title: The radiosurgical treatment of arteriovenous malformations: obliteration, morbidities, and performance status.
abstract: OBJECTIVE
  This study examined the single-center treatment outcomes of arteriovenous malformations (AVMs) of the brain using stereotactic radiosurgery, with regard to obliteration, predictive factors, morbidities, and patient performance status.
  
  
  METHODS
  127 patients were treated between 1990 and 2008 by use of linear accelerator or Gamma Knife. Their median age was 37 years, the median AVM volume was 7.3 cc (range, 0.014-113.13 cc), and the median follow-up duration was 42 months (range, 6-209 months). Forty-two percent of patients presented with intracranial hemorrhage, 31% received embolization, and 8% underwent prior resection. Thirty-one percent of patients received more than one round of radiosurgery.
  
  
  RESULTS
  64% of patients had complete obliteration confirmed by magnetic resonance imaging or angiography. Positive predictors of obliteration included pretreatment hemorrhage (p = 0.042), smaller AVM volume (odds ratio = 1.25; 95% CI, 1.03-1.52), and larger marginal dose (odds ratio = 0.292; 95% CI, 0.100-0.820), whereas embolization (p < 0.001) was a negative predictor . The annual risk of hemorrhage after radiosurgery was 2.2%, and the risk of death as a result of hemorrhage was 0.6-1.3%. Eleven percent of patients reported new or worsened neurologic symptoms. Radiosurgery was effective in treating AVM-related headaches (p < 0.001) but did not improve the performance status of patients.
  
  
  CONCLUSIONS
  Stereotactic radiosurgery is an effective tool in the treatment of AVMs and amelioration of AVM-related headaches, but it did not affect the patients' performance status. Factors affecting obliteration include prior hemorrhage, marginal dose, prior embolization, and AVM volume. Risk of hemorrhage persists in the latency period after radiosurgery, and it remains finite even after complete obliteration.
authors.affiliation: Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Daniel Q
authors.initials: DQ
authors.lastname: Sun
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Carson
authors.forename: Shaan M
authors.initials: SM
authors.lastname: Raza
authors.forename: Sachin
authors.initials: S
authors.lastname: Batra
authors.forename: Lawrence R
authors.initials: LR
authors.lastname: Kleinberg
authors.forename: Michael
authors.initials: M
authors.lastname: Lim
authors.forename: Judy
authors.initials: J
authors.lastname: Huang
authors.forename: Daniele
authors.initials: D
authors.lastname: Rigamonti
mesh_terms: D000293:Adolescent; D000328:Adult; D002543:Cerebral Hemorrhage / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D002648:Child; D004621:Embolization, Therapeutic / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D012306:Risk; D014653:Vascular Headaches / Q000209:etiology / Q000601:surgery; D055815:Young Adult