The purpose of this study is to see whether designing radiation to spare the vertebral bone marrow can limit the rates of lymphopenia during standard of care chemoradiation therapy and in the time to count recovery in the ensuing weeks. Secondary endpoints will examine whether this leads to improved disease control whether this is predictive of improved clinical outcomes such as rates of local recurrence (LR), metastasis free survival (MFS), overall survival (OS), and progression free survival (PFS) which will be followed prospectively up to 5 years.

This phase III trial studies the side effects of combination chemotherapy, 3-dimensional conformal radiation therapy, and an autologous peripheral blood stem cell transplant, and to see how well they work in treating young patients with atypical teratoid/rhabdoid tumor of the central nervous system. Giving high-dose chemotherapy before an autologous peripheral blood stem cell transplant stops the growth of cancer cells by stopping them from dividing or killing them. Giving colony-stimulating factors, such as G-CSF, helps stem cells move from the bone marrow to the blood so they can be collected and stored. Chemotherapy or radiation therapy is then given to prepare the bone marrow for the stem cell transplant. The stem cells are then returned to the patient to replace the blood-forming cells that were destroyed by the chemotherapy or radiation therapy.