title: Detection of irreversible changes in susceptibility-weighted images after whole-brain irradiation of children.
abstract: BACKGROUND
  Whole-brain irradiation is part of the therapy protocol for patients with medulloblastomas. Side effects and complications of radiation can be detected by follow-up magnetic resonance imaging (MRI). Susceptibility-weighted images (SWI) can detect even very small amounts of residual blood that cannot be shown with conventional MRI. The purpose of this study was to determine when and where SWI lesions appear after whole-brain irradiation.
  
  
  METHODS
  MRI follow-up of seven patients with medulloblastoma who were treated with whole-brain irradiation were analyzed retrospectively. SWI were part of the initial and follow-up MRI protocol. De novo SWI lesions, localization, and development over time were documented.
  
  
  RESULTS
  At time of irradiation, mean age of the patients was 13 years (±4 years). Earliest SWI lesions were detected 4 months after radiation treatment. In all patients, SWI lesions accumulated over time, although the individual number of SWI lesions varied. No specific dissemination of SWI lesions was observed.
  
  
  CONCLUSIONS
  Whole-brain irradiation can cause relatively early dot-like SWI lesions. The lesions are irreversible and accumulate over time. Histopathological correlation and clinical impact of these SWI lesions should be investigated.
authors.affiliation: Institute of Neuroradiology, University of Schleswig-Holstein, Arnold-Heller-Straße 3-Haus 41, Campus Kiel, 24105 Kiel, Germany. s.peters@neurorad.uni-kiel.de
authors.forename: S
authors.initials: S
authors.lastname: Peters
authors.forename: R
authors.initials: R
authors.lastname: Pahl
authors.forename: A
authors.initials: A
authors.lastname: Claviez
authors.forename: O
authors.initials: O
authors.lastname: Jansen
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology / Q000528:radiation effects; D001930:Brain Injuries / Q000209:etiology* / Q000473:pathology*; D002528:Cerebellar Neoplasms / Q000150:complications / Q000473:pathology / Q000532:radiotherapy; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008527:Medulloblastoma / Q000150:complications / Q000473:pathology / Q000532:radiotherapy; D011832:Radiation Injuries / Q000209:etiology* / Q000473:pathology*; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity