title: Radiosurgery for treatment of brain metastases: estimation of patient eligibility using three stratification systems.
abstract: OBJECTIVE
  To compare three patient stratification systems predicting survival: recursive partitioning analysis (RPA), score index for radiosurgery in brain metastases (SIR), and a proposed basic score for brain metastases (BS-BM).
  
  
  METHODS
  We analyzed the outcome of 110 patients treated with Leksell Gamma Knife radiosurgery between December 1999 and January 2003. The BS-BM was calculated by evaluating three main prognostic factors: Karnofsky performance status, primary tumor control, and presence of extracranial metastases.
  
  
  RESULTS
  The median survival was 27.6 months for RPA Class I, 10.7 months for RPA Class II, and 2.8 months for RPA Class III (p <0.0001). Using the SIR, the median survival was 27.7, 10.8, 4.6, and 2.4 months for a score of 8-10, 5-7, 4, and 0-3, respectively (p <0.0001). The median survival was undefined in patients with a BS-BM of 3 (55% at 32 months) and was 13.1 months for a BS-BM of 2, 3.3 months for a BS-BM of 1, and 1.9 months for a BS-BM of 0 (p <0.0001). The backward elimination model in multivariate Cox analysis identified SIR and BS-BM as the only two variables significantly associated with survival (p = 0.031 and p = 0.043, respectively).
  
  
  CONCLUSIONS
  SIR and BS-BM were the most accurate for estimating survival. They were specific enough to identify patients with short survival (SIR 0-3 and BS-BM 0). Because of it simplicity, BS-BM is easier to use.
authors.affiliation: Gamma Knife Center and Department of Neurosurgery, Hôpital Erasme, Route de Lennik 808, Brussels B-1070, Belgium.
authors.forename: José
authors.initials: J
authors.lastname: Lorenzoni
authors.forename: Daniel
authors.initials: D
authors.lastname: Devriendt
authors.forename: Nicolas
authors.initials: N
authors.lastname: Massager
authors.forename: Phillippe
authors.initials: P
authors.lastname: David
authors.forename: Salvador
authors.initials: S
authors.lastname: Ruíz
authors.forename: Bruno
authors.initials: B
authors.lastname: Vanderlinden
authors.forename: Paul
authors.initials: P
authors.lastname: Van Houtte
authors.forename: Jacques
authors.initials: J
authors.lastname: Brotchi
authors.forename: Marc
authors.initials: M
authors.lastname: Levivier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001932:Brain Neoplasms / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery; D011879:Radiotherapy Dosage; D012044:Regression Analysis; D016019:Survival Analysis; D016896:Treatment Outcome