title: Patterns of recurrence after stereotactic radiosurgery for treatment of meningiomas.
abstract: OBJECTIVE
  The purpose of this study was to evaluate patterns of failure after stereotactic radiosurgery (SRS) for meningiomas and factors that may influence these outcomes.
  
  
  METHODS
  Based on a retrospective chart review, 279 patients were treated with SRS for meningiomas between January 1999 and March 2011 at Wake Forest Baptist Health. Disease progression was determined using serial imaging, with a minimum follow-up of 6 months (median 34.2 months).
  
  
  RESULTS
  The median margin dose was 12.0 Gy (range 8.8-20 Gy). Local control rates for WHO Grade I tumors were 96.6%, 84.4%, and 75.7% at 1, 3, and 5 years, respectively. WHO Grade II and III tumors had local control rates of 72.3%, 57.7%, and 52.9% at 1, 3, and 5 years, respectively. Tumors without pathological grading had local control rates of 98.7%, 97.6%, and 94.2% at 1, 3, and 5 years, respectively. Of the local recurrences, 63.1% were classified as marginal (within 2 cm of treatment field). The 1-, 3-, and 5-year rates of distant failure were 6.5%, 10.3%, and 16.6%, respectively, for Grade I tumors and 11.4%, 17.2%, and 22.4%, respectively, for Grade II/III tumors. Tumors without pathological grading had distant failure rates of 0.7%, 3.2%, and 6.5% at 1, 3, and 5 years, respectively. Wilcoxon analysis revealed that multifocal disease (p < 0.001) and high-grade histology (WHO Grade II or III; p < 0.001) were significant predictors of local recurrence. Additionally, male sex was a significant predictor of distant recurrence (p = 0.04). Multivariate analysis also showed that doses greater than or equal to 12 Gy were associated with improved local control (p = 0.015).
  
  
  CONCLUSIONS
  In this patient series, 12 Gy was the minimum sufficient margin dose for the treatment of meningiomas. Male sex is a risk factor for distant failure, whereas high-grade histology and multifocal disease are risk factors for local failure.
authors.affiliation: Department of Radiation Oncology, and.
authors.forename: Elizabeth N
authors.initials: EN
authors.lastname: Kuhn
authors.forename: Glen B
authors.initials: GB
authors.lastname: Taksler
authors.forename: Orrin
authors.initials: O
authors.lastname: Dayton
authors.forename: Amritraj G
authors.initials: AG
authors.lastname: Loganathan
authors.forename: Tamara Z
authors.initials: TZ
authors.lastname: Vern-Gross
authors.forename: J Daniel
authors.initials: JD
authors.lastname: Bourland
authors.forename: Adrian W
authors.initials: AW
authors.lastname: Laxton
authors.forename: Michael D
authors.initials: MD
authors.lastname: Chan
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Tatter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000601:surgery*; D008579:Meningioma / Q000401:mortality / Q000601:surgery*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology*; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome; D055815:Young Adult