A real-world analysis of stereotactic body radiotherapy combined with immunotherapy in advanced or recurrent non-small cell lung cancer (NSCLC): A single-center experience

Background: We aimed to assess the value of stereotactic body radiotherapy (SBRT) delivered under the situation of controlled or progressed disease during ICI therapy in advanced or recurrent NSCLC. Methods: We retrospectively collected patients with advanced or recurrent NSCLC who received SBRT concurrently with ICI in our institution between January 2017 and December 2021. Patients were divided into two groups, including those for whom SBRT was delivered initially or to the residual tumors during the first- or later-line ICI treatment (Group 1), and those for whom SBRT was given to the progressed tumors irrespective of first- or later-line ICI treatment (Group 2). Results: A total of 144 patients were included. With median follow-up duration of 25.6 (range: 3.6 to 56.2) months, median progression-free survival (PFS) was 13.7 (95 % CI: 10.4 to 17.1) months and median overall survival (OS) was 52.8 [95 % CI: 30.6 to not available (NA)] months. In Group 1 (n = 78), median PFS was 17.9 (95 % CI: 14.5 to 29.8) months while median OS was not reached and 5-year OS rate was 61.2 %. In Group 2 (n = 66), median PFS was 8.0 (95 % CI: 6.0 to 13.1) months and median OS was 30.6 (95 % CI: 21.5 to NA) months. Conclusions: SBRT combined with ICI demonstrated favorable survival for advanced or recurrent NSCLC, delivered in a controlled-disease situation as well as to progressed diseases with salvage-intent. Future prospective studies are warranted to investigate the optimal SBRT dose regimen and appropriate combination strategy to synergize ICI.