Sequential thoracic radiotherapy following immunotherapy in advanced non-small cell lung cancer: a real-world retrospective cohort study on efficacy and safety

Immunotherapy (IO) plays a pivotal role in treating advanced non-small-cell lung cancer (NSCLC). However, its effectiveness in achieving local control remains suboptimal. In contrast, consolidation radiotherapy offers distinct advantages for local disease management. Nevertheless, evidence regarding the efficacy and safety of sequential thoracic radiotherapy (TRT) following systemic IO in patients with advanced NSCLC is still limited. This single-center, retrospective cohort study enrolled 62 eligible patients with advanced NSCLC. All patients received either IO monotherapy or chemotherapy combined with IO, followed by sequential TRT. We analyzed progression-free survival (PFS), overall survival (OS), treatment response, and adverse events. Survival outcomes were calculated from the initiation of IO. The median PFS and OS were 9 months and 15 months, respectively. Treatment responses varied: five patients (8.06%) achieved a complete response (CR), 36 (58.06%) a partial response (PR), 19 (30.65%) had stable disease (SD), and two (3.23%) experienced progressive disease (PD). Patients who achieved CR or PR after IO demonstrated significantly longer PFS and OS compared to those with SD or PD (median PFS: 11.00 vs. 7.00 months, hazard ratio (HR): 0.45, 95% confidence interval (CI): 0.22–0.91, P < 0.001; median OS: not reached vs. 8.00 months, HR: 0.29, 95% CI: 0.13–0.67, P < 0.001). The treatment-related adverse events were manageable, with a low incidence of high-grade radiation pneumonitis (0%) and esophagitis (0%). The sequential administration of TRT after IO in patients with advanced NSCLC demonstrated potential feasibility in delaying disease progression and showed encouraging survival signals, with a manageable toxicity profile. However, these findings are constrained by the study’s retrospective design and necessitate validation through prospective controlled trials.