Gamma Knife® Surgery
Common Gamma Knife® Surgery Questions
What is Gamma Knife® surgery?
Gamma Knife® surgery is a unique method that delivers extremely focused radiation beams to targets in the brain. Two-hundred and one individual beams converge to one focal point. The radiation source used is called cobalt. These sources are positioned in a hemisphere so that all the beams can converge at a single point. The shape and dose of the radiation is optimized to hit only the target, without damaging surrounding healthy tissue.
Leskell Gamma Knife® is not a knife in the normal sense of the word. The doctor makes no incisions in your head. Instead, very precisely focused beams of radiation are directed to the treatment area in the brain. Gamma Knife® surgery offers a safe and effective treatment for more than 40,000 patients every year. The treatment procedure is simple, painless and straightforward.
Why is it called surgery?
Radiosurgery (one-session treatment) has such a dramatic and precise effect in the target zone that the changes are considered "surgical." Through the use of three-dimensional computer-aided planning and the high degree of immobilization of the patient, the treatment can minimize the amount of radiation to surrounding healthy brain tissue. Gamma Knife® precision is submillimeter. Stereotactic radiosurgery is routinely used for brain tumors and lesions. It may be the primary treatment (utilized when a tumor is inaccessible by surgical means) or a boost or adjunct to other treatments with a recurring or malignant tumor.
How does it work?
Stereotactic radiosurgery works the same as all other forms of radiation treatment. It does not remove the tumor or lesion, but it distorts the DNA of the tumor cells. The cells then lose their ability to reproduce and retain fluids. The tumor reduction occurs at the rate of the normal growth rate of the specific tumor cell. In lesions such as AVMs (a tangle of blood vessels in the brain), radiosurgery causes the blood vessels to thicken and close off. The shrinking of a tumor or closing off of a vessel occurs over a period of time. For benign tumors and vessel, this will usually be 18 months to two years. For malignant and metastatic tumors, results may be seen as soon as a couple of months, as these cells are very fast-growing.
Who determines if radiosurgery is appropriate?
Medical necessity can be determined by a neurosurgeon, radiation oncologist or other medical specialist after evaluating a prospective patient's medical condition. Treatment options are then determined and discussed with patient and family so an informed decision may be made.
Are there side effects after Gamma Knife® surgery?
Patients may experience side effects, but they are often very mild. Headache, dizziness, seizures or nausea may be experienced immediately after treatment, but the effects will disappear soon after the procedure.
What about the radiation risk?
The dose of radiation is extremely focused to the target in the brain, and the dose outside the target is very low.
First Gamma Knife Procedure a Great Success
The first Gamma Knife procedure at Covenant’s Gamma Southwest was
performed on January 30 with Shirley Brown. The team of physicians and
clinicians worked diligently though the procedure to assure success.
Shirley has been diagnosed with a meningioma and previously had radiosurgery
in June 2006. She had already met with the Gamma Knife team in Dallas
but didn’t feel comfortable doing the surgery there. She said she was
“waiting for the right doctor.” When she heard the Gamma Knife was going to be in Lubbock, she decided
to have it here.
Shirley compared the Gamma Knife to radiosurgery, saying,
“It was better because it doesn’t move around you. It’s
quieter than the other, and the helmet is more comfortable.”
Shirley said she is feeling fine. She had a little swelling following the
procedure, but she was never sick or uncomfortable. She said the surgery
was a much better alternative than an open-head surgery.
“The staff is fabulous,” stated Brown.
“I was especially appreciative of the way they made me feel comfortable.
They held my hand and my head to help me know that everything was going
to be all right. If you have to have the experience, it was great. It
was good to do it here (in Lubbock). It's the greatest thing to come
to this town in a long time.”
- Neuro Network, March 2007