Gamma Knife FAQ
What is Gamma Knife radiosurgery?
Gamma Knife is not a knife, but rather a sophisticated system that can be used to replace brain surgery or whole brain radiation in some situations. It uses a single, high dose of gamma radiation delivered via up to 192 individual beams which intersect at a single spot with the accuracy of less than one-tenth of a millimeter (about the thickness of a sheet of paper).
A Gamma Knife procedure treats brain lesions with enough radiation to control them, so that they disappear, shrink or stop growing. It can be used to treat targets even in the most critical, difficult-to-access areas of the brain without delivering significant radiation doses to healthy, normal brain tissue. Referred to as “surgery without a scalpel,” the Gamma Knife procedure does not require the surgeon to make an incision in the scalp, nor an opening in the skull.
Gamma Knife is more precise and delivers less dose to normal tissue than other radiosurgical tools that are currently available.
What is involved in a typical Gamma Knife treatment?
On the day of treatment, the patient is given light sedation. Next, local anesthesia is used to secure a head frame to the patient’s head. The frame is used in conjunction with an imaging procedure to accurately locate the target. With the frame in place, the patient undergoes an MRI or CT scan, or in the case of an arteriovenous malformation (AVM), angiography, in order to locate the lesion in the brain to be treated. Using the imaging procedure, the treating team can define the position of the lesion(s) inside the patient’s head. While the patient rests, the treatment team (which typically consists of a neurosurgeon, radiation oncologist and physicist) uses a computer to devise a treatment plan. This takes from 30 to 90 minutes to complete, depending upon the geometry and location of the target(s).
When the individual treatment plan is completed, the patient lies on the Gamma Knife couch so that their head is precisely positioned for treatment. The patient is then moved automatically, into the machine, and treatment begins. Treatment typically lasts from 20 minutes to 2 hours, during which time the patient feels nothing. At the completion of the treatment, the patient is automatically moved out of the machine, and the head frame is removed. The patient usually goes home at this point, but may remain in the hospital overnight for observation on occasion.
How many sessions is Gamma Knife radiosurgery?
Gamma Knife is typically completed in a single-day with patients arriving in the morning and able to return home later in the day. Occasionally, physicians may choose to deliver the treatment over a few days.
Does Gamma Knife work?
The Gamma Knife is not an experimental form of treatment. It is a highly effective method of treating brain tumors and neurological and functional disorders and its use is supported by two decades of clinical research published in the mainstream medical literature.
Developed in 1968, it has been used in the treatment of over one million patients. There are over 3,000 peer reviewed publications describing the use of the Gamma Knife in an array of clinical conditions including brain tumors, vascular malformations, movement disorders and facial pain.
The results reported by Gamma Knife centers are typically as good as those achieved with other techniques, with lower complication rates.
What studies have been done or are being done to show the effectiveness of Gamma Knife treatment?
The number of peer-reviewed, published scientific articles documenting patient outcomes with Gamma Knife far outweighs any other form of stereotactic radiosurgery. Gamma Knife centers and universities have published more than 3,000 papers and have treated more than one million patients worldwide during the last 50 years. The fact that 75 percent of all published radiosurgical literature, including most of the multicenter trials, is based on the use of the Gamma Knife is especially significant given that both Gamma Knife and Linac systems were introduced in the same era.
How many patients have received Gamma Knife treatment?
More than one million patients have been treated with Leksell Gamma Knife—about 80,000 patients every year.
What does the patient feel during the Gamma Knife treatment?
There might be mild pain from administration of the local anesthetic used during placement of the head frame (similar to the sensation of having blood drawn). Patients have reported that they feel a pressure sensation when the frame is applied, but not pain.
What can a patient expect after Gamma Knife treatment?
After the treatment session is finished, the head frame is removed. Sometimes there is a little bleeding from where the pins contact the patient’s head. Pressure is applied to stop the bleeding and Band-aids may be used to keep the pin sites clean. It is usually recommended that the patient refrain from physical activity over the next 18 to 24 hours.
How quickly will the Gamma Knife® treatment work?
The effects of Gamma Knife radiosurgery occur over a period of time that can range from several weeks to several years, depending on the condition being treated.
Can Gamma Knife treatment be given more than once?
Yes, treatment may be repeated if recommended.
Gamma Knife’s 4-Part Process
See how Gamma Knife’s advanced technology helps heal brain tumors and other disorders.
Safe, Software-Guided Treatment
Precise targeting without surgery makes Gamma Knife the brain disorder treatment of choice.
What Can It Treat?
Gamma Knife helps treat many different types of brain lesions with unprecedented success.