Safety Study of High Dose Temozolomide to Treat Relapsed/Refractory Central Nervous System (CNS) Malignancy

Inclusion Criteria: * Patients or their health care proxies must be able to provide consent to participate in this trial. * Patients must have one of the following diagnoses which has not responded or recurred following at least one prior chemotherapy regimen or radiation therapy: * anaplastic astrocytoma, glioblastoma multiforme or oligodendroglioma * primary CNS lymphoma * malignant disease metastatic to the CNS * Patients must be candidates for high dose chemotherapy and autologous stem cell transplant according to the following criteria: * Patients must be between the ages of 18 and 70 years (inclusive) * Patients must have a left ventricular ejection fraction greater than or equal to 45% by MUGA or echocardiogram * Patients must have adequate pulmonary function with FEV1, FVC and DLCO greater than or equal to 50% of predicted * Patients must have serum direct bilirubin less than or equal to 2.0 mg/dl and transaminases less than or equal to 3x institutional upper limit of normal * Patients must have serum creatinine less than or equal to 2 mg/dl with creatinine clearance greater than or equal to 60 ml/min (either calculated or measured) * Patients must have an ECOG performance status between 0 and 2 * Patients must be at least 4 weeks from last cytoreductive chemotherapy. * Expected survival of at least 3 months Exclusion Criteria: * Patients with uncontrolled metastatic disease outside of the CNS which would itself, in the investigator's opinion, limit survival to less than 6 months * Patients with uncontrolled seizures are ineligible. * Patients with a history of myocardial infarction within the preceding 6 months, significant arrhythmia within the preceding 3 months, or uncontrolled hypertension or congestive heart failure are ineligible. * Patients with unstable angina are ineligible. * Pregnant or lactating women are ineligible. * Male and female patients who do not agree to practice approved methods of birth control for the duration of the study are ineligible. * Patients with uncontrolled, active infection are ineligible. * Patients infected with HIV are ineligible.