If you are to undergo IGRT, your doctor will likely use CT scanning to conduct a treatment simulation session.
Imaged-guided Radiation Therapy (IGRT)
Image-guided radiation therapy (IGRT) is the use of frequent imaging during a course of radiation therapy for the purpose of improving the precision and accuracy of the delivery of treatment.
In IGRT, machines that deliver radiation, such as a linear accelerator (for x-ray or photon) or cyclotron/synchrotron (for proton), are equipped with special imaging technology that allow the physician to image the tumor immediately before or even during the time radiation is delivered, while the patient is positioned on the treatment table. Using specialized computer software, these images are then compared to the reference images taken during simulation. Any necessary adjustments are then made to the patient's position and/or radiation beams in order to more precisely target radiation at the tumor and avoid healthy surrounding tissue.
Computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US) and x-ray imaging may be used for IGRT by visualizing bony or soft-tissue anatomy. Other methods for IGRT use markers placed on the patient's body surface or implanted within the patient's body.
IGRT is used to treat tumors in areas of the body that are prone to movement, such as the lungs (affected by breathing), liver, and prostate gland, as well as tumors located close to critical organs and tissues. It is often used in conjunction with intensity-modulated radiation therapy (IMRT), proton beam therapy, stereotactic radiosurgery, or stereotactic body radiotherapy (SBRT), which are advanced modes of high-precision radiotherapy that utilize computer-controlled x-ray accelerators to deliver precise radiation doses to a malignant tumor or specific areas within the tumor.
If you are to undergo IGRT, your doctor will likely use CT scanning to conduct a treatment simulation session. Other imaging procedures may be used to help determine the exact shape and location of your tumor, and a special device may be created to help you maintain the same exact position during each treatment. Your doctor will give you specific instructions based on the type of exam being performed.
Side Effects
Imaging performed prior to or during radiation therapy sessions is painless.
During the radiation therapy session, you may see or hear equipment moving around you during the imaging procedure. Patients may sometimes smell an odd smell during treatment that is caused by the ozone produced by the linear accelerator. Some patients may also see a colored light when they receive their treatment; this event is especially true for patients having their brain treated.
Side effects of radiation treatment include problems that occur as a result of the treatment itself as well as from radiation damage to healthy cells in the treatment area.
AThe number and severity of side effects you experience will depend on the type of radiation and dosage you receive and the part of your body being treated. You should talk to your doctor and nurse about any side effects you experience so they can help you manage them.
Radiation therapy can cause early and late side effects. Early side effects occur during or immediately after treatment and are typically gone within a few weeks. Common early side effects of radiation therapy include tiredness or fatigue and skin problems. Skin in the treatment area may become more sensitive, red, irritated, or swollen. Other skin changes include dryness, itching, peeling and blistering.
Early side effects may include:
Hair loss in the treatment area
Mouth problems and difficulty swallowing
Eating and digestion problems
Diarrhea
Nausea and vomiting
Headaches
Soreness and swelling in the treatment area
Urinary and bladder changes
Long term side effects, which are rare, include:
Brain changes
Spinal cord changes
Lung changes
Kidney changes
Colon and rectal changes
Infertility
Joint changes
Lymphedema
Mouth changes
Secondary cancer
There is a slight risk of developing cancer from radiation therapy. Following radiation treatment for cancer, you should be checked on a regular basis by your radiation oncologist for recurring and new cancers.
Using techniques such as IGRT, imaging specialists are maximizing the cancer-destroying capabilities of radiation treatment while minimizing its effect on healthy tissues and organs and the side effects of the treatment itself.
Image-guided radiation therapy (IGRT) is the use of frequent imaging during a course of radiation therapy for the purpose of improving the precision and accuracy of the delivery of treatment.