title: Treatment of young children with CNS-positive acute lymphoblastic leukemia without cranial radiotherapy.
abstract: BACKGROUND
  Due to the long-term sequelae of cranial radiotherapy (CRT), contemporary treatment protocols for children with acute lymphoblastic leukemia (ALL) aim to limit the use of prophylactic CRT. For patients with central nervous system (CNS) involvement with ALL at diagnosis, the use of CRT remains common. Children <5 years of age are a particularly challenging subgroup in whom the consequences of CRT can be devastating.
  
  
  METHODS
  This study retrospectively describes the overall (OS) and event-free survival (EFS) of young children (1-5 years) who were treated for CNS-positive ALL at the Hospital for Sick Children between 2000 and 2013.
  
  
  RESULTS
  Of a total of 19 patients, two were treated with upfront CRT, both as part of the conditioning regimen prior to HSCT. All patients received intensification of CNS-directed chemotherapy by triple intra-thecal chemotherapy (84.2%), use of dexamethasone in induction (57.9%) and maintenance (66.7%), and high-dose methotrexate (77.8%). The OS was 84.2 ± 8.4% and EFS was 79.0 ± 9.4% with a median follow-up time of 4.3 years (range, 2.6-8.2). The cumulative incidence of CNS relapse was 5.2 ± 5.1%.
  
  
  CONCLUSIONS
  We conclude that omission of CRT from the treatment of young children with ALL involving the CNS is associated with acceptable survival and avoids potentially devastating late effects in this group.
authors.affiliation: Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Marta
authors.initials: M
authors.lastname: Wilejto
authors.affiliation: Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Di Giuseppe
authors.affiliation: Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Johann
authors.initials: J
authors.lastname: Hitzler
authors.affiliation: Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Sumit
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Oussama
authors.initials: O
authors.lastname: Abla
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D016543:Central Nervous System Neoplasms / Q000188:drug therapy* / Q000401:mortality*; D002675:Child, Preschool; D003907:Dexamethasone / Q000008:administration & dosage; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000401:mortality*; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D003907:Dexamethasone; D008727:Methotrexate
keywords: acute lymphoblastic leukemia (ALL); long-term survival; pediatric oncology; radiation therapy