Stereotactic Body Radiotherapy for Lung Tumors at the Pulmonary Hilum

High-dose irradiation to the pulmonary hilar region is generally considered to be of high risk in causing bronchial injury. The aim of this retrospective study is to investigate the safety and efficacy of stereotactic body radiotherapy (SBRT) for patients with lung tumors in the pulmonary hilum. 21 patients who underwent SBRT for lung tumors within 2 cm from a major bronchus were retrospectively analyzed. The total biologically effective doses ranging from 50.7 to 157.5 Gy (median, 100 Gy) were given to the tumors by SBRT. The overall survival rates at 1 and 2 years after SBRT were 90.0% and 62.2%, respectively. Nine patients were alive and 15 irradiated tumors were controlled during the follow-up period of 10-54 months (median, 20 months). Nine patients died of tumor progression and one patient each died of hemoptysis, infectious pneumonia, and epidural hemorrhage. Severe late toxicity (a parts per thousand yen grade 3) was seen in three patients of whom two had previously received repeated radiotherapy. SBRT for lung tumors located in the pulmonary hilar region may be tolerable and acceptable, if multiple treatments to the same major bronchus are avoided, and irradiated volumes are carefully taken into consideration.