Stereotactic Ablative Radiotherapy Using CyberKnife for Stage I Non-small-cell Lung Cancer: A Retrospective Analysis

Background/Aim: We evaluated the effectiveness and safety of stereotactic ablative radiotherapy (SABR) delivered using Cyberknife in patients with stage I non-smallcell lung cancer. Patients and Methods: The clinical results of 153 patients with 161 lung cancers treated with CyberKnife between May 2014 and August 2020 at the Osaka University Hospital were retrospectively analyzed. The median age was 80 years (range=48-99 years). Nine patients (5.6%) had interstitial pneumonia. The median radiation dose was 52 Gy (range=40-70 Gy) in 4-10 fractions, and the median followup extended to 21.4 months (range=0-68.9 months). Results: The 2-year local control, progression-free, and overall survival rates were 91.9%, 61.7%, and 84.8%, respectively. Toxicities of grade >= 3 were observed in 13 (8.1%) patients; one patient with interstitial pneumonia developed grade 5 radiation pneumonitis and one patient developed grade 5 bronchopulmonary hemorrhage. Conclusion: In patients with stage I non-small-cell lung cancer, SABR using Cyberknife was effective with acceptable toxicity.