Efficacy and safety of radiotherapy as a bridging strategy to CD19-targeted CAR-T therapy: systematic review and meta-analysis

Radiotherapy (RT) is increasingly used as bridging therapy before CD19-targeted CAR-T infusion in large B-cell lymphoma, but its clinical role remains uncertain. We conducted a systematic review and meta-analysis of 16 studies involving 488 patients with large B-cell non-Hodgkin lymphoma who received bridging RT. Pooled estimates showed an overall response rate (ORR) of 74.6% and complete response (CR) rate of 55%. The 1-year progression-free survival (PFS) and overall survival (OS) rates were 57.7% and 72.1%, respectively. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 76.8% and 36.9% of patients, with grade ≥3 events in 6.7% and 19.1%, respectively. Compared with systemic bridging, RT was associated with superior survival, while outcomes were comparable to non-bridging cohorts. These findings suggest that bridging RT is a feasible, well-tolerated, and potentially advantageous in selected patients undergoing CAR-T therapy.