title: Validity of prognostic grading indices for brain metastasis patients undergoing repeat radiosurgery.
abstract: OBJECTIVE
  We tested the validity of 5 prognostic indices, Recursive Partitioning Analysis (RPA), Score Index for Radiosurgery (SIR), Basic Score for Brain Metastases (BSBM), Graded Prognostic Assessment (GPA), and Modified-RPA, for patients who underwent repeat stereotactic radiosurgery (re-SRS).
  
  
  METHODS
  For this study, we used our database, which included 804 patients who underwent gamma knife re-SRS during the period 1998-2013.
  
  
  RESULTS
  There were statistically significant survival differences among patients stratified into 3 or 4 groups based on the 5 systems (P < 0.001). With RPA, SIR, BSBM, and the Modified-RPA, there were statistically significant median survival time (MST) differences between any 2 pairs within the 3/4 groups. With the GPA system, however, the MST difference between the GPA 3.5-4.0 and GPA 3.0 groups did not reach statistical significance (P = 0.48). There were large patient number discrepancies among the 3/4 groups in the RPA, SIR, BSBM, and GPA whereas patient numbers were very similar among the 3 Modified-RPA system groups. Our present results show the RPA and BSBM systems to reflect changes less well, with 86%-95% of patients remaining in the same categories between the first and second SRS procedures. However, with SIR, GPA, and the Modified-RPA, 25%-31% of patients were categorized into different subclasses, either better or worse. With the modified-RPA system, such categorical change correlated well with post-re-SRS MSTs.
  
  
  CONCLUSIONS
  Among the 5 systems, based on patient number proportions, MST separation among the 3/4 groups, and/or detailed reflection of status changes, the Modified-RPA system was shown to be most applicable to re-SRS patients.
authors.affiliation: Katsuta Hospital Mito GammaHouse, Hitachi-naka, Japan; Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, Tokyo, Japan. Electronic address: BCD06275@nifty.com.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Katsuta Hospital Mito GammaHouse, Hitachi-naka, Japan; Department of Neurosurgery, Kyoto Prefectural University of Medicine Graduate School of Medical Sciences, Kyoto, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Kawabe
authors.affiliation: Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Higuchi
authors.affiliation: Clinical Research Center, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Neurosurgery, Graduate School, Tokyo Medical and Dental University School of Medicine, Tokyo, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nariai
authors.affiliation: Katsuta Hospital Mito GammaHouse, Hitachi-naka, Japan; Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Katsuta Hospital Mito GammaHouse, Hitachi-naka, Japan.
authors.forename: Bierta E
authors.initials: BE
authors.lastname: Barfod
authors.affiliation: Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, Tokyo, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kasuya
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011379:Prognosis; D011829:Radiation Dosage; D016634:Radiosurgery / Q000379:methods*; D012086:Reoperation; D015203:Reproducibility of Results; D016019:Survival Analysis; D055815:Young Adult
keywords: Brain metastases; Prognostic index; Radiosurgery; Recurrence