Radiation therapy is a common and effective part of breast cancer treatment. It helps destroy cancer cells and reduces the chance of recurrence (cancer returning). Whether radiation therapy is used after surgery or to manage more advanced stages of breast cancer, it can be a crucial part of your care plan.

Knowing what to expect during radiation therapy can help ease your concerns. From how the therapy works, to possible side effects, and the different types of radiation therapies, this article covers everything you need to know to feel more informed and empowered as you undergo breast cancer treatment.

When Is Radiation Used?

Radiation therapy is most often given after a lumpectomy (also called breast-conserving surgery) — to remove a small tumor and surrounding normal tissue. Radiation helps kill cancer cells that remain after surgery and prevents new cancer cells from forming in the treatment area. Breast cancer recurs in less than 5 percent of people 10 years after surgery and radiation.

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 areas of the breast, in the skin, or the lymph nodes. Radiation therapy can help target any remaining cancer cells that couldn’t be surgically removed.

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
• Control symptoms such as ulceration and bleeding from locally advanced breast tumors

Types of Radiation Therapy

Several types of radiation therapy can be used to kill cancer cells, and researchers are continually developing new methods that target cancer cells more precisely, sparing healthy tissue.

External Beam Radiation Therapy

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

Photon Beam Radiation Therapy

This type of external beam radiation uses photon beams to target tumors. Photon beams are the same type of radiation used in X-rays but are much more powerful when used to treat cancer.

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

• Intensity-modulated radiation therapy (IMRT)
• Helical tomotherapy (a type of IMRT)
• Image-guided radiation therapy
• MRI-guided radiation therapy
• Stereotactic radiosurgery
• Three-dimensional conformal radiation therapy

These treatment options may have 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.

Another type of photon beam therapy is intraoperative radiation therapy, which targets only part of the breast. It takes place during surgery — so both your surgery and your radiation may be completed before you wake up. Only certain individuals with particular types of cancer can be given IORT, and researchers continue to investigate this therapy.

Proton Beam Radiation Therapy

Proton beam radiation therapy is another type of external beam radiation therapy. It uses proton beams instead of photon beams. It can target cancer cells more precisely, limiting damage to surrounding healthy tissue. Proton therapy is increasingly available, but not all oncology centers offer it for breast cancer yet.

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. The end where the tumor was removed will hold the radioactive seeds. They 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.

This kind of radiotherapy is rarely used today for breast cancer.

What Is the Best Radiation for Breast Cancer?

The best type of radiation for breast cancer depends on several factors. These include the size and location of the tumor, whether it has spread, and your overall health. Your radiation oncologist will recommend the most appropriate type of radiation for you.

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, you should discuss the details of your situation and your treatment goals with your health care providers.

What To Expect With Radiation for Breast Cancer

If you were recently diagnosed with breast cancer, you may be wondering, how many rounds of radiation are normal for breast cancer? Radiation treatments often start four to eight weeks after chemotherapy or surgery, 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 plan lasts.

Ask your radiation oncologist if you need to take any steps before undergoing treatments. For example, doctors often recommend avoiding the 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 require less time — just one to three weeks — and may be delivered twice daily.

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 return for your daily treatments, you’ll lie in the same position. The radiation will be delivered to one particular area for a few minutes, and you may be treated in two to five sites. Overall, each session may take between 30 and 45 minutes.

Brachytherapy

Brachytherapy is typically given 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’re in
• What other treatments you’re currently receiving or had previously

Side Effects of Radiation Therapy

Radiation therapy can cause side effects, but they vary from person to person. Some people experience few side effects, while others experience more that affect their daily lives. Keep reading to learn more about what you might expect.

Short-Term Side Effects

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

You can take steps to reduce these possible 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.

Find Your Team

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, more than 74,000 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.