IGRT - Image-Guided Radiation Therapy

Overview of IGRT - Image-Guided Radiation Therapy in India

Image-guided radiation therapy (IGRT) refers to a method of delivering radiation treatments to cancer patients using imaging technology to assist with target localisation. This method utilises high-energy beams of radiation, relying on energies such as X-rays, protons, or others in order to destroy cancerous cells. At the time of treatment, images are obtained prior to the delivery of radiation to improve the accuracy and accuracy of the radiation delivery to maximise its efficacy.

When utilised for IGRT, the images will allow the use of higher than traditional doses of radiation to destroy tumors while minimising the amount of healthy tissue damage as a result of the radiation treatments through the reduction of time between doses of radiation delivered to the patient, thereby reducing the treatment duration for patients receiving IGRT.

IGRT is being utilised as the standard of care in the delivery of radiation therapy to patients with cancer. All types of cancer can be treated with IGRT. IGRT can also be used for treating non-cancerous tumors that cause significant health concerns to the patient.

What Is Image-Guided Radiation Therapy (IGRT)?

IGRT (image-guided radiation therapy) falls under the broader category of EBRT (external beam radiation therapy). It is a type of radiation therapy that can be used to destroy malignant cells or shrink and/or get rid of malignant tumors.

If your cancer is located near a body part that moves during treatment (for example, your lungs are moving when you breathe), you will require IGRT to ensure the correct targeting of the area being treated. The radiation therapy staff need to perform daily imaging procedures so that they can accurately focus their treatment on the desired targets. By using IGRT technology, the radiation therapy staff can do all of this.

IGRT also uses a LINAC (linear accelerator) machine, which delivers focused pods of radiation to the area of malignancy in the form of high-energy photon/x-ray beams to kill malignant cells and tumors. The LINAC machine does not touch you.

As with all EBRT, IGRT utilises the images generated by imaging tests to target areas within the body where malignant cells or tumor masses are located. Using imaging tests prior to treatment will allow the radiation oncologist to accurately target the location of the tumor and provide immediate direction to refocus the delivery of treatment should it be necessary. This ensures that the beams of radiation remain focused on the malignant target and have minimal contact with nearby healthy tissue.

Types of IGRT - Image-Guided Radiation Therapy:

Procedure:

How To Prepare For IGRT

Before undergoing image-guided radiation therapy, you will have an appointment with a physician who is trained in the use of radiation to treat cancer, known as a radiation oncologist. The radiation oncologist will go over the pros and cons of image-guided radiation therapy, or IGRT, with you.

Should you decide to proceed with IGRT, the radiation therapy team will develop a detailed treatment plan for you that will require multiple types of imaging to determine exactly where your cancer is located and where the most radio-sensitive tissues are in your body.

Your radiation therapy will involve different types of imaging (2D, 3D, or 4D) to help create a treatment plan, position the treatment within your body, and direct (aim) the radiation to this area so that as little healthy tissue and/or organs near your cancer are impacted/treated.

What to Expect During IGRT

Prior to having IGRT (image-guided radiation therapy), the first step is to have a simulation of your body. Your oncologist will take a CT scan of the area that has cancer so they can observe how it looks and moves over a time frame while receiving treatment.

During this session, your physician may place small metallic markers (or "fiducials") or mark you with colored ink so that the radiation therapy team can identify which area of your body to treat. Depending on the location and type of cancer that the physician is treating, they may create a customised device (or "mask") to keep your body in place during treatment.

Once you begin receiving treatment, your radiation therapy equipment will be aligned with the fiducials and will use imaging equipment (which is part of your radiation therapy equipment) to take images and then send those images to the treatment room.

In the treatment room, the oncology team will then compare the images taken during your treatment with the original CT images and adjust your treatment area based on the two images if needed. Depending on the adjustment needed, the radiation team may adjust the radiation beams or adjust your body for the best delivery of the radiation therapy.

After everything has been positioned properly, the radiation will be delivered to you. During the delivery of radiation therapy, you may hear equipment move around you or may see some equipment moving around you, but there should be no pain or discomfort associated with the delivery of radiation therapy.

Recovery From Image-Guided Therapy

IGRT provides a means of viewable images to assist with treatment delivery, using conventional imaging technology (CT-scan, MRI, and PET-scan) as opposed to using high-tech methods such as radiation therapy itself. The added exposure to radiation resulting from the use of two or more imaging tests at one time is generally regarded as being a small amount or no risk to the patient.

At the present time, IGRT does not produce any side effects when provided by itself; however, there are some side effects related to the radiation therapy itself, which are related to factors such as the location of the tumour treated, the amount of radiation delivered and the length of treatment. Typical side effects are also common and include: skin discomfort, fatigue, or nausea. 

Your radiation oncology team can advise the patient on what are the typical side effects and how long the patient is expected to take before returning to their routine. The radiation oncology team can also give the patient suggestions on ways to keep as comfortable and pain-free as possible during their recovery.