title: Delayed cerebral vasculopathy following cranial radiation therapy for pediatric tumors.
abstract: BACKGROUND
  Radiation-induced cerebrovascular injury is a well-known phenomenon. We analyze reported cases of delayed radiation-induced cerebrovasculopathy that present as moyamoya syndrome and/or intracerebral hemorrhage and to statistically analyze the relationship between radiation dose and the interval period between radiation and the presentation of cerebrovasculopathy.
  
  
  METHODS
  Patients ages <21 years at the time of radiation were included in analysis. A review of previous publications yielded 77 cases of delayed radiation-induced cerebrovasculopathy consisting of 45 cases of moyamoya syndrome, 30 cases of intracerebral hemorrhage, and two cases of both.
  
  
  RESULTS
  The median age at radiation was 4.8 years, with a range of 0.5-20 years. Approximately, 75% of these patients received radiation at the age of <9 years. The median interval period for moyamoya cases was 3.3 years (range: 0.3-20; P < 0.001), whereas the median interval period from radiation to presentation for intracerebral hemorrhage cases was 7.5 years (range: 0.8-27). There was significant association between radiation dose and interval from radiation to moyamoya syndrome (P < 0.001), whereas for patients with intracerebral hemorrhage, the association was insignificant (P = 0.31).
  
  
  CONCLUSIONS
  Pediatric patients who presented with moyamoya generally presented earlier than those who presented with intracerebral hemorrhage, suggesting that moyamoya may be a factor that predisposes the patient to intracerebral hemorrhage. In patients who presented with moyamoya, there was a statistically significant correlation between increasing doses of radiation and shorter time from radiation to disease presentation.
authors.affiliation: Yale School of Medicine, New Haven, Connecticut.
authors.forename: Chenyang
authors.initials: C
authors.lastname: Wang
authors.affiliation: Yale School of Medicine, New Haven, Connecticut; Department of Therapeutic Radiology, Yale School of Medicine, New Haven, Connecticut.
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Roberts
authors.affiliation: Yale School of Medicine, New Haven, Connecticut; Department of Therapeutic Radiology, Yale School of Medicine, New Haven, Connecticut.
authors.forename: Ranjit S
authors.initials: RS
authors.lastname: Bindra
authors.affiliation: Yale School of Medicine, New Haven, Connecticut; Department of Neurosurgery, Yale School of Medicine, New Haven, Connecticut.
authors.forename: Veronica L
authors.initials: VL
authors.lastname: Chiang
authors.affiliation: Yale School of Medicine, New Haven, Connecticut; Department of Therapeutic Radiology, Yale School of Medicine, New Haven, Connecticut. Electronic address: James.b.yu@yale.edu.
authors.forename: James B
authors.initials: JB
authors.lastname: Yu
mesh_terms: D001932:Brain Neoplasms / Q000532:radiotherapy*; D002543:Cerebral Hemorrhage / Q000453:epidemiology / Q000209:etiology*; D002561:Cerebrovascular Disorders / Q000453:epidemiology / Q000209:etiology*; D002648:Child; D006801:Humans; D009072:Moyamoya Disease / Q000453:epidemiology / Q000209:etiology*; D011878:Radiotherapy / Q000009:adverse effects*
keywords: cerebrovasculopathy; intracerebral hemorrhage; moyamoya; radiation