Like surgery, radiation is a localized treatment. The radiation is aimed at a specific area and affects only that area. (Chemotherapy and hormone therapy, in contrast, are systemic treatments and affect your entire body through your bloodstream.)

Radiation is ordinarily used in conjunction with a lumpectomy. Some women who have a mastectomy may also receive radiation. It is used to get rid of any cancer cells that may have been left behind after removing the cancer and breast tissue. Radiation treatments are scheduled and spaced out, once a day for a given number of weeks. There is always a balance between killing as many of the cancer cells as possible and avoiding injury to the normal tissue. The treatment schedule varies from place to place.

Radiation is ordinarily used in conjunction with a lumpectomy

Even though the actual radiation treatment is quite short—minutes—it can be quite difficult for someone to get to the hospital every day for as many as six weeks, especially if she lives in a rural area or doesn’t have transportation. In fact, some women choose a mastectomy over a lumpectomy and radiation solely because the thought of getting to the hospital every day for six week is so daunting.

Seeking to find ways to give effective but less time consuming radiation for women who have had a lumpectomy, researchers developed what is called partial breast radiation. It is given directly to the tumor site over a shorter period of time, sparing the rest of the breast.

Usually, radiation is given in two parts. First, the breast as a whole is radiated from the collarbone to the ribs and the breastbone to the side, making sure the entire area is treated, including, if necessary, lymph nodes. This is the major part of the treatment and lasts about five weeks. Second, you may be given a boost—extra radiation to the tumor’s location.

When you meet with the radiologist, make sure you are offered options. Ask what your risk of local recurrence is with and without radiation therapy. Ask about different techniques like whole breast radiation (WBI), accelerated whole breast radiation (AWBI), accelerated partial breast radiation (APBI), and even intraoperative radiation (IORT). Also ask your radiologist why they are recommending one option versus another.

Each radiation option takes a different approach and it’s important to understand your treatment. Partial breast radiation requires the placement of a balloon into the biopsy cavity at surgery so the treatment can be delivered directly to the tumor bed twice a day for five days. The whole breast option takes six weeks, while the accelerated whole breast approach takes only three weeks. Intraoperative radiation is given while you are on the operating table and so is the quickest, if it is an option for you.

Partial breast radiation

Partial breast radiation is a safe option for women with early breast cancer (less than two cm, negative sentinel node), particularly if postmenopausal. It can be done with classical radiation machines, usually in five visits.

Balloon-delivered intracavitary brachytherapy

This is the most commonly used form of partial breast radiation in the U.S. It takes advantage of the fact that after a tumor is removed there is a cavity left behind in the breast that fills up with fluid as the area slowly heals. Since tumor cells are most likely to be left behind in the lining of that cavity, it makes sense to use the cavity to deliver the radiation. If you have this type of radiation, your surgeon will insert an empty surgical balloon with an attached catheter into the cavity. The treatments themselves consist of hooking the protruding catheter to a computerized delivery device that fills the balloon with the radioactive material. This is done twice a day, six hours apart, for five days. At the end of each treatment the radioactive material is removed and you are unattached from the treatment machine, free to go about your business. You are not radioactive. There are several radiation delivery devices on the market, each with its own benefit. Most commonly used is the Mammosite. If you are interested in using this approach, the key is to find an experienced treatment team and going with the device they are most comfortable with using.

Interstitial brachytherapy

This was previously used to give an extra boost of radiation before the days of the electron beam. Now it has a more primary role. For this procedure, thin plastic tubing is hooked like thread into a needle and drawn through a spot on the breast where the biopsy was done. The tubes are placed while you’re in the operating room or during an outpatient procedure. The number of tubes varies, and sometimes they are inserted in two layers. Small radioactive pellets called iridium seeds, which give off high energy for a very short distance, are put into the tubes, treating the immediate area of the biopsy. This implant is left in for 36 to 48 hours; the time varies depending on how active the seeds are, how big your breast is, and how big the tumor was.

Since the radioactive material stays in the catheters the whole time, this radiation can be picked up by people around you, although not in large doses. Normally that’s no problem, but for some people, such as pregnant women, exposure to even that much radiation could be dangerous. You will be kept in the hospital with a sign on the door that reads “Caution: radioactive.” After about 36 hours, both the radio­active sources and the tubes are removed, a process that requires no anesthesia. After this, you can go home, unless there’s some other reason for you to remain hospitalized. While this approach allows a the radiation dose to be given more precisely where it is needed, it is also the most technically difficult way to do partial breast irradiation and so is used less often.

Conformal or intensity-modulated partial breast irradiation

This approach uses external beam radiation. The treatment lasts four or five days.


This approach to radiation starts in the operating room but continues into the postoperative period. It is also partial breast radiation. This technique depends on the placing of a balloon or catheter into the biopsy cavity in the operating room so it can later be loaded or filled with radioactive material.


Frequently Asked Questions

I had a mastectomy. Do I still need to have radiation?

Radiation isn’t routine after a mastectomy. But studies suggest it may benefit some women. Women with four or more positive axillary lymph nodes; one to three positive nodes and a tumor over five centimeters; and those with involvement of the skin overlying the breast or the chest wall, may benefit from postmastectomy radiation therapy. Women with an intermediate risk of local recurrence (10 to 20%) might consider postmastectomy radiation if they had close margins (cancer cells at the edge of the mastectomy) and significant amounts of invasion in the lymphatic or blood vessels in the breast tissue (called lymphovascular invasion). Women with triple negative breast cancer, those younger than 45, or those who have tumors with lymphovascular invasion may also benefit.

In general, postmastectomy radiation reduces the chance of local recurrence from five to 10% to three to five percent. If the chance of recurrence is higher, as in the situations mentioned above, the benefit is also higher. Why, then, shouldn’t everyone who has had a mastectomy also have radiation? Because radiation has its own risks. Studies show that people who had cancer on the left side and got radiation had an increase in heart disease, although this risk has decreased substantially as radiation techniques have improved. Furthermore, recent studies have shown a doubling of the risk of lung cancer 10 years after postmastectomy radiation therapy. (This risk is related to smoking history as well as the amount of lung that has been treated and, interestingly, does not apply to radiation therapy after breast conservation.)

As with all the decisions related to breast cancer treatment, it ends up being a balance of risk versus benefit. When the risk of local recurrence is high enough after a mastectomy, radiation is worthwhile. Talk to your doctors and consider your own feelings, then make the decision that feels best for you.

What becomes more complicated is how to integrate the postmastectomy radiation therapy with potential reconstruction. If you fit in this category, it is best that your surgeon, radiation therapist, and plastic surgeon work collaboratively to ensure the best result.

Is radiation really necessary after a lumpectomy?

Many studies have found that radiation reduces a woman’s risk of having the tumor come back in the breast. (This is called a local recurrence.) These studies found that when a woman does not have radiation she has a risk of recurrence of around 30%. If she does have radiation, her risk is reduced to about seven percent. Some studies have shown that older women (women who are 70 and over) and have small tumors that are estrogen receptor- (ER-) positive, and take the drug tamoxifen may not need radiation. For this reason, older women should talk to their doctor about the risks and benefits of radiation.

What are the side effects associated with radiation?

The side effects of radiation depend on the part of the body being treated. Those who receive radiation to the breast and have soft bones may have asymptomatic rib fractures—you don’t feel them, but they show up on X-ray. Depending on how your chest is built, a little of the radiation may get to your lung and give you a cough.

Another common side effect is developing redness that looks like a sunburn. The severity varies considerably from person to person. As you may expect, there is a correlation between skin color and reaction to radiation therapy—the fairer your skin, the worse reaction you’re likely to experience.

The other major symptom virtually every radiation patient has is tiredness. The body seems to exhaust its resources coping with the radiation and doesn’t have much energy for anything else. The fatigue usually gets worse toward the end of the treatment, and its severity depends on what else is going on in your life. The fatigue may last several weeks after the treatment has finished, or longer if you have already received chemotherapy; it may even begin after the course of treatment is over.

When the breast is being radiated, it may swell and become more sensitive. This sensitivity, like the other side effects, can take months to disappear, and you may find that breast especially sore or sensitive when you’re premenstrual.

Often the skin feels a little thicker right after radiation, and sometimes it’s darker colored. That will gradually resolve itself over time. The nipple may get crusty, but that too will go away as the skin regenerates. This can take up to six months, and in the meantime you’ll look like you’ve been out sunbathing with one breast exposed.

If you have received a lot of radiation to the lymph node areas, it will compound whatever scarring the surgery caused, and the combination can also increase your risk of lymphedema. A rare side effect of radiation to the lymph nodes is problems with the nerves that go from the arm to the hand, causing numbness to the fingertips.

Aside from skin reactions and tiredness, there can be later side effects. Some women get costochondritis, a kind of arthritis that causes inflammation of the space between the breasts where the ribs and breastbone connect. The pain can be scary, and may lead you to wonder if the cancer has spread. It’s easy to reassure yourself, though. Push your fingers down right at that junction; if it hurts, it’s costochondritis and can be treated with aspirin and antiarthritis medicines. The pain will go away in a few weeks.

When the treatments are over, you’ll continue to have tenderness and soreness in your breast that will gradually go away. Some women continue to have sharp, shooting pains from time to time—how often varies from woman to woman.

I had a lumpectomy. My oncologist says I need to have radiation and then take hormone therapy for five years. Why do I need both?

Radiation is designed to kill off any errant tumor cells that remain after surgery. Hormone therapy is used to prevent or arrest the development of future breast cancer by keeping estrogen from getting into tumor cells. By adding both radiation and hormone therapy to lumpectomy, your doctors are trying to give you more insurance against a recurrence. You can read more about hormone therapy here.

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