Chemotherapy Followed by Radiation Therapy in Treating Younger Patients With Newly Diagnosed Localized Central Nervous System Germ Cell Tumors

Inclusion Criteria:

* Patients must be newly diagnosed with localized primary CNS NGGCT (Stratum 1) or localized primary CNS germinoma (Stratum 2); germ cell tumors located in the suprasellar, pineal, bifocal (pineal + suprasellar) and ventricles are eligible; tumors present in the above mentioned locations and with unifocal parenchymal extension are eligible

  * Stratum 1(NGGCT): Patients must have one of the following criteria:

    * Patients with serum and/or CSF hCGbeta \> 100 mIU/mL or any elevation of serum and/or CSF alpha-fetoprotein (AFP) \> 10 ng/mL or greater than the institutional normal are eligible, irrespective of biopsy results
    * Patients with any of the following elements on biopsy/resection are eligible, irrespective of serum and/or CSF hCGbeta and AFP levels: endodermal sinus tumor (yolk sac), embryonal carcinoma, choriocarcinoma, malignant/immature teratoma, and mixed GCT with malignant GCT elements
  * Stratum 2 (Germinoma): Patients must have both serum and CSF markers obtained (unless obtaining CSF is medically contraindicated) and must have one of the following criteria to be eligible:

    * Patients with institutional normal AFP (or =\< 10 ng/mL if no institutional normal exists) in both serum and CSF (unless medically contraindicated) AND hCGbeta 5 to =\< 50 mIU/mL in serum and/or CSF (unless medically contraindicated) (only 1 is required to be elevated) are eligible; no histologic confirmation required
    * Patients with bifocal (pineal + suprasellar) involvement or pineal lesion with diabetes insipidus (D1) AND hCGbeta =\< 100 mIU/mL in serum and/or CSF AND institutional normal AFP (or =\< 10 ng/mL if no institutional normal exists) in both serum and CSF (unless medically contraindicated) are eligible; no histologic confirmation required
    * Patients with histologically confirmed germinoma or germinoma mixed with mature teratoma and hCGbeta =\< 100 mIU/mL in serum and/or CSF and institutional normal AFP (or =\< 10 ng/mL if no institutional normal exists) in both serum and CSF (unless medically contraindicated) are eligible
* All patients must have a cranial MRI with and without gadolinium at diagnosis/prior to enrollment; if surgical resection is performed, patients must have pre-operative and post-operative cranial MRI with and without gadolinium; the post-operative brain MRI should be obtained within 72 hours of surgery; if patient has a biopsy only, post-operative cranial MRI is recommended but not required; all patients must have a spine MRI with gadolinium obtained at diagnosis/prior to enrollment; Note: if the spine study is performed for the first time after surgical resection or biopsy, it is recommended to be obtained with and without gadolinium
* Lumbar CSF must be obtained prior to study enrollment unless medically contraindicated; if a patient undergoes surgery and lumbar CSF cannot be obtained at this time, then it should be performed at least 10 days following surgery before study enrollment; false positive cytology can occur within 10 days of surgery; Note: patients with positive CSF cytology obtained prior to 10 days after surgery may have cytology repeated to determine eligibility
* Patients must have CSF tumor markers obtained prior to enrollment unless medically contraindicated; ventricular CSF obtained at the time of CSF diversion procedure (if performed) is acceptable for tumor markers but lumbar CSF is preferred; in case CSF diversion and biopsy/surgery are combined, CSF tumor markers should be collected first
* Patients must be enrolled on ALTE07C1 prior to enrollment on ACNS1123; patients must be enrolled within 31 days of definitive diagnostic surgery (day 0) or clinical diagnosis
* Peripheral absolute neutrophil count (ANC) \>= 1,000/uL
* Platelet count \>= 100,000/uL (transfusion independent)
* Hemoglobin \>= 8.0 g/dL (may receive red blood cell \[RBC\] transfusions)
* Creatinine clearance or radioisotope glomular filtration rate (GFR) \>= 70 mL/min/1.73 m\^2 OR serum creatinine based on age/gender as follows:

  * 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) and 1.4 mg/dL (female) (13 to \< 16 years of age)
  * 1.7 mg/dL (male) and 1.4 mg/dL (female) (\>= 16 years of age)
* Total bilirubin =\< 1.5 times upper limit of normal (ULN) for age
* Serum glutamic oxaloacetic transaminase (SGOT) (aspartate aminotransferase \[AST\]) and serum glutamate pyruvate transaminase (SGPT) (alanine aminotransferase \[ALT\]) \< 2.5 times ULN
* Patients with seizure disorder may be enrolled if well controlled
* Patients must not be in status, coma, or assisted ventilation prior to study enrollment

Exclusion Criteria:

* Patients with mature teratoma or completely resected immature teratoma with normal tumor markers are not eligible
* Patients with tumors located outside the ventricles (basal ganglia, thalamus) are not eligible
* Patients with metastatic disease by cranial or spinal MRI evaluation or CSF cytology (unless medically contraindicated) are not eligible
* Patients must not have received any prior tumor-directed therapy other than surgical intervention and corticosteroids
* Female patients who are pregnant are ineligible
* Lactating females are not eligible unless they have agreed not to breastfeed their infants
* Female patients of childbearing potential are not eligible unless a negative pregnancy test result has been obtained
* Sexually active patients of reproductive potential are not eligible unless they have agreed to use an effective contraceptive method for the duration of their study participation
* All patients and/or their parents or legal guardians must sign a written informed consent
* All institutional, Food and Drug Administration (FDA), and National Cancer Institute (NCI) requirements for human studies must be met