HYPOFRACTIONATION – WHAT IT IS AND IS IT BENEFICIAL?

ASTRO statement suggests shorter courses of treatment were effective in older women with early stage, low risk breast cancer.

Since 2013, a new radiation therapy option for some breast cancer patients has been available - it is called hypofractionation. Conventional fractionation has been defined as a dose of 180-200 rads a day to a total dose of around 6000 rads. Therefore it usually took about 6 weeks to deliver whole breast treatment. Hypofractionation is a regimen where fewer, higher dose treatments are given looking for the same biological effect. We have known since the early 1900s that side effects of radiation were related to not only total dose but the size of the daily dose - and long experience suggested that 180-200 rads per day seemed to be the safest when it came to balancing best outcomes with the fewest late complications - that is why it became the standard or conventional fractionation scheme. However many of our assumptions about radiation were based on animal studies and equipment that would no longer be appropriate in the modern era. Starting in the 1980s countries like Canada and Great Britain began looking at shorter courses of radiation. Initially these countries needed to treat patients faster because they had fewer treatment centers and shorter courses decreased the length of waiting lists at those centers. However these centers soon realized that their patients were doing just as well as those treated in the US with longer courses. They had the same chance of being cured of their cancer, and no worse risk of late side effects with the shorter, higher dose courses. Instead of 6-6.5 weeks, these patients were getting treatment done in as little as 4 weeks. There were no research studies done in the US however on this method of treatment until the early 2000s. Ultimately these studies predicted the same results as the Canadians and Europeans had seen. In Dec 2011, ASTRO (American Society for Radiation Oncology) published a consensus statement on the use of hypofractionation in breast cancer, suggesting that shorter courses of treatment were effective in older women with early stage, low risk breast cancer. This recommendation really took off in Sept 2013 when the first five Choosing Wisely guidelines for Radiation Oncology were published. Choosing Wisely is a national initiative (www.choosingwisely.org) that encourages patients and physicians to look at tests and treatments that were being done that either did not benefit patients or were felt to be unnecessary or not cost effective. In that first set of guidelines was a recommendation on hypofractionation in breast cancer. ASTRO recommended that women over 50 years old who had early stage breast cancer be offered shorter course treatment - what we call hypofractionation. Since then, the number of women in the US getting hypofractionation has been increasing every year. So - who should get hypofractionation? Right now the recommendations based on the Dec 2011 paper are as follows - women 50 years and older with invasive breast cancer who have small low grade breast cancers, negative lymph nodes and no indications for chemotherapy may be considered for shorter courses. Some women should not get hypofractionation. Younger women, women with high grade cancers, women with positive lymph nodes, women who need chemotherapy, or women with DCIS are not considered candidates for hypofractionation, although women with DCIS (in situ cancers) might be candidates for short course treatment - the panel felt they did not have enough data to make a recommendation for DCIS either way although since that time more research may suggest that women with DCIS are OK for hypofractionation. Also women with diseases like lupus or rheumatoid arthritis may not be good candidates for hypofractionation because they already are at increased risk for late side effects from radiation. Hypofractionation is now being offered at the Covenant Cancer Treatment Center in Radiation Oncology and many of our patients are benefitting from the shorter course of therapy. Although not all women should get hypofractionation, if it is offered, it is because we feel it is safe and effective therapy for our patients.