title: Linear accelerator-based stereotactic radiosurgery in recurrent glioblastoma: a single center experience.
abstract: OBJECTIVE
  Management of patients with recurrent glioblastoma (GB) comprises a therapeutic challenge in neurooncology owing to the aggressive nature of the disease with poor local control despite a combined modality treatment. The majority of cases recur within the high-dose radiotherapy field limiting the use of conventional techniques for re-irradiation due to potential toxicity. Stereotactic radiosurgery (SRS) offers a viable noninvasive therapeutic option in palliative treatment of recurrent GB as a sophisticated modality with improved setup accuracy allowing the administration of high-dose, precise radiotherapy. The aim of the study was to, we report our experience with single-dose linear accelerator (LINAC) based SRS in the management of patients with recurrent GB.
  
  
  METHODS
  Between 1998 and 2010 a total of 19 patients with recurrent GB were treated using single-dose LINAC-based SRS. The median age was 47 (23-65) years at primary diagnosis. Karnofsky Performance Score was > or = 70 for all the patients. The median planning target volume (PTV) was 13 (7-19) cc. The median marginal dose was 16 (10-19) Gy prescribed to the 80%-95% isodose line encompassing the planning target volume. The median follow-up time was 13 (2-59) months.
  
  
  RESULTS
  The median survival was 21 months and 9.3 months from the initial GB diagnosis and from SRS, respectively. The median progression-free survival from SRS was 5.7 months. All the patients tolerated radiosurgical treatment well without any Common Toxicity Criteria (CTC) grade > 2 acute side effects.
  
  
  CONCLUSIONS
  Single-dose LINAC-based SRS is a safe and well- tolerated palliative therapeutic option in the management of patients with recurrent GB.
authors.affiliation: Gulhane Military Medical Academy, Department of Neurosurgery, Ankara, Turkey.
authors.forename: Sait
authors.initials: S
authors.lastname: Sirin
authors.forename: Kaan
authors.initials: K
authors.lastname: Oysul
authors.forename: Serdar
authors.initials: S
authors.lastname: Surenkok
authors.forename: Omer
authors.initials: O
authors.lastname: Sager
authors.forename: Ferrat
authors.initials: F
authors.lastname: Dincoglan
authors.forename: Bahar
authors.initials: B
authors.lastname: Dirican
authors.forename: Murat
authors.initials: M
authors.lastname: Beyzadeoglu
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000601:surgery; D005260:Female; D005909:Glioblastoma / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000601:surgery; D010166:Palliative Care; D016634:Radiosurgery / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult