More than 350,000 Gamma Knife® procedures have been performed since the technology first became available in 1968. Almost a third of these patients (16%) sought relief from blood vessel problems (i.e. AVMs). Nearly two-thirds (77%) were treated for brain tumors, including cancer, glial tumors and rarer types of tumors. A small percentage (7%) sought treatment to relieve functional disorders like unmanageable pain, trigeminal neuralgia, Parkinson’s disease and epilepsy.
Treating Brain Tumors
Radiosurgery performed by the Gamma Knife is useful in the management of both benign and malignant brain tumors, especially tumors originating elsewhere in the body that have metastasized to the brain. Radiosurgery often can treat tumors that may have been termed inoperable because of their location in hard-to-access areas of the brain, or those treated unsuccessfully by conventional surgery, chemotherapy and/or radiation therapy.
Arteriovenous Malformations (AVMs)
AVMs are abnormal collections of arteries and veins that connect directly, instead of through a network of capillaries. When located in the brain, these abnormalities can cause severe bleeding, headaches or seizures. While many AVMs can be removed with conventional microsurgery, radiosurgery may offer a much less invasive option with less risk of neurologic injury.
This nerve disorder causes disabling facial pain that feels like an electric shock. Radiosurgery can create a lesion on the nerve, blocking its pain signals. This procedure is typically reserved for older patients or for patients with recurrent pain after other operations for trigeminal neuralgia.
These noncancerous tumors, also called schwannomas, develop on the nerve that affects balance and hearing. Radiosurgery can effectively control the growth of small tumors in the majority of cases, with a lower risk of deafness or loss of facial movement, compared with conventional surgery.
Tumors of the pea-sized “master gland,” which is located deep within the brain, can cause a variety of problems because the pituitary controls the thyroid, adrenal and reproductive glands. Radiosurgery may be employed to stop the growth that can occur from these tumors.
Movement disorders suitable for treatment include Parkinson’s disease, essential tremor, primary or secondary dystonia, tremor from multiple sclerosis or brain injury, and other movement disorders. Gamma Knife radiosurgery is used to create a thalamotomy (lesion of the thalamus) for the management of tremor. It is mainly performed in older patients or those who have medical risks that make open surgery hazardous.