Combination Chemotherapy with High-dose Methotrexate and Cytarabine with or without Brain Irradiation for Primary Central Nervous System Lymphomas

Due to the limited clinical experience there is no standard treatment of primary CNS-lymphomas (PCNSL). Based on the actual data it seems that high-dose methotrexate (HTMRX) and high-dose cytarabine (ARA-C) qualify as treatments of choice for this disease. The role of radiation therapy is still unclear, due to the high long-term toxicity, especially in elderly patients. We treated 14 HIV negative patients with 4–5 cycles of methotrexate (MTX) at 3500 mg/m² and MTX 15 mg intrathecal weekly or MTX 8000 mg/m² weekly without intrathecal treatment. Younger patients (< 60 y) received 3 weeks after last MTX dose a whole-brain irradiation (45 Gy + 9 Gy boost), older patientsts were not irradiated and continued CT. The following treatment consisted in ARA-C 3000 mg/m² d1 + 2 every 3 weeks for two cycles. All patients received steroids for two months or until the end of radiotherapy. The overall response rate was 100%, 12/14 CR (86%). Two patients died still on treatment but not due to lymphoma (1 pulmonary embolism, 1 herpes encephalitis). Toxicity was very mild with no grade 3–4 non-haematological toxic events and almost 100% grade 3–4 leucopenia without episodes of neutropenic fever. After a median follow up of 39 months the PFS and OS are 65% (9/14) and 78% (11/14) respectively, and compare well with other trial results.