Efficacy and Safety Profile of a Rituximab, Methotrexate, and Thiotepa-Based Regimen in Newly Diagnosed Primary CNS Lymphoma.

To evaluate the efficacy and safety of the RMT regimen as first-line induction therapy for primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL), we retrospectively analyzed 36 patients treated with 4-6 cycles of RMT. After 4 induction cycles, the overall response rate and complete response rate were 97.2% and 80.6%, respectively. With a median follow-up of 19.9 months, the 2-year progression-free survival (PFS) and overall survival rates were 64.4% and 79.3%. The 2-year PFS was 100% in patients receiving sequential autologous stem cell transplantation (ASCT), 67.9% with maintenance therapy (BTKi/IMiD), and 45.5% with induction only. The most common Grades 3-4 adverse event was neutropenia (33.3%); all were manageable without treatment discontinuation. These findings indicate that the RMT regimen demonstrates excellent efficacy and a favorable safety profile in PCNS-DLBCL, including elderly patients; sequential ASCT is the preferred consolidation strategy, while BTKi/IMiD maintenance provides a viable alternative for sustained disease control.