title: Radiation Therapy for Residual or Recurrent Atypical Meningioma: The Effects of Modality, Timing, and Tumor Pathology on Long-Term Outcomes.
abstract: Optimal use of stereotactic radiosurgery (SRS) vs external beam radiation therapy (EBRT) for treatment of residual/recurrent atypical meningioma is unclear.
  
  
  
  To analyze features associated with progression after radiation therapy.
  
  
  
  Fifty radiation-naive patients who received SRS or EBRT for residual and/or recurrent atypical meningioma were examined for predictors of progression using Cox regression and Kaplan-Meier analyses.
  
  
  
  Thirty-two patients (64%) received adjuvant radiation after subtotal resection, 12 patients (24%) received salvage radiation after progression following subtotal resection, and 6 patients (12%) received salvage radiation after recurrence following gross total resection. Twenty-one patients (42%) received SRS (median 18 Gy), and 7 (33%) had tumor progression. Twenty-nine patients (58%) received EBRT (median 54 Gy), and 13 (45%) had tumor progression. Whereas tumor volume (P = .53), SRS vs EBRT (P = .45), and adjuvant vs salvage (P = .34) were not associated with progression after radiation therapy, spontaneous necrosis (hazard ratio [HR] = 82.3, P < .001), embolization necrosis (HR = 15.6, P = .03), and brain invasion (HR = 3.8, P = .008) predicted progression in univariate and multivariate analyses. Tumors treated with SRS/EBRT had 2- and 5-year actuarial locoregional control rates of 91%/88% and 71%/69%, respectively. Tumors with spontaneous necrosis, embolization necrosis, and no necrosis had 2- and 5-year locoregional control rates of 76%, 92%, and 100% and 36%, 73%, and 100%, respectively (P < .001).
  
  
  
  This study suggests that necrosis may be a negative predictor of radiation response regardless of radiation timing or modality.
  
  
  
  AM, atypical meningiomaEBRT, external beam radiation therapyGTR, gross total resectionLC, locoregional controlOS, overall survivalPOE, preoperative embolizationRT, radiation therapySRS, stereotactic radiosurgerySTR, subtotal resection.
authors.affiliation: ‡Washington University School of Medicine, St. Louis, Missouri; §Department of Pathology and Immunology, Washington University, St. Louis, Missouri; ¶Department of Neurosurgery, Washington University, St. Louis, Missouri; ‖Department of Radiation Oncology, Washington University, St. Louis, Missouri.
authors.forename: Sam Q
authors.initials: SQ
authors.lastname: Sun
authors.forename: Chunyu
authors.initials: C
authors.lastname: Cai
authors.forename: Rory K J
authors.initials: RK
authors.lastname: Murphy
authors.forename: Todd
authors.initials: T
authors.lastname: DeWees
authors.forename: Ralph G
authors.initials: RG
authors.lastname: Dacey
authors.forename: Robert L
authors.initials: RL
authors.lastname: Grubb
authors.forename: Keith M
authors.initials: KM
authors.lastname: Rich
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Zipfel
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Dowling
authors.forename: Eric C
authors.initials: EC
authors.lastname: Leuthardt
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Simpson
authors.forename: Clifford G
authors.initials: CG
authors.lastname: Robinson
authors.forename: Michael R
authors.initials: MR
authors.lastname: Chicoine
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Perrin
authors.forename: Jiayi
authors.initials: J
authors.lastname: Huang
authors.forename: Albert H
authors.initials: AH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008579:Meningioma / Q000473:pathology / Q000532:radiotherapy*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000601:surgery; D016016:Proportional Hazards Models; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome