title: The role of radiotherapy following gross-total resection of atypical meningiomas.
abstract: OBJECTIVE
  Atypical (WHO Grade II) meningiomas comprise a heterogeneous group of tumors, with histopathology delineated under the guidance of the WHO and a spectrum of clinical outcomes. The role of postoperative radiotherapy for patients with atypical meningiomas who have undergone gross-total resection (GTR) remains unclear. In this paper, the authors sought to clarify this role by reviewing their experience over the past 2 decades.
  
  
  METHODS
  The authors retrospectively analyzed all patients at their institution who underwent GTR between 1992 and 2011 with a final histology demonstrating atypical meningioma. Information regarding patients, tumor characteristics, and postoperative adjuvant therapy was gleaned from medical records. Time to recurrence and overall survival were analyzed using univariate, multivariate, and Kaplan-Meier survival analyses.
  
  
  RESULTS
  Forty-five patients who met the inclusion criteria underwent GTR for atypical meningiomas. By a median follow-up of 44.1 months, 22% of atypical meningiomas had recurred. There was no recurrence in 12 (92%) of 13 patients who received postoperative radiotherapy or in 19 (59%) of 32 patients who did not undergo postoperative radiotherapy (p = 0.085), demonstrating a strong trend toward improved local control with postoperative radiotherapy. No other factors were significantly associated with recurrence in univariate or multivariate analyses.
  
  
  CONCLUSIONS
  This retrospective series supports the observation that postoperative radiotherapy likely results in lower recurrence rates of gross totally resected atypical meningiomas. Although a multicenter prospective trial will ultimately be needed to fully define the role of radiotherapy in managing gross totally resected atypical meningiomas, the authors' results contribute to a growing number of series that support routine postoperative radiotherapy as an adjuvant treatment for these lesions.
authors.affiliation: Department of Neurological Surgery, The University of Miami Miller School of Medicine, Miami, FL, USA.
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: Komotar
authors.forename: J Bryan
authors.initials: JB
authors.lastname: Iorgulescu
authors.forename: Daniel M S
authors.initials: DM
authors.lastname: Raper
authors.forename: Eric C
authors.initials: EC
authors.lastname: Holland
authors.forename: Kathryn
authors.initials: K
authors.lastname: Beal
authors.forename: Mark H
authors.initials: MH
authors.lastname: Bilsky
authors.forename: Cameron W
authors.initials: CW
authors.lastname: Brennan
authors.forename: Viviane
authors.initials: V
authors.lastname: Tabar
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Sherman
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
authors.forename: Philip H
authors.initials: PH
authors.lastname: Gutin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D008579:Meningioma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000517:prevention & control*; D019635:Neurosurgical Procedures / Q000379:methods; D011878:Radiotherapy; D012189:Retrospective Studies; D016896:Treatment Outcome