title: Radiation schedules in relation to obliteration and complications in hypofractionated conformal stereotactic radiotherapy of arteriovenous malformations.
abstract: OBJECTIVE
  The purpose of this investigation was to assess the obliteration rate and complications following different radiation schedules of hypofractionated conformal stereotactic radiotherapy for cerebral arteriovenous malformations (AVMs).
  
  
  METHODS
  Twenty-five patients were treated with 35 Gy in 5 fractions, whereas 31 patients were treated with 30-32.5 Gy (mean: 31.6 +/- 0.23 Gy) in 5 fractions. A complete angiographic follow-up is available for 40 patients.
  
  
  RESULTS
  Thirty-seven out of 40 patients (92.5%) have so far shown obliteration of their AVMs after a mean time of 3.2 +/- 0.26 years (range: 2-8 years). The mean AVM volume in these patients was 8.2 +/- 1.0 cm(3) (range: 1.5-29 cm(3)). There was a higher rate of obliteration (88%) in patients treated with 35 Gy compared to those treated with < 35 Gy (78%), even if this was not statistically significant. There was a significantly shorter time to obliteration in patients treated with 35 Gy. All patients who experienced symptomatic radionecrosis belonged to the group treated with 35 Gy.
  
  
  CONCLUSIONS
  A radiation schedule of 35 Gy in 5 fractions may be more effective than a radiation schedule of <35 (30-32.5) Gy in obliterating AVMs. This may, however, be at the price of an increased risk of symptomatic radionecrosis.
authors: Department of Neurosurgery, Umeå University Hospital, Umeå, Sweden. peter_lindvall_nkk @ hotmail.com
authors: Peter
authors: P
authors: Lindvall
authors: Per
authors: P
authors: Bergström
authors: Michael
authors: M
authors: Blomquist
authors: A Tommy
authors: AT
authors: Bergenheim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology / Q000528:radiation effects*; D002533:Cerebral Angiography; D016009:Chi-Square Distribution; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000209:etiology; D011832:Radiation Injuries / Q000473:pathology; D016634:Radiosurgery / Q000009:adverse effects*; D016896:Treatment Outcome