Intensity Modulated Radiation Therapy (IMRT) is a highly advanced and personalized technology for treating cancer. This treatment option allows the oncologist to target cancer cells with radiation beams without causing excessive damage to nearby healthy cells. A linear accelerator is used to deliver the radiation to a precise location on the outside of the body. Radiation therapy is an outpatient treatment meaning that you can return home once each treatment is finished. 

Our radiation oncologists at Rocky Mountain Cancer Centers provide IMRT radiation at our locations throughout Colorado including the Denver, Boulder and Colorado Springs regions to treat multiple types of cancer. 

How Does IMRT Work?

IMRT uses 3D CT or MRI images to plan the treatment. First, images are taken to map out your body so that your medical team can see the location, size, and shape of the tumor(s). This information will be used to determine where to point the radiation beams and how intense those beams should be in order to be most effective. Getting the precise angle of the radiation beams means that healthy nearby cells are less likely to be impacted. 

Let’s take a closer look at the steps of IMRT so that you know what to expect.

Step 1:Imaging 

CT scan technology is used to create a 3D image of the tumor. 

Step 2: Treatment Planning

Your oncologist and dosimetrist (a dosimetrist is responsible for calculating the correct dose of radiation) will evaluate the size, shape, and type of tumor in order to determine the best treatment plan moving forward. This includes setting the right dosage so that nearby healthy cells are less likely to be impacted while ensuring that it’s strong enough to treat the tumor. 

Step 3: Treatment Simulation 

Treatment simulation is the process of making sure that your body is in the right position for the treatment. During this appointment, you will come into the room with the linear accelerator and lie on the table to find the right position for your body to be in. They may place some small marks on your body to ensure that the radiation targets the same spot each time you come in. Your doctor will also identify if you need any immobilizers put in place so that your body remains in the same position each time. Immobilizers may include special face masks or wedges. No radiation treatment will be given during the treatment simulation appointment. 

Step 4: Treatment

The treatment process takes less than one hour from start to finish and is painless. You will be positioned in the same way that you were during the treatment simulation as the linear accelerator machine sends radiation beams to the identified tumor. Most people will receive IMRT treatment five days a week for a period of a few weeks. 

Possible Side Effects of IMRT Radiation Therapy

While every effort is put in place to limit the impact that the radiation beams have on healthy cells, there are some side effects to IMRT that can’t be completely avoided. Common side effects include:

Fatigue: As your cells work to repair themselves, it’s common for you to feel tired following IMRT treatment. Keep in mind; you may feel fatigued even if you haven’t done much physical activity. Listen to your body and rest as needed. This fatigue can last for months following treatment.

Skin Issues: Radiation can impact the skin, causing it to become dry, itchy, and flakey. Some people say that after several treatments, their skin starts to feel like a sunburn and may begin to peel. Usually, these skin issues go away once the treatment is complete. In the meantime, talk with your doctor or care team as soon as you start experiencing any issues because there are options for treating dry and irritable skin and helping you through treatment.

Low Blood Counts: Radiation therapy and chemotherapy can reduce your white blood cells, red blood cells, and platelets. White blood cells are important for fighting infection, red blood cells carry oxygen, and platelets help you stop bleeding. Your doctor will want to test your blood counts in case treatments need to be adjusted. 

Other side effects that are more specific to the location of treatment include:

  • Head and Neck: loss of hair, taste changes, difficulty swallowing
  • Chest: Cough, shortness of breath, changes in the throat
  • Abdomen and Pelvis: changes to the urinary tract, intestines, and reproductive system, diarrhea, vomiting, or nausea 

Should You Get IMRT?

While more than half of all cancer patients receive radiation therapy during their cancer treatment, there are specific instances in which IMRT may be recommended. This includes:

  • Shrinking cancer before surgery: IMRT may be recommended to shrink the cancer cells so that there are fewer present at the time of surgery. It also may reduce the chances of the cancer cells spreading.
  • Treat cancer in a difficult-to-reach location: Some cancer is located in areas of the body that it’s not as easy to operate on. IMRT can be adjusted to reach those areas better.
  • Symptom relief for advanced cancer: IMRT may offer some relief for patients who are experiencing discomfort from advanced cancer. For example, it may be used to relieve pain or break up bowel blockages. 
  • Eliminate cancer cells after surgery: IMRT may be recommended to treat remaining cancer cells that are still in the body after the tumor is removed. The radiation can kill cancer cells in the area that may not be visible. 

After IMRT Radiation Treatment

When you leave the cancer treatment center, you’ll be able to do normal daily activities.

IMRT radiation does not make you radioactive, and you don’t need to avoid touching, hugging, or kissing other people because of the treatment.

You may feel more tired than usual after treatment for several weeks.

Call a member of your radiation oncology care team if:

  • You have pain that doesn’t go away.
  • You have new or unusual lumps, bumps, or swelling.
  • You experience nausea, vomiting, or diarrhea.
  • You experience unexpected or unplanned weight loss.
  • You develop a persistent fever or cough.
  • You develop unusual rashes, bruises, or bleeding.