Radiation Therapy

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What is Radiation Therapy? • External Beam Radiation

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What is Radiation Therapy?
Radiation therapy is a form of treatment that uses the same type of rays—commonly called X-rays—that are used to create an image of the chest, or of a broken bone. For treatment purposes, the X-rays are of higher intensity. High doses of radiation can destroy the ability of cells to grow and multiply. Both normal and cancer cells are affected, but normal cells can recover quickly, while the abnormal, rapidly multiplying cancer cells, are permanently damaged. Giving a course of radiation therapy after a lumpectomy can help ensure that no cancer cells remain in the breast area.

Unlike chemotherapy—a systemic treatment that treats the entire body—radiation therapy is considered a local treatment, because it treats only the cancer area.

Radiation therapy is administered at medical centers staffed by teams of professionals specializing in radiation oncology. There are two ways to administer radiation therapy. The oldest and most common, external beam radiation therapy, or EBRT, uses a complex device that aims the beam at the breast area from several angles. A newer method is brachytherapy. It relies on tiny radioactive seeds placed temporarily directly into the breast.

 

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External Beam Radiation

Therapy Treatment Planning
A full course of external beam radiation therapy spans five to seven weeks. The goal is to deliver the optimal dose to the breast area, with the least impact on the surrounding normal tissues. This requires an approach carefully tailored to each case.

Using a simulation unit, the radiation oncologist staff will determine the best angles for the beam. Then they will outline the treatment ports—places on your body where the beam will be aimed. These ports will be temporarily marked with colored ink. Don't wash these marks off until you're told to do so. Later, they may be replaced by tiny tattoos. These markings will ensure that the beam is aimed accurately every treatment session.

The simulation may take several hours. The information obtained will be entered into a computer to develop your treatment plan. Sometimes a special cast will be fabricated for your chest to ensure consistent positioning. Once the planning is completed, the treatments can begin.

How Treatment is Given
The treatments are given by a radiation therapist in accordance with the plan developed for you by the team. Typically, you will arrive at the facility at the appointed time each day. You may want to bring a friend for moral support during the first session or two. You may also want to bring an iPod or a book to read in case you have to wait. The first treatment will take longer than the others, in order to make sure the position of the machine matches the angles that were worked out during simulation.

Don't use deodorant, because deodorants contain aluminum that may interfere with the radiation beam. Use cornstarch, or a prescription deodorant recommended by your physician. Wear a two-piece outfit so you can change easily into a patient gown from the waist up.

The treatment is given in a room that has thick concrete walls and lead-lined doors, to protect those who are outside the treatment area from radiation. The device used to deliver radiation is called a linear accelerator. At first the whole set up may seem complex and intimidating. But don't be alarmed. A TV monitor lets the staff keep you in sight at all times, in case you need anything.

The radiation therapist will adjust the position of the machine according to the previously determined settings, then step out of the room. During the actual exposure you must remain as still as possible. The unit will be repositioned one or two times to change the angle of the beam. Each exposure lasts only a few minutes and you won't see or feel anything.

The full course of treatment runs about five weeks, with sessions from Monday through Friday, and rest and recovery periods during weekends. If you have to miss a day or two, discuss the situation with your doctor or nurse. You can make up the days at the end, but the efficiency of the treatment depends on having as few delays as possible.

The start of your therapy will depend on whether you are also undergoing chemotherapy. Depending on the practices of the facility where you are being treated, you may have chemotherapy and radiotherapy simultaneously, or be started on chemotherapy, then treated with radiation, then again with chemotherapy. Sometimes the delay may be as long as several weeks or several months. There is little danger of the cancer cells spreading during this delay.

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Side Effects of External Beam Radiation Therapy
Radiation therapy is a safe, proven treatment with few unwanted side effects. Most of them are not serious and disappear quickly. The most common are fatigue and skin changes. You will not have nausea or lose your hair, as you might with chemotherapy, and you certainly won't be radioactive. Most people find that they can go through radiation therapy while maintaining their normal work schedule and lifestyle.

Fatigue
Stress related to your illness, daily trips for treatment, and the effects of radiation on normal cells may lead to fatigue. Most people begin to feel tired after a few weeks of radiation therapy. You can help yourself by not trying to do too much. If you feel tired, limit your activities, use your leisure time in a restful way, and try to get more sleep at night.

If you continue working a full-time job while undergoing radiation therapy, talk with your employer about adjusting your work schedule, or try working at home for a period of time.

Skin Changes
The energy waves used in radiation therapy have an effect on the skin that resembles the effect of intense sunlight. Some skin irritation and redness, similar to a sunburn, may develop by the third or fourth week of treatment. Don't rub or scratch the affected area. Use mild soap, being careful not to wash off port markings, if you have any. Wear soft clothing, preferably cotton, and protect the treated area from sunlight. Advise your doctor or nurse at once if your skin cracks or blisters, so that they can instruct you on proper care.

Caring for Your Skin During Radiation Therapy

• Be extra kind to skin in the treatment area. Don't use any soaps, lotions, deodorants, cosmetics, talcum powder, or other substances in the treated area without talking with your doctor.

•Do not use adhesive tape on treated skin. If bandaging is necessary, use paper tape. Apply the tape outside of the treatment area.

• Do not apply heating pads or ice packs to the area. Use only lukewarm water for bathing the treated area.

• Use an electric shaver if you must shave the area—but only after checking with your doctor or nurse.

• Protect the area from the sun. Cover the treated skin with light clothing before going outside. Ask your doctor if you should use a lotion that contains a sunblock. If so, use a PABA product with a protection factor of at least 15. Continue to protect your skin from sunlight for at least one year after radiation therapy.

Other Side Effects
Radiation therapy may cause breast swelling and tenderness, so you may find sleeping on your stomach uncomfortable. Try using pillows to create a comfortable position. The swelling will subside after treatment.

In addition, you may have tenderness in the breast and chest area for up to a year, but seldom will it be severe enough to require pain medication.

On a long term basis, the breast may become slightly smaller or larger. The breast may also become slightly firmer, but significant hardening is rare.

Brachytherapy
Another method for treating the breast area is brachytherapy. Instead of an external beam, brachytherapy uses a radioactive source that is placed directly into the area where the tumor was. There are two brachytherapy methods: interstitial and single-balloon.

For interstitial brachytherapy, 10-20 thin, hollow plastic tubes will be inserted into the breast. A machine called an Afterloader will thread the radioactive source into each hollow tube, one at a time. A CT scan and a computerized program plot the precise placement of radioactive source to insure that the entire area receives an even dose of radiation. After the treatment, which last 5-10 minutes, you will be free to go home. You will have a total of ten treatments over five days.

Single-catheter brachytherapy works on a similar principle. After the cancerous lump is removed, the surgeon places a thin tube with a balloon at the end, into the breast, and inflates the balloon with saline, creating a space.

For the treatment itself, a small radioactive pellet is threaded through the tube into the balloon, and left in place for five minutes. This procedure is repeated twice a day for five days. You are free to leave the hospital between treatments.

Studies have shown that brachytherapy and external beam therapy are similarly effective in destroying cancer cells within the breast, and reducing the chance of local cancer recurrence.

Brachytherapy creates a higher intensity nearest the tumor site, with less spillover to surrounding normal tissues, such as lungs or heart.

The main advantage of brachytherapy is that women who do not have easy access to a radiation therapy facility five days a week, for five to seven weeks, can complete a course of treatment in five days. This may make the difference between choosing lumpectomy with radiation, or settling for a mastectomy.

 

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