrent chemotherapy. The National Cancer Institute Common Terminology Criteria for Adverse Events Version 3. 0 was used to evaluate the RILI grade. The incidence of grade ≥2 RILI ( symptomatic RILI, SRILI ) within 6 months after radiotherapy served as the end point. The predictive factors for RILI were analyzed using logistic regression model. Results In all patients, 215 ( 84%) were male, and 41(16%) were female. The mean age at diagnosis was 59.2 years. Forty?three (16.7%) patients had grade ≥2 RILI. The mean duration between the incidence of RILI and the beginning of radiotherapy was 64 days ( 20?169 days) . Univariate analysis showed that smoking, peripheral or central tumor location, mean lung dose ( MLD) for both lungs, and V5?V20 for both lungs were suspected to be associated with the development of SRILI (P=0.108,0.106,0.030,0.049). Multivariate analysis showed the MLD and V5?V20 for both lungs were independent predictive factors for SRILI P=(0.048). Conclusions For patients with LA?NSCLC treated with involved?field IMRT, the MLD and the volume of low?dose region in dose volume histogram for both lungs are significantly correlated with the incidence of SRILI.
