Effect of heavy-ion radiotherapy on pulmonary function in stage I non-small cell lung cancer patients

Study objectives: The purpose of this study was to investigate the effect of heavy-ion radiotherapy on pulmonary function in patients with clinical stage I non-small Cell lung cancer (NSCLC) patients. Design: Retrospective study. Setting: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan. Patients: From a total of 81 patients who were not candidates for surgical resection due to medical reasons or patient refusal, and who were treated with carbon beam radiotherapy from October 1994 to February 1999, the 52 patients who had completed the repeat overall pulmonary function tests at 6 and 12 months after undergoing heavy-ion radiotherapy were examined. The total heavy-ion irradiation dose ranged from 59.4 to 95.4 photon gray equivalents (GyE) with a mean dose of 76.2 GyE. Interventions and measurement: Pulmonary function was evaluated prior to heavy-ion radiotherapy and at 6 and 12 months after heavy-ion radiotherapy. Comparisons of all pulmonary function indexes between, before, and at 6 and 12 months after heavy-ion radiotherapy were made using repeated-measures analysis of variance using the Dunnett test for post hoc comparison. Results: A statistically significant decrease in FEV1 and total lung capacity was detected at both 6 and 12 months after the patient had undergone heavy-ion radiotherapy. No significant decreases in other pulmonary function indexes in patients were observed at either 6 or 12 months after heavy-ion radiotherapy. The magnitude of the decrease in all pulmonary function indexes was < 8% at both 6 and 12 months after heavy-ion radiotherapy. Conclusions: These findings suggest that heavy-ion radiotherapy is feasible for stage I NSCLC patients without a severe loss of pulmonary function.