title: MRI abnormalities in children following sequential chemotherapy, hyperfractionated accelerated radiotherapy and high-dose thiotepa for high-risk primitive neuroectodermal tumours of the central nervous system.
abstract: BACKGROUND
  Intensive postsurgical therapies have improved survival in children with primitive neuroectodermal tumour, but there is concern that the combination of chemotherapy and radiotherapy may result in a compound injury to normal brain. The purposes of this analysis were to characterise what types of imaging abnormalities occur, identify risk factors and explore how treatment-related changes may be distinguished from tumour.
  
  
  METHODS
  One hundred fifty-three MRI studies in 14 children treated with sequential chemotherapy, hyperfractionated accelerated radiotherapy and high-dose thiotepa were retrospectively analysed at a paediatric national referral centre.
  
  
  RESULTS
  We observed 11 episodes of new focal enhancing lesions, 5 of which were transient and judged to be treatment related. In addition, 7/14 (50%) of children demonstrated moderate to severe brain volume loss featuring a leukodystrophy pattern.
  
  
  CONCLUSIONS
  Treatment-related brain MRI abnormalities occurred frequently in this series with a risk of misdiagnosis as tumour. A proportion of patients suffer generalised white matter injury, which has not been appreciated as a side effect of this particular therapy.
authors.affiliation: Department of Paediatric Neuroradiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK; Department of Oncology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Stefanie C
authors.initials: SC
authors.lastname: Thust
authors.forename: Esther
authors.initials: E
authors.lastname: Blanco
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Michalski
authors.forename: W K
authors.initials: WK
authors.lastname: Chong
authors.forename: Mark N
authors.initials: MN
authors.lastname: Gaze
authors.forename: Kim
authors.initials: K
authors.lastname: Phipps
authors.forename: Kshitij
authors.initials: K
authors.lastname: Mankad
mesh_terms: D000293:Adolescent; D018906:Antineoplastic Agents, Alkylating / Q000009:adverse effects / Q000627:therapeutic use; D001930:Brain Injuries / Q000209:etiology / Q000473:pathology*; D001932:Brain Neoplasms / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy / Q000009:adverse effects / Q000379:methods; D019583:Dose Fractionation, Radiation; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D017599:Neuroectodermal Tumors / Q000473:pathology / Q000628:therapy*; D011832:Radiation Injuries / Q000209:etiology / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors; D013852:Thiotepa / Q000008:administration & dosage* / Q000009:adverse effects; D016896:Treatment Outcome
chemical_list: D018906:Antineoplastic Agents, Alkylating; D013852:Thiotepa
keywords: cerebral primitive neuroectodermal tumour; chemotherapy; medulloblastoma; paediatrics; radiation oncology; thiotepa