Last updated: Jun 12, 2008
During partial breast radiation, only the tumor site gets treatment.
Radiation therapy is very good at reducing the odds of cancer striking again in the treated breast. Following lumpectomy alone, a patient typically "has roughly a 30% to 40% risk of breast cancer coming back in the same breast, depending on the size of the tumor and the histology [grade]," says Dennis E. Hallahan, MD, chairman of the department of radiation oncology at Vanderbilt University in Nashville. "Surgery with radiation reduces that risk down to 10% over the course of a lifetime."

Radiation trends
Newer, experimental techniques called partial breast radiation involve treating only the cancer site, not the entire breast. Research on patients who didn't get radiation treatment showed that 85% to 90% of cases of breast cancer recurrences happened near the location of the first tumor.

"Instead of giving the whole breast radiation and putting a patient through the extra toxicity, why not just give a whopping dose to that area?" asks Janice Kim, MD, a radiation oncologist at Fred Hutchinson Cancer Research Center in Seattle. If you get partial breast radiation, you'll probably get it twice a day for roughly a week—beating the usual schedule by about five weeks.

You may also be a candidate for MammoSite, in which the radiation is delivered over the course of several days via a small balloon attached to a thin tube inserted directly into the lumpectomy site.