Radiation Therapy for Breast Cancer

Overview
Radiation therapy helps prevent the return or spread of cancer. It is most frequently used after surgery, especially lumpectomy. If you have had a mastectomy, your doctor may decide that you don’t need radiation therapy. However, some doctors feel that it is safer to have radiation after a mastectomy if your tumor involved lymph nodes, is larger than five centimeters, or in certain other instances. In breast cancer where surgery is not an option, radiation therapy can help shrink tumor size, slow or prevent the spread of tumors, and may help treat pain.

Even if the surgeon has successfully removed all of the tumors, a few cancer cells may remain behind, too small to detect. Radiation therapy helps to eliminate these remaining cancer cells. It is believed that cancer cells are more vulnerable to radiation since they divide so rapidly. Radiation kills cancer cells more easily, but the normal, healthy cells of your body are better able to survive and heal.

Radiation therapy comes in two main forms, external beam radiation and internal radiation. They can be used separately or together. Your doctors will decide which type is best for you based on what type of surgery you had and where your tumors are located.

External beam radiation is the most common form used for breast cancer. In external beam radiation, beams of energy are projected from a machine into your body, carefully targeted onto locations such as the whole breast, lymph nodes, or other areas affected by cancer.

Some doctors may recommend you receive another treatment called hyperthermia just before radiation treatments. Also known as thermotherapy or thermal therapy, hyperthermia involves heating the cancer tissue to high temperatures. It is believed that this may make the cancer cells more susceptible to radiation. This treatment is still being researched and is not yet widely available.

Internal radiation, also known as brachytherapy, is direct and localized. It involves implanting a small catheter (tube) or device into the body near the surgical site from which the tumors were removed. During the radiation therapy, small radioactive pellets will be introduced via the catheter or device. This type of radiation therapy is not as common, and is still undergoing clinical trials. Internal radiation may require much less time than external beam therapy.

What does it involve?
Radiation therapy can be useful at almost any stage of breast cancer. It is usually delivered a few weeks after surgery to allow for healing. If chemotherapy is also planned, radiation therapy usually comes after chemotherapy.

When you arrive for your first external beam radiation appointment, the radiation therapist will take an x-ray called a port film to establish the best position for you to be in during treatment. They will tattoo small marks on your skin to indicate where the beam should be targeted. Do not try to wash this off or retouch it. In each appointment, the therapist will position you carefully on the table. You will need to lie still while the radiation is delivered. Try to stay relaxed. You will not feel anything during the treatment, although gradually over several treatments, your skin in that area will develop a burn, like a sunburn. This may be painful, but can be treated with topical ointments.

Radiation therapy is usually delivered five days a week during the treatment period, which can last as long as seven weeks. Receiving the treatment takes about 30 minutes, but preparation time may take longer. In accelerated breast irradiation, treatment is given twice daily for only one to three weeks. Similarly, in hypofractionated radiation therapy, larger doses are given for shorter periods of time.

For internal radiation therapy, the first step involved is planning. You may receive several scans including computerized tomography (CT), ultrasound, and mammography (x-ray) that help the radiation therapist pinpoint exactly where to place the implant. This may happen before or after your surgery. Next, the implants will be placed. The surgeon may implant a small balloon or strut device within your breast during tumor removal surgery. The implant is placed in the cavity left behind by the tumor. Another method takes place later, after surgery, and involves inserting several needles into the breast while under local anesthetic and sedation. The needles will then be replaced by catheters. In either delivery route, the implants will be removed when treatment is complete. The actual treatment during internal radiation therapy may be received twice a day for as little as five days. During treatment, the implants will be attached to a computer-controlled machine that delivers radioactive material for carefully calculated periods of time, then removes it.

After receiving radiation therapy, you will typically have follow-up appointments every three to six months. It’s important to attend every appointment and to tell your doctor about any potential symptoms or side effects you may be experiencing. After five years, you will probably only need to attend one appointment each year.

Intended Outcomes
Radiation therapy helps prevent the return or spread of cancer by killing cancer cells, shrinking tumors, and destroying any remaining cells after tumors have been removed. Radiation therapy improves survival rates in women who have breast cancer.

Results
In one summary of several large research studies, lumpectomy paired with radiation was shown to have equal rates of survival when compared with mastectomy as treatments for early breast cancer.

In another summary of several large research studies involving women who had breast cancer that had spread to their lymph nodes, mastectomy paired with radiation therapy was shown to have significant increases in rates of survival when compared with mastectomy without radiation therapy.

Constraints
Most common side effects of external beam radiation are short-term. These include fatigue, swelling, the sensations of heaviness in the treated breast, and skin damage similar to sunburn. These changes are usually gone within six to 12 months after external beam radiation treatment ceases, but may linger for as long as two years. Some women find that their breasts become smaller and firmer after receiving external beam radiation.

Less common side effects include nerve damage that can leave the shoulder, arm and hand feeling painful, weak or numb, and the weakening of the ribs, causing them to break more easily. External beam radiation can also make it more difficult to breastfeed in the future.

A very rare but serious side effects of external beam radiation can include developing a different type of cancer called angiosarcoma.

External beam radiation treatment can cause problems if given after breast reconstruction surgery. However, having external beam radiation treatment may limit reconstruction options later.

External beam radiation to the axillary (armpit) lymph nodes can cause lymphedema, or swelling, in the arm or hand on the side targeted by the treatment. Lymphedema can develop at any time after treatment, even years later. Those who have received external beam radiation to the axillary lymph nodes must take extra care to protect that arm and hand, and to avoid receiving blood pressure checks or blood draws on that side.

Internal radiation can cause pain, bruising and infection in the treated area. It can also cause the fat in the breast area to break down. Like external beam radiation, in rare cases it can also weaken the ribs and cause them to break more easily. As of 2012, clinical studies indicated that internal radiation has higher rates of skin and wound complications than external beam radiation.