Radiation therapy (also known as radiotherapy) uses targeted, high-energy X-rays to kill cancer cells. The goal of radiation therapy is to kill any cancer that might be left in or around the breast after surgery.
Radiation therapy after surgery is an option for most women who have:
Radiation therapy is often given to women who are treated with lumpectomy (also called breast conserving surgery) for DCIS.
In rare cases, radiation therapy is given to women treated with mastectomy for DCIS.
Learn more about treatment for DCIS.
For a summary of research studies on lumpectomy plus radiation therapy in the treatment of DCIS, visit the Breast Cancer Research section.
For most women, radiation therapy is recommended after lumpectomy since much of the breast tissue is left intact. It lowers the chances of breast cancer recurrence by about 50 percent and lowers the chances of breast cancer death by about 20 percent .
Many women who have a mastectomy do not benefit from radiation therapy. However, in some cases, radiation is used after mastectomy to treat the chest wall and the lymph nodes in the underarm area (axillary nodes) and around the collarbone.
Not everyone can have radiation therapy. Being pregnant or having certain health conditions can make radiation therapy harmful.
Women who have breast implants (both saline and silicone) can usually have radiation therapy. However, implants can make radiation therapy planning more complex. Radiation therapy can cause scarring and hardening of the implant, leading to a less natural look.
If your treatment plan includes mastectomy, radiation therapy and breast reconstruction, discuss possible risks with your breast surgeon and radiation oncologist.
Learn more about breast reconstruction.
Although the exact treatment for breast cancer varies from person to person, treatment guidelines help ensure quality care. These guidelines are based on the latest research and the consensus of experts. The National Comprehensive Care Network (NCCN) and American Society of Clinical Oncology (ASCO) are two respected organizations that regularly update and post their guidelines online. The National Cancer Institute (NCI) also has overviews of treatment options.
Breast cancer treatment is most effective when all parts of the treatment plan are followed. So, it is important to follow your treatment plan (for medications and other therapies) prescribed by your health care provider in terms of:
Radiation therapy after lumpectomy lowers the risk of breast cancer recurrence and increases the chances of survival [4,13]. In most cases, it is recommended after lumpectomy.
Radiation therapy for early breast cancer usually involves treatment five days a week for three to seven weeks. Getting to and from the treatment center this many times can be hard, especially if you live far away or, if children or elderly family members rely on you to take care of them. If you need a ride to and from treatment or help with child care or elder care, there are often resources that can help. Family and friends often want to help, but do not know how. These are ways they can help you. Some organizations offer programs to assist with transportation or costs related to transportation, child care and elder care. Others offer lodging if you need a place to stay overnight so that you can get treatment.
Don’t hesitate to ask for help from your co-survivors or contact organizations that offer help with transportation, lodging, child care or elder care. It is very important to complete your radiation therapy without gaps or delays.
Learn more about the importance of following your breast cancer treatment plan.
Radiation therapy can harm normal tissue, so it needs to be carefully planned and precisely given. This helps ensure the radiation kills as many cancer cells as possible while doing as little damage as possible to other parts of your body.
Radiation therapy is planned specifically for your breast cancer and the shape of your body, so sessions cannot be split between different treatment centers. Your therapy plan is based on:
Your radiation oncologist oversees the radiation planning session. During the planning session, you will lie on a special table while the radiation oncologist decides the proper dose of radiation and the best areas to receive the radiation. He/she will use a CT scan to guide the radiation planning.
During the planning session, the radiation oncologist will put small marks (about the size of a pinhead) on your skin. These marks ensure you are correctly positioned for each treatment. They may be ink spots, or they may be tattoos. If they are ink spots, it is important not to wash them off until after you finish radiation therapy.
Your radiation oncologist leads a team that includes technicians and nurses. The team will work with you at each radiation therapy session. During each session, you will lie on a special table. Most often, your entire breast will be given a dose of radiation. If lymph nodes removed during surgery were found to have cancer, often the area around the lymph nodes is also treated with radiation. Learn more about lymph nodes.
Each session lasts about 20 minutes. Most of this time is spent positioning your body to ensure the treatment is given exactly as planned. Treatment is usually given once a day, five days a week, for three to seven weeks. The schedule of radiation sessions is designed to treat your breast cancer and varies from person to person.
Some women may get a shortened course (only three to four weeks) of radiation therapy . This is called accelerated, hypofractionated whole-breast irradiation and is like standard radiation therapy except that it uses a slightly higher dose of radiation per session (hypofractionation). This reduces the number of treatment sessions (making this an accelerated therapy).
After your radiation therapy sessions end, you may have more radiation (called a boost) to the part of the breast that had the original tumor. This boost radiation is given to increase the amount of radiation therapy given to the area at highest risk for breast cancer recurrence. Your boost radiation session is similar to a regular session.
Things to remember while going through radiation therapy
Adapted from the National Cancer Institute materials .
If you do not live near the radiation treatment center, it can be hard to get to and from therapy sessions. Sometimes, there are programs that offer help with local or long-distance transportation and lodging. Learn more about these programs.
Radiation therapy has some side effects. Some begin during treatment, while others may occur months or even years later.
Most often, side effects from radiation therapy begin within a few weeks of starting treatment and go away within a few weeks after treatment ends .
During and just after treatment, your treated breast may be sore. Mild pain relievers such as ibuprofen or acetaminophen can ease breast tenderness.
The treated breast may also be rough to the touch, red (like a sunburn) and swollen. Sometimes the skin may peel, as if it were sunburned. Your radiation oncologist may suggest special creams to ease this discomfort. Sometimes the skin peels further and the area may become tender and sensitive (called a moist reaction). This is most common in the skin folds and the underside of the breast. If this occurs, let your oncologist or nurse know, and he/she can give you creams and pads to make the area more comfortable until it heals.
Fatigue is common during radiation therapy and may last for several weeks after treatment ends.
Nausea is not common with radiation therapy. And, you shouldn’t lose the hair on your head. However, you may lose some hair under the arm or on the breast or chest area receiving radiation (this may be an issue for men with breast cancer).
Learn more about easing pain related to radiation therapy.
Over time, you may notice firmness or shrinkage of the breast. You may also have mild tanning of the skin in the treated area or red discoloration, especially around the surgical scar(s). These changes are often permanent.
Women who have lymph nodes in the underarm area (axillary nodes) removed may develop lymphedema. Lymphedema is a condition in which fluid collects in the arm (or other areas such as the hand, fingers, chest or back), causing it to swell. The chances of getting lymphedema are greater if your treatment includes both :
Lymphedema is also more likely in women who are overweight .
Learn more about lymphedema.
Although rare with modern radiation therapy, treatments can injure the normal tissues near the radiation field of the breast or chest wall. The following are rare side effects:
These conditions may occur a few months or years after radiation therapy.
In rare cases, radiation therapy can cause a second cancer. The most common cancers that have been linked to radiation therapy are sarcomas (cancers of the connective tissue) [17-18]. However, the risk of a second cancer is very small and the benefits of radiation therapy almost always outweigh the risks.
Two main drawbacks of radiation therapy are the frequency and length of the treatment. Treatment is usually given once a day, five days a week, for three to seven weeks. Techniques that shorten the course of treatment continue to be studied in clinical trials. The results of these trials will decide whether these therapies become part of standard care.
After talking with your health care provider, we encourage you to consider joining a clinical trial of radiation therapy for breast cancer.
BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service that can help you find a clinical trial that fits your health needs.
Learn more about clinical trials.
Read our perspective on the emerging techniques in radiation therapy (November 2009).*
Accelerated partial breast irradiation delivers radiation only to the area around the tumor bed (the tissue in and around the space where the tumor was removed during lumpectomy). This reduces the number of treatment sessions (accelerated therapy). Not everyone can have this type of radiation therapy.
Accelerated partial breast irradiation can be done by brachytherapy, three-dimensional conformal external beam or by intraoperative radiation therapy. These techniques are still under study.
Brachytherapy uses targeted radiation therapy placed inside the tumor bed. Implanted radiation "seeds" (interstitial radiation therapy) or a single small balloon device (intracavitary radiation therapy) can be used to deliver the radiation.
Some early findings suggest accelerated partial breast irradiation with brachytherapy may be as effective as standard radiation therapy in reducing rates of breast cancer recurrence [19-22]. However, follow-up time on these studies is short and the long-term effects of brachytherapy are not yet known. It is also not clear which women are the best candidates for brachytherapy and whether the cosmetic look of the breast is as good with brachytherapy as with standard radiation therapy [14,22].
Although brachytherapy is available at some medical centers and may be appropriate in select cases, its long-term safety and effectiveness are still under study.
Three-dimensional (3D) conformal external beam radiation therapy uses standard external beam radiation to target only the tumor bed.
Studies on 3D conformal external beam radiation therapy are limited at this time. Some early findings suggest the cosmetic look of the breast may be worse with 3D conformal external beam radiation therapy than with standard radiation therapy . In general, this therapy should only be given as part of a clinical trial. However, select women may be appropriate for treatment outside of a clinical trial.
With intra-operative radiation therapy, a single dose of radiation is given to the tumor bed during lumpectomy. This dose of radiation is higher than in a standard radiation session.
Some early findings suggest that intra-operative radiation therapy is less effective than standard radiation therapy at reducing rates of breast cancer recurrence . Intra-operative radiation therapy needs further study before its risks and benefits are fully known. At this time, it is being studied mainly in Europe.
Our commitment to research
At Susan G. Komen®, we are committed to ending breast cancer forever. Our global research grants and scientific programs are essential driving forces for achieving this mission. Many of the world’s leaders in breast cancer research have been supported by Komen’s Research and Scientific Programs – including three Nobel Laureates. Komen’s funding has supported research that has resulted in a better understanding of breast cancer; earlier detection; personalized, less invasive treatments for what was once a “one-treatment-fits-all” disease; and improved survival rates. Learn more about the exciting research we are funding.
Learn more about talking to your health care provider.
Komen Support Resources
Interactive Treatment Navigation Tool
Breast Cancer 101 - Radiation Therapy
Radiation Therapy Video
Facts for Life: Radiation Therapy and Side Effects
Questions to Ask Your Doctor on Radiation Therapy
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