Treatment of stage I non-small cell lung cancer with CyberKnife, image-guided robotic stereotactic radiosurgery

The object of our study was to evaluate the clinical characteristics and outcomes of patients with stage I non-small cell lung cancer (NSCLC) who underwent radiosurgery using the CyberKnife, a newly developed technology to deliver radiation from multiple angles with a real-time target tracking system. A retrospective analysis of eight patients with stage I NSCLC who were treated with curative intent using the CyberKnife between 2002 and 2007 at a cancer center in Korea was performed. Among eight patients (seven men and one woman), three patients were ineligible for surgery due to poor lung function while four patients refused surgical treatment. Tumor size ranged from 19 to 50 mm in the maximal diameter (12 to 113 ml in volume). The administered radiation dose varied from 36 to 54 Gy in three fractions. All of the patients tolerated the treatment very well without any significant side effects. Complete response was achieved and was sustained for almost two years in one male patient until the patient died from a cerebrovascular accident. Seven patients showed radiographic partial response at 1-3 months. Re-growth of tumor at the treated site was observed in only one patient demonstrating an excellent local control rate, although systemic spread or regional lymph node metastasis of disease occurred in six patients during follow-up. CyberKnife treatment is very safe and is able to achieve a high local control rate, suggesting its role as a reasonable alternative therapeutic modality in early lung cancer.