Of 328 enrolled eligible patients , diagnoses were medulloblastoma ( n = 112 ) , ependymoma ( n = 82 ) , supratentorial primitive neuroectodermal tumor ( sPNET , n = 38 ) and other malignant brain tumors ( n = 96 ) , and were randomized to 72 weeks of standard dose chemotherapy ( Regimen A , n = 162 ) or DI chemotherapy ( Regimen B , n = 166 ) .