title: Gamma knife radiosurgery for brainstem cavernous malformations.
abstract: OBJECTIVE
  The goal of this retrospective study was to evaluate the efficacy and safety of gamma knife radiosurgery (GKS) for the treatment of brainstem cavernous malformations (CMs).
  
  
  METHODS
  Between January of 2009 and December of 2014, 43 patients (20 males and 23 females) with brainstem CMs were treated at the West China Hospital, Sichuan University, Gamma Knife Center. The mean age of these patients was 41.7 years. All of the patients experienced 1 or more episodes of symptomatic bleeding (range 1-4) before undergoing GKS. The mean volume of the malformations at the time of GKS was 442.1mm3, and the mean prescribed marginal radiation dose was 11.9Gy. The mean follow-up period after radiosurgery was 36 months (range 12-120 months).
  
  
  RESULTS
  Before GKS, 50 hemorrhages (1.2 per patient) were observed (25.0% annual hemorrhage rate). Three hemorrhages following GKS were observed within the first 2 years (3.92% annual hemorrhage rate), and 1 hemorrhage was observed in the period after the first 2 years (1.85% annual hemorrhage rate). In this study of 43 patients, new neurological deficits developed in only 1 patient (2.32%; permanent paresthesia on the left side of the face and the right lower limb of the patient). There were no deaths in this study.
  
  
  CONCLUSIONS
  GKS is a favorable alternative treatment for brainstem CMs. Using a low marginal dose treatment might reduce the rate of hemorrhage and radiation-induced complications.
authors: Department of Neurosurgery, West China Hospital, Sichuan University, China.
authors: Hong Bin
authors: HB
authors: Liu
authors: Department of Neurosurgery, West China Hospital, Sichuan University, China.
authors: Yi
authors: Y
authors: Wang
authors: Department of Neurosurgery, West China Hospital, Sichuan University, China.
authors: Sen
authors: S
authors: Yang
authors: Department of Neurosurgery, West China Hospital, Sichuan University, China.
authors: Fei Long
authors: FL
authors: Gong
authors: Department of Neurosurgery, West China Hospital, Sichuan University, China.
authors: Yang Yang
authors: YY
authors: Xu
authors: Department of Neurosurgery, West China Hospital, Sichuan University, China. Electronic address: wcnscn@163.com.
authors: Wei
authors: W
authors: Wang
mesh_terms: D000328:Adult; D000368:Aged; D001933:Brain Stem / Q000098:blood supply* / Q000601:surgery; D016543:Central Nervous System Neoplasms / Q000150:complications / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D020786:Hemangioma, Cavernous, Central Nervous System / Q000150:complications / Q000601:surgery*; D006801:Humans; D020300:Intracranial Hemorrhages / Q000209:etiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D055815:Young Adult
keywords: Annual hemorrhage rate; Brainstem; Cavernous malformation; Gamma knife surgery; Stereotactic radiosurgery