Partial Breast Radiation to the Lumpectomy Cavity With IMRT in Elderly Women

The standard treatment for women with invasive breast cancer is local excision follow by
whole breast radiation. The local recurrence rates are low, side effects are low, and the
cosmetic outcome is excellent. The treatments, however, need to be given daily for 5 1/2 to
6 1/2 weeks, making the treatment difficult, particularly for the elderly and for women who
need to travel long distances for the therapy. The goal of this study is to determine the
toxicity and efficacy of giving the radiation in a shorter time, using higher daily doses of
radiation.

The risk of recurrence in the elderly population is lower, and since majority of recurrences
occur close to the area where the tumor previously was, it is hypothesized that radiation to
that area of the breast would be sufficient to obtain low risk of recurrence. When a smaller
volume of tissue is treated, more radiation can be given daily, and therefore the treatment
can be shortened. The risk of side effects increases as the dose per daily treatment
increases. Therefore, the goal is to study the short term side effects, long term side
effects, and cosmetic outcome of daily radiation using higher daily doses for shorter period
of time. We will also follow the recurrence rate. Because less of the breast tissue will be
treated, there may be a small increased risk of recurrence. Because the higher fraction size
can result in more side effects we will be using intensity modulated radiation (IMRT). IMRT
is the most advanced individually tailored radiation treatment technique that results in the
least amount of side effects. It allows tight monitoring of the dose in the untreated
breast.

Seventy five women diagnosed with stage I breast cancer will participate. Participants must
have a lumpectomy, clear margins and no lymphovascular invasion to be eligible. A treatment
planning CT scan will be obtained. If the lumpectomy cavity can be clearly delineated, an
IMRT plan will be generated with predefined strict dose requirement criteria. The patients
will be treated once daily, 5 days a week, for a total of 10 treatments (instead of standard
28-33). The patients will be evaluated for toxicity weekly during the treatment, and weekly
for additional 4 weeks. At each of these evaluations, they will fill out a short 10 minute
questionnaire detailing their side effects. Follow-up will continue every 3 months for 3
years, and every 6 months for 2 more years. At each of these follow-ups a short
questionnaire will be filled out by the patients detailing any toxicity, as well as their
perception of the cosmetic outcome. A cosmesis questionnaire will be also be filled out by
the evaluating physician before radiation, at 6, 12, 18, and 24 months, and yearly for 3
more years. A total of 5 years of follow-up is planned. Participants will also have the
option of consenting to the photograph portion of the study. Those who do will have
photographs taken of their breasts (excluding faces) at the time they complete the cosmetic
questionnaire, to evaluate the cosmetic outcome.