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

All participants enrolled will undergo surgical resection prior to treatment. The maximal resection that can be achieved without undue risk to the patient will be attempted, with decisions about feasibility and extent of resection left to the discretion of the neurosurgeon. In instances where an STR is the best extent of resection achieved prior to start of therapy, a "second-look" surgery may be performed between cycles of chemotherapy after discussion with the principal investigator.

All participants enrolled on S-1 will undergo

Route of administration: Intravenously (IV)

Route of administration: Intravenously (IV)

Route of administration: Intravenously (IV)

Route of administration: Intravenously (IV)

Route of administration: Intravenously (IV)

Route of administration: Intravenously (IV)

Route of administration: Intravenously (IV)

Route of administration: subcutaneous (SQ)

Route of administration: subcutaneous (SQ) or Intravenously (IV)

All participants in stratum N will undergo craniospinal irradiation (CSI) with boost to the primary tumor site once they reach 36 months of age. The dose given is based on the molecular risk group and disease response to chemotherapy as noted in the arm descriptions. The type of radiation used includes conformal radiation therapy (photons) or intensity modulated radiation therapy (IMRT) or proton beam therapy.

Participants watch a 75-minute caregiver education video program and receive access to interactive games on a smartphone or tablet throughout the optional cognitive study.

Standard-of-care (SOC) treatment during main cognitive study. After the one-year serial cognitive evaluation, participants will be offered participation in the cognitive study group I intervention.

Route of administration: Intravenously (IV) \& Intra Ventricular (IVT)