Gamma Knife®

About the procedure

Initial determination

A neurosurgeon, radiation oncologist or other medical specialist can determine whether Gamma Knife radiosurgery is medically necessary after evaluating your medical condition. Treatment options are then determined and discussed with you and your family so an informed decision can be made. 

Gamma Consult

Before surgery

Important: The evening prior to treatment, you must not eat or drink anything after midnight.

Planning for Gamma Knife radiosurgery with your doctor will help the procedure go more smoothly. Please remember to ask your physician for instructions on how to take any pre-surgery medications. Also, bring any medications with you that need to be taken before or after the surgery. A family member or close friend must accompany you to the hospital the day of the Gamma Knife procedure.


On the morning of your surgery, you will come to the UK Chandler Hospital Main Admitting Office. A patient parking garage is located next to the hospital. Once admitted, you will be taken to the Gamma Knife suite area, where the nurse will assess you and place an intravenous line.

Frame placement

The Gamma Knife procedure requires that a frame be mounted to your head that will be very important during the surgery. The purpose of the frame is two-fold. First, it provides a necessary method to keep you completely still during treatment. Secondly, the frame acts as a reference for the computer software to coordinate the system. Prior to frame placement you will be given a mild sedative that will greatly reduce your awareness of the treatment and will eliminate any pain. No hair will be shaved from your head. The frame will then be attached to your skull and held firmly in place by four pins. A local anesthetic is administered to the pin sites for comfort. The frame will remain on until the treatment is completed.

Imaging and planning


Following frame placement you will be transported to an imaging area to receive your MRI and/or CT scan. You will return to the Gamma Knife Center while the Gamma Knife team reviews your imaging studies and plans your specific radiation dose. The plan is calculated with Gamma Knife's 3-D computer mapping model to determine the exact location of the target. This planning period may take a few hours, during which you may visit with your family, eat and move around as tolerated.


Gamma Surgery

With a strategic plan prepared for your treatment, you will be placed on the Gamma Knife bed in the surgery room. The frame is held securely in a large metal helmet called a collimator that is mapped to the coordinates that have been pre-programmed. A video camera and intercom system enables the Gamma Knife team to monitor your condition from the control room during treatment. Once everything is in place, the treatment begins.  

The treatment will take between 15 minutes and several hours depending upon the size of the lesion and prescribed amount of radiation. Be assured that you will not feel any pain from radiation throughout the procedure. Also, you can bring a CD if you want to listen to music while being treated.


When the procedure is finished, the frame is removed and the pin sites will be covered with antibiotic ointment. You can leave for home about one hour after frame removal if you have someone to drive you home. An overnight stay may be required for some patients. You can return to your normal activities the next day. The side effects are often very mild. Headache, dizziness or nausea can be experienced immediately after the treatment, but the effects will generally disappear after an hour. A very small number of patients may experience seizures.

The entire procedure, including frame mounting, scanning, dose planning and treatment, takes approximately four to eight hours. You will be seen for scheduled follow-ups depending on the condition for which you were treated.

Long-term effects

Radiation treatment usually takes months or longer to achieve the final result. The frequency and timing of your follow-up depends upon the condition for which you are being treated.

Metastatic malignant brain tumors are usually followed at two- to three-month intervals. Benign tumors such as meningiomas or acoustic neuromas usually are only followed once a year.

Page last updated: 1/26/2016 12:04:55 PM