OBJECTIVE: Recurrent atypical and malignant meningiomas are difficult to treat successfully. Chemotherapy to date has been unsuccessful, and radiosurgery is limited to smaller tumors. Reoperation alone provides limited tumor control and limited prolonged survival. The addition of brachytherapy at the time of operation is an option. Here, we report the results of our series of patients with recurrent malignant meningioma treated with resection and brachytherapy with permanent low-dose 125I.
METHODS: The charts of patients in our database with recurrent atypical and malignant meningiomas treated by surgical resection and permanent 125I brachytherapy at the University of California, San Francisco, between 1988 and 2002 were selected for this study. Calculations of disease-free survival and overall survival curves were made by the Kaplan-Meier actuarial method. Univariate analysis between Kaplan-Meier curves was based on the log-rank statistic, with a significance level set at a value of P ≤ 0.05.
RESULTS: Seventeen patients had recurrent malignant meningioma, and four had recurrent atypical meningioma. The median number of sources implanted after surgical resection was 30 (range, 4–112 sources), with a median total activity of 20 mCi (range, 3.3–85.9 mCi). The median time to progression after brachytherapy was 11.6 months for patients with malignant meningioma and 10.4 months for the combined group. There was a trend toward longer disease-free survival time in patients after gross total resection versus subtotal resection and in patients with tumors located at the convexity and parasagittally versus at the cranial base. These differences did not reach statistical significance. The median overall survival after diagnosis was 9.4 years for patients with atypical meningioma, 6.6 years for those with malignant meningioma, and 8.0 years for all patients combined. Survival from the time of resection and implantation of 125I was 1.6 years for patients with atypical meningioma, 2.4 years for patients with malignant meningioma, and 2.4 years for the combined group. Thirty-three percent of patients had complications requiring surgical intervention. Radiation necrosis occurred in 27% of patients; 13% underwent surgery for radiation necrosis. In addition, 27% had a wound breakdown and required surgical intervention.
CONCLUSION: The options for patients with recurrent atypical or malignant meningiomas are limited. Our results suggest that for tumors not suitable for radiosurgery, resection followed by permanent brachytherapy should be considered as a potential salvage treatment. However, this approach results in a relatively high complication rate in these heavily treated patients and requires meticulous surgical technique and medical therapies to assist with wound healing after surgery.