Grade 2 meningioma and radiosurgery.

Object: World Health Organization Grade 2 meningiomas are aggressive tumors associated with a high recurrence rate leading to repeated surgical procedures, which can seriously worsen a patient's neurological status. Although radiosurgery is an increasingly popular technique, its role in the management of Grade 2 meningiomas has yet to be defined. In this study the authors aimed to evaluate radiosurgery in achieving control of proven tumor progression occurring after resection of Grade 2 meningioma.
Methods: This retrospective study included consecutive patients who, between 2000 and 2012, had undergone radiosurgery for radiologically proven progression of a previously surgically treated Grade 2 meningioma.
Results: Twenty-seven patients were eligible for analysis. There were 9 men and 18 women with a mean age of 59 years. The mean radiation dose was 15.2 Gy (range 12-21 Gy), and the mean target volume was 5.4 cm(3) (range 0.194-14.2 cm(3)). Thirty-four radiosurgical procedures were performed in the 27 patients. The mean progression-free survival after radiosurgery was 32.4 months among those with progression in a target irradiated volume and 26.4 months among those with progression in any intracranial meninges. With a mean follow-up of 56.4 months (range 12-108 months), the 12-, 24-, and 36-month actuarial local control rates for all patients were 75%, 52%, and 40%, respectively, and the regional control rates were 75%, 48%, and 33%. A single case of transient hemiparesis completely resolved without sequelae.
Conclusions: Radiosurgery appears to be a safe and effective treatment for the local control of delayed progression after resection of a Grade 2 meningioma. Higher radiation doses similar to those applied for malignant tumors should be recommended when possible.