Stereotactic radiosurgery in patients with multiple intracranial meningiomas.

Purpose: Stereotactic radiosurgery (SRS) delivers a potent, highly focused dose of radiation to the tumor while sparing the surrounding normal tissues. The purpose of this study was to assess the outcome of patients with intracranial meningiomas treated with SRS.

Methods: A total of 73 patients with 221 benign meningiomas treated between 1991 and 2005 with SRS and followed up for more than a year were reviewed. Fifty patients (68%) were treated with SRS to the primary meningioma while 23 (32%) received SRS to relapsing tumors adjacent or distant from the site of the initial meningioma that was previously treated with surgery alone. Mean tumor margin dose was 14 Gy (range 10-16). SRS was delivered after surgery in 117 meningiomas (55 patients).

Results: The median age at diagnosis was 47 years (range 16-74) and the median follow-up 5.8 years (range 1-13.6). The 3- and 5-year overall survival (OS) rates for all patients were 95% and 90%, respectively. The mean gross tumor volume decreased from 4.17 cm3 to 3.23 cm(3) after SRS (p=0.057). Twenty-two (10%) meningiomas increased after SRS. In addition, clinical symptoms improved in 36% and remained stable in 45% of the patients. With regard to morbidity of SRS, only 7 patients (9.6%) had late complications, including edema (N=4), brain necrosis (N=4), gliosis (N=1), and paresis of the III pair nerve (N=1). There was no treatment-related mortality.

Conclusion: SRS for patients with multiple intracranial meningiomas is effective yielding a high rate of local tumor control, whereas treatment-related morbidity remains low.