Stereotactic body radiation therapy for lung metastases.

INTRODUCTION Stereotactic body radiation therapy (SBRT) has an emerging role in patients affected with pulmonary metastases. Purpose of this study was to evaluate efficacy and tolerability of SBRT in a cohort of patients treated between 2003 and 2009 at our institution. METHODS A total of 61 patients with oligometastatic lung tumors (single pulmonary nodules in 73.7%) were included in the study. SBRT was performed with a stereotactic body frame and a 3D-conformal technique. Fifty-one patients received 26 Gy in 1 fraction, 22 a dose of 45 Gy in 3 fractions and 3 a dose of 36 Gy in 4 fractions. Primary tumor was lung cancer in 45.7% of patients, colorectal cancer in 21.3% and a variety of other origins in 33%. The primary endpoint was local control, secondary endpoints were survival and toxicity. RESULTS After a median follow-up interval of 20.4 months, local control rates at 2 and 3 years were 89% and 83.5%, overall survival 66.5% and 52.5%, cancer-specific survival 75.4% and 67%, progression-free survival 32.4% and 22.3%. Tumor volume was significantly associated to survival, with highest rates in patients with single small tumors. Median survival time was 42.8 months, while median progression-free survival time was 11.9 months. Toxicity profiles were good, with just one case of grade III toxicity (pneumonitis). CONCLUSION This study shows that SBRT is an effective and safe local treatment option for patients with lung metastases. Definitive results are strictly correlated to clinical selection of patients.