Treatment Guidelines | Surgery | Radiation Therapy | Chemotherapy | Drug Therapies

Radiation therapy is a form of treatment that uses high intensity x-rays or particles to destroy cancer cells. After surgery to remove the cancer, x-ray beams are aimed at the breast to destroy any remaining cancer cells. This treatment is also used to destroy remaining cancer cells in the axillary (underarm) lymph nodes and, in rare instances, in lymph nodes above the collarbone and in the chest wall.

Radiation therapy is also sometimes used to reduce the size of a tumor before surgery and to treat recurrent cancer. Radiation therapy cannot be used instead of surgery, nor can it be used as a substitute for most drug treatments. Often, both chemotherapy and radiation treatments are used; chemotherapy to destroy cancer cells that may have spread throughout the body and radiation to destroy cancer cells locally (in the breast and axillary areas only).

How Radiation Therapy Works

High doses of radiation can interfere with the cell cycle through which both normal cells and abnormal cancer cells grow and reproduce to form two new cells. It is thought to work by damaging the DNA in the cells, making them unable to divide. DNA (deoxyribonucleic acid) is the part of the cell that carries the genetic code for the division and growth of cells.

Administration of Radiation Therapy

External Beam Radiation

External beam radiation therapy itself is a painless procedure with few side effects, but it does require daily trips to the hospital for treatment sessions over a period of six to eight weeks. In this treatment, radiation is focused from a source outside the body on the site of the cancer. This procedure is like getting a diagnostic x-ray, but the radiation is more intense.

Before radiation treatments start, the physician and his staff will determine the best angles for aiming the high-energy beam to reach the breast area, with as little effect on surrounding tissues as possible. They will then make ink marks on the skin to outline the places on the body where the beam will be aimed. These markings will be used at each treatment session to ensure that the radiation beam is aimed consistently and accurately.

The full course of treatment usually runs from 6 to 8 weeks, with daily sessions from Monday through Friday, and rest and recovery periods during weekends. Patients are generally advised not to use antiperspirant or deodorant on the side being treated, because these preparations contain aluminum that may interfere with the radiation beam. During the actual exposure, the patient must remain as still as possible. Each exposure lasts only a few minutes and is completely painless.

Accelerated Breast Irradiation

In this treatment, external beam radiation therapy is delivered in the same manner, however slightly larger doses are given over a shorter time period, such as 3 week. This approach appears to have comparable results to external beam radiation therapy administered according to the conventional schedule.

Brachytherapy (Internal Radiation)

Brachytherapy, also known as internal radiation, is a different way of delivering radiation therapy according to a schedule that is much less inconvenient or prolonged. This form of breast radiation therapy uses a small balloon attached to a thin tube. The deflated balloon is inserted into the space left by the lumpectomy and is filled with a salt water solution. The balloon and tube are left in place throughout treatment, with the end of the tube sticking out of the breast. Twice a day during the 5-day treatment period, a source of radioactivity is placed into the middle of the balloon through the tube and then removed. The balloon is then deflated and removed. Brachytherapy can be done at the time of lumpectomy or within several weeks afterward.
Possible Side Effects of External Beam Radiation Therapy
Side effects of external beam radiation therapy vary from patient to patient; some women experience no or mild side effects throughout the course of treatment. Most side effects are not serious, and disappear quickly.

The most common temporary side effects are:
• Fatigue - most people experience fatigue after a few weeks of radiation therapy. It is helpful to limit activities and to plan schedules so that there is more time for rest.
• Skin irritation and redness, similar to a sunburn - these symptoms may develop by the third or fourth week of treatment. Exposure of the area to sunlight should be avoided, and the use of any lotions or creams should be discussed with the physician.
• Swelling and tenderness in breast and chest area - the swelling should subside after treatment ends, but some women experience a degree of tenderness for up to a year after treatment.

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