Patients with parasagittal meningiomas are at greater risk of developing peritumoral symptomatic edema after SRS. Close follow-up after SRS may be particularly important in such patients. These results highlight the need to pursue strategies that could decrease the incidence of postradiosurgical edema in patients with parasagittal meningioma.

It has been asserted that relief of trigeminal nerve pain following irradiation results from axonal degeneration and neuronal death. However, there could be another explanation of the observed clinical phenomena: pain relief may result from altered neuronal function. It is argued that optimal treatment of trigeminal neuralgia with stereotactically-delivered radiation may be achieved by altering neuronal behavior without tissue destruction. Multiple lines of evidence demonstrate that radiation can focally alter neuronal physiology. These experimental and clinical observations are reviewed. Radiomodulation may offer a tool by which hypermetabolic foci may be down-regulated in order to restore homeostasis within a malfunctioning neural circuit and treat clinical symptoms of functional and behavioral disorders.

Although the length of follow-up is limited, we report our initial experience with CyberKnife treatment of TS. Our results demonstrate tumor control rates and clinical outcomes that parallel those of previous reports using gamma knife radiosurgery; however, long-term follow-up studies are needed.