title: Stereotactic radiosurgery for glioblastoma: retrospective analysis.
abstract: OBJECTIVE
  This retrospective study was done to better understand the conditions for which stereotactic radiosurgery (SRS) for glioblastoma may be efficacious.
  
  
  METHODS
  Between 2000 and 2007, 33 patients with a pathological diagnosis of glioblastoma received SRS with the Novalis Shaped Beam Radiosurgery system. Eighteen patients (54%) underwent salvage SRS for recurrence while 15 (45%) patients received upfront SRS following standard fractionated RT for newly diagnosed glioblastoma.
  
  
  RESULTS
  There were no RTOG grade >2 acute side effects. The median survival after SRS was 6.7 months (range 1.4 - 74.7). There was no significant difference in overall survival (from the time of initial diagnosis) with respect to the timing of SRS (p = 0.2). There was significantly better progression free survival in patients treated with SRS as consolidation versus at the time of recurrence (p = 0.04). The majority of patients failed within or at the margin of the SRS treatment volume (21/26 evaluable for recurrence).
  
  
  CONCLUSIONS
  SRS is well tolerated in the treatment of glioblastoma. As there was no difference in survival whether SRS is delivered upfront or at recurrence, the treatment for each patient should be individualized. Future studies are needed to identify patients most likely to respond to SRS.
authors.affiliation: Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA. tithi_biswas@urmc.rochester.edu
authors.forename: Tithi
authors.initials: T
authors.lastname: Biswas
authors.forename: Paul
authors.initials: P
authors.lastname: Okunieff
authors.forename: Michael C
authors.initials: MC
authors.lastname: Schell
authors.forename: Therese
authors.initials: T
authors.lastname: Smudzin
authors.forename: Webster H
authors.initials: WH
authors.lastname: Pilcher
authors.forename: Robert S
authors.initials: RS
authors.lastname: Bakos
authors.forename: G Edward
authors.initials: GE
authors.lastname: Vates
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Walter
authors.forename: Andrew
authors.initials: A
authors.lastname: Wensel
authors.forename: David N
authors.initials: DN
authors.lastname: Korones
authors.forename: Michael T
authors.initials: MT
authors.lastname: Milano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000401:mortality / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D005909:Glioblastoma / Q000401:mortality / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods; D012189:Retrospective Studies; D016879:Salvage Therapy / Q000379:methods; D016896:Treatment Outcome