Gamma Knife Radiosurgery

At UK HealthCare, we are committed to improving the lives and health of patients using the most advanced health care techniques. Gamma Knife radiosurgery is a perfect example.

With Gamma Knife radiosurgery, our neuroscience team can treat neurological (brain) disorders and diseases without invasive surgery. The system's leading-edge technology allows our specialists to operate on the brain without general anesthesia or incisions. 

About the Procedure: What to Expect

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. 

Before surgery: The evening prior to treatment, you must not eat or drink anything after midnight. 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. You can bring a CD if you want to listen to music while being treated.

Arrival: 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.

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. The treatment will take 15 minutes to 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.

Post-op: 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.

Conditions Treated

Both benign (non-life threatening) and malignant (life-threatening) brain tumors are treated with Gamma Knife. The radiation damages the DNA of the tumor cells, which causes the cells to lose their ability to reproduce. The tumor tissue that remains after the radiation treatment will typically shrink. Gamma Knife is very effective toward treating deep-seated tumors that otherwise may have been deemed too risky to for surgery.

  • Brain metastasis: Cancerous tumors can spread from other parts of the body to the brain that can cause seizures, headaches or neurological deficits. Gamma Knife is useful in combination with surgery and whole brain radiation to minimize or eliminate the spreading tumors.
  • Pituitary tumors: The pituitary gland controls the thyroid, adrenal and reproductive glands. A tumor in this gland will cause an abnormal secretion of hormones and result in many problems. Since the pituitary is located especially deep within the brain, Gamma Knife surgery is ideal for treating this type of abnormality.
  • Meningioma: This type of tumor grows from the membrane covering for the brain and spinal cord and may occur in many different brain locations. Gamma Knife is used best to target the various meningiomas without damaging the surrounding tissue.
  • Astrocytomas: Derived from connective tissue cells, astrocytomas are the most common type of childhood brain tumor. These tumors are found most often in the cerebellum. Gamma Knife precision is often advantageous for treating children and avoids wider spread areas of radiation which may injure the vulnerable, developing brain.
  • Craniopharyngioma: These benign tumors are also located in an area near the base of the brain in close proximity to sensitive nerve structures and hormone centers. Craniopharyngiomas create hormonal imbalances causing poor growth and short stature. Gamma Knife can operate within the safe zones as not to damage the surrounding structures.
  • Glial neoplasms: Glial cells provide support and nutrition to the brain, maintain homeostasis and participate in signal transmission in the nervous system. Gamma Knife may be used in combination with chemotherapy for malignant cases and treatment for recurrences of malignant glioma after more standard therapy.
  • Acoustic neuromas: Tumors can develop directly on nerves that affect balance and hearing. Gamma Knife treatment inhibits the growth of these tumors with a lower risk of deafness or loss of facial movement compared to conventional surgery.

Gamma Knife can also be used to treat these conditions:

  • Arteriovenous malformations (AVMs): This type of abnormal blood vessel formation can cause severe bleeding, headaches or seizures. Traditional measures would remove the AVMs with a scalpel but come with more risk of injury than a non-invasive radiation procedure. One treatment of Gamma Knife radiation may cause the abnormal blood vessels to thicken and close off over the course of several months.
  • Trigeminal neuralgia: This nerve disorder causes severe and disabling facial pain. By strategically placing a lesion on the nerve, the pain signals will be blocked. Gamma Knife provides the most desirable level of precision necessary to effectively treat trigeminal nerve disorders. This procedure is more frequently being used in the first treatment for trigeminal neuralgia when medicines fail to provide adequate pain relief.

Why Consider Gamma Knife?

Proven reliability:

  • Hundreds of thousands of patients have undergone the procedure worldwide.
  • Gamma Knife is very safe - no Gamma Knife site in the world has experienced a fatality.
  • Gamma Knife surgery is one-third the total cost of traditional neurosurgery.
  • The success of Gamma Knife has been well documented in medical literature and is recognized around the world as a standard of treatment.


  • Because no incision is made, there is a low risk of infection or hemorrhage.
  • Complications from general anesthesia are avoided since it is usually not required.
  • High accuracy of the gamma rays limits radiation exposure to surrounding tissues.

Patient accessibility:

  • Very short hospitalization, usually within one day.
  • Patients can resume their previous activities the next day.
  • Patients experience little discomfort during the procedure or during recovery.
  • Patients who previously needed or were untreatable with open-skull surgery now have a relatively simple and painless procedure available to them.
  • Gamma Knife surgery is covered by most insurance plans.

How It Works

Gamma Knife radiosurgery is a state-of-the-art, non-invasive procedure that uses highly focused gamma rays to safely treat tumors and abnormalities deep inside the brain without surgery.

The "knife" of Gamma Knife isn't a knife at all. Gamma Knife uses beams of gamma radiation to destroy abnormalities such as lesions and tumors inside the skull without surgical incisions or general anesthesia, greatly reducing the risk of complications and side effects.

Over 200 separate beams of gamma radiation pass harmlessly through the skull and brain until they meet up at the target - a lesion or tumor. At the target, the 200+ beams combine to destroy only the targeted abnormality, leaving the rest of the brain and skull completely unharmed and untouched.

The UK Gamma Knife Center uses the most advanced version, the Leksell Gamma Knife Perfexion. The Gamma Knife Perfexion allows us to target abnormalities with even more efficiency and precision. The Leksell Gamma Knife allows us to target abnormalities with even more efficiency and precision.

Gamma Knife Vs. Accuray CyberKnife

Gamma Knife stereotactic radiosurgery (SRS) is the gold standard used in SRS procedures for intracranial surgeries. It has been used for nearly four decades, with more than 350,000 cases treated worldwide. It has provided the data for more than 2,000 medical publications. Gamma Knife is used as the standard against which other technologies, such as the Accuray CyberKnife, are measured.

UK HealthCare's team of specialists offers the following comparison of Gamma Knife and CyberKnife:

Gamma Knife CyberKnife
201-source cobalt unit designed exclusively for non-invasive brain surgery 201-source cobalt unit designed exclusively for non-invasive brain surgery
Radiologic accuracy better than 0.3 mm 1 mm accuracy; dose outside the target area is two to six times greater than with Gamma Knife
Rigid immobilization to prevent head movement using a lightweight stereotactic head frame fixed to the outer skull. Provides exact MR and CT correlation from planning to treatment delivery in 3D. Non-rigid immobilization reduces head movement by using a thermoplastic face mask that is shrink-wrapped to the table during treatment. Provides relative MR and CT correlation from planning to treatment delivery in 3D. The CyberKnife is inherently less accurate since the positioning is optically guided, not head-frame based.
Treatment delivered during one session Single or multiple treatments, possibly over a period of days
Target position is confirmed 10 times per second Target position confirmed once every 10 seconds


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Learn more

What conditions can be treated using Gamma Knife Radiosurgery?
Multi-disciplinary team and Gamma Knife
What conditions can be treated using Gamma Knife Radiosurgery?
Multi-disciplinary team and Gamma Knife