• Many people with breast cancer will undergo radiation therapy to help destroy cancer cells.
• Radiation therapy can be given externally (by a machine) or internally (by radioactive material placed inside the body).
• Some newer types of radiation therapy take less time than the traditional six to eight weeks, potentially causing less damage to healthy tissue and fewer side effects.

Radiation therapy, also called radiotherapy, often plays a part in breast cancer treatment. A doctor called a radiation oncologist guides these treatments, which are given by a team of radiation therapy technologists and supervised by radiation oncology nurses, dosimetrists, and medical physicists. The physician, assisted by the dosimetrist and physicist, will determine your treatment plan and review treatment options, talk with you about possible short- and long-term side effects, and guide you through your course of therapy.

Radiation therapy uses high-energy X-rays or particles to damage cells’ DNA, which controls how cells grow and divide. The cancer cells often can’t repair themselves, so they die, while healthy cells can more easily heal and survive.

When Is Radiation Used?

Radiation therapy is most often given after a lumpectomy (also called a partial mastectomy) — surgery to remove a small area of tumor and surrounding tissue. Radiation helps kill any cancer cells that remain after surgery and prevents new cancer cells from forming in the treatment area. For people with early-stage breast cancer, a lumpectomy plus radiation cuts the risk of cancer returning in half.

If you have a total or modified radical mastectomy — surgery to remove all your breast tissue and, often, nearby lymph nodes — you may still need radiation therapy if your tumor was large or cancer cells were found in other breast areas, the skin, or the lymph nodes. Radiation treatments can help kill the cancer cells that couldn’t be surgically removed. However, many people don’t require radiation after a mastectomy.

You may also need to get radiation in other circumstances, such as to:

• Treat metastatic breast cancer (cancer that has spread to other parts of the body)
• Use instead of surgery if your tumor can’t be removed that way or you aren’t in good enough health to undergo surgery
• Shrink a tumor before surgery to make it easier to take out, although this use of radiation is rare

Whether radiation is useful for you depends on characteristics related to both you and your cancer. For example, if you have just a small tumor and are over age 65, radiation may provide less benefit. However, every individual must discuss the details of their own situation with their physicians.

Types of Radiation Therapy

Several types of radiation exist to kill cancer cells, and researchers are continually developing new ways to destroy cancer cells while leaving healthy tissue alone.

External Beam Radiation

With external beam radiation, a large machine often delivers the radiation. Traditionally, the entire breast and lymph nodes were treated, but with newer imaging and surgical techniques, sometimes only part of the breast requires treatment.

Some newer types of external beam radiation therapy may deliver more radiation to areas that might contain cancer cells and less to healthy tissues. Also called partial breast irradiation, these techniques include:

• Intensity-modulated radiation therapy (IMRT)
• Three-dimensional conformal radiation therapy (3D-CRT)
• Image-guided radiation therapy (IGRT)

These treatment options may lead to fewer side effects because they don’t damage your normal tissues as much. You can ask your doctor if these options are recommended in your case.

While most radiation treatments involve X-ray beams, some types of external beam radiation use high-energy particles such as protons or neutrons. This type of treatment can better target cancer cells while leaving healthy tissue unaffected. However, not all facilities offer proton and neutron therapies, which still are considered investigational for breast cancer.

Brachytherapy

Brachytherapy, also known as internal radiation therapy, involves placing radioactive substances inside your body, directly next to the tumor. A doctor uses a thin tube or applicator to put radioactive seeds, pellets, or ribbons (tiny pieces of radioactive material) in or near the cancer.

Brachytherapy may require surgically placing a small device in the breast. One end, located where the tumor was removed, will hold the radioactive seeds, which are placed through a thin tube that sticks out of the skin of your breast at the other end. Only the part of the breast around the device gets treated, so brachytherapy can be used only for certain small cancers.

Intraoperative Radiation Therapy

Another kind of treatment that targets only part of the breast, intraoperative radiation therapy (IORT), takes place during surgery — so both your surgery and your radiation may be completed before you wake up. Only certain individuals with particular cancers can be given IORT, and researchers continue to investigate this therapy.

What To Expect During Radiation Therapy

Radiation treatments often start three to eight weeks after surgery or three to four weeks after chemotherapy, but therapy schedules may differ from person to person. Your health and the characteristics of your breast cancer, such as whether it has spread to the lymph nodes, will determine how long your radiation treatment lasts.

Ask your radiation oncologist if you need to take any steps before undergoing treatments. For example, doctors often recommend avoiding use of supplements that contain antioxidants, including vitamins A, C, D, and E.

External Beam Radiation

External beam radiation typically requires treatment five days per week for one to six weeks. Partial breast irradiation may be quicker — just one to three weeks — and may be delivered twice a day.

If you’ll be receiving external beam radiation therapy, you will likely first undergo a simulation to help your care team determine which area to target. This planning session takes about an hour while you lie on a table. Cushions and restraints will help you hold your position without moving.

When you come back for your daily treatments, you’ll lie in the same position. The radiation will be delivered to one particular area for 30 seconds to a few minutes, and you may be treated in two to five sites. Overall, each session might take between 10 and 30 minutes.

Brachytherapy

Brachytherapy is typically given once or twice daily for five days. The radioactive seeds will be delivered to your tissue and left in place for a few minutes before being removed. You usually can go home between treatments.

Radiation for Metastatic Cancer

If you need radiation to treat metastatic cancer, your radiation oncologist may plan other radiation treatments to kill cancer cells or treat symptoms. The schedule will depend on factors such as the size and location of your tumors, how much pain you are in, and which other treatments you are undergoing now or had in the past.

Radiation Side Effects

Many people experience side effects from radiation treatments, but these issues vary from person to person. Some people develop many health problems that affect their daily lives, while others notice just a few minor effects.

Short-Term Side Effects

Some side effects come on quickly after you start treatment. They tend to be mild and more easily treated and disappear once you complete radiation therapy. Short-term side effects of radiation therapy to the breast include:

• Tiredness or weakness that may not get better with rest
• Skin changes, such as dryness, peeling, blistering, irritation, itching, swelling, or appearing sunburned or tanned
• Soreness or tenderness in the breast, nipple, or armpit
• Infection of the area around a brachytherapy device

If you receive radiation therapy to another part of the body to treat metastatic cancer, you may experience additional effects in that area. For example, radiation treatments to the brain could cause loss of hair on your head, headaches, hearing or memory loss, or seizures.

Long-Term Side Effects

Other radiation-related side effects may not occur until months or years after you finish treatment. Common side effects that may arise later on and may be permanent include:

• Skin changes, including darker color, thicker skin, or more visible pores on the treated breast
• Telangiectasias (spider veins), a group of red or purple blood vessels on the breast’s surface
• Greater or less sensitivity in your treated breast
• Increased or decreased size of the breast
• Lymphedema (swelling in the breast, chest, or arm)
• Hair loss in the treated area, such as the armpit

Radiation therapy may also lead to changes in nearby tissues. It’s possible to end up with a broken rib, lung inflammation (pneumonitis), damage to your heart tissue or blood vessels, irregular or skipped heartbeats, or numbness or tingling in your shoulder or arm. However, these side effects are rare — new radiation technology allows doctors to more accurately treat your cancer while leaving your healthy tissue alone.

If you undergo radiation therapy, you will have a slightly increased risk of developing another cancer later. However, this also is rare.

You can take steps to reduce these side effects or your risk of developing them. Talk with your treatment team to learn more, and tell your doctor about any new or worsening problems.

Talk With Others Who Understand

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, more than 58,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Have you gone through radiation therapy for breast cancer? What type were you given? Share your experiences in the comments below, or start a conversation by posting on your Activities page.