title: Gamma knife radiosurgery in the management of arteriovenous malformations of the Basal Ganglia region of the brain.
abstract: OBJECTIVE
  The authors report the results of gamma knife (GK) radiosurgery on a clinical series of selected patients with basal ganglia arteriovenous malformations (BGAVMs) in the brain. Clinical, epidemiological, anatomical and functional characteristics of BGAVMs and of supratentorial cortical AVMs are comparatively analyzed, and their influence on radiosurgical outcome is discussed.
  
  
  METHODS
  At our Department, 33 BGAVMs (21 with FU > 2 years) and 209 cortical AVMs (110 with FU > 2 years) with a radiosurgical volume </= 10 cc were treated with GK between February 1993 and July 2001. Mean age, male/female ratio (M/F), and incidence of haemorrhagic onset in the two subgroups of patients were as follows: 25.5 years (5 - 62 years), 16 M/17 F, and 30/33 (91%) in BGAVMs; 34.4 years (8 - 74 years), 124 M/85 F, and 107/209 (51%) in cortical AVMs. Statistical analysis performed using the contingency table method and deviance analysis according to generalized linear models showed that the differences in age and incidence of haemorrhagic onset were highly significant.
  
  
  RESULTS
  The rates of complete obliteration, permanent morbidity, bleeding/rebleeding during the latency period, and unsuccessful embolisation attempts in the two subgroups of patients were as follows: 81%, 4%, 8%, and 41.7%, respectively, in BGAVMs; 85.5%, 2%, 2%, and 2% in cortical AVMs. Statistical analysis did not show any significant difference between the two subgroups of patients in the rates of complete obliteration, permanent morbidity, or latency period bleeding/rebleeding, while difference in failed embolization rates resulted to be highly significant (P = 0.00003).
  
  
  CONCLUSIONS
  In our experience, the different clinical, epidemiological and anatomico-functional characteristics of BGAVMs and cortical AVMs do not seem to influence the radiosurgical outcome, since complete obliteration and permanent neurological sequelae rates were very similar in these two subgroups of patients. GK may be considered the first choice treatment modality for BGAVMs with < 10 cc volume, since it offers a very high cure rate, very low permanent morbidity, and zero mortality. Although haemorrhagic onset is much more frequent in BGAVMs than in cortical AVMs, the difference between the bleeding/rebleeding rates in the two subgroups of patients during the latency period is not statistically significant, and seems to be limited to the first year after GK.
authors.affiliation: Department of Neurosurgery, University Hospital, Verona, Italy. antonio.nicolato@mail.azosp.vr.it
authors.forename: A
authors.initials: A
authors.lastname: Nicolato
authors.forename: R
authors.initials: R
authors.lastname: Foroni
authors.forename: A
authors.initials: A
authors.lastname: Crocco
authors.forename: P G
authors.initials: PG
authors.lastname: Zampieri
authors.forename: F
authors.initials: F
authors.lastname: Alessandrini
authors.forename: A
authors.initials: A
authors.lastname: Bricolo
authors.forename: M A
authors.initials: MA
authors.lastname: Gerosa
mesh_terms: D000293:Adolescent; D000328:Adult; D001479:Basal Ganglia / Q000098:blood supply*; D020145:Basal Ganglia Hemorrhage / Q000175:diagnosis / Q000601:surgery; D002533:Cerebral Angiography; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology; D016634:Radiosurgery; D012008:Recurrence