Increasing Radiation Dose Reduces Treatment Time for Women who Choose Breast-Sparing Treatment

This conclusion by researchers from Fox Chase Cancer Center (Philadelphia, PA, USA) is good news for women who might opt to have a mastectomy instead of a lumpectomy because of the time commitment needed for the usual six-week radiation course with the breast-sparing surgical option.

The curative outcome for early-stage breast cancer is the same whether a woman chooses to have a lumpectomy or mastectomy (the removal of the entire breast). Many factors influence a woman's decision when considering the two alternatives. One of these factors is the time commitment for the recommended radiation course that follows a lumpectomy. Radiation significantly reduces the chance that cancer will recur in the affected breast, but the usual time commitment--five days a week for six or seven weeks--can be a barrier for choosing this treatment option.

In the first known study of its kind, physicians at Fox Chase demonstrated that treatment time can be shortened from six to four weeks using IMRT (intensity-modulated radiation therapy), a highly sophisticated system of delivering external-beam radiation that allows for more even dose distribution and accuracy as well as lower doses to organs such as lung and heart, thus reducing side effects.

Using IMRT, this study evaluated the delivery of a higher daily dose of radiation over four weeks (versus a lower dose over six to seven weeks). During that same time period, the lumpectomy site where the tumor was removed was treated with a high-dose radiation "boost.” The conventional boost is usually administered after the four to five weeks of whole breast irradiation and adds another one to two weeks to the treatment time.

Fox Chase radiation oncologist Gary Freedman, M.D., and his colleagues demonstrated that in addition to safely increasing the dose to the whole breast during the four-week period, it is possible to deliver the boost concurrently, eliminating the extra two weeks.

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 primary endpoint was acute skin toxicity. At the end of treatment, none of the women had grade III or IV skin toxicity or dermatitis (skin inflammation). Twelve percent had grade 0, 65% had grade I, and 23% had grade II dermatitis. All toxicity had resolved within six weeks after treatment.

Dr. Freedman concluded by recommending a longer follow-up to compare the outcomes five years after treatment. The study was published in the June 1, 2007, International Journal of Radiation Oncology Biology Physics.


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Fox Chase Cancer Center