Gamma Knife® Surgery Process

Gamma Knife radiosurgery is a radically different approach to brain surgery that yields extremely positive results.
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The Gamma Knife is a revolutionary instrument that uses radiation, or gamma rays, to selectively destroy brain tumors or blood vessel abnormalities deep within the brain. It can also be used to treat functional neurological disorders, such as trigeminal neuralgia.

One Outpatient Session
Gamma Knife radiosurgery is a one-session treatment, as opposed to traditional radiation therapy which is administered over time in multiple sessions. No knife is used during surgery, therefore no incision is made. Because the patient’s skull is left intact, there is no scarring, no lengthy recovery period, little risk of infection and less psychological stress. The Gamma Knife treatment, typically performed on an outpatient basis, is virtually painless and does not usually require general anesthesia. Most patients return to normal activities within 24 to 48 hours.

No Incision
This non-invasive neurosurgical alternative is used for the treatment of malignant and benign brain tumors, vascular malformations and trigeminal neuralgia. The energy of 201 narrow beams of cobalt radiation is focused on a specific target within the brain. Individually, these low-density beams are too weak to cause any significant damage; however, when they converge on the target, they arrest growth and destroy abnormal cells. Healthy brain tissue remains safe and intact.

A Multidisciplinary Team
Patients referred to our Gamma Knife program will be cared for by a multidisciplinary team of specialists including neurosurgeons, radiation oncologists, medical physicists and neuro-nurses. Referring physicians also are encouraged to be active partners in the treatment process.

Stereotactic Frame Placement
On the day of treatment, an intravenous (IV) line may be given to the patient in order to administer needed medications. Next, the stereotactic frame is attached to the patient’s head using four pins. A small amount of local anesthesia is used at the four sites to help the patient feel comfortable. The frame placement is usually not painful, but may produce a feeling of pressure for about 15 minutes. The lightweight aluminum-alloy head frame is used as a measurement tool to set the exact coordinates and accurately target the brain abnormality. Frame placement is usually completed within 20 minutes.

Imaging Tests
A member of the clinical team accompanies the patient to the imaging area. Depending on the condition being treated, tests may include one or more of the following: an MRI, CT scan, angiography or a combination of these. These tests are performed with the stereotactic frame on the patient’s head. The frame’s special markers are what allow the physician to view on film the exact location of the abnormality and where to deliver the dosage. The imaging tests may take an hour or longer to complete.

Planning
During this important step, the patient is able to relax for an hour or more and can have a light snack while the neurosurgeon, radiation oncologist and physicist review the patient’s films and map out a course of treatment. They determine how many areas to treat, what the appropriate radiation dose should be for each area and the time required. During this time, many patients choose to visit with their families, read or take a nap.

The Gamma Knife
The patient is taken to the Gamma Knife couch where the coordinates are set to the predetermined values. Lying down, the stereotactic frame the patient is wearing is attached to a collimator helmet on the table. The collimator helmet, which contains201 holes, is specifically selected for each patient. Each collimator has different size holes, which may be plugged to protect certain vital areas of the brain. A treatment plan may include the use of several collimators during one or multiple cycles.

At this point, the patient is ready to move into the unit and the clinical team leaves the treatment room. During this phase, the patient is monitored at all times through cameras. A microphone located in the helmet allows for two way communication with the clinical team. The couch, with the patient lying on it, then moves backward into the Gamma Knife treatment hood, and docks with the radiation sources. During treatment, the patient feels no discomfort. Because there are no moving parts, no sound is emitted from the Gamma Knife unit. The total treatment time depends on the size and/or shape of the area to be treated and the dosages required for a successful outcome.

Recovery
After treatment, the frame is removed and adhesive bandages are placed over the pin sites. Generally, most patients do not experience side effects and can go home the same day. Patients who undergo an angiogram remain in the unit flat in bed for up to eight hours to avoid headaches or complications. Typically, patients can expect to spend four to eight hours in the hospital, depending on their treatment plan.

Follow-Up
Patients are given specific instructions from their nurse prior to discharge. Since the effects of Gamma Knife radiosurgery occur over a period of time—weeks or even years—the patient’s treatment will be followed up by the consulting or referring physician, as well as the Gamma Knife Center’s medical team. Periodic diagnostic imaging tests will be necessary, and patients are instructed to continue their medication as prescribed by their physician(s).