title: Development of a model to predict permanent symptomatic postradiosurgery injury for arteriovenous malformation patients. Arteriovenous Malformation Radiosurgery Study Group.
abstract: OBJECTIVE
  To better predict permanent complications from arteriovenous malformation (AVM) radiosurgery.
  
  
  METHODS
  Data from 85 AVM patients who developed symptomatic complications following gamma knife radiosurgery and 337 control patients with no complications were evaluated as part of a multi-institutional study. Of the 85 patients with complications, 38 patients were classified as having permanent symptomatic sequelae (necrosis). AVM marginal doses varied from 10-35 Gy and treatment volumes from 0.26-47.9 cc. Median follow-up for patients without complications was 45 months (range: 24-92).
  
  
  RESULTS
  Multivariate analysis of the effects of AVM location and the volume of tissue receiving 12 Gy or more (12-Gy-Volume) allowed construction of a significant postradiosurgery injury expression (SPIE) score. AVM locations in order of increasing risk and SPIE score (from 0-10) were: frontal, temporal, intraventricular, parietal, cerebellar, corpus callosum, occipital, medulla, thalamus, basal ganglia, and pons/midbrain. The final statistical model predicts risks of permanent symptomatic sequelae from SPIE scores and 12-Gy-Volumes. Prior hemorrhage, marginal dose, and Marginal-12-Gy-Volume (target volume excluded) did not significantly improve the risk-prediction model for permanent sequelae (p >/= 0.39).
  
  
  CONCLUSIONS
  The risks of developing permanent symptomatic sequelae from AVM radiosurgery vary dramatically with location and, to a lesser extent, volume. These risks can be predicted according to the SPIE location-risk score and the 12-Gy-Volume.
authors.affiliation: Department of Radiation Oncology, University of Pittsburgh School of Medicine, PA, USA. jflickin+@pitt.edu
authors.forename: J C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: D
authors.initials: D
authors.lastname: Kondziolka
authors.forename: L D
authors.initials: LD
authors.lastname: Lunsford
authors.forename: A
authors.initials: A
authors.lastname: Kassam
authors.forename: L K
authors.initials: LK
authors.lastname: Phuong
authors.forename: R
authors.initials: R
authors.lastname: Liscak
authors.forename: B
authors.initials: B
authors.lastname: Pollock
mesh_terms: D016022:Case-Control Studies; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D015601:Injury Severity Score; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology / Q000601:surgery*; D016015:Logistic Models; D008954:Models, Biological; D015999:Multivariate Analysis; D016634:Radiosurgery / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D018570:Risk Assessment; D012307:Risk Factors