Radiation therapy for breast cancer uses high-energy X-rays, protons or other particles to kill cancer cells. Rapidly growing cells, such as cancer cells, are more susceptible to the effects of radiation therapy than are normal cells.
The X-rays or particles are painless and invisible. You are not radioactive after treatment, so it is safe to be around other people, including children.
Radiation therapy for breast cancer may be delivered in two ways:
Radiation therapy may be used to treat breast cancer at almost every stage. Radiation therapy is an effective way to reduce your risk of breast cancer recurring after surgery. In addition, it is commonly used to ease the symptoms caused by cancer that has spread to other parts of the body (metastatic breast cancer).
External beam radiation uses high-powered beams of energy to kill cancer cells. Beams of radiation are precisely aimed at the cancer using a machine that moves around your body.
Radiation therapy kills cancer cells. It is used after surgery to help prevent recurrence. It can also be used to provide relief from pain and other symptoms of advanced breast cancer.
Here are the main ways radiation therapy is used to treat breast cancer. Discuss these treatment options with a doctor who specializes in radiation therapy for cancer (radiation oncologist).
After a lumpectomy for breast cancer, radiation therapy is typically used. Lumpectomy is a surgery that removes only the tumor and a small amount of normal breast tissue around it. Adding radiation after a lumpectomy lowers the risk of cancer recurrence in the affected breast. Recurrences can take place months or years later because of cancer cells left behind after surgery. Radiation helps to destroy remaining cancer cells.
Lumpectomy combined with radiation therapy is often referred to as breast conservation therapy. In clinical trials comparing lumpectomy with and without radiation therapy, the addition of radiation therapy resulted in significantly decreased rates of breast cancer recurrence and proved to be as effective as having the entire breast removed. In special situations if the risk of recurrence is very low, your radiation oncologist may also discuss the option of avoiding radiation after a lumpectomy.
External beam radiation of the whole breast. One of the most common types of radiation therapy after a lumpectomy is external beam radiation of the whole breast (whole-breast irradiation). The entire schedule of radiation therapy (course) is divided into daily treatments (fractions).
For many years, whole-breast irradiation was typically delivered in one radiation treatment a day, five days a week (usually Monday through Friday), for about five to six weeks. Accelerated radiation approaches are now common. For example, with an approach called hypofractionated radiation therapy, you receive slightly larger doses in fewer sessions. This shortens the entire regimen by two weeks, enabling the treatment to be completed in three to four weeks. Clinical trials have shown that these shorter regimens work as well as longer regimens at preventing recurrences of breast cancer and may reduce the risk of some side effects.
Removal of the entire breast (mastectomy) does not eliminate the risk of recurrence in the remaining tissues of the chest wall or lymph nodes. In many situations, the risk of recurrence is high enough that radiation is recommended after mastectomy. This type of radiation is called post-mastectomy radiation therapy and is typically administered five days a week for five to six weeks.
Factors that may put you at a high enough risk of breast cancer recurrence in your chest wall or lymph nodes to warrant consideration of radiation after mastectomy include:
Radiation therapy can also be used to treat:
If breast cancer has spread to other parts of your body (metastasized) and a tumor is causing pain or some other symptom, radiation can be used to shrink the tumor and ease that symptom.
Proton therapy offers more precise radiation dose delivery to the treatment target and protection of nearby healthy tissue. This is because proton beams, unlike X-rays, do not travel beyond the target. Therefore, researchers hope that proton therapy will decrease the risk of serious long-term complications of radiation therapy. However, proton therapy still carries risk of side effects because the targeted area may contain skin, muscle, nerves and other important tissue.
Proton therapy is being researched in patients with early-stage and locally advanced breast cancer.
Side effects from radiation therapy differ significantly depending on the type of treatment and which tissues are treated. Side effects tend to be most pronounced toward the end of your radiation treatment. After your sessions are complete, it may be several days or weeks before side effects clear up.
Common side effects during treatment may include:
Depending on which tissues are exposed, radiation therapy may cause or increase the risk of:
You will meet with your radiation therapy team, health care professionals who work together to plan and provide your radiation treatment. Team members usually include:
Before you begin treatment, your radiation oncologist will review your medical history with you and give you a physical exam to assess whether you would benefit from radiation therapy. Your oncologist will also discuss the potential benefits and side effects of your radiation therapy.
Before your first treatment session, you'll go through a radiation therapy planning session (simulation), in which a radiation oncologist carefully maps your breast area to target the precise location of your treatment. During the simulation:
Before internal radiation therapy (brachytherapy) is started, a special device for placement of the radioactive material is placed in the area from where the tumor was taken (tumor bed). This may be done during your cancer surgery or as a separate procedure several days later.
Radiation therapy usually begins three to eight weeks after surgery unless chemotherapy is planned. When chemotherapy is planned, radiation usually starts three to four weeks after chemotherapy is finished. You will likely get radiation therapy as an outpatient at a hospital or other treatment facility.
A common treatment schedule (course) includes one radiation treatment a day, five days a week (usually Monday through Friday), for about five to six weeks. Spreading out your sessions helps your healthy cells recover from radiation exposure while cancer cells die.
Whole-breast irradiation can frequently be shortened to three to four weeks. In addition, partial-breast irradiation may be completed in five days or less. Your radiation oncologist can help decide the course that is right for you.
A typical external radiation therapy session generally follows this process:
Delivery of the radiation may last only a few minutes, but expect to spend 15 to 45 minutes for each session, as it can take several minutes to set you up in the exact same position each day. This step ensures precise radiation therapy delivery.
Radiation therapy is painless. You may feel some discomfort from lying in the required position, but this is generally short-lived.
After the session, you're free to go about your regular activities. Take any self-care steps at home that your doctor or nurse recommends, such as taking care of your skin.
In some cases, once the main radiation therapy sessions have been completed, your doctor may recommend a radiation boost. This commonly means four to five additional days or fractions of radiation directed at the place of highest concern. For example, after whole-breast irradiation is complete, a boost of radiation is commonly given to area where the tumor was removed from (lumpectomy cavity).
For internal radiation, the radioactive source is inserted once or twice a day for a few minutes in the implanted radiation delivery device. This is usually done on an outpatient basis, and you can leave between sessions.
After the course of treatment, the radiation delivery device is removed. You may be given pain medication before the radiation delivery device is removed. The area may be sore or tender for several days or weeks as the tissue recovers from the surgery and radiation.
After you complete radiation therapy, your radiation oncologist or other medical providers will schedule follow-up visits to monitor your progress, look for late side effects and check for signs of cancer recurrence. Make a list of questions you want to ask your medical providers.
After your radiation therapy is completed, tell your medical providers if you experience: