title: Local control after radiosurgery for brain metastases: predictive factors and implications for clinical decision.
abstract: BACKGROUND
  To evaluate the local control of brain metastases (BM) in patients treated with stereotactic radiosurgery (SRS), correlate the outcome with treatment parameters and lesion characteristics, and define its implications for clinical decisions.
  
  
  METHODS
  Between 2007 and 2012, 305 BM in 141 consecutive patients were treated with SRS. After exclusions, 216 BM in 100 patients were analyzed. Doses were grouped as follows: ≤15 Gy, 16-20 Gy, and ≥21 Gy. Sizes were classified as ≤10 mm and >10 mm. Local control (LC) and overall survival (OS) were estimated using the Kaplan-Meier method. Log-rank statistics were used to identify the prognostic factors affecting LC and OS. For multivariate analyses, a Cox proportional model was applied including all potentially significant variables reached on univariate analyses.
  
  
  RESULTS
  Median age was 54 years (18-80). Median radiological follow-up of the lesions was 7 months (1-66). Median LC and the LC at 1 year were 22.3 months and 69.7%, respectively. On univariate analysis, tumor size, SRS dose, and previous whole brain irradiation (WBRT) were significant factors for LC. Patients with lesions >10 and ≤10 mm had an LC at 1 year of 58.6% and 79.1%, respectively (p = 0.008). In lesions receiving ≤15 Gy, 16-20 Gy, and ≥21 Gy, the 1-year LC rates were 39.6%, 71.7%, and 92.3%, respectively (p < 0.001). When WBRT was done previously, LC at 1 year was 57.9% compared with 78.4% for those who did not undergo WBRT (p = 0.004). On multivariate analysis, dose remained the single most powerful prognostic factor for LC. Median OS for all patients was 17 months, with no difference among the groups.
  
  
  CONCLUSIONS
  Dose is the most important predictive factor for LC of BM. Doses below 16 Gy correlated with poor LC. The SRS dose as salvage treatment after previous WBRT should not be reduced unless there is a pressing reason to do so.
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. tamara.azevedo@gmail.com.
authors.forename: Tâmara Ribeiro
authors.initials: TR
authors.lastname: de Azevedo Santos
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. carmentundisi@yahoo.ca.
authors.forename: Carmen Freire
authors.initials: CF
authors.lastname: Tundisi
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. hendersonramos@uol.com.br.
authors.forename: Henderson
authors.initials: H
authors.lastname: Ramos
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. macontemaia@hotmail.com.
authors.forename: Maria Aparecida Conte
authors.initials: MA
authors.lastname: Maia
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. cassiopellizzon@aol.com.
authors.forename: Antônio Cássio Assis
authors.initials: AC
authors.lastname: Pellizzon
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. mlgobosilva@gmail.com.
authors.forename: Maria Letícia Gobo
authors.initials: ML
authors.lastname: Silva
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. rcfogaroli@terra.com.br.
authors.forename: Ricardo César
authors.initials: RC
authors.lastname: Fogaroli
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. michael.chen@ig.com.br.
authors.forename: Michael Jenwei
authors.initials: MJ
authors.lastname: Chen
authors.affiliation: Department of Neurosurgery, AC Camargo Cancer Center, São Paulo, Brazil. sergio.hideki.suzuki@terra.com.br.
authors.forename: Sérgio Hideki
authors.initials: SH
authors.lastname: Suzuki
authors.affiliation: Department of Neurosurgery, AC Camargo Cancer Center, São Paulo, Brazil. joseeduardosouzadiasjunior@gmail.com.
authors.forename: José Eduardo Souza
authors.initials: JE
authors.lastname: Dias
authors.affiliation: Department of Neurosurgery, AC Camargo Cancer Center, São Paulo, Brazil. psanematsu@yahoo.com.br.
authors.forename: Paulo Issamu
authors.initials: PI
authors.lastname: Sanematsu
authors.affiliation: Department of Radiation Oncology, AC Camargo Cancer Center, São Paulo, Brazil. dougguedes@uol.com.br.
authors.forename: Douglas Guedes
authors.initials: DG
authors.lastname: de Castro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D003661:Decision Support Techniques; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D009367:Neoplasm Staging; D009369:Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D011379:Prognosis; D016634:Radiosurgery / Q000401:mortality*; D011879:Radiotherapy Dosage; D015996:Survival Rate; D055815:Young Adult