title: Stereotactic linac-based radiosurgery in the treatment of cerebral arteriovenous malformations located deep, involving corpus callosum, motor cortex, or brainstem.
abstract: OBJECTIVE
  To evaluate patient outcome and obliteration rates after radiosurgery (RS) for cerebral arteriovenous malformations (AVM) located deep, in the motor cortex or brainstem and those involving corpus callosum.
  
  
  METHODS
  This analysis is based on 65 patients. AVM classification according to Spetzler-Martin was 13 patients Grade 2, 39 Grade 3, 12 Grade 4, and 1 Grade 5. Median RS-based AVM score was 1.69. Median single dose was 18 Gy. Mean treatment volume was 5.2 cc (range, 0.2-26.5 cc). Forty patients (62%) experienced intracranial hemorrhage before RS. Median follow-up was 3.0 years.
  
  
  RESULTS
  Actuarial complete obliteration rate (CO) was 50% and 65% after 3 and 5 years, respectively. CO was significantly higher in AVM <3 cm (p < 0.02) and after doses >18 Gy (p < 0.009). Annual bleeding risk after RS was 4.7%, 3.4%, and 2.7% after 1, 2, and 3 years, respectively. AVM >3 cm (p < 0.01), AVM volume >4 cc (p < 0.009), and AVM score >1.5 (p < 0.02) showed a significant higher bleeding risk. Neurologic dysfunction improved, completely dissolved, or remained stable in 94% of patients.
  
  
  CONCLUSIONS
  Surgically inaccessible AVM can be successfully treated using RS with acceptable obliteration rates and low risk for late morbidity. The risk of intracranial hemorrhage is reduced after RS and depends on RS-based AVM score.
authors.affiliation: Department of Radiotherapy, German Cancer Research Center, Heidelberg, Germany. A.Zabel@dkfz-heidelberg.de
authors.forename: Angelika
authors.initials: A
authors.lastname: Zabel-du Bois
authors.forename: Stefanie
authors.initials: S
authors.lastname: Milker-Zabel
authors.forename: Peter
authors.initials: P
authors.lastname: Huber
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schlegel
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001933:Brain Stem / Q000098:blood supply*; D002543:Cerebral Hemorrhage / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000098:blood supply*; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000098:blood supply*; D019106:Postoperative Hemorrhage / Q000209:etiology; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D016896:Treatment Outcome