Clinical outcomes of cyberknife stereotactic radiosurgery for lung metastases

Zhen Wang, Qing-Tao Kong, Jing Li, Xin-Hu Wu, Bing Li, Ze-Tian Shen, Xi-Xu Zhu, Yong Song

Abstract

Background: Cyberknife stereotactic radiosurgery is an emerging noninvasive technique for treating oligometastatic cancer. The aim of this study is to evaluate the efficacy and tolerability of cyberknife for the treatment of patients with lung metastases.
Materials and methods: A total of 134 lung metastases in 95 patients were treated with cyberknife in the radiotherapy center of our hospital from March 2009 to March 2013. The number of lung metastases per patient ranged from one to four (single lesions in 63 patients, 66.3%). The average tumor volume was 14.6 cm3 and the prescribed radiation dosage ranged from 30 to 60 Gy, fractionated one to five times with a 60% to 88% isodose line. The primary end point was local control (LC); secondary end points were survival and toxicity.
Results: The median follow-up was 17 months (ranging from 4 to 46 months). The 1-year LC rate was 97.6%, the 2-year LC rate was 90.6%, and the 3-year LC rate was 87.0%. The median survival time was 38.0 months and the median progression-free survival (PFS) time was 14.0 months. The 2-year PFS rate was 29.0% and the overall survival (OS) rate was 61.3%. No grade 4 or higher toxicity was encountered.
Conclusions: Cyberknife is safe and effective treatment for patients with lung metastases.