Stereotactic body radiation therapy using CyberKnife for T1N0M0 lung cancer patients with severe pulmonary dysfunction.

We retrospectively investigated the efficacy and safety of stereotactic body radiotherapy (SBRT) for T1N0M0 lung cancer using CyberKnife (CK) among 13 patients with severe pulmonary dysfunction which was defined as forced expiratory volume in 1 s (FEV1.0) of <1 L. The prescribed dose was 54 Gy in 3 fractions but adjusted for some patients if their tumors were in close proximity to the organs at risk (54 Gy/3 fractions: n = 11; 50 Gy/5 fractions: n = 1; 60 Gy/8 fractions: n = 1). During follow up (median follow-up: 27 months), we evaluated local control, overall survival and toxicity, using diagnostic imaging and laboratory tests. The patients' median FEV1.0 was 0.84 L. Of the 13 patients, 3 were diagnosed as having lung cancer histologically and 10 diagnosed clinically. Their 2-year rates for overall survival and local control were 89 and 100%, respectively. So far, we have seen no adverse effects of grade 2 or higher. We concluded that CK-SBRT is effective and well tolerated for T1N0M0 lung cancer, even in patients with severe pulmonary dysfunction, but should be further evaluated with a larger cohort and longer follow-up periods.