Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed ependymoma that is unlikely to respond to existing therapy
and for which no curative therapy exists

- Evidence of tumor by MRI or CT scan

- Tumor must be at least 5 mm

- No brain stem tumors

PATIENT CHARACTERISTICS:

Age:

- 6 months and over

Performance status:

- Karnofsky 60-100%

Life expectancy:

- At least 2 months

Hematopoietic:

- WBC at least 2,000/mm3

- Platelet count greater than 50,000/mm3

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 renal failure

- 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

Other:

- Not pregnant or nursing

- Fertile patients must use effective contraception during and for 4 weeks after study

- No serious active infections or fever

- No other serious concurrent 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 and recovered (6 weeks for nitrosoureas)

- No concurrent antineoplastic agents

Endocrine therapy:

- Concurrent corticosteroids for cerebral edema allowed (must be on stable dose for at
least 1 week prior to study)

Radiotherapy:

- At least 8 weeks since prior radiotherapy and recovered

Surgery:

- Not specified

Other:

- No prior antineoplaston therapy