title: Clinico-radiological outcomes following gamma knife radiosurgery for pediatric arteriovenous malformations.
abstract: OBJECTIVE
  The aim of this study was to evaluate clinico-radiological outcomes following gamma knife radiosurgery (GKS) for pediatric arteriovenous malformations (AVMs).
  
  
  METHODS
  The present series included 39 children (3-17 years of age) who underwent GKS for cerebral AVMs between January 2002 and February 2008. Twenty-five patients presented with hemorrhages. The median AVM volume was 1.5 cm³, and the median marginal dose was 20 Gy. All patients continued to have follow-up for more than 24 months with serial magnetic resonance images (MRIs)/angiograms. Current school performance has been evaluated using a telephone survey answered by the patients' parents.
  
  
  RESULTS
  Follow-up angiograms, available in 34 patients, confirmed complete obliteration in 16 patients. Serial MRIs indicated obliteration of the nidus in one of five patients without angiography. The diffuse nidus structure and low marginal dose were significantly associated with incomplete obliteration. Twelve patients underwent a second GKS, and subsequent angiographies, available in six patients, demonstrated complete obliteration in two of them. Complications included new-onset seizures (n = 1), apraxia (n = 1), and temporal horn entrapment requiring a shunt operation (n = 1). School performance declined in 14 out of 32 patients. Both the AVM volume and modified AVM score were found to be reliable predictors of school performance.
  
  
  CONCLUSIONS
  The results of the present study substantiate the diffuse and other atypical features of pediatric AVMs as major determinants of treatment failure following GKS. Considering the apparent declination of school performance, future prospective studies would be required to investigate the possible late-effects of GKS on neuropsychological function.
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Kangnam-Gu, Seoul, 135-710, Republic of Korea.
authors.forename: Je Young
authors.initials: JY
authors.lastname: Yeon
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Shin
authors.forename: Jong-Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Seung-Chyul
authors.initials: SC
authors.lastname: Hong
authors.forename: Jung-Il
authors.initials: JI
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D015901:Angiography, Digital Subtraction; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000453:epidemiology / Q000209:etiology; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D016634:Radiosurgery / Q000009:adverse effects; D016896:Treatment Outcome