Retrospective analysis of steroid therapy for radiation-induced lung injury in lung cancer patients

Purpose: To disclose characteristics of lung cancer patients developing radiation-induced lung injury treated with or without corticosteroid therapy. Methods and materials: Radiographic changes, symptoms, history of corticosteroid prescription, and clinical course after 50-70 Gy of thoracic radiotherapy were retrospectively evaluated in 385 lung cancer patients. Results: Radiation-induced lung injury was stable without corticosteroid in 307 patients (Group 1), stable with corticosteroid in 64 patients (Group 2), and progressive to death despite corticosteroid in 14 patients (Group 3). Fever and dyspnea were noted in 11%, 50% and 86% (p < 0.001), and in 13%, 44% and 57% (p < 0.001) patients in Groups 1-3, respectively. Median weeks between the end of radiotherapy and the first radiographic change were 9.9, 6.7 and 2.4 for Groups 1-3, respectively (p < 0.001). The initial prednisolone equivalent dose was 30-40 mg daily in 52 (67%) patients. A total of 16 (4.2%) patients died of radiation pneumonitis or steroid complication with a median survival of 45 (range, 8-107) days. Conclusion: Development of fever and dyspnea, and short interval between the end of radiotherapy and the first radiographic change were associated with fatal radiation-induced lung injury. Prednisolone 30-40 mg daily was selected for the treatment in many patients