title: Embolization Followed by Radiosurgery for the Treatment of Brain Arteriovenous Malformations (AVMs).
abstract: BACKGROUND
  Embolization has been proposed to reduce the size of the arteriovenous malformation (AVM) nidus in advance of radiosurgical treatment. Embolization followed by radiosurgery for brain AVMs, however, is controversial.
  
  
  OBJECTIVE
  We assessed the impact of embolization on nidal size before radiosurgical treatment and evaluated cure rates and complications by using embolization followed by radiosurgery.
  
  
  METHODS
  A retrospective review of our institutional AVM database identified 91 patients treated from 1995 to 2009 with embolization followed by radiosurgery. Pre- and postembolization AVM volumes were measured with angiography, and the modified radiation-based AVM scores (RBAS) also were calculated pre- and postembolization. RBAS determined from pre-embolization volumes were correlated with postradiosurgical obliteration.
  
  
  RESULTS
  Median AVM volume declined from 18.8 mL (interquartile range, 10.2-32.2 mL) to 9.9 mL (3.1-19.2 mL) after embolization, P < 0.00003. Median RBAS scores decreased from 2.6 mL (1.8-3.9 mL) to 1.8 mL (1.0-2.8 mL), P < 0.00003. Two of 91 (2.2%) had new fixed deficits after embolization; however, no patient had new disabling deficits (modified Rankin Scale score >2). A total of 71 of 91 (79%) have had >3 years' follow-up, and 40 (56%) had complete obliteration, with 38 (53%) having excellent outcomes (complete obliteration without neurologic decline). Excellent outcome was seen in 90% of patients with modified RBAS score <1, 66% of patients with score 1-1.5, 50% patients with score 1.5-2, and 43% of patients with score >2.
  
  
  CONCLUSIONS
  These data suggest that embolization of brain AVMs can safely and effectively reduce the treatment volume before radiosurgery. Combined therapy with embolization and radiosurgery does not appear to adversely affect rates of excellent outcome.
authors.affiliation: Department of Radiology, Stanford University Medical Center, Stanford, California, USA; Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA. Electronic address: mmarks@stanford.edu.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Marks
authors.affiliation: Department of Radiology, Stanford University Medical Center, Stanford, California, USA; Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Mary L
authors.initials: ML
authors.lastname: Marcellus
authors.affiliation: Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Justin
authors.initials: J
authors.lastname: Santarelli
authors.affiliation: Department of Radiology, Stanford University Medical Center, Stanford, California, USA; Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Dodd
authors.affiliation: Department of Radiology, Stanford University Medical Center, Stanford, California, USA; Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Huy M
authors.initials: HM
authors.lastname: Do
authors.affiliation: Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Chang
authors.affiliation: Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Adler
authors.affiliation: Department of Neurology, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Mlynash
authors.affiliation: Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA; Department of Neurology, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Gary K
authors.initials: GK
authors.lastname: Steinberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002533:Cerebral Angiography; D002648:Child; D003131:Combined Modality Therapy; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006261:Headache / Q000209:etiology; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000628:therapy*; D020300:Intracranial Hemorrhages / Q000209:etiology; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D012640:Seizures / Q000209:etiology; D016896:Treatment Outcome; D055815:Young Adult
keywords: Arteriovenous malformation (AVM); Embolization; Radiosurgery