Analysis of clinical characteristics of symptomatic radiation-induced lung injury in patients with non-small cell lung cancer after radiotherapy

Objective: To analyze the clinical characteristics of symptomatic radiation-induced lung injury (SRILI) in patients with non-small cell lung cancer (NSCLC) after radiotherapy. Methods: A retrospective analysis was performed on the patients with NSCLC who received radiotherapy in our hospital from January 2000 to May 2007 and who developed SRILI during therapy or follow-up and received related treatment in our hospital. The symptoms, clinical signs, imaging findings, and hematological changes of the patients were observed. The SRILI was diagnosed and classified by 2 radiation oncologists and 1 radiologist according to CTC 3.0 criteria. Results: A total of 81 SRILI patients were included in the analysis. Of them, 35 had grade 2 SRILI, 42 had grade 3 SRILI, 0 had grade 4 SRILI, and 4 had grade 5 SRILI. The median time from beginning of radiotherapy to onset of SRILI symptoms was 8.3 weeks (ranging from 1.3 to 32.3 weeks). Among the SRILI symptoms, cough was observed in 95% of the patients, short breath in 69% of the patients, and fever in 48% of the patients. The median highest body temperature was 38.3 ℃. The clinical signs, found in relatively few patients, included coarse breath sound as the common one, seen in about 50% of the patients. The imaging findings included lung consolidation, air bronchogram, patchy opacities, and linear opacities, most of which were found in the radiation field. The hematological changes included slightly elevated percentage of neutrophils (median = 77.4%). Conclusions: The symptoms of SRILI occurred at 8.3 (median) weeks after the beginning of radiation. The clinical characteristics of SRILI include cough, short breath, fever, coarse breath sound, imaging findings of lung consolidation, patchy opacities, and linear opacities, which are mostly found in the radiation field, and slightly elevated percentage of neutrophils. (authors)