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 upper limit of normal (ULN) for age
* Alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase (SGPT)) =\< 5 x institutional upper limit of normal for age
* Albumin \>= 2 g/dL
* Creatinine clearance or radioisotope glomerular filtration rate (GFR) \>= 70 mL/min/1.73 m\^2 or a serum creatinine based on age/gender as follows:

  * 0.6 mg/dL (1 to \< 2 years of age)
  * 0.8 mg/dL (2 to \< 6 years of age)
  * 1.0 mg/dL (6 to \< 10 years of age)
  * 1.2 mg/dL (10 to \< 13 years of age)
  * 1.5 mg/dL (male) or 1.4 mg/dL (female) (13 to \< 16 years of age)
  * 1.7 mg/dL (male) or 1.4 mg/dL (female) (\>= 16 years of age)
* Female patients of childbearing potential must not be pregnant or breast-feeding; female patients of childbearing potential must have a negative serum or urine pregnancy test
* 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 according to institutional guidelines must be obtained; assent, when appropriate, will be obtained according to institutional guidelines

Exclusion Criteria:

* Patients with any clinically significant unrelated systemic illness (serious infections or significant cardiac, pulmonary, hepatic or other organ dysfunction), that would compromise the patient's ability to tolerate protocol therapy or would likely interfere with the study procedures or results
* Patients with inability to return for follow-up visits or obtain follow-up studies required to assess toxicity to therapy
* Patients with active seizures or a history of seizure are not eligible for study entry, with the exception of patients with documented febrile seizure