title: Role of Gamma Knife surgery in patients with 5 or more brain metastases.
abstract: OBJECTIVE
  The authors evaluated overall survival and factors predicting outcome in patients with ≥ 5 brain metastases who were treated with Gamma Knife surgery (GKS).
  
  
  METHODS
  Medical records from patients with ≥ 5 brain metastases treated with GKS between 1997 and 2010 at the Cleveland Clinic Gamma Knife Center were retrospectively reviewed. Patient demographics, tumor characteristics, treatment-related factors, and outcome data were evaluated.
  
  
  RESULTS
  One hundred seventy patients were identified, with a median age of 58 years. The female/male ratio was 1.2:1. Gamma Knife surgery was used as an upfront treatment in 35% of patients and as salvage treatment in 65% of patients with multiple brain metastases. The median overall survival after GKS was 6.7 months (95% CI 5.5-8.1). At the time of GKS, 128 patients (75%) had concurrent extracranial metastases, and in 69 patients (41%) multiple extracranial sites were involved. Ninety-two patients (54%) had a history of whole-brain radiation therapy, and 158 patients (93%) had a Karnofsky Performance Scale (KPS) score ≥ 70. The median total intracranial disease volume was 3.2 cm(3) (range 0.2-37.2 cm(3)). A total intracranial tumor volume ≥ 10 cm(3) was observed in 32 patients (19%). Lower KPS score at the time of treatment (p < 0.0001), patient age > 60 years (p = 0.004), multiple extracranial metastases (p = 0.0001), and greater intracranial burden of disease (p = 0.03) were prognostic factors for poor outcome in the univariate and multivariate analyses.
  
  
  CONCLUSIONS
  In this study, GKS was safe and effective for upfront and salvage treatment in patients with ≥ 5 brain metastases. Gamma Knife surgery should be considered as an additional treatment modality for these patients, especially in the subset of patients with favorable prognostic factors.
authors.affiliation: The Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Alireza Mohammad
authors.initials: AM
authors.lastname: Mohammadi
authors.forename: Pablo F
authors.initials: PF
authors.lastname: Recinos
authors.forename: Gene H
authors.initials: GH
authors.lastname: Barnett
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Weil
authors.forename: Michael A
authors.initials: MA
authors.lastname: Vogelbaum
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Chao
authors.forename: John H
authors.initials: JH
authors.lastname: Suh
authors.forename: Nicholas F
authors.initials: NF
authors.lastname: Marko
authors.forename: Paul
authors.initials: P
authors.lastname: Elson
authors.forename: Gennady
authors.initials: G
authors.lastname: Neyman
authors.forename: Lilyana
authors.initials: L
authors.lastname: Angelov
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology / Q000601:surgery*; D001932:Brain Neoplasms / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016634:Radiosurgery / Q000295:instrumentation* / Q000401:mortality; D012189:Retrospective Studies; D016879:Salvage Therapy / Q000295:instrumentation* / Q000401:mortality; D015996:Survival Rate; D016896:Treatment Outcome; D047368:Tumor Burden