Radiation Therapy as an Effective Salvage Strategy for Secondary CNS Lymphoma

Abstract

We assessed the efficacy of radiation therapy (RT) in the management of secondary central nervous system (CNS) lymphoma. The cohort comprised 44 patients with systemic diffuse large B-cell lymphoma (DLBCL) secondarily involving the brain and/or leptomeninges at initial diagnosis or relapse that was treated with RT. Of these patients, 29 (66%) were in systemic remission when CNS disease was diagnosed. The overall response rate to RT by magnetic resonance imaging was 88% (42% complete, 46% partial). The median overall survival (OS) after RT initiation was 7months (95% confidence interval 4-10months). The OS curve plateaued at 31% from 2 to 8years. OS was superior in patients who achieved a complete or partial response to RT, underwent stem cell transplantation after RT, and had brain parenchymal (vs leptomeningeal) disease. Eight cases of CNS disease progression occurred after RT: 1 involved the brain parenchyma, and 7 involved the spine and/or cerebrospinal fluid and/or meninges. We conclude that RT is associated with high response rates and may contribute to long-term OS. In addition, RT may provide CNS disease control that facilitates successful salvage with stem cell transplantation in patients with chemotherapy-refractory disease.