Analysis of risk factors of radiation-induced lung toxicity in non-small cell lung cancer patients treated with postoperative radiotherapy

Abstract

Objective To evaluate the incidence and risk factors of symptomatic radiation-induced lung toxicity (SRILT) in non-small cell lung cancer (NSCLC) patients treated with modern radiotherapy after surgery. Methods Clinical data of consecutive NSCLC patients treated with postoperative three-dimensional conformal or intensity-modulated radiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences between November 2002 and December 2011 were retrospectively analyzed. According to the Common Terminology Criteria for Adverse Events (CTCAE, version 3.0), SRILT was defined as ≥grade 2 radiation-induced lung toxicity. Potential clinical risk factors and dosimetric parameters for SRILT were evaluated using logistic regression model. Results Among 227 enrolled patients, 190 cases underwent lobectomy and 37 patients received pneumonectomy. Twenty-three patients (10.1%) developed SRILT after lobectomy. Seventeen patients experienced grade 2 SRILT, 5 cases of grade 3 SRILT and 1 case of grade 4 SRILT. Univariate analysis showed that postoperative concurrent chemoradiotherapy, relatively large PTV, mean lung dose and V20- V40 were significantly correlated with the incidence of SRILT (P=0.015, 0.048 and<0.001). Multivariate analysis demonstrated that postoperative concurrent chemoradiotherapy and V20 were significantly associated with the incidence of SRILT (P=0.017 and P=0.009). Conclusions The incidence of SRILT is relatively low in NSCLC patients after postoperative radiotherapy. Concurrent chemoradiotherapy and V20 are risk factors of SRILT. Key words: Lung neoplasm/surgery; Lung neoplasm/radiotherapy; Radiation-induced lung injury