- Reduce the late cognitive, auditory, and endocrinologic effects in children with newly diagnosed standard-risk posterior fossa primitive neuroectodermal tumor or medulloblastoma by reducing the adjuvant craniospinal radiotherapy dose by 25%, but maintaining a therapeutic efficacy (86% 3-year relapse-free survival) of current standard therapy by using maintenance chemotherapy comprising lomustine, cisplatin, and vincristine alternated with cyclophosphamide and etoposide.