This study is testing a combination of atovaquone, a drug already used for parasites, and radiation therapy (RT) to treat children with newly diagnosed or relapsed brain tumors, specifically high-grade glioma and medulloblastoma. Atovaquone might help improve radiation by blocking a protein called STAT3, which helps cancer cells survive. The study is looking at both the short-term and long-term safety of atovaquone when used with RT.

• Study Length: Participation involves multiple visits over a period of time.
• Eligibility: Children 2 to 25 years old with specific brain tumors can join. They must meet certain health criteria, like stable seizures and good liver function.
• Risks: As with any drug, there could be side effects. Pregnant girls and those with certain health issues can't participate.

This study could offer new treatment options for children with difficult-to-treat brain cancers.