Vorinostat and Radiation Therapy Followed by Maintenance Therapy With Vorinostat in Treating Younger Patients With Newly Diagnosed Diffuse Intrinsic Pontine Glioma

Inclusion Criteria: * Patients with newly diagnosed diffuse intrinsic pontine gliomas (DIPGs), defined as tumors with a pontine epicenter and diffuse involvement of at least 2/3 of the pons, are eligible without histologic confirmation; patients with brainstem tumors that do not meet these criteria or not considered to be typical intrinsic pontine gliomas will only be eligible if the tumors are biopsied and proven to be an anaplastic astrocytoma, glioblastoma multiforme, gliosarcoma, or anaplastic mixed glioma; patients with juvenile pilocytic astrocytoma, fibrillary astrocytoma, gangliogliomas, or other mixed gliomas without anaplasia are not eligible; patients with disseminated disease are not eligible, and magnetic resonance imaging (MRI) of spine must be performed if disseminated disease is suspected by the treating physician * Karnofsky \>= 50% for patients \> 16 years of age and Lansky \>= 50 for patients =\< 16 years of age; patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score * Patients must not have received any prior treatment except dexamethasone and/or surgery * Peripheral absolute neutrophil count (ANC) \>= 1000/uL * Platelet count \>= 100,000/uL (transfusion independent, defined as not receiving platelet transfusions within a 7 day period prior to enrollment) * Hemoglobin \>= 8.0 g/dL (may receive red blood cell \[RBC\] transfusions) * Creatinine cl…