Atypical menginomas demonstrate increased clinical aggressiveness characterized by recurrence and diminished survival. The optimal management of atypical meningioma in the recurrent setting is especially not well defined. To characterize outcomes following salvage treatment of recurrent atypical meningioma and to identify risk factors for further recurrence. Retrospective chart review was performed on 65 patients who underwent salvage treatment of atypical meningioma at a single institution. Data were analyzed using the Kaplan-Meier method and Cox proportional hazards modeling. Sixty-five patients with recurrent atypical meningioma and median imaging follow-up of 4.0 years (range 1.9-6.6 years) underwent 62 surgeries and 114 radiation treatments (RT) for salvage therapy. Salvage modality was surgery (21%), surgery/RT (25%), or RT alone (54%), associated with 2 year local freedom from recurrence (LFFR) of 36, 59, and 73%, respectively (P = 0.01). Twenty percent of patients experienced CTCAE grade ≥ 3 toxicity with salvage therapy. Thirty-nine percent of patients experienced ≥ 3 recurrences. The median disease-free survival intervals after first and second salvage treatments were 2.9 and 1.3 years, respectively. On univariate Cox analysis, prior subtotal resection, prior RT, tumor diameter > 2.5 cm, and multifocal local recurrence were associated with recurrence after salvage therapy. On multivariate logistic regression, only multifocal local recurrence was associated with further recurrence. Recurrent atypical meningioma is clinically and pathologically more aggressive than primary atypical meningioma, and the likelihood of durable local control with salvage therapy is lower. Future efforts should identify patients at risk of recurrence, and aggressive upfront treatment should be employed.
Keywords: Atypical meningioma; Meningioma; Radiation; Radiotherapy; Salvage; Stereotactic radiosurgery.