title: Stereotactic radiosurgery for newly diagnosed brain metastases: comparison of three dose levels.
abstract: OBJECTIVE
  Three doses were compared for local control of irradiated metastases, freedom from new brain metastases, and survival in patients receiving stereotactic radiosurgery (SRS) alone for one to three newly diagnosed brain metastases.
  
  
  METHODS
  In all, 134 patients were assigned to three groups according to the SRS dose given to the margins of the lesions: 13-16 Gy (n = 33), 18 Gy (n = 18), and 20 Gy (n = 83). Additional potential prognostic factors were evaluated: age (≤ 60 vs. > 60 years), gender, Karnofsky Performance Scale score (70-80 vs. 90-100), tumor type (non-small-cell lung cancer vs. melanoma vs. others), number of brain metastases (1 vs. 2-3), lesion size (< 15 vs. ≥ 15 mm), extracranial metastases (no vs. yes), RPA class (1 vs. 2), and interval of cancer diagnosis to SRS (≤ 24 vs. > 24 months).
  
  
  RESULTS
  For 13-16 Gy, 18 Gy, and 20 Gy, the 1-year local control rates were 31, 65, and 79%, respectively (p < 0.001). The SRS dose maintained significance on multivariate analysis (risk ratio: 2.25; 95% confidence interval: 1.56-3.29; p < 0.001). On intergroup comparisons of local control, 20 Gy was superior to 13-16 Gy (p < 0.001) but not to 18 Gy (p = 0.12); 18 Gy showed a strong trend toward better local control when compared with 13-16 Gy (p = 0.059). Freedom from new brain metastases (p = 0.57) and survival (p = 0.15) were not associated with SRS dose in the univariate analysis.
  
  
  CONCLUSIONS
  SRS doses of 18 Gy and 20 Gy resulted in better local control than 13-16 Gy. However, 20 Gy and 18 Gy must be compared again in a larger cohort of patients. Freedom from new brain metastases and survival were not associated with SRS dose.
authors.affiliation: Department of Radiation Oncology, University of Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany, Rades.Dirk@gmx.net.
authors.forename: Dirk
authors.initials: D
authors.lastname: Rades
authors.forename: Dagmar
authors.initials: D
authors.lastname: Hornung
authors.forename: Oliver
authors.initials: O
authors.lastname: Blanck
authors.forename: Kristina
authors.initials: K
authors.lastname: Martens
authors.forename: Mai Trong
authors.initials: MT
authors.lastname: Khoa
authors.forename: Ngo Thuy
authors.initials: NT
authors.lastname: Trang
authors.forename: Michael
authors.initials: M
authors.lastname: Hüppe
authors.forename: Patrick
authors.initials: P
authors.lastname: Terheyden
authors.forename: Jan
authors.initials: J
authors.lastname: Gliemroth
authors.forename: Steven E
authors.initials: SE
authors.lastname: Schild
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000401:mortality / Q000556:secondary / Q000601:surgery; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000401:mortality / Q000556:secondary / Q000601:surgery; D008875:Middle Aged; D011379:Prognosis; D016634:Radiosurgery / Q000379:methods*; D012878:Skin Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D013223:Statistics as Topic; D015996:Survival Rate