Treatment of Relapsed/Refractory Intracranial Glioma in Patients Under 22 Years of Age

This study is testing a treatment that delivers the drug Avastin (bevacizumab) directly into the brain's blood supply via a specialized arterial injection, for children and adults with relapsed or treatment-resistant brain tumors including glioblastoma and diffuse brainstem glioma. **You may be eligible if...** - You have a confirmed or radiologically diagnosed relapsed or treatment-resistant brain tumor (such as glioblastoma, anaplastic astrocytoma, oligodendroglioma, or brainstem glioma) - You have at least one measurable tumor site - You have a Karnofsky/Lansky performance score of 60% or higher (able to care for self with some help) - You have adequate blood counts and organ function **You may NOT be eligible if...** - You are pregnant or breastfeeding - You have significant uncontrolled medical or psychiatric conditions - You had a craniotomy (brain surgery) less than 2 weeks ago Talk to your doctor to see if this trial is right for you.