Inclusion Criteria:

Disease Characteristics

- Histologically confirmed Medulloblastoma, cerebral PNET or Ependymoma

- Refractory or relapsed disease

- Measurable disease by MRI or detection of tumor cells in cerebrospinal fluid
Patients characteristics

- Performance status ECOG ≥ 3 or Karnofsky Status ≥ 40%

- Life expectancy ≥ 8 weeks

Hematological:

- Absolute leukocyte count ≥ 2.0 x 10^9 /l

- Hemoglobin ≥ 10g/dl

- Platelet count ≥ 70 x 10^9/l

Renal:

- Creatinine no greater than 1.5 times UNL

- No overt renal disease

Hepatic:

- Bilirubin less than 2.5 times UNL

- AST and ALT less than 5 times UNL

- No overt hepatic disease

Pulmonary:

- No overt pulmonary disease

Cardiovascular:

- No overt cardiovascular disease

Other:

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No uncontrolled infection Prior concurrent therapy

- More than 2 weeks since prior systemic chemotherapy

- More than 4 weeks since prior radiotherapy

- No other concurrent anticancer or experimental drugs Examinations required

- Examination of lumbar CSF

- Cranial and spinal MRI within 14 days prior to start of treatment