title: Gamma knife radiosurgery of the symptomatic brain stem cavernous angioma with low marginal dose.
abstract: OBJECTIVE
  To analyze the outcome of gamma knife radiosurgery (GKS) using low marginal dose for the symptomatic brain stem cavernous angioma (BSCA).
  
  
  METHODS
  39 patients (16 males, 23 females) were treated with GKS for BSCA from January 1997 to September 2012. Clinical data were analyzed retrospectively. The mean age was 41.5 years. All patients had a history of symptomatic bleeding once or more before performing GKS. Mean volume of BSCA was 1095.3mm(3) and median prescribed marginal dose was 13 Gy.
  
  
  RESULTS
  Mean follow-up period since diagnosis was 4.1 years. The number of hemorrhagic events between initial diagnosis and GKS was 5 over a total of 14.9 patients-years with annual hemorrhagic rate of 33.6%. Following GKS, there were five hemorrhagic events within the first 2 years (8.1%/year) and two after the first 2 years (2.4%/year). The difference was not statistically significant. Neurologic status improved in 24 patients (61.5%), and stationary in eleven (28.2%). 4 patients (10.3%) experienced the exacerbation of symptoms at the last follow-up and none of them were related to the radiation injury. Significant volume reduction after GKS was observed in 24 patients (61.5%). Surgical excision was performed in one patient due to swelling and rebleeding after GKS. Age at presentation, sex, mass size of BSCA, and location, GKS dose did not affect post-GKS hemorrhage.
  
  
  CONCLUSIONS
  GKS for BSCA using relatively low marginal dose is safe and effective. Long-term prospective study is needed to confirm the optimal dose for BSCA.
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Byung Sup
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Je Young
authors.initials: JY
authors.lastname: Yeon
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Jong-Soo
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Seung-Chyul
authors.initials: SC
authors.lastname: Hong
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. Electronic address: jilee@skku.edu.
authors.forename: Jung-Il
authors.initials: JI
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D020295:Brain Stem Neoplasms / Q000601:surgery*; D005260:Female; D020786:Hemangioma, Cavernous, Central Nervous System / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D016896:Treatment Outcome; D055815:Young Adult
keywords: Brain stem; Cavernous angioma; Gamma knife radiosurgery