Computed tomography to assess pulmonary injury associated with concurrent chemo-radiotherapy for inoperable non-small cell lung cancer

Objective: To characterize serial computed tomography (CT) findings of pulmonary injury after a uniform regimen of concurrent chemo-radiotherapy in inoperable non-small cell lung cancer, and to compare the radiation-induced lung toxicity with other concurrent chemo-radiation regimens. Methods: Twenty-four patients with advanced non-small cell lung cancer received 2 induction cycles of cisplatin and vinblastine, followed by 2 further cycles of cisplatin and vinblastine, concurrent with 60 Gy radiation at 2 Gy per fraction. Radiation-induced lung injury in the acute and chronic phases was assessed by serial CT scans and compared with preradiation baseline scans. Acute radiation pneumonitis was evaluated using the Common Toxicity Criteria, and chronic radiation fibrosis was graded according to the European Organisation for Research and Treatment of Cancer - Radiation Therapy Oncology Group Scale. Results: Seventeen (81%) patients had characteristic CT findings of radiation-induced pulmonary damage, which were confined to the radiation ports. Although patchy nonhomogeneous and air-space opacities characterized acute radiation pneumonitis, and homogeneous opacities with loss of volume were typical for chronic fibrosis, ground-glass opacities were found frequently in both phases. Acute radiation pneumonitis grade 1 was seen in 29% and grade 2 in 9.5%. Chronic radiation fibrosis grades 1, 2 and 3 were found in 14%, 33% and 19% of the patients respectively. Median survival time was 13 months. Conclusion: CT enables detailed evaluation of radiation-induced pulmonary injury after concurrent chemo-radiation for inoperable non-small cell lung cancer. Although survival time with the present regimen is comparable to other concurrent chemo-radiation regimens, a high incidence of radiation injury was found, though the severity was not life threatening.