Pemetrexed Disodium in Treating Patients With Recurrent Malignant Gliomas, Primary CNS Lymphoma, or Brain Metastases

OBJECTIVES: Primary * Determine the 6-month progression-free survival rate in patients with recurrent malignant gliomas treated with pemetrexed disodium. * Determine the time to progression in patients with recurrent malignant gliomas, primary CNS lymphoma (PCNSL), or brain metastases treated with pemetrexed disodium. Secondary * Determine the radiographic response in patients with recurrent malignant gliomas, PCNSL, or brain metastases treated with pemetrexed disodium. * Determine the time to response in patients treated with this drug. * Determine the duration of response in patients treated with this drug. * Determine the overall survival of patients treated with this drug. * Collect safety data on patients with intracranial tumors treated with this drug. OUTLINE: Patients receive pemetrexed disodium IV over 10 minutes on day 1. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed periodically. PROJECTED ACCRUAL: A total of 47 patients will be accrued for this study.