title: Clinical outcomes of brain metastases treated with Gamma Knife radiosurgery with 3.0 T versus 1.5 T MRI-based treatment planning: have we finally optimised detection of occult brain metastases?
abstract: BACKGROUND
  The goal of this study was to determine if clinically relevant endpoints were changed by improved MRI resolution during radiosurgical treatment planning.
  
  
  METHODS
  Between 2003 and 2008, 200 consecutive patients with brain metastases treated with Gamma Knife radiosurgery (GKRS) using either 1.5 T or 3.0 T MRI for radiosurgical treatment planning were retrospectively analysed. The number of previously undetected metastases at time of radiosurgery, distant brain failures, time delay to whole brain radiotherapy (WBRT), overall survival and likelihood of neurological death were determined.
  
  
  RESULTS
  Additional metastases were detected in 31.3% and 24.5% of patients at time of radiosurgery with 3.0 T and 1.5 T MRI, respectively (P = 0.27). Patients with multiple metastases at diagnostic scan were more likely to have additional metastases detected by 3.0 T MRI (P < 0.1). Median time to distant brain failure was 4.87 months and 5.43 months for the 3.0 T and 1.5 T cohorts, respectively (P = 0.44). Median time to WBRT was 5.8 months and 5.3 months for the 3.0 T and 1.5 T cohorts, respectively (P = 0.87). Median survival was 6.4 months for the 3.0 T cohort, and 6.1 months for the 1.5 T cohort (P = 0.71). Likelihood of neurological death was 25.3% and 16.7% for the 3.0 and 1.5 T populations, respectively (P = 0.26).
  
  
  CONCLUSIONS
  The 3.0 T MRI-based treatment planning for GKRS did not appear to affect the likelihood of distant brain failure, the need for WBRT or the likelihood of neurological death in this series.
authors.affiliation: Department of Neurosurgery, Wake Forest University Health Sciences, Winston Salem, North Carolina, USA.
authors.forename: Amritraj G
authors.initials: AG
authors.lastname: Loganathan
authors.forename: Michael D
authors.initials: MD
authors.lastname: Chan
authors.forename: Natalie
authors.initials: N
authors.lastname: Alphonse
authors.forename: Ann M
authors.initials: AM
authors.lastname: Peiffer
authors.forename: Annette J
authors.initials: AJ
authors.lastname: Johnson
authors.forename: Kevin P
authors.initials: KP
authors.lastname: McMullen
authors.forename: James J
authors.initials: JJ
authors.lastname: Urbanic
authors.forename: Paul A
authors.initials: PA
authors.lastname: Saconn
authors.forename: J Daniel
authors.initials: JD
authors.lastname: Bourland
authors.forename: Michael T
authors.initials: MT
authors.lastname: Munley
authors.forename: Edward G
authors.initials: EG
authors.lastname: Shaw
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Tatter
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Ellis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D016634:Radiosurgery / Q000401:mortality*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods / Q000706:statistics & numerical data*; D061089:Radiotherapy, Image-Guided / Q000401:mortality*; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult