Erlotinib and Radiation Therapy in Treating Young Patients With Newly Diagnosed Glioma

RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells. Erlotinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth and by blocking blood flow to the tumor. It may also make tumor cells more sensitive to radiation therapy. Giving radiation therapy together with erlotinib may kill more tumor cells. PURPOSE: This phase I/II trial is studying the side effects and best dose of erlotinib when given together with radiation therapy and to see how well they work in treating young patients with newly diagnosed glioma.