Of @ enrolled eligible patients , diagnoses were medulloblastoma ( n = @ ) , ependymoma ( n = @ ) , supratentorial primitive neuroectodermal tumor ( sPNET , n = @ ) and other malignant brain tumors ( n = @ ) , and were randomized to @ weeks of standard dose chemotherapy ( Regimen A , n = @ ) or DI chemotherapy ( Regimen B , n = @ ) .