Combination Chemotherapy in Treating Younger Patients With Newly Diagnosed, Non-metastatic Desmoplastic Medulloblastoma

Inclusion Criteria: * Patients must be newly diagnosed and have a confirmed histologic diagnosis of nodular desmoplastic (ND) medulloblastoma or medulloblastoma with extensive nodularity (MBEN) from rapid central pathology screening review; please note: patients with Gorlin syndrome are eligible * Patient must have negative lumbar cerebrospinal fluid (CSF) cytology (lumbar CSF must be obtained unless medically contraindicated); CSF cytology for staging should be performed preferably no sooner than 14 days post operatively to avoid false positive CSF, ideally, CSF should be obtained between day 14 and day 21 to allow for final staging status before enrollment onto the study; Note: patients with positive CSF cytology obtained prior to 14 days after surgery may have cytology repeated to determine eligibility and final CSF status * Patients must have: * Pre-operative cranial magnetic resonance imaging (MRI) (recommended with gadolinium) or pre-operative computed tomography (CT) (recommended with contrast) * Post-operative cranial MRI with and without gadolinium within 72 hours of surgery * Spinal MRI pre-op with and without gadolinium or post-op with and without gadolinium preferably within 72 hours of surgery * Patients must be enrolled on study within 31 days of definitive surgical resection at which time tissue is acquired to determine a diagnosis; patients must be enrolled before treatment begins; the date protocol therapy is projected to start must be no later than f…