Melphalan, Carboplatin, Mannitol, and Sodium Thiosulfate in Treating Patients With Recurrent or Progressive CNS Embryonal or Germ Cell Tumors

Inclusion Criteria: * Subjects with histologically confirmed CNS embryonal tumor (primitive neuroectodermal tumor \[PNET\], medulloblastoma, atypical teratoid rhabdoid tumor \[ATRT\], medulloepithelioma, pineoblastoma or ependymoblastoma), or germ cell tumor, are eligible; subjects may be enrolled on study as first-line treatment; diagnosis will be made on the basis of computed tomography (CT)-assisted or stereotactic biopsy, open biopsy, surgical resection, cerebrospinal fluid (CSF) cytology, or elevated tumor markers * Subjects may be enrolled as part of first-line treatment; those subjects who enroll as first-line treatment will not be restricted from traditional treatments in the future; at least 14 days must have elapsed since completion of cranial radiotherapy and 28 days since completion of chemotherapy; at least 28 days must have elapsed since completion of total spine radiotherapy * Subjects with no previous radiotherapy treatment must have a consultation with a radiation oncologist or providers must have a discussion in the context of Neuro-Oncology Tumor Board within 60 days prior to start of IA/BBBD chemotherapy to determine the need for radiotherapy prior to or after IA/BBBD * Glomerular filtration rate (GFR) or creatinine clearance (CrCl) (24 hour urine) greater than 30 ml/min corrected for body surface area * Absolute granulocyte count \>= 1.0 x 10\^3/mm\^3 * Platelets \>= 100 x 10\^3/mm\^3 * Creatinine \< 1.5 * Total bilirubin \< 2.0 mg/dl * Aspartate aminotr…