Inclusion Criteria:

- Consensus of diagnosis must be reached by a multidisciplinary pediatric
neuro-oncology team by considering both clinical evidence and MRI presentation.
Tissue diagnosis is not required.

- The patient must have undergone prior external beam radiotherapy to a dose of 54-60
Gy to the brain stem. At least 4 weeks but no more than 14 weeks must have elapsed
from the completion of radiotherapy.

- The patient must be in adequate general condition for study, with Lansky or Karnofsky
Performance Score of > or = to 50 at study entry .

Lansky Performance scale will be used for patients ≤16 years of age.

- The patient must be > to or = to 3 and ≤ 21 years old.

- Patient must weigh a minimum of 8 kg.

Exclusion Criteria:

- Clinical and/or radiographic (MRI) progression of tumor following external beam
radiation therapy.

- Metastatic disease.

- Untreated symptomatic hydrocephalus determined by treating physician.

- AST or ALT > 2x the upper limit of normal.

- Platelets < 100,000/mcL.

- ANC < 1000/mcL.

- Abnormal PT (Inr) >1.5 INR or PTT > 42 sec (may be corrected with FFP,
cryoprecipitate, vitamin K, etc).

- Total bilirubin > 2.0 mg/dl.

- Serum creatinine > 1.5x the upper limit of normal for age, or calculated creatinine
clearance or nuclear GFR < 70 ml/min/1.73 m2.