Efficacy of stereotactic body radiotherapy in treatment of early-stage peripheral non-small cell lung cancer

Objective To evaluate the clinical efficacy of stereotactic body radiotherapy in treatment of patients with early-stage peripheral non-small cell lung cancer (NSCLC). Methods A retrospective analysis of 40 newly diagnosed early stage (T1/T2N0M0) peripheral NSCLC patients treated with Cyberknife in Chinese PLA General Hospital from January 2012 to November 2014 was carried out. There were 9 women and 31 men with the median age of 74.5 years old (ranging from 43 to 90 years old). The primary outcome measurements included overall survival (OS) and progression-free survival (PFS), the secondary outcome measurements were objective response rate (ORR), disease control rates (DCR), local failure-free survival (LFFS), regional failure-free survival (RFFS) and no distant metastasis-free survival (DMFS), and the failure mode and adverse reactions were observed at the same time. Results The median follow-up was 28.5 months (range, 7-44 months) with two cases lost to follow up. Complete response (CR) was achieved in 16 patients (42.1%), partial response (PR) in 7 patients (18.4%), stable disease (SD) in 9 patients (23.7%), and progressive disease (PD) in 8 patients (21.1%). The objective response rate (ORR) was 60.5%, and the primary tumor local control rate was 81.6%. One-year OS rate and three-year OS rate were 89.5% and 83.3% respectively for the entire group. One-year OS rate and three-year OS rate were 100.0% and 100.0% for T1 tumor, and 68.8% and 45.8% for T2 tumor, respectively (P=0.000). For the entire group, one-year PFS rate and three-year PFS rate were 88.6% and 78.2%, one-year LFFS rate and three-year LFFS rate were 97.0% and 89.5%, one-year DMFS rate and three-year DMFS rate were 91.5% and 87.9%, respectively. GradeⅠand gradeⅡradiation pneumonitis were observed in 12 patients (31.6%) and 4 patients (10.5%), respectively. GradeⅠfatigue was observed in 8 patients (21.1%), and gradeⅢ or above adverse reaction was not found. Conclusion Cyberknife stereotactic radiotherapy provides a treatment option for early stage non-small cell lung cancer patients, with high local control rate, overall survival rate, distant disease control and low adverse reaction.