Tipifarnib and Radiation Therapy in Treating Young Patients With Brainstem Glioma

Inclusion Criteria: * Newly diagnosed non-disseminated intrinsic diffuse brainstem glioma * Karnofsky performance scale (KPS) (for \> 16 yrs of age) or Lansky performance score (LPS) (for =\< 16 years of age) =\> 50 assessed within two weeks prior to registration * Prior/concurrent therapy: * Chemo: No prior therapy allowed * Radiation therapy (XRT): No prior therapy allowed * Bone Marrow Transplant: None prior * Anti-convulsants: Patients receiving EIACDs will not be eligible; however, patients may switch from EIACDs to non-EIACDs and must then be on non-EIACDs for a minimum of 7 days prior to registration * Growth factors: Off all colony forming growth factor(s) \> 2 weeks prior to registration (G-CSF, GM-CSF, erythropoietin) * Absolute neutrophil count \>= 1,000/mm\^3 * Platelets \>= 100,000/mm\^3 (transfusion independent) * Hemoglobin \>= 8 gm/dL (transfusion independent) * Serum creatinine that is less than the upper limit of institutional normal for age or GFR \> 70 ml/min/1.73m2 * Bilirubin =\< 1.5 time upper limit of normal for age * SGPT (ALT) and SGOT (AST) \< 2.5 times institutional upper limit of normal * Female patients of childbearing potential must have negative serum or urine pregnancy test; patient must not be pregnant or breast-feeding * Patients of childbearing or child fathering potential must be willing to use a medically acceptable form of birth control, which includes abstinence, while being treated on this study * Signed informed consent ac…