Antineoplaston Therapy in Treating Patients With Recurrent or Refractory Oligodendroglioma

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed incurable oligodendroglioma that progressed during or is recurrent or residual after initial therapy, including radiotherapy and/or chemotherapy Measurable tumor by MRI scan performed within two weeks prior to study entry Tumor must be at least 5 mm No brain stem tumors PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: At least 2 months Hematopoietic: WBC at least 2,000/mm^3 Platelet count at least 50,000/mm^3 Hepatic: Bilirubin no greater than 2.5 mg/dL SGOT/SGPT no greater than 5 times upper limit of normal No hepatic failure Renal: Creatinine no greater than 2.5 mg/dL No history of renal conditions that contraindicate high dosages of sodium Cardiovascular: No severe heart disease No uncontrolled hypertension No history of congestive heart failure No history of other cardiovascular conditions that contraindicate high dosages of sodium Pulmonary: No severe lung disease (e.g., chronic obstructive pulmonary disease) Other: Not pregnant or nursing Fertile patients must use effective contraception during and for 4 weeks after study participation No serious active infections No other serious concurrent disease PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics At least 4 weeks since prior immunotherapy Chemotherapy: See Disease Characteristics At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas) Endocrine therapy: Concurrent corticosteroids allowed Radiotherapy: See Disease Characteristics At least 8 weeks since prior radiotherapy Surgery: Recovered from any prior surgery Other: No prior antineoplaston therapy