Carboplatin, Melphalan, Etoposide Phosphate, Mannitol, and Sodium Thiosulfate in Treating Patients With Previously Treated Brain Tumors

Inclusion Criteria: * Subjects with pathologic evidence of an anaplastic oligodendroglioma or mixed glioma (i.e. oligoastrocytoma) are eligible; histopathologic diagnosis will be made using World Health Organization classification criteria; to qualify as a mixed tumor there must be a minimum of 25% oligodendroglial element * Surgical procedure may have been complete resection, partial resection, or biopsy * Subjects must have had prior treatment with temozolomide; at least 28 days must have elapsed since completion of temozolomide or other chemotherapy * If subject has not undergone radiation therapy, then subject must have undergone prior consultation with a radiation oncologist (who is not an investigator on this study); if the subject has undergone radiation therapy, then at least 14 days must have elapsed since completion of radiation * Subjects performance status must be (Karnofsky performance status \[KPS\] greater than or equal to 50; Eastern Cooperative Oncology Group \[ECOG\] less than or equal to 2) * White blood cell count \>= 2.5 x 10\^3/mm\^3 * Absolute granulocyte count \> 1.5 x 10\^3/mm\^3 * Platelets \>= 100 x 10\^3/mm\^3 * Serum creatinine \< 1.5 x upper limit of normal * Bilirubin \< 1.5 x upper limit of normal * Subjects baseline serum glutamic oxaloacetic transaminase (SGOT)/serum glutamate pyruvate transaminase (SGPT) must be \< 2.5 x institutional upper limit of normal * Subjects must sign a written informed consent in accordance with institutional guid…