Antineoplaston Therapy in Treating Children With Brain Tumors

DISEASE CHARACTERISTICS: * Histologically confirmed (except if medically contraindicated) childhood brain tumor for which no curative therapy exists * Measurable tumor by MRI scan performed within two weeks prior to study entry * Tumor must be at least 5 mm PATIENT CHARACTERISTICS: Age: * 6 months to 17 years Performance status: * Karnofsky 60-100% Life expectancy: * At least 2 months Hematopoietic: * WBC greater than 2000/mm\^3 * Platelet count greater than 50,000/mm\^3 Hepatic: * Bilirubin no greater than 2.5 mg/dL * SGOT and 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 history of heart failure * No history of other cardiovascular conditions that contraindicate high dosages of sodium * No uncontrolled hypertension Pulmonary: * No severe lung disease Other: * Not pregnant or nursing * Fertile patients must use effective contraception during and for 4 weeks after study participation * No serious active infections or fever * No other serious concurrent disease PRIOR CONCURRENT THERAPY: Biologic therapy: * At least 4 weeks since prior immunotherapy * No concurrent immunomodulating agents Chemotherapy: * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas) and recovered * No concurrent antineoplastic agents Endocrine therapy: * Concurrent corticosteroids for cerebral edema allowed (must be on stable dose for at least 1 week before study entry) Radiation therapy: * At least 8 weeks since prior radiotherapy and recovered Surgery: * Recovered from any prior surgery Other: * No prior antineoplaston therapy