title: Stereotactic radiosurgery for recurrent ependymoma.
abstract: BACKGROUND
  Patients with recurrent intracranial ependymomas were evaluated to assess local control, overall survival, and complications from stereotactic radiosurgery (SRS).
  
  
  METHODS
  Twelve patients (with a total of 17 tumors) with recurrent ependymoma underwent SRS. Local failure was defined as tumor progression within the prescription isodose volume, and marginal failure was defined as tumor progression adjacent to the SRS prescription isodose volume. Tumor progression away from the prescription volume was considered distant failure. Eleven of the 12 patients had undergone previous resection and external beam radiation therapy (46-56 Grays [Gy]; median, 54 Gy) before radiosurgery, and 1 patient had failure after complete resection alone. Age at SRS ranged from 5-56 years (median, 29 years). Three patients were female. The marginal tumor dose was 12-24 Gy (median, 18 Gy). One to 14 isocenters (median, 4 isocenters) were utilized to irradiate volumes of 0.3-15.5 cm(3) (median, 3.2 cm(3)).
  
  
  RESULTS
  The duration of follow-up ranged from 2.5-60 months (median, 22.5 months). The median overall survival after SRS was 3.4 years (range, 1.4-5 years). In-field local control was achieved in 14 of the 17 tumor sites and estimated 3-year local control was 68%. There were two in-field failures and one marginal failure. Distant failure occurred in two patients. Two patients developed treatment-related complications after SRS.
  
  
  CONCLUSIONS
  SRS provides good local tumor control for patients with recurrent intracranial ependymoma and may have a favorable impact on survival. SRS should be evaluated more extensively in the initial treatment of patients with ependymoma to minimize local failure after surgical management.
authors.affiliation: Division of Radiation Oncology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Stafford
authors.forename: B E
authors.initials: BE
authors.lastname: Pollock
authors.forename: R L
authors.initials: RL
authors.lastname: Foote
authors.forename: D A
authors.initials: DA
authors.lastname: Gorman
authors.forename: D F
authors.initials: DF
authors.lastname: Nelson
authors.forename: P J
authors.initials: PJ
authors.lastname: Schomberg
mesh_terms: D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000401:mortality / Q000601:surgery*; D002648:Child; D004806:Ependymoma / Q000401:mortality / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects; D012189:Retrospective Studies; D015996:Survival Rate