Veliparib, Radiation Therapy, and Temozolomide in Treating Younger Patients With Newly Diagnosed Diffuse Pontine Gliomas

Inclusion Criteria: * Patients with newly diagnosed diffuse intrinsic pontine gliomas (DIPGs), defined as tumors with a pontine epicenter and diffuse intrinsic involvement 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, anaplastic mixed glioma, or fibrillary astrocytoma * Patients with juvenile pilocytic astrocytoma, pilomyxoid 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 * Patient must be able to swallow oral medications to be eligible for study enrollment * Karnofsky \>= 50% for patients \> 16 years of age or 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 have not received any prior therapy other than surgery and/or steroids * Absolute neutrophil count \>= 1,000/mm\^3 * Platelets \>= 100,000/mm\^3 (unsupported) * Hemoglobin \>= 10 g/dL (unsupported) * Total bilirubin =\< 1.5 times upp…