4. Performance Level: Karnofsky >/= 70% for patients >10 years of age and Lansky Play-Performance Scale >/=70 for children </= 10 years of age. Neurologic deficits in patients with CNS tumors must have been relatively stable for a minimum of 2 weeks prior to study entry. Patients who are unable to walk because of paralysis, but who are up in a wheelchair will be considered ambulatory for the purpose of assessing the performance score.