Stereotactic Gamma Knife surgery safety and efficacy in the management of symptomatic benign confined cavernous sinus meningioma

Considering the proximity to cranial nerves from II to VI and the internal carotid artery microsurgery for cavernous sinus meningioma (CSM) has its limits of complete resection, with high potential tumor recurrences, cranial nerve and vascular morbidity. Gamma Knife surgery (GKS) is an advanced modality as primary treatment for patients harboring symptomatic benign confined CSM as well as adjuvant therapy to postoperative residual tumor giving a high rate of tumor control, stabilizing or even improving clinical condition with low morbidity. The aim of this study is to evaluate the safety and efficacy of GKS used in the management of 62 patients with symptomatic benign confined CSM < 3 cm in maximum diameters treated at the International Medical Centre (IMC), Cairo, Egypt, from 2005 to end of 2012, with mean follow-up period of 36 months (range, 24-96 months) by reviewing their clinical and radiological data. For 51 patients GKS was performed as a primary treatment. The diagnosis was based on typical clinical and imaging findings and in 11 patients GKS was used as adjuvant to post-operative tumor residual with histological confirmation. There were 43 females and 19 males. The median age at the time of treatment was 48 years. The mean tumor volume was 5.7 cc, the mean tumor marginal radiation dose was 14.4 Gy, the mean isodose line was 38 %, and the mean tumor coverage was 94.4 %. The optic pathway received < 8 Gy and the brain stem < 10 Gy. At most recent follow-up, 57 patients (92 %) had stable or improved cranial nerve deficits. Post-GKS cranial nerve complications were detected in five patients (8 %). Tumor volume was controlled in 60 patients (96 %) at most recent follow-up MRI; 12 patients had a reduction in tumor size and 42 had stable tumor size, while tumor size progression was detected in two patients. The tumor progression-free survival at 3 and 5 years in 40 patients who completed at least 5 years of follow-up was 95 %. Gamma Knife surgery is a safe and effective option for the treatment of cavernous sinus meningioma not only as an adjuvant to surgery but also as an alternative to surgical removal in tumors confined mainly to the cavernous sinus.