ASTRO Releases Guidelines for Hypofractionated Whole Breast Radiation Therapy

ASTRO released guidelines last week that define appropriate fractionation of whole breast irradiation (WBI) based on a finding that hypofractionated (HF) WBI is an effective treatment for many patients with early-stage breast cancer.

The ASTRO Health Services Research Committee published guidelines on HF-WBI in the Aug. 4, 2010, issue of the International Journal of Radiation Oncology•Biology•Physics after determining that breast conserving surgery followed by WBI lowers the risk of tumor recurrence and improves survival, according to an ASTRO press release.

“Most studies used conventionally fractionated (CF) radiation, which involves daily treatments for up to seven weeks,” ASTRO stated. “Despite its effectiveness, conventional fractionation has some drawbacks, including the inconvenience associated with undergoing treatment for a long period of time and the total costs.”

Those costs include direct health care expenditures and opportunity costs to the patient from being away from home and work. The higher dose used in HF-WBI for each treatment results in fewer total treatments, with patients typically finishing radiation in four weeks or less.

In assessing trials on HF-WBI, the ASTRO Health Services Research Committee found little difference in the local control and survival outcomes for selected patients treated with either CF-WBI or HF-WBI.

The task force answered the following questions in drafting the guidelines:

1. Which patients obtain equivalent results from HF-WBI and CF-WBI?

2. What is the role of a tumor-bed radiation boost in patients treated with HF-WBI?

3. What are appropriate regimens for HF-WBI and tumor-bed boost?

4. What are the characteristics of an acceptable radiotherapy plan for patients treated with HF-WBI?

5. What insights relevant to the radiobiology of breast cancer can be gained from recently published clinical trials comparing CF-WBI with HF-WBI?