Antineoplaston Therapy in Treating Children With Rhabdoid Tumor of the Central Nervous System

DISEASE CHARACTERISTICS: Histologically confirmed Rhabdoid tumor of the central nervous system that is unlikely to respond to existing therapy and 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 at least 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 uncontrolled hypertension No severe heart disease No history of congestive heart failure No history of other cardiovascular conditions that contraindicate high dosages of sodium 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 concomitant disease PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior immunotherapy and recovered 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 a stable dose for at least 1 week before study entry) Radiotherapy: At least 8 weeks since prior radiotherapy and recovered Surgery: Not specified Other: No prior antineoplaston treatment