Intensity Modulated Radiation Therapy (IMRT)
A highly-advanced and personalized type of radiation treatment, Intensity Modulated Radiation Therapy (IMRT) gives radiation oncologists the ability to precisely target a cancerous tumor while reducing radiation exposure to the nearby healthy cells. Given from outside the body with a linear accelerator, IMRT is given in a cancer center or at a hospital on an outpatient basis. At Affiliated Oncologists in the Chicagoland area, we provide easy access to IMRT to patients at our locations in Chicago Ridge, Mokena, Hazel Crest, Tinley Park, New Lenox, Palos Heights and Oak Lawn.
How Does IMRT Work?
IMRT is a state-of-the-art type of 3-D conformal radiation treatment. 3-D CT or MRI images are used to plan the treatment. Images are taken to create a map of your body. This tells the radiation team exactly where the cancer is located as well as the shape and size of the tumor(s).
The radiation oncology team will use these images to decide exactly where to point the radiation beams and how much intensity to use. IMRT allows some beams to be more intense than others so that the radiation tumors can conform around the tumor for exact tissue targeting. They can also target the tumor from various angles. Ultimately this will reduce the amount of radiation exposure to the nearby healthy tissue and organs, causing fewer side effects.
Intensity Modulated Radiation Therapy: What Can You Expect?
There are several steps before you actually receive IMRT to be sure the radiation beams are directed exactly where they should be for every treatment given. The following steps are often included in the radiation therapy treatment process.
- Step 1: Imaging - A specialized team of radiation oncology experts use CT scan technology to create a 3-D image of your tumor.
- Step 2: Treatment Planning - A radiation oncologist views the 3-D image to determine the shape, size, and locations they will target. Based on the size and location of the tumor, the radiation oncologist and physicist create a treatment plan including the proper dosages that will minimize damage to healthy tissue while effectively managing the tumor.
- Step 3: Treatment Simulation - Once a plan is created, the cancer care team will set up an appointment that is only for positioning your body and deciding if there are any “immobilizers” needed. This is important because the radiation beams are most effective when delivered to the exact same spot at every treatment session. The team may make some marks on your body or decide if there is something that needs to be used to keep you in the same position each time. No radiation is actually given during the simulation. If you are being treated for head or neck cancers a special face mask may be created that will keep your head in the exact same spot for each treatment. This is custom designed and may take a few days to get it back and make sure it is correct.
- Step 5: Treatment - Each radiation treatment session lasts less than an hour for most patients at one of our cancer centers in the Chicagoland area. You will be placed in the exact spot that was decided during the simulation. A linear accelerator, the large machine you’ll be lying underneath, will be used to send the radiation beams according to the plan. This is a painless process.
- Step 6: Recurring Treatments - Depending on the type of tumor, size, location, and other factors, you will typically need multiple sessions over the next five to eight weeks, although individualized plans may vary.
Side Effects of External Beam Radiation Therapy
While the carefully focused beams of radiation reduce the amount of impact on nearby healthy tissue, there is some impact that can’t be avoided. The most common side effects of external beam radiation therapy, such as IMRT, include:
- Fatigue - feeling exceptionally tired, even if you haven’t done much. This is normal while your cells are working to repair themselves.
- Skin problems. Because the radiation goes through the skin, you might experience dryness or itchiness in the area where the radiation was pointed. After several treatments it may feel more like a sunburn and could even peel. This typically goes away after treatment is done.
- Low blood counts. Radiation therapy, especially when combined with chemotherapy, can reduce the number of white blood cells that fight infection, red blood cells to carry oxygen, and platelets that help you stop bleeding. Your cancer care team is mostly likely going to request blood work often to keep an eye on your blood counts and make treatment adjustments as needed.
There can be other side effects of radiation therapy depending on where the tumor is located.
- Head and neck - If radiation is given in the head or neck area you might experience hair loss, mouth and taste changes, or trouble swallowing.
- Chest - Radiation therapy can cause a cough, shortness of breath or throat changes depending on where the radiation beams are pointed.
- Abdomen and Pelvis - Radiation therapy in the stomach and pelvic areas can impact your urinary tract, intestines and reproductive system. If you have diarrhea, nausea, vomiting, sexual problems or urinary tract problems, be sure you tell your oncology team.
There are various products and medications that are known to make side effects easier to manage. Be open with your cancer care team about any side effects you’re experiencing so they can help you.
When Do Radiation Oncologists Recommend IMRT?
More than half of cancer patients receive some form of radiation therapy during their cancer treatment process. There are a few common uses of external beam radiation therapy such as IMRT:
- To shrink cancer before surgery - This is done so that there are fewer cancer cells present at the time surgery is performed. This makes the cancer less likely to spread when the tumor is removed.
- To kill any cancer cells that may remain after surgery - After a cancer surgeon carefully removes the cancerous tumor, there can be some cancer cells that remain in the general area. Radiation therapy is given in the area surrounding the surgery site to kill any cells that may have started to grow outward but aren’t visible to the naked eye.
- To treat cancer that is in an area that’s not easy to perform surgery on.
- To help relieve symptoms of advanced-stage cancer - For those who have advanced cancer, palliative radiation can be used to relieve pain or other problems such as bowel blockages or trouble swallowing.