ABSTRACT
INTRODUCTION: To evaluate the feasibility, efficacy and safety of stereotactic ablative radiotherapy (SABR) to the primary tumor and lymph nodes in patients with locally advanced non-small cell lung cancer (LA-NSCLC) who are ineligible for or refused concomitant chemoradiation. MATERIALS AND METHODS: In accordance with the PRISMA and MOOSE guidelines, a systematic review with meta-analysis was conducted. The study included reports that assessed the outcomes of SABR treatment in patients with LA-NSCLC. Studies evaluating SBRT as a boost following primary radiotherapy were excluded. The primary outcomes measured were local control (LC) and overall survival (OS). The secondary endpoint was the incidence of severe toxicity (grades 3-5). A meta-regression analysis was performed to explore the relationship between LC, OS, and severe toxicity. The Biologically Effective Dose (BED) was analyzed as a continuous variable. Statistical significance was defined as a p-valueâ¯<â¯0.05. RESULTS: A total of seven studies (3 prospective and 4 retrospective studies) involving 268 patients (SBRT to primary and lymph nodes) were included in the analysis. The pooled 1-year LC rate was 80â¯% (95â¯% CI: 63-94â¯%), and the factors significantly associated with LC were BEDGy10 (pâ¯=â¯0.005) and neoadjuvant chemotherapy (pâ¯=â¯0.005). The 1-year and 2-year OS rates were 74â¯% (95â¯% CI: 58-90â¯%) and 55â¯% (95â¯% CI: 34-76â¯%), respectively. Meta-regression analysis indicated a linear relationship between OS and LC, with a 0.7â¯% increase in OS for each 1â¯% improvement in LC (pâ¯=â¯0.005). The pooled rate of grade 3 acute toxicity was 5â¯% (95â¯% CI: 1-10â¯%), and the rate of grade 5 toxicity was 1.7â¯% (95â¯% CI: 0-3â¯%). CONCLUSION: Promising results (LC and OS) with limited toxicity (feasibility) using SABR in LA-NSCLC warrant further research, emphasizing the need for larger, well-designed trials for further validation of the approach.
