Atypical Meningiomas: Recurrence, Re-Operation and Radiotherapy

Introduction: Atypical meningiomas (WHO grade II) represent a therapeutic challenge given their high recurrence rate and greater mortality compared with WHO grade I meningiomas. Traditionally, treatment has entailed attempts at gross total resection with radiation therapy reserved for residual disease or recurrences.

Methods: We retrospectively reviewed our patient database of atypical meningioma patients over the past 10 years to assess surgical and radiotherapeutic treatments administered, treatment-related complications, radiographic-clinical progression after treatment and mortality. We identified 45 patients with atypical meningiomas and excluded two patients with incomplete hospital records.

Results: The average age of our patients was 59.7 years. 43 atypical meningioma patients underwent a total of 62 surgeries. Thirty patients underwent one initial surgical resection; 8 patients underwent a second resection for recurrence; 4 patients underwent 3 resections; and 1 patient underwent 4 resections for recurrences. The rate of post-operative complication was 12.9% (8/62). Five patients had post-operative wound infections requiring treatment and one patient had a post-operative hematoma requiring surgical evacuation. There was one case of wound breakdown in a patient with a previously-irradiated scalp and one case of lower extremity venous thrombosis. Clinical follow-up ranged from 11 to 120 months with average follow-up of 43 months and median follow-up of 65 months. 19 patients (44%) developed clinical-radiographic evidence of recurrence at an average of 32.4 months after surgical resection. Of the recurrences, 12 were treated with repeat surgery and radiation therapy, 3 were treated with radiation therapy alone and 2 with surgery alone. Radiation therapy included Gamma Knife (GK), CyberKnife (CK), intensity-modulated radiation therapy (IMRT), or some combination of the above. There was one case of symptomatic radiation necrosis (1/15 or 6.6%). The survival rate at last follow-up of our patient cohort was 95.3%.

Conclusions: Given their high rates of recurrence, atypical meningiomas require close clinical follow-up and an individualized treatment strategy. Re-operation, radiotherapy or combination therapy can be effective strategies at managing disease progression while minimizing treatment-related morbidity. Treatment planning that attempts to anticipate future therapies in the form of further surgery or radiotherapy may improve clinical outcomes in these patients.