title: Radiosurgery for large cerebral arteriovenous malformations.
abstract: BACKGROUND
  Radiosurgery is an effective treatment option for patients with small to medium sized arteriovenous malformations. However, it is not generally accepted as an effective tool for larger (>14 cm(3)) arteriovenous malformations because of low obliteration rates. The authors assessed the applicability and effectiveness of radiosurgery for large arteriovenous malformations.
  
  
  METHODS
  We performed a retrospective study of 46 consecutive patients with more than 14 ml of arteriovenous malformations who were treated with radiosurgery using a linear accelerator and gamma knife (GK). They were grouped according to their initial clinical presentation-17 presented with and 29 without haemorrhage. To assess the effect of embolization, these 46 patients were also regrouped into two subgroups-25 with and 21 without preradiosurgical embolization. Arteriovenous malformations found to have been incompletely obliterated after 3-year follow-up neuroimaging studies were re-treated using a GK.
  
  
  RESULTS
  The mean treatment volume was 29.5 ml (range, 14.0-65.0) and the mean marginal dose was 14.1 Gy (range, 10.0-20.0). The mean clinical follow-up periods after initial radiosurgery was 78.1 months (range, 34.0-166.4). Depending on the results of the angiography, 11 of 33 patients after the first radiosurgery and three of four patients after the second radiosurgery showed complete obliteration. Twenty patients received the second radiosurgery and their mean volume was significantly smaller than their initial volume (P = 0.017). The annual haemorrhage rate after radiosurgery was 2.9% in the haemorrhage group (mean follow-up 73.3 months) and 3.1% in the nonhaemorrhage group (mean follow-up 66.5 months) (P = 0.941). Preradiosurgical embolization increased the risk of haemorrhage for the nonhaemorrhage group (HR, 28.03; 95% CI, 1.08-6,759.64; P = 0.039), whereas it had no effect on the haemorrhage group. Latency period haemorrhage occurred in eight patients in the embolization group, but in no patient in the nonembolization group (P = 0.004).
  
  
  CONCLUSIONS
  Radiosurgery may be a safe and effective arteriovenous malformation treatment method that is worth considering as an alternative treatment option for a large arteriovenous malformation.
authors.affiliation: Department of Neurosurgery, Dongguk University College of Medicine, Goyang, Gyeonggi-do, South Korea.
authors.forename: Seung-Yeob
authors.initials: SY
authors.lastname: Yang
authors.forename: Dong Gyu
authors.initials: DG
authors.lastname: Kim
authors.forename: Hyun-Tai
authors.initials: HT
authors.lastname: Chung
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Paek
authors.forename: Jae Hyo
authors.initials: JH
authors.lastname: Park
authors.forename: Dae Hee
authors.initials: DH
authors.lastname: Han
mesh_terms: D000328:Adult; D002533:Cerebral Angiography; D002543:Cerebral Hemorrhage / Q000517:prevention & control; D003487:Cyanoacrylates / Q000627:therapeutic use; D004621:Embolization, Therapeutic / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D007431:Intraoperative Complications / Q000517:prevention & control; D008279:Magnetic Resonance Imaging; D008297:Male; D011300:Preoperative Care / Q000706:statistics & numerical data; D016634:Radiosurgery / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003487:Cyanoacrylates