Gamma Knife Radiosurgery for Benign Cavernous Sinus Tumors: Treatment Concept and Outcomes in 120 Cases

Abstract

Availability of modern computer-aided robotized devices, such as the Automatic Positioning System (APS TM ; Elekta Instruments AB, Stockholm, Sweden) and Perfexion TM (Elekta Instruments AB), allowed us to develop the original concept of robotic gamma knife microradiosurgery, which is based on the very precise irradiation of the lesion with regard to conformity and selectivity; intentional avoidance of the excessive irradiation of functionally-important anatomical structures, particularly cranial nerves, located both within and in the vicinity of the target; and delivery of sufficient irradiation energy to the tumor with the intention to attain lesion shrinkage, while keeping the marginal dose sufficiently low for prevention of possible complications. The results of such treatment strategy were evaluated retrospectively in 120 patients with benign cavernous sinus neoplasms (pituitary adenomas, meningiomas, schwannomas, and hemangiomas), who were followed up from 24 to 78 months (mean 47 months) after radiosurgery. Tumor growth control and shrinkage rates were 98% and 68%, respectively. More than 50% volume reduction was noted in 25% of lesions. The most prominent volumetric tumor response was observed in hemangiomas, followed by schwannomas, pituitary adenomas, and meningiomas. Treatment-related complications were marked in 7% of cases, and were mainly related to transient isolated cranial neuropathy appearing within several months after radiosurgery. Major morbidity was limited to one patient (0.8%). Application of microradiosurgical treatment principles provides effective and safe management of benign cavernous sinus tumors and is associated with high probability of lesion shrinkage and minimal risk of complications.

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

“…Based on the published literature, surgeryrelated morbidity for CSM was higher than that for stereotactic radiosurgery (SRS), including either gross total and subtotal resection. Patients receiving SRS experienced lower rates of tumor recurrence compared with patients who underwent surgery alone [4,7]. Long-term studies of meningioma involving the cavernous sinus after surgery reported recurrence rates of 9.6 % after complete resection and 15.2 % after subtotal resection [6,13].…”

“…For these reasons, application of SRS, particularly GKS to cavernous sinus meningioma, has been generally accepted as the primary treatment of tumors < 3 cm in greatest dimension, not significantly compromising the optic pathway. Larger tumors >3 cm in maximum diameters or those with marked optic pathway compression benefits surgical debulking and optic nerve decompression followed by adjunctive Gamma Knife surgery (GKS) for residual or fractionated stereotactic radiosurgery or radiotherapy [7,8].…”

Therapeutic Effect of Hypofractionated Stereotactic Radiotherapy Using CyberKnife for High Volume Cavernous Sinus Cavernous Hemangiomas

“…16,17 The conventional goal of GKS is achieving tumor growth control, and reducing the mass volume is important to restore nerve function particularly related to direct compression of the cranial nerves. 18 Single-session GKS is more effective for small or medium-sized CSCHs than for larger tumors. Hypofractionated SRT using CyberKnife has been used for primary or postoperative management of patients with CSCHs with favorable results.…”

Visual Symptoms Outcomes in Cavernous Sinus Radiosurgery and a Systematic Review

“…Meningiomas remain adherent to surrounding structures, bone, dura, sinuses, and the carotid wall, reducing the possibility of achieving complete surgical resection. Postoperative morbidity in cases of cavernous sinus tumors, particularly related to dysfunction of the CN, varies from 18% up to 63% [5,[15][16][17].…”