title: Factors associated with successful arteriovenous malformation radiosurgery.
abstract: OBJECTIVE
  To analyze the clinical and angiographic variables that affect the results of arteriovenous malformation (AVM) radiosurgery and to propose a new method of reporting patient outcomes after AVM radiosurgery. This method incorporates both the obliteration status of the AVMs and the postoperative neurological condition of the patient.
  
  
  METHODS
  Patient outcomes were defined as excellent (nidus obliteration and no new deficits), good (nidus obliteration with a new minor deficit), fair (nidus obliteration with a new major deficit), unchanged (incomplete nidus obliteration without a new deficit), poor (incomplete nidus obliteration with any new deficit), and dead. Two hundred twenty patients who underwent AVM radiosurgery at our center before 1992 were subjected to a multivariate analysis with patient outcomes as the dependent variable.
  
  
  RESULTS
  Multivariate analysis determined four factors associated with successful AVM radiosurgery: smaller AVM volume (P=0.003), number of draining veins (P=0.001), younger patient age (P=0.0003), and hemispheric AVM location (P=0.002). Preradiosurgical embolization was a negative predictor of successful AVM radiosurgery (P=0.02).
  
  
  CONCLUSIONS
  AVM obliteration without new neurological deficits can be achieved in at least 80% of patients with small volume, hemispheric AVMs after single-session AVM radiosurgery. Future studies on AVM radiosurgery should report patient outcomes in a fashion that incorporates all the factors involved in successful AVM radiosurgery.
authors.affiliation: Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: B E
authors.initials: BE
authors.lastname: Pollock
authors.forename: J C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: L D
authors.initials: LD
authors.lastname: Lunsford
authors.forename: A
authors.initials: A
authors.lastname: Maitz
authors.forename: D
authors.initials: D
authors.lastname: Kondziolka
mesh_terms: D000328:Adult; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016634:Radiosurgery; D016896:Treatment Outcome