Individualized Treatment Plan in Children and Young Adults With Relapsed Medulloblastoma and Ependymoma

This study creates individualized treatment plans for children and young adults whose brain tumors — specifically medulloblastoma or ependymoma — have come back after initial treatment. The team analyzes the tumor tissue from a new surgery to guide personalized therapy. **You may be eligible if...** - You have recurrent (returned) medulloblastoma or ependymoma — either your first or second relapse - Your tumor can be accessed surgically and enough tissue can be collected - You have recovered from prior chemotherapy, radiation, or surgery **You may NOT be eligible if...** - Your tumor cannot be safely reached by surgery - You have not yet fully recovered from previous cancer treatments - You received certain treatments too recently (e.g., chemotherapy within 7 days, antibody therapy within 21 days) Talk to your doctor to see if this trial is right for you.