Munson Health
Intensity Modulated Radiation Therapy

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by McCoy K




Radiation therapy uses radiation to kill cancer cells and shrink tumors.
Intensity modulated radiation therapy (IMRT) uses radiation beams of different intensities. The beams deliver appropriate doses of radiation to the tumor and reduce the dose to nearby healthy tissue.
Radiation of Tumor
Radiation of Tumor
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What to Expect

Prior to Procedure

Planning for IMRT is complex and generally takes 2-5 days. Planning may include:

Description of the Procedure

Using the marks made on your skin as a guide, the radiation therapist will position you on the treatment table. Films or ultrasound may be used to check the accuracy of the treatment setup. The therapist leaves the room to control the movements of the radiation machine. The treatment delivers radiation in a three-dimensional manner. This will help to conform as closely as possible to the shape of the tumor. The healthy tissue receives smaller doses of radiation than the tumor.
You will be asked to remain still during the radiation treatment. You may breathe normally. In general, you will not feel or sense anything during treatment. However, the machine can be stopped if you feel sick or uncomfortable. The therapists will be observing you with a monitor. You will be able to communicate to them should you need to.

Immediately After Procedure

You will be able to leave and resume your normal daily activities. Receiving IMRT does not make you radioactive. You do not need to avoid being around other people because of the treatment.

How Long Will It Take?

Each session will take 15-30 minutes. Patients are typically scheduled for IMRT five days per week for 4-8 weeks.

How Much Will It Hurt?

Holding one position may become a little uncomfortable, but it is not painful.

Post-procedure Care

During treatment, your doctor will want to see you at least once a week. You may have blood tests or other studies performed.
After your treatment is completed, you will come in for regular visits to monitor for side effects and healing and check for signs of recurrent disease. You may require further testing, medicine, or rehabilitative treatment. Be sure to follow your doctor’s instructions.

Call Your Doctor

After arriving home, contact your doctor if any of the following occurs:
In case of an emergency, call for medical help right away.


American Cancer Society

National Cancer Institute



Canadian Cancer Society

HealthLink BC



Understanding radiation therapy. American Cancer Society website. Available at: Accessed April 29, 2013.

IMRT. International Radiosurgery Support Association website. Available at: Accessed April 29, 2013.

Intensity-modulated radiation therapy (IMRT). American College of Radiology and Radiological Society of North America website. Available at: Updated March 7, 2013. Accessed April 29, 2013.

Radiation therapy and you. National Cancer Institute website. Available at: Accessed April 29, 2013.

Radiation therapy for cancer. National Cancer Institute website. Available at: Updated June 30, 2010. Accessed April 29, 2013.


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