Clinical outcomes of single dose stereotactic radiotherapy for lung metastases.

Introduction: Stereotactic body radiation therapy is an emerging noninvasive technique for the treatment of oligometastatic cancer. The use of small numbers of large doses achieve a high percentage of local control. The aim of this study was to evaluate the efficacy and tolerability of SBRT for the treatment of lung metastases in a cohort of patients treated between 2008 and 2012 at our institution.

Patients And Methods: A total of 66 patients with oligometastatic lung tumors (single pulmonary nodules in 40 patients; 61%) were included in the study. SBRT was performed with a stereotactic body frame and a 3-D conformal technique. Forty-nine central tumors received 23 Gy in a single fraction and 54 peripheral tumors received a dose of 30 Gy in a single fraction. The primary end point was local control; secondary end points were survival and toxicity.

Results: Median follow-up was 15 months (range, 3-45 months). Local control rates at 1 and 2 years were 89.1% and 82.1%, overall survival rates were 76.4% and 31.2%, cancer-specific survival rates were 78.5% and 35.4%, and progression-free survival rates were 53.9% and 22%, respectively. Median survival time was 12 months, and median progression-free survival time was 10 months. Toxicity profiles were good, with 2 cases of Grade 3 toxicity (pneumonitis).

Conclusion: SBRT is an effective and safe local treatment option for patients with lung metastases, although it remains investigational; longer follow-up to confirm results is required.