Methotrexate, Glucarpidase, and Leucovorin in Treating Patients With Newly Diagnosed Primary Central Nervous System Lymphoma

OBJECTIVES: Primary * To determine the dose-limiting toxicity of methotrexate (MTX) when given in combination with glucarpidase in patients with newly diagnosed primary CNS lymphoma (PCNSL). * To determine the incidence of immediate reactions related to the use of glucarpidase in these patients. * To define a safer, more practical, and simpler regimen for delivering multiple courses of high-dose MTX using glucarpidase and 'short' leucovorin calcium rescue in these patients. * To monitor quality of life and mental function during and after therapy in these patients. Secondary * To use this regimen as a platform for phase III studies in PCNSL. * To record disease response, duration of response, and overall survival of patients treated with this regimen. OUTLINE: This is a multicenter, dose-escalation study of high-dose methotrexate (HD-MTX). Patients receive HD-MTX IV over 4 hours on day 1. Beginning 22 hours after the start of HD-MTX, patients receive glucarpidase IV over 15 minutes on day 2 followed by leucovorin calcium orally or IV on days 2-7. Treatment repeats every 14 days for up to 6 courses in the absence of disease progression or unacceptable toxicity. Within 2-4 weeks after completion of study treatment, patients achieving maximum response are stratified according to age (\< 60 years vs ≥ 60 years) and may undergo whole brain radiotherapy (WBRT) once daily, 5 days a week, for 3 to 5 weeks. Patients undergo blood sample collection periodically to assess glucarpidase antibodies and MTX levels. Patients are assessed for mucositis incidence and severity periodically, and complete quality of life assessments using the EORTC QLQ-30 questionnaire and the Mini-Mental State questionnaire at baseline, during, and after completion of study. After completion of study treatment, patients are followed at 6 weeks after WBRT, every 3 months for 1 year, every 4 months for 1 year, every 6 months for 3 years, and then annually thereafter.