title: Repeated linac-based radiosurgery in high-grade cerebral arteriovenous-malformations (AVM) Spetzler-Martin grade III to IV previously treated with radiosurgery.
abstract: BACKGROUND
  Aim was to access outcome and toxicity of repeated linac-based radiosurgery in incompletely obliterated cerebral AVM.
  
  
  METHODS
  Between 1998 and 2008, 11 patients were treated with repeated radiosurgery. The median dose to the 80%-isodose was 15 Gy (range, 12-18 Gy). During initial radiosurgery the median dose was 18 Gy (range, 9-22 Gy).
  
  
  RESULTS
  The median time interval between initial radiosurgery and re-treatment was 9 years (range, 4-16 years). The median follow-up was 26 months (range, 2-115 months). Treatment response was seen in 8 patients (89%). Complete (partial) obliteration was achieved in 5 (3) patients (56%, 33%, respectively).The median time to complete obliteration was 26 months (range, 5-45 months). Pre-existing neurological symptoms improved in 2 patients (18%), were stable in 7 patients (64%) and worsened in 2 patients (18%). Prevalence of intracranial hemorrhage was 9% (1/11). Post-re-treatment intracranial hemorrhage rate was 2.7% (1/38 years at risk). During follow-up, no secondary malignancies or toxicity>grade III were observed.
  
  
  CONCLUSIONS
  Repeated linac-based radiosurgery in incompletely obliterated cerebral AVM is an effective treatment option with a high rate of treatment response and an acceptable risk for side effects. Marginal doses above 15 Gy might further improve the rate of complete obliterations.
authors.affiliation: Department of Radiation Oncology, University of Heidelberg, Germany. Henrik.Hauswald@med.uni-heidelberg.de
authors.forename: Henrik
authors.initials: H
authors.lastname: Hauswald
authors.forename: Stefanie
authors.initials: S
authors.lastname: Milker-Zabel
authors.forename: Florian
authors.initials: F
authors.lastname: Sterzing
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schlegel
authors.forename: Juergen
authors.initials: J
authors.lastname: Debus
authors.forename: Angelika
authors.initials: A
authors.lastname: Zabel-du Bois
mesh_terms: D000293:Adolescent; D000328:Adult; D001164:Arteriovenous Fistula / Q000601:surgery*; D002648:Child; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage