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Women may only need four weeks of radiation therapy following
a lumpectomy, according to the results of
a recent study. Radiation therapy is commonly administered to women with early-stage breast cancer
following a lumpectomy to help ensure that the any remaining cancer cells are
destroyed. Typically, women undergo six to seven weeks of radiation following a
lumpectomy. However, the new study suggests that limiting radiation therapy to four
weeks at a higher dose may be as effective as the traditional regimen and could reduce side effects.
Researchers at Fox Chase Cancer Center presented the results of their five-year study at the annual meeting
for the American Society for Radiation Oncology in November 2009. The study showed that treatment time
can be shortened from the historical six to seven weeks to just four weeks using
IMRT (intensity-modulated radiation therapy), a highly sophisticated system of delivering
external-beam radiation. According to a Fox Chase news release, this system uses advanced
computer optimized planning and radiation delivery techniques that create more optimal
dose distributions, greater sparing of the skin and lower doses to organs such as
lung and heart--thus reducing potential side effects.
When delivering high doses of radiation, we have to consider the level of side effects and
the cosmetic result," explained Gary Freedman, MD, radiation oncologist at Fox Chase, in
a news release. "In this phase II study, women reported acceptable side effects that
were no different than would be expected from a usual, more prolonged length of
treatment. In addition, with long term follow-up we see cure rates and cosmetic results
that are similar to a longer six-week treatment course."
In the study, researchers examined the effectiveness of delivering a higher daily dose of radiation over
four weeks, compared to a lower dose over six to seven weeks. According
to the researchers, another way of reducing treatment length was by incorporating
a "boost" into the same four weeks. The lumpectomy site where the tumor was
removed is usually treated with a high-dose radiation "boost." The standard "boost" is
typically administered after the five weeks of whole breast irradiation and can add
another one to two weeks to the treatment time.
The researchers found that the risk of a breast cancer recurrence was low for women in the study. The
study included 75 women treated with 2.25 Gy for 20 days (versus 2 Gy per day with conventional therapy) and a
2.8 Gy boost concurrently (versus sequentially delivering the boost after whole breast irradiation).
The risk of recurrence within five years in the treated breast was 1.4%, which the
researchers say compares favorably to results with conventional radiation. In addition, the
researchers report that patients and their physicians considered the cosmetic results good or excellent in most women.
"This more accelerated treatment regimen should be an option for women who want to be treated in
a shorter period of time," says Freedman, in a Fox Chase Center news release. "This may
particularly appeal to women who drive a long distance for radiation, have busy
schedules at home or work, or have a large insurance co-pay for each daily radiation treatment."
Freedman cautioned that this treatment schedule may not be for all women. "There may be
patients who are uncomfortable with the idea of an accelerated treatment and want
to be treated with a more conventional six to seven week course of treatment,"
he said in the news release. "In addition, we need more research to
determine which women are ideal candidates for this treatment because of
differences in anatomy or other treatments for their breast cancer."
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