Linear Accelerator

More than half of cancer patients in the U.S. undergo radiation therapy. Most of these treatments would not be possible without a machine called a linear accelerator (LINAC).

What are Linear Accelerators?

Linear accelerators have been used to treat cancer since the 1950s. There are different types of LINAC machines, but they all have one thing in common. They send radiation, such as X-rays or electron beams, through your body and into your tumor. This is known as “external beam radiation.”

Today’s machines are often equipped with 3-D imaging capabilities like CT scanning. Most use special software that can “match” radiation beams to the size and shape of your tumor. This means external beam radiation is safer, by being more precise than ever before.

LINAC machines deliver several types of radiation therapy. These include:

• Image-guided radiation therapy (IGRT)
• Intensity-modulated radiation therapy (IMRT)
• Stereotactic radiosurgery (SRS)
• Stereotactic body radiotherapy (SBRT)

The type of radiation therapy you’ll need depends on several factors. These include the size and location of your tumor, what organs are near the tumor and whether you also need other cancer treatments.

Types of Cancer Treated with a Linear Accelerator

Radiation therapy using a LINAC can treat a broad range of cancers. These include brain and spine tumors, and cancers of the head and neck, lung, breast, esophagus, stomach, rectum, uterus, prostate, bladder, liver, and bones.

External beam radiation may be the only treatment you need, or it may be combined with other treatments such as chemotherapy or cancer surgery.

What to Expect from Radiation Therapy Using a LINAC

Your Mercy care team will make sure you understand what to expect before, during and after radiation therapy using a LINAC. Different treatments have different requirements. For example:

• All patients will need to undergo a "simulation." This is typically a CT scan performed in the treatment position. Sometimes a simulation may also include an MRI or a PET scan.
• Some patients will need tiny “markers” (also called fiducials) placed in their body, or small tattoos inked on their skin. These fiducial markers, electromagnetic transponders and tattoos help your care team quickly locate your tumor. They also ensure your body is positioned correctly during each treatment.
• You may also need to use a custom-fit “positioning device” to help you stay still during treatment. These include full-size body molds, face masks or head frames.
• All types of external radiation may cause temporary side effects. These often include fatigue and skin changes (such as redness, itching or peeling). You may also have problems in the specific part of your body receiving radiation. These can range from headaches and trouble swallowing, to digestion problems or bladder changes.
• Like any medical treatment, external radiation poses immediate and long-term risks. Our team will make sure you're fully informed before you begin treatment. If your doctor recommends you have radiation therapy, it’s because he or she believes the benefits outweigh the risks. Your care team will carefully plan your treatments to ensure they are safe and effective.

If you have questions or concerns about external beam radiation or the LINAC machine, please talk to one of your Mercy caregivers. We are ready to help you beat your cancer with advanced technology and the most compassionate, expert care.