title: Gamma knife radiosurgery for cerebellopontine angle meningiomas: a multicenter study.
abstract: BACKGROUND
  Resection of cerebellopontine angle (CPA) meningiomas may result in significant neurological morbidity. Radiosurgery offers a minimally invasive alternative to surgery.
  
  
  OBJECTIVE
  To evaluate, in a multicenter cohort study, the outcomes of patients harboring CPA meningiomas who underwent Gamma Knife radiosurgery (GKRS).
  
  
  METHODS
  From 7 institutions participating in the North American Gamma Knife Consortium, 177 patients with benign CPA meningiomas treated with GKRS and at least 6 months radiologic follow-up were included for analysis. The mean age was 59 years and 84% were female. Dizziness or imbalance (48%) and cranial nerve (CN) VIII dysfunction (45%) were the most common presenting symptoms. The median tumor volume and prescription dose were 3.6 cc and 13 Gy, respectively. The mean radiologic and clinical follow-up durations were 47 and 46 months, respectively. Multivariate regression analyses were performed to identify the predictors of tumor progression and neurological deterioration.
  
  
  RESULTS
  The actuarial rates of progression-free survival at 5 and 10 years were 93% and 77%, respectively. Male sex (P = .014), prior fractionated radiation therapy (P = .010), and ataxia at presentation (P = .002) were independent predictors of tumor progression. Symptomatic adverse radiation effects and permanent neurological deterioration were observed in 1.1% and 9% of patients, respectively. Facial spasms at presentation (P = .007) and lower maximal dose (P = .011) were independently associated with neurological deterioration.
  
  
  CONCLUSIONS
  GKRS is an effective therapy for CPA meningiomas. Depending on the patient and tumor characteristics, radiosurgery can be an adjuvant treatment to initial surgical resection or a standalone procedure that obviates the need for resection in most patients.
authors.affiliation: *Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia; ‡Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania; §Department of Neurosurgery, Barrow Neurological Institute, Phoenix, Arizona; ¶Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio; ‖Department of Surgery, Division of Neurosurgery, University of Sherbrooke, Sherbrooke, Quebec, Canada; #Department of Neurosurgery, Yale University, New Haven, Connecticut; and **Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Dale
authors.initials: D
authors.lastname: Ding
authors.forename: Robert M
authors.initials: RM
authors.lastname: Starke
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kano
authors.forename: Peter
authors.initials: P
authors.lastname: Nakaji
authors.forename: Gene H
authors.initials: GH
authors.lastname: Barnett
authors.forename: David
authors.initials: D
authors.lastname: Mathieu
authors.forename: Veronica
authors.initials: V
authors.lastname: Chiang
authors.forename: Sacit B
authors.initials: SB
authors.lastname: Omay
authors.forename: Judith
authors.initials: J
authors.lastname: Hess
authors.forename: Heyoung L
authors.initials: HL
authors.lastname: McBride
authors.forename: Norissa
authors.initials: N
authors.lastname: Honea
authors.forename: John Y K
authors.initials: JY
authors.lastname: Lee
authors.forename: Gazanfar
authors.initials: G
authors.lastname: Rahmathulla
authors.forename: Wendi A
authors.initials: WA
authors.lastname: Evanoff
authors.forename: Michelle
authors.initials: M
authors.lastname: Alonso-Basanta
authors.forename: L Dade
authors.initials: LD
authors.lastname: Lunsford
authors.forename: Jason P
authors.initials: JP
authors.lastname: Sheehan
mesh_terms: D000328:Adult; D000368:Aged; D002528:Cerebellar Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D002530:Cerebellopontine Angle; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008579:Meningioma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D016634:Radiosurgery; D011879:Radiotherapy Dosage; D012044:Regression Analysis; D016896:Treatment Outcome; D047368:Tumor Burden