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Gamma Knife Treatment - How It Works

Despite its name, Gamma Knife radio-surgery does not make a surgical incision. Rather, our highly skilled team of specialists including a neurosurgeon, a radiation oncologist and a medical physicist develop a treatment plan that uses directed beams of radiation to treat brain-related disorders without having to open up the skull.

The Gamma Knife is so precise that healthy tissue close to the treatment site is left unharmed. Treatment is normally done on an outpatient basis, so the patient can go home in just a few hours and usually resume normal activities the next day. This safe, noninvasive approach is nearly painless and avoids the possibility of damage to arteries, nerves and other important structures.

Most Gamma Knife treatments are completed in half a day. There are five steps in the procedure:

1. The Gamma Knife head frame is fitted.
To ensure effective planning and pinpoint accuracy of the Gamma Knife radiation treatment, the patient is fitted with a lightweight head frame that will remain in place for the entire procedure. The frame keeps your head stable during the treatment planning and procedure. A local anesthetic is applied to the site of the pins to ensure patient comfort.

2. An image of the treatment area is taken.
With the head frame in place, the patient will then go next door to the Outpatient Imaging Department for an MRI, CT scan or angiography (depending on your diagnosis.) These images are used by Paula Petti, Ph.D., and David Larson, M.D., Ph.D., to plan and map your individual treatment dosage.

3. The treatment team plans the procedure.
With information from the new images, the treatment team uses sophisticated computers to create a 3-dimensional image map of the patient's brain and an individualized plan in preparation for the patient's Gamma Knife treatment.

4. The procedure is performed.
Once the plan is completed, the patient will go to the Gamma Knife unit for the procedure. During the procedure, the patient lies down and the head frame will be attached to a device called a collimator, which is part of the Gamma Knife system. The collimator ensures pinpoint accuracy of the radiation treatment. Then, the physician will use the Gamma Knife®Perfexion™ to deliver 192 very precise cobalt-60 gamma ray beam to the treatment area.

The Gamma Knife procedure is safe and effective because individual gamma ray beams are too weak to damage healthy tissue on their way to the target area but are very powerful when they merge simultaneously at the area of focus. A single treatment is usually all that is needed. The actual time required to complete the treatment varies depending on your individual condition and diagnosis.

5. You are discharged to go home.
Once the treatment is completed, the head frame and pins will be removed. Four small bandages will be placed at the sites of the pins. The patient then returns to the Gamma Knife waiting area for recovery and observation by our staff. After it has been determined that the patient is stable and able to walk, eat and drink liquids, the patient is discharged to rest at home.

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