Stereotactic Radiosurgery

Types

Gamma Knife machine

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Mayo Clinic uses two types of stereotactic radiosurgery: Gamma Knife and a form that uses a linear accelerator (LINAC). Stereotactic radiosurgery can treat conditions such as:

• Cancerous and noncancerous brain tumors
• Blood vessel abnormalities in the brain, such as an arteriovenous malformation (AVM)
• Chronic pain caused by trigeminal neuralgia

The type, location and size of your tumor help your medical team determine whether Gamma Knife or LINAC radiosurgery is appropriate for you.

Gamma Knife radiosurgery

At Mayo Clinic's Gamma Knife center in Rochester, Minn., surgeons and radiation oncologists use gamma radiation to destroy diseased tissue while preserving the surrounding healthy tissue. You'll be fitted with a lightweight head frame to hold your head still during treatment. You'll also have a computerized tomography (CT) scan or magnetic resonance imaging (MRI), or both, to help pinpoint the target for treatment.

Gamma Knife surgery involves a team of medical experts from neurosurgery, radiation oncology and medical physics. Your treatment team uses highly sophisticated computer software to determine the size, location and shape of the area to be treated.

Read more about Gamma Knife radiosurgery.

LINAC

LINAC delivers precisely focused radiation with extreme accuracy to treat tumors and other problems deep in the brain or other areas of the body, with limited risk. You'll be fitted with a lightweight head frame to hold your head still during treatment. If your tumor is in your lung, liver or spine, you'll be placed in an immobilization device to hold your body still and prevent movement during treatment.

You'll also have a CT scan or MRI, or both, to help pinpoint the target for treatment. Your team uses complex treatment-planning systems to direct the radiation to the tumor and minimize the radiation to normal tissues. The LINAC rotates around you during treatment, delivering focused radiation to the area or areas mapped out by your treatment team.

SRS vs. SBRT

Stereotactic radiosurgery (SRS), typically used for brain or spine tumors or other abnormalities, delivers the radiation dose in one session and can be delivered with the Gamma Knife or LINAC. A repeat dose is sometimes needed.

Stereotactic body radiotherapy (SBRT) delivers radiation treatment over three to five sessions to treat tumors outside of the brain, such as the spine, lung and liver. SBRT is delivered using LINAC.

Types of SBRT include:

• Liver SBRT. This is typically used to treat tumors that have spread to the liver, or liver or bile duct tumors that can't be removed with surgery.
• Lung SBRT. This is typically used to treat small primary lung cancers or tumors that have spread to the lung and are not considered removable.
• Spine SBRT. This is typically used for tumors that started elsewhere in the body and spread to the bones of the spine (metastatic). Treatment for metastatic tumors of the spine can involve combinations of surgery, radiation therapy and chemotherapy, depending on your age, general health, and tumor size and number.