title: Gamma Knife radiosurgery for cerebral arteriovenous malformations in children/adolescents and adults. Part II: Differences in obliteration rates, treatment-obliteration intervals, and prognostic factors.
abstract: OBJECTIVE
  To evaluate and compare obliteration rates (OBRs) and treatment-obliteration intervals (TOIs) for cerebral arteriovenous malformations (cAVMs) treated with Gamma Knife radiosurgery in children/adolescents and adults; and to determine factors predicting the OBR and TOI in these two populations.
  
  
  METHODS
  This study concerned 62 children/adolescents and 193 adults observed for > or = 3 years. Fisher exact two-tailed and Wilcoxon rank-sum tests, multiple logistics, and Cox proportional hazard models were used for statistical analysis.
  
  
  RESULTS
  The overall OBR was 85.5% in children/adolescents and 87.6% in adults (p = 0.671), but children/adolescents showed higher 36-month actuarial OBRs (69.35%) and shorter median TOIs (25.7 months) than adults (66.84% and 28.2 months; p = 0.006 and p = 0.017, respectively). In children/adolescents, lower Spetzler-Martin grades (p = 0.043) and younger age (p = 0.019) correlated significantly with OBRs, and lower Spetzler-Martin grades (p = 0.024) and noneloquent cAVM locations (p = 0.046) with TOIs. In adults, low flow through the cAVM and < 6.2-cm3 volume were associated with both OBR and TOI (p = 0.012 and p = 0.002, respectively).
  
  
  CONCLUSIONS
  The differences in OBRs within 3 years and TOIs, although slight, seem to show that pediatric cAVMs behave differently from those in adults after Gamma Knife radiosurgery.
authors.affiliation: Department of Neurosurgery, University of Verona and University Hospital, Verona, Italy. antonio.nicolato@mail.azosp.vr.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Nicolato
authors.forename: Francesco
authors.initials: F
authors.lastname: Lupidi
authors.forename: Marco F
authors.initials: MF
authors.lastname: Sandri
authors.forename: Roberto
authors.initials: R
authors.lastname: Foroni
authors.forename: Piergiuseppe
authors.initials: P
authors.lastname: Zampieri
authors.forename: Carlo
authors.initials: C
authors.lastname: Mazza
authors.forename: Alberto
authors.initials: A
authors.lastname: Pasqualin
authors.forename: Alberto
authors.initials: A
authors.lastname: Beltramello
authors.forename: Massimo
authors.initials: M
authors.lastname: Gerosa
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D016634:Radiosurgery; D011879:Radiotherapy Dosage; D019233:Retreatment; D012189:Retrospective Studies; D013997:Time Factors