Background: Primary central nervous system lymphoma (PCNSL) is a rare aggressive non-Hodgkin's lymphoma. There are limited data on the management of PCNSL outside of clinical trials.

Objectives: To report experience with three main high-dose methotrexate (HDMTX)-based protocols for PCNSL treatment at one medical center.

Methods: We conducted a retrospective review of the medical records of patients diagnosed with PCNSL who were treated at Soroka Medical Center between 2007 and 2019.

Results: The study included 36 patients, median age 64.9 years; 33 patients received a HDMTX backbone induction therapy, 21 (58.3%) received consolidation treatment in addition. In the entire cohort, 25 patients (75.7%) achieved complete remission (CR, CRu-unconfirmed), with mean progression-free survival (PFS) 32 ± 6.9 months and median overall survival (OS) 59.6 ± 12.4 months. More aggressive regiment such as combination of rituximab, HDMTX, cytarabine and thiotepa had better responses 5 (100%) CR, but also a higher incidence of side effects such as neutropenic fever 5 (100%). In subgroup analysis by age (younger vs. older than 60 years), the PFS was 24.2 vs. 9.3 months, and OS was 64.1 vs. 19.4 months, respectively.

Conclusions: A difference in CR and PFS favored a more aggressive protocol, but the toxicity of the multiagent combinations was significantly higher. The prognosis in younger was better than in older patients, with higher rates of CR, PFS, and OS, although not statistically significant. Overall treatment outcomes are encouraging; however, there is a real need for an adaptive approach for older patients and balancing among the effectiveness and side effects.