Imatinib Mesylate With or Without Radiation Therapy in Treating Young Patients With Newly Diagnosed or Recurrent Glioma

Phase I/II trial to estimate the maximum tolerated dose of imatinib mesylate in newly diagnosed brain stem gliomas and recurrent high grade gliomas and to assess the effectiveness of imatinib mesylate in treating young patients who have newly diagnosed intrinsic brain stem glioma. Imatinib mesylate may interfere with the growth of tumor cells by blocking the enzymes necessary for their growth. Radiation therapy uses high-energy x-rays to damage tumor cells. Combining imatinib mesylate with radiation therapy may kill more tumor cells.