Radiation therapy is sometimes part of the treatment plan for a woman diagnosed with breast cancer. Geraldine Jacobson, MD, MPH, radiation oncologist at University of Iowa Hospitals and Clinics, talks about radiation therapy treatment options for breast cancer:

How does radiation therapy work?

Radiation therapy is the branch of medicine that uses radiation to treat cancers. Radiation is energy. In the context of breast cancer, when we deliver radiation, that energy hits cancer cells, injures the DNA of the cells so they can’t divide, grow, and repair, so the cancer cells die. The normal part of the body is able to repair and heal itself from the radiation, but the cancer cells can’t.

Do all women diagnosed with breast cancer need radiation therapy?

No, women are diagnosed at different stages and in different situations. The main things that determine that is what kind of surgery the woman had and how extensive her breast cancer is.

Are there different types of radiation therapy available for breast cancer?

There are. The main two categories are external beam or internal radiation. With the external beam, the radiation is delivered from the outside. With the internal radiation, some sort of applicator is placed within where the cancer was removed and radiation is placed in that applicator for internal radiation. I think the main distinctions we make is when we’re treating with the external radiation, we have some control over how many treatments we give and also whether we treat the whole breast or part of the breast.

Could you explain how conformal radiation therapy works?

It works like any other radiation in that the energy hits the cancer cells and kills them. Conformal radiation is a particular kind of treatment delivery where the radiation oncologist and the planners use multiple beams that shape the radiation. In the case of breast cancer, they shape the radiation, usually around the lumpectomy cavity. The advantage is that instead of the whole breast being treated, we’re just treating the area that’s at highest risk for cancer.

What is hypo-fractionation radiation and how is that different from conformal radiation?

That’s sort of like apples and oranges and when we talk about radiation to the breast. We talk about how much area we’re going to treat—and usually that’s whole breast or part of the breast—and that’s what we’re talking about with conformal. We’re treating part of the breast and we’re shaping the radiation.

Our other treatment decision is how long we want this treatment to last. Do we want it to last a week, two weeks, three weeks? Standard breast radiation, which we’ve done for many years, usually involves six weeks of daily treatment, Monday through Friday. Hypofractionation is a way of treating where we’re giving a little more radiation each time, but we’re getting the radiation done faster and the total dose is less. We have several scientific studies that have been going on for several years, which tell us that in certain women, hypofractionation—which is getting the treatment done more quickly—is just as good a treatment as the longer radiation course.

I understand there is also what might be considered an internal type of radiation therapy for breast cancer called MammoSite®. How is this therapy different?

This is one of the new things in radiation therapy and is a kind of partial breast irradiation and kind of an internal radiation. With MammoSite®—or there’s other brands that do something similar—after the lump is removed in breast conservation, a MammoSite® applicator is put in and it’s like a balloon and it’s expanded to fill that cavity and then a source of radiation is put in the center of this balloon and it treats the area at risk for breast cancer from the inside.

There are two things about this that are attractive.

• We’re treating the area where the lump was—and not treating the whole breast, treating less of an area with radiation
• The whole course of treatment is done faster, so instead of six weeks, we’re getting the radiation done in five to eight days

How is the type of radiation therapy treatment determined for each woman?

There’s three major factors. It depends on:

• The stage of the breast cancer. What are the medical indications—what kind of radiation is the woman going to need to reduce the risk of the cancer coming back
• The woman herself. How much time she can have to treat, how far she lives from the radiation center, the size and shape of her breast, where her tumor was
• The technology available to the radiation oncologist, and there’s quite a lot of variation, depending on how large the center is—where it is

What is your best advice for a newly diagnosed breast cancer patient when it comes to radiation therapy treatment?

My best advice would be to make sure that she talks to a radiation oncologist. I know from talking with members of my family and my experience as a patient, that lots of people like to ask the first doctor they meet about their whole course of treatment. But radiation therapy is very specialized, so they’ll get the best information by talking directly to the radiation oncologist.

The other thing I really feel strongly about is that an educated patient is likely to get better treatment and understand her treatment. There’s a lot of information out there from—you name it, American Cancer Society, National Cancer Institute, Susan G. Komen. There’s a lot of information available online and in pamphlet form that describe the basic treatments for breast cancer that’s understandable in ordinary language. I think if women try to find that information and then talk to a radiation oncologist about their options, they’ll probably come up with a good plan they understand and feel comfortable with.

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Geraldine Jacobson, MD, MPH

Holden Comprehensive Cancer Center

UI Breast Health