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Gamma Knife FAQ

Frequently Asked Questions about Gamma Knife

View a discussion with Mischer Neuroscience Institute Director Dong Kim, M.D. about Gamma Knife radiosurgery and all the benefits this treatment can offer.

Below are frequently asked questions with answers about Gamma Knife:

Am I a Candidate for Gamma Knife?

You may be a candidate for this procedure if you've been diagnosed with a benign or malignant brain tumor, an abnormal blood vessel formation or a functional disorder, such as trigeminal neuralgia.

To determine whether you qualify, a multidisciplinary team will review your case. Team members will review your medical and surgical history, findings from your clinical examination and your imaging and function studies.

Why is Gamma Knife Radiosurgery a Better Alternative?

Gamma Knife radiosurgery offers a broad range of benefits, and in many cases, fewer complications than conventional procedures.

Since the procedure doesn't require incisions, it's safe, bloodless, relatively painless, doesn't leave scars and reduces the risk of complications such as infection, bleeding or leakage of spinal fluid.

  • The procedure is so precise and on target that it rarely affects healthy tissue nearby.
  • Since it is incision-free, it enables patients to leave the hospital faster, with a shorter recovery period so they can get on with their lives.
  • It is the treatment of choice for many people. Most of our patients have conditions that can't be treated by conventional neurosurgery, whose lesions are hard to reach or are located in a functionally critical area of the brain, or whose age or physical condition increases the risks associated with anesthesia and conventional surgery.
  • This procedure can be combined with chemotherapy and other forms of radiation to treat brain tumors. It can also be used to help destroy residual tumors or malformations after patients have undergone other types of treatment or when other procedures have been unsuccessful.
  • For adults, only a local anesthetic is needed, which reduces the possible side effects and other potential problems associated with general anesthetics.
  • Gamma Knife radiosurgery requires only one treatment instead of many over several weeks. Yet it can be repeated safely, if necessary.
  • Gamma Knife therapy rarely results in hair loss, a common side effect of other radiation therapy treatments.
  • It's less expensive than conventional neurosurgery because there's no need for a long hospital stay, expensive medication and rehabilitation.
  • It's reimbursed by most insurance companies, PPOs, HMOs and Medicare.

I'm Scheduled for Gamma Knife. What Should I Expect?

In most cases, treatment is delivered as an outpatient procedure. You will arrive at Memorial Hermann-Texas Medical Center the morning of your procedure. Fluids will be administered intravenously to keep you from becoming dehydrated, since eating and drinking are not permitted until the procedure is completed. A mild sedative and a local anesthetic (children will receive a general anesthetic) will also be administered.

After the sedative and anesthetic take effect, you'll be fitted with a lightweight head frame with tiny pins that will keep the frame secured to your head.

This will allow the physician to position your head accurately while keeping it still during the procedure. Some patients experience slight tightness, pressure or discomfort during the frame application.

Using diagnostic imaging techniques such as MRI, CT scan and angiography, the Gamma Knife team will identify the precise location of your tumor or malformation and prepare your treatment plan.

You will be placed on a motorized bed that will move you in and out of a shielded dome; your headgear will be attached to a helmet that allows gamma rays to pass through. In the treatment position, gamma rays from the dome are directed through 201 holes in the helmet.

Individually, these tiny rays are harmless, but at the precise point where they intersect, their combined strength is enough to alter the tumor or lesion so its cells can no longer reproduce.

During the treatment, your physician will operate the Gamma Knife from a console next to the treatment room and will interact with you using cameras and two-way microphones. Since you will remain conscious throughout the procedure, you will be able to communicate with the treatment team as needed.

What Happens After the Procedure is Over?

After your treatment, the frame will be removed. Slight bleeding may occur at pin sites. You will remain in the hospital for a few hours for observation.

Because children require a general anesthetic, they are required to stay in the hospital longer, occasionally overnight. Once discharged, you typically can resume your normal activities.

A few people experience side effects after Gamma Knife radiosurgery. Side effects will be discussed with you. In general, they are dependent on the radiation dose, site of the disease and additional factors.

The rate at which your condition will improve could range from a few weeks to several years, depending on your condition. Most abnormalities stop growing or eventually disappear. In rare cases, the condition does not respond to Gamma Knife radiosurgery.

Where Can I Get More Information?

For more information, contact the Gamma Knife Program at Memorial Hermann-Texas Medical Center at 713.704.7100.