Wei Jiang¹, Jianyang Wang², Jingbo Wang², Jun Liang², Zhouguang Hui², Xiaozhen Wang², Zongmei Zhou², Luhua Wang²

¹Department of RadiationOncology, Cancer Hospital, Chinese Academy of Medical Sciences & Pekingunion       Medical College, ²Chinese Academy ofMedical Sciences & Peking union       Medical College, Cancer Hospital

Objective:To investigate the clinical outcomes andtoxicity of stereotactic body radiotherapy (SBRT) with amoderate dose fractionfor medically inoperable stage I non-small cell lung cancer (NSCLC).

Method:Patients treated with hypofractionated SBRT using fixed-field IMRT orvolumetric-modulated arc therapy at our hospital from June 2005 to December2013 were analyzed. The prescription doses ranged from 50 to 78Gy in total withfour to six Gy per fraction. The median follow-up period was 20 months. 

Result:A total of 65 patients were analyzed, including 43 primary NSCLC and 22patients with recurrent or secondary primary NSCLC. An objective response(complete responseor partial response) was achieved at six months in 84.6% ofpatients. The three-year local control rate was 90.8%. The Kaplan-Meierestimates of local failure-free, progression-free, overall survival andcancer-specific survival rates at three years were 90.3%, 64.3%, 69.1% and84.2%, respectively. The rate of symptomatic radiation pneumonitis was 16.9%,including one patient with Grade 5 who had a comorbidity. 

Conclusion: Favorablelocal control and outcome was achieved with a moderate SBRT regimen in patientswith inoperable stage I NSCLC with acceptable toxicity. A schedule of 6 Gy*12fractions may be promising, and a large-scale prospective study is in process.

Key Words: Stereotactic bodyradiotherapy  non-small cell lung