Atypical Meningiomas: Recurrence, Reoperation, and Radiotherapy.

INTRODUCTION: Atypical meningiomas (World Health Organization [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 (AM) 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 AMs and excluded 2 patients with incomplete hospital records.

RESULTS: The average age of our patients was 59.7 years. Forty-three AM 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 postoperative complication was 12.9% (8/62). Five patients had postoperative wound infections requiring treatment, and 1 patient had a postoperative hematoma requiring surgical evacuation. There was 1 case of wound breakdown in a patient with a previously irradiated scalp and 1 case of lower-extremity venous thrombosis. Clinical follow-up ranged from 11-120 months with average follow-up of 43 months and median follow-up of 65 months. Nineteen 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 these. 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, AMs require close clinical follow-up and an individualized treatment strategy. Reoperation, 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. Seventeen patients underwent adjuvant radiation therapy: 7 patients with intensity-modulated radiation therapy (IMRT), 4 patients with Gamma Knife (GK), and 2 with CyberKnife (CK). Four patients underwent multiple treatments.