Dr Wang on a Retrospective Study of CNS Bridging Radiotherapy Prior to CAR T in B-Cell Lymphoma

“This was a retrospective study which included 26 patients with relapsed/refractory B-cell lymphoma involving the central nervous system who received bridging radiation [therapy] followed by CAR T at City of Hope.”

Pule Wang, MD, a radiation oncology fellow in the Department of Radiation Oncology at City of Hope, discussed the design of a retrospective study which examined the role of bridging radiation therapy prior to CAR T-cell therapy in patients with central nervous system (CNS) involvement from relapsed/refractory B-cell lymphomas.

The study, findings from which were presented by Wang during the 2025 American Society for Radiation Oncology (ASTRO) Annual Meeting, included 26 patients with relapsed/refractory B-cell lymphoma involving the CNS who were treated with bridging radiation therapy followed by CAR T-cell therapy at City of Hope, she began. The median patient age was 66 years (range, 39-81) and the median Karnofsky Performance Status was 80 (range, 40-90), she continued. All of the enrolled patients had secondary CNS lymphoma. Specifically, disease histologies consisted of diffuse large B-cell lymphoma (n = 22) and mantle cell lymphoma (n = 4), she added.

Wang and her coauthors performed a subgroup analysis of patients with brain parenchymal disease (n=14), since this was the most relevant group to the question of whether to use focal or whole-brain retreatment, she said. Eight patients underwent whole brain radiation and 6 patients received involved site partial brain radiation, she added. Patients also received involved site orbits (n = 3) and involved spine (n = 9) radiation.

The study included patients with neuroaxis disease involving the brain, spinal cord, or leptomeninges. CNS responses were assessed following bridging radiation therapy and after CAR T-cell therapy via International PCNSL Collaborative Group guidelines. The study authors evaluated efficacy outcomes, neurotoxicity and overall survival (OS). OS was elucidated from the end of bridging radiation therapy using Kaplan-Meier curves.