What is Intensity Modulated Radiation Therapy (IMRT)?

Intensity Modulated Radiation Therapy (IMRT) is an advanced form of radiation treatment that allows radiation oncologists to precisely target tumor cells. It is a noninvasive therapy that uses Computed Tomography (CT) or other imaging modalities to build three-dimensional diagnostic images and map treatment plans to deliver tightly focused radiation beams of varying intensity to cancerous tumors without needles, tubes or catheters. Varying the intensity of these beams enhances the ability of IMRT to maximize dosage and minimize the amount of radiation distributed to surrounding healthy tissue.

How does radiation therapy work?

Radiation therapy uses high-energy rays or particles to destroy the cancer cells and shrink the tumor while minimizing the adverse effects on nearby healthy organs and tissue. Although some normal cells are affected by radiation therapy, they recover from the effects of radiation better than cancer cells.

What are the benefits of IMRT?

More precise.
With IMRT, your doctor can target your cancer with a high-resolution radiation beam that conforms as closely as possible to the shape of a tumor. This means the specific cancer can be treated more safely and effectively.

More control.
IMRT allows your radiation oncologist to develop a plan based on the three-dimensional images that delivers varying strengths of radiation to different parts of the tumor. The dose can be higher in the most aggressive areas of the tumor and lower in areas where the beam is near or passing through healthy tissue or structures.

More options.
Because IMRT enhances control of radiation delivery, physicians can now often treat tumors once considered untreatable because they are so close to vital organs and structures. In prostate cancer cases, IMRT reduces radiation to the bladder and rectum. Thanks to IMRT, physicians can more safely treat tumors in the prostate, bladder, and testicle.

What can I expect with IMRT?

Our radiation oncologists will design an individual IMRT treatment for you.

Step 1: Preparation

Before you begin IMRT treatments, you will attend a preparation session, which may take 45-90 minutes. During this session, we will perform X-ray and computed-tomography (CT) exams to help your doctors design your specialized treatment plan. Your doctors may also place marks on your skin with colored, semi-permanent ink or a small tattoo to help them align the IMRT equipment during your treatments.

Keeping the IMRT equipment aligned with the target area means that you will need to maintain a set position and keep very still during your treatments. To make you more comfortable and enhance the accuracy of your treatment, your doctor may develop special molded plastic or foam devices that help you keep the same position.

Step 2: Treatment Planning

Following the preparation session, your doctors will design a treatment that is right for your specific needs. This process may take several days because it will involve input from your radiation oncologist, physicist and dosimetrist. Once it is complete, you will begin your IMRT treatments.

Step 3: Treatment Sessions

The first IMRT treatment session may last longer than subsequent appointments because your doctor may wish to perform additional X-ray exams and checks. A typical IMRT session lasts about 15 to 20 minutes, the same amount of time required for a standard radiation treatment.

In the treatment room, you will see a large machine called a linear accelerator, which will deliver the radiation beams. It can be rotated around your body with great precision.

Using the ink marks on your skin made during the planning session, the radiation therapist will position you on the table below the machine. Before the machine is turned on, the radiation therapist will leave the room. Although the linear accelerator is controlled remotely, the therapist can still see and talk to you. You will not see or hear the radiation and usually not feel anything. However, if you feel uncomfortable, the machine can be stopped at any time.

We know battling cancer is challenging for you and your family, and we are dedicated to providing you with advanced and personal cancer care. Because we offer a full array of cancer treatment and support services, including radiation therapy, and the latest technologies such as IMRT, you and your family can receive all your care and support services in one convenient location. If you have any questions or need more information about your treatment, please let us know.

Will I have any side effects with IMRT?

Many patients react differently to cancer treatment. IMRT may often decrease the risk and severity of common side effects of radiation therapy. In fact, the increased precision of IMRT means some patients experience very few side effects.

However, because this is radiation therapy to the prostate, potential side effects include mild bladder irritation, rectal irritation, change in erectile function, and possible fatigue. Whether or not you experience any of these primarily depends upon the treatment dose and the part of the body that is treated.

Most of the side effects that occur during radiation therapy can be easily managed. Discuss any side effects with your doctor so he or she can work with you throughout your treatment to prevent or control them with medication or diet.

How many treatments will I need?

Radiation treatments are designed to use small amounts of radiation over a series of days in order to help protect normal body tissue is the treatment area. Usually radiation therapy is given five days a week for six to eight weeks.

Because IMRT is specifically designed for each patient, your treatments will vary depending on your specific needs. Your doctor will discuss each stage of treatment with you and will help you understand your overall treatment plan.