Comparison of single- and five-fraction schedules of stereotactic body radiation therapy for central lung tumours: A single institution experience

Background: Stereotactic body radiation therapy (SBRT) is a treatment option for patients with early-stage non-small cell lung cancer who are medically inoperable or decline surgery. Here we compare the outcome of patients with centrally located lung tumours who underwent either single fraction (SF)- or five-fraction (FF-) SBRT at a single institution over 5 years. Methods: Between January 2009 and October 2014, patients with centrally located lung tumours who underwent SBRT were included in this study. Data were retrospectively collected using an institutional review board-approved database. For analysis, the Kaplan-Meier method and competing risks method were used. Results: In total, 11 patients received 26-30 Gy in 1 fraction, whereas 31 patients received 50-60 Gy (median 55 Gy) in 5 fractions. After a median follow-up of 12 months for SF-SBRT and 17 months for FF-SBRT groups (p=0.64), 1-year overall survival rates were 82 and 87%, respectively. SF- and FF-SBRT groups showed no significant difference in grade 3+ toxicity (p=0.28). The only grade 4 toxicity (n=1) was reported in the SF-SBRT group. All toxicities occurred >12 months after the SBRT. Conclusions: SF- and FF-SBRT have comparable overall survival. SF-SBRT may have some utility for patients unable to have multi-fraction SBRT.