MYCN and medulloblastoma: Thereafter we adopted the same treatment strategy in all those patients presenting with newly recognized,2,3 poor prognostic factors both for histology and biological alterations, such as large cell/anaplastic (LC/A) morphologic subtypes, TP53 mutations, and/or MYC and MYCN.4,5 This strategy was maintained with some amendments until the approval of the SIOP high-risk medulloblastoma protocol2 where, among the 3 randomized arms following induction chemotherapy(CT), one included the use of hyperfractionated accelerated radiotherapy (HART) to deliver craniospinal irradiation (CSI).