Molecular and Clinical Risk-Directed Therapy for Infants and Young Children With Newly Diagnosed Medulloblastoma

Inclusion Criteria - Screening Phase (All Patients) * Participants with presumptive/suspected newly diagnosed medulloblastoma. * Participant meets one of the following criteria at the time of screening: * Age \< 36 months OR Age ≥ 36 months and \< 60 months with presumptive/suspected non-metastatic disease * Participant must have adequate tumor tissue from primary tumor for central review of pathology and molecular classification by methylation and IHC * Participant must be able to begin treatment as outlined in the protocol within 36 days of definitive surgery (day of surgery is Day 0). In case a second surgery is clinically indicated to remove the residual tumor prior to starting treatment, the second surgery will be considered as the definitive surgery (Day 0). * Parent or legal guardian can understand and is willing to sign a written informed consent document according to institutional guidelines. Exclusion Criteria - Screening Phase * Participants with other clinically significant medical disorders (i.e., serious infections or significant cardiac, pulmonary, hepatic, psychiatric, or other organ dysfunction) that could compromise their ability to tolerate protocol therapy or would interfere with the study procedure. Inclusion Criteria - Study Enrollment (All Patients) * Participant must be \< 60 months of age at time of enrollment. * Note: Each treatment stratum has additional specific age requirements * Participant must have confirmation of newly diagnosed med…