A Study About Safety and Efficacy of Pirfenidone to Treat Grade 2 or Grade3 Radiation-induced Lung Injury.

Inclusion Criteria: 1. 18-75 years old (including 18 and 75 years); 2. clinically diagnosed grade 2 or 3 radiation-induced lung injury; 3. the course of radiation-induced lung injury is less than 2 months; 4. ECOG 0-2; 5. the expected survival time is more than 6 months; 6. the functional level of major organs meets the following standards: ANC≥3.0×109/L，PLT≥100×109/L，Hb≥90g/L, TBIL、BUN and Cr≤1.5×ULN， ALT、AST≤2.0×ULN 7. capable of eating solid food upon enrollment; 8. subjects will voluntarily participate in this study and sign the informed consent. Exclusion Criteria: 1. have a history of chronic bronchial acute attack or severe pulmonary heart disease; 2. pneumonectomy; 3. tumor progression; 4. severe pulmonary infection; 5. creatinine clearance rate \< 30ml/min, severe renal disease or need dialysis; 6. concomitant with other serious diseases: for example, myocardial infarction within 6 months, uncontrolled diabetes, etc., were considered not suitable for the participants in the study; 7. patients with active peptic ulcer; 8. pregnant women and patients with mental illness; 9. participating in clinical trials of other drugs within 3 months; 10. the investigator determined that subject was not suitable.