Clinical outcomes of single‐fraction stereotactic radiation therapy of lung tumors

BACKGROUND The objective of the current study was to investigate the effects and the morbidities of single‐fraction stereotactic radiation therapy (SRT) for lung tumors. METHODS A Microtron device was modified to deliver stereotactic irradiation under respiratory gating. Between August 1998 and December 2004, 59 malignant lung tumors (11 primary tumors, 48 metastases) that measured < 40 mm in greatest dimension were treated by single‐fraction SRT. Nine tumors received a minimal dose of < 30 grays (Gy), and 50 tumors received a minimal dose of ≥ 30 Gy. The macroscopic target volume ranged from 1 cc to 19 cc (mean, 5 cc). RESULTS The 1‐year and 2‐year local progression‐free rates (LPFRs) were 93% and 78%, respectively. The overall survival rate was 76.5% at 1 year and 41% at 2 years. Local regrowth of the irradiated tumor was a direct cause of death in two patients. Only the minimal radiation dose to the reference target volume tended to have an influence on the LPFR (P = 0.068). The 2‐year LPFRs for patients who received irradiation doses of ≥ 30 Gy and < 30 Gy were 83% and 52%, respectively. With regard to morbidities, Grade 3 respiratory symptoms (according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late radiation morbidity scoring scheme) were noted in one patient. CONCLUSIONS The results from the current study suggested that single‐fraction SRT was tolerable and was capable of attaining excellent local control in patients who had malignant lung tumors that measured < 4 cm in greatest dimension. Cancer 2006. © 2006 American Cancer Society. The authors investigated the effects and morbidities of single‐fraction stereotactic radiation therapy (SRT) for lung tumors. The results suggested that single‐fraction SRT was tolerable and was capable of attaining excellent local control in patients who had malignant lung tumors smaller than 4 cm in greatest dimension.