Risk and predictors for early radiation pneumonitis in patients with stage III non-small cell lung cancer treated with concurrent or sequential chemoradiotherapy

BACKGROUND: The rate of radiation pneumonitis (RP) for patients receiving chemoradiotherapy has been various across studies. Whether it is related to different chemotherapy schedules used in combination with radiation therapy were evaluated in this study. New factors associated with RP were also investigated. METHODS AND MATERIALS: A total of 369 consecutive patients with Stage III non small cell lung cancer treated with chemoradiotherapy were followed after radiotherapy (RT). Among them 262 patients received concurrent chemoradiotherapy followed by consolidation chemotherapy and 107 patients received only sequential chemotherapy after RT. RP was graded according to Common Terminology Criteria for Adverse Events version 4.0. RESULTS: The rate of grade ≥ 2 were 39.7%, 31% and 33.6% in the concurrent DP (docetaxel/cisplatin), concurrent NP (vinorelbine/cisplatin) and sequential group, and grade ≥ 3 RP were 18.4%, 9.5%, and 11.2% respectively. The rate of grade ≥ 3 RP was significantly higher in concurrent DP group than that in concurrent NP group (p = 0.04). RP occurred earlier in concurrent DP group than that in the other two groups. There were no significant differences in response rate among the three groups. In the multivariate analysis, age (OR = 1.99, p = 0.038 and OR = 8.90, p < 0.001), chemotherapy schedule (OR = 1.45, p = 0.041 and OR = 1.98, p = 0.013), mean lung dose(OR = 1.42, p < 0.001 and OR = 1.64, p < 0.001), and planning target volume(OR = 1.004, p = 0.001 and OR = 1.005, p = 0.021) were predictors for both grade ≥ 2 and grade ≥ 3 RP. Response to treatment was a new predictor for grade ≥ 3 RP only (OR = 4.39, p = 0.034). CONCLUSIONS: Response to treatment was found to be a new predictor for grade ≥ 3 RP. Compared to concurrent NP schedule, concurrent DP schedule achieved similar response to treatment but resulted in a higher risk of grade ≥ 3 RP.