Gamma Knife radiosurgery, also called stereotactic radiosurgery, is a very precise form of therapeutic radiology. Even though it is called surgery, a Gamma Knife procedure does not involve actual surgery, nor is the Gamma Knife really a knife at all. It uses beams of highly-focused gamma rays to treat small- to medium-size lesions, usually in the brain. Many beams of gamma radiation join to focus on the lesion under treatment, providing a very intense dose of radiation without a surgical incision or opening.
Gamma Knife radiosurgery is called "surgery" because a result similar to an actual surgical procedure is created by a one-session radiation therapy treatment. The beams of radiation are very precisely focused to reach the tumor, lesion, or other area being treated with minimal effect on surrounding healthy tissue.
Gamma Knife radiosurgery is most often used to treat tumors and other lesions in the brain. It is also used to treat certain neurological conditions, such as trigeminal neuralgia (a condition in which pressure on the trigeminal nerve causes spasms of extreme facial pain) and acoustic neuroma (a noncancerous tumor in the brain that affects the nerves that control hearing).
Gamma Knife radiosurgery may be used in situations where the brain lesion cannot be reached by conventional surgical techniques. It may also be used in persons whose condition is such that they might not be able to tolerate a surgical procedure, such as craniotomy, to treat their condition.
Because the therapeutic effects of a Gamma Knife procedure occur rather slowly over time, it is not used for persons whose condition requires more immediate therapy.
Gamma Knife radiosurgery may be used to treat certain conditions of the brain in particular instances. Brain conditions that may be treated with a Gamma Knife procedure include, but are not limited to, the following:
- brain tumors
- brain cancer
- arteriovenous malformations, or AVM (a type of blood vessel defect)
- trigeminal neuralgia
- acoustic neuroma
Gamma Knife radiosurgery has shown some promise for treating conditions such as tremor and rigidity related to Parkinson's disease, epilepsy, and chronic pain.
There may be other reasons for your physician to recommend Gamma Knife radiosurgery.
If you are pregnant or suspect that you may be pregnant, you should notify your physician. Radiation exposure during pregnancy may lead to birth defects.
Other risks may include, but are not limited to, the following:
- swelling of the brain
Some risks and side effects may be related to the location and size of the area being treated by the Gamma Knife procedure. These may include:
- hair loss near treated area (generally temporary)
- loss of balance
- vision problems
There may be other risks depending upon your specific medical condition. Be sure to discuss any concerns with your physician prior to the procedure.