Image-Guided Radiation Therapy (IGRT)

Image-guided radiation therapy (IGRT) is a specialized method of radiation therapy. As the name suggests, IGRT uses images, taken at the outset of each radiation treatment, to precisely guide the delivery of the radiation. In some facilities, radiation oncologists are using IGRT to help them better deliver the radiation dose to their patient’s cancer.

Normal structures and tumors can move between treatments due to differences in organs filling or movements while breathing. IGRT ensures the radiation is delivered to the cancer exactly as it is during each session. This technique allows doctors to target more precisely, which spares surrounding healthy tissues.

What Is IGRT?

Radiation treatments use high-energy waves to minimize or eliminate cancer cells. Because radiation is powerful, it can impact surrounding tissues if it is not delivered precisely, especially if tumors move between treatments. Image-guided radiation therapy allows radiation oncologists to deliver radiation accurately during each and every treatment session. 

IGRT allows delivery of conformal radiation treatment guided by imaging equipment, such as CT, ultrasound, or stereoscopic X-rays. This equipment provides detailed imaging of the cancer just before the patient is given the radiation treatment. By using these images before and during treatment, the oncologist can adjust the position of the radiation beams or the patient to accurately deliver the radiation. 


Why Doctors Recommend IGRT

IGRT is a radiation technique used with many kinds of cancers, but it is particularly advantageous for cancers located near sensitive organs or with tumors that might move between radiation therapy sessions. 

IGRT has many advantages for different kinds of cancer patients, including: 

  • IGRT is highly precise and accurate.
  • IGRT allows oncologists to better monitor the position, size, and shape of the tumor.
  • Because it is so precise, oncologists may feel comfortable delivering higher doses of radiation via IGRT, which makes the treatment more effective.
  • The precision of IGRT also decreases the exposure of surrounding healthy tissues to radiation, minimizing side effects.

How Does IGRT Work?

Before beginning treatment, all patients first undergo a CT scan as part of the planning process. Later, doctors will compare this earlier image with the images taken just before each treatment. 

The device used to deliver radiation — such as a linear accelerator — is fitted with imaging technology. This is how the images are taken before and during each treatment. During IGRT, doctors “fuse” the new images with the CT scan images to see if the treatment needs to be changed. 

If so, they will change the position of the radiation beams or the patient. This allows doctors to better target the cancer while avoiding nearby healthy tissue. 

In some cases, doctors will implant a tiny piece of material called a fiducial marker near or in the tumor to help them localize the tumor during IGRT.

Cancers Treated with IGRT

IGRT can be used to treat many different kinds of cancer. Because of its adaptable delivery, however, it is particularly useful for the treatment of cancers that may move between radiation treatments. The precision of IGRT also makes it an ideal treatment for cancers located near critical or sensitive organs and/or tissues.

Cancers commonly treated with IGRT include:

What to Expect During IGRT

Before you begin IGRT, your oncologist will perform a “simulation session.” During a simulation session, he or she will perform a CT scan to create reference images of your cancer. This allows your oncologist to see how your cancer moves or progresses during the coming treatments. 

During your simulation session, your doctor may place small markers (fiducial markers) or colored ink to help the radiation team identify the correct area. Depending on the type and location of your cancer, your doctor may also create a device to hold your body in place during treatments. 

At the outset of each radiation treatment, the equipment will be carefully aligned with the markers on the skin. The imaging equipment, which is part of the radiation equipment, then takes images of the cancer and sends them to the treatment room. 

There, your oncology team compares these new images with the original CT scans and adjusts your treatment area accordingly. This may involve adjusting the radiation beams or your body. 

Then the radiation is delivered. During radiation, you may see or hear equipment moving around you, but it should be painless.

Side Effects of IGRT

While the precision of modern treatment options like IGRT minimizes the side effects of radiation, they are not eliminated entirely. Depending on the location and stage of your cancer, as well as your health and other factors, you may experience different kinds and severities of symptoms.

Why Choose SERO for IGRT

With more than 20 locations across the Charlotte region, choosing SERO for your image-guided radiation treatment isn’t just a matter of convenience, it’s a matter of expertise. Our more than 30 board-certified oncologists work closely with patients to determine the most effective and least invasive treatment plan possible.

Often, that plan includes IGRT. Our cancer care teams understand the impact we can have when we combine modern cancer technologies like IGRT with our best-in-class care. Together, we can change the future of cancer care in the Carolinas and the future of patients like you.


What’s the difference between IMRT and IGRT?

Whereas IGRT adjusts the position of the patient or radiation to precisely target the cancer, IMRT adjusts the shape and dosage of the radiation to better treat the tumor. IGRT is a way to guide IMRT - some abbreviate both as IG-IMRT. Both help oncologists to precisely target the cancer while avoiding surrounding tissues.

Is IGRT effective?

Yes, IGRT is very effective. The survival rates for IGRT vary from cancer to cancer, but it is one of the most effective external beam radiation therapies.

Does IGRT hurt?

No, each IGRT session is painless.

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