Atypical (WHO Grade II) meningiomas (AM) comprise a heterogeneous group of tumors, with a spectrum of histopathologies and clinical outcomes.

     The role of postoperative radiotherapy (RT) for patients with AM who have undergone gross total resection (GTR) remains unclear - a role we sought to clarify by reviewing our experience over the past 2 decades.

     Fifty-two patients underwent GTR for AM. After a mean follow-up of 51.9 months, overall survival was 81% and 17% of patients had recurred.

     We retrospectively analyzed all patients at our institution who underwent GTR with final histology demonstrating atypical meningioma from 1992-2011. Information regarding patients, tumor characteristics, and postoperative adjuvant therapy was evaluated from medical records. Time to recurrence and overall survival were analyzed using univariate, multivariate, and Kaplan-Meier survival analyses.

     There was no recurrence in 13/14 (93%) patients who received postoperative RT, compared to 26/38 (68%) patients without postoperative RT (p = .08), demonstrating a strong trend toward improved local control with postoperative RT. No other factors were significantly associated with recurrence in univariate or multivariate analyses.

     This is a retrospective study.

     This retrospective series supports the observation that postoperative radiotherapy likely results in lower recurrence rates of gross totally resected atypical meningiomas.

     Although a multi-center prospective trial will ultimately be needed to fully define the role of radiotherapy in managing gross totally resected AM, our results contribute to a growing number of series that support routine postoperative RT as an adjuvant treatment for these lesions.