Implementation and utilization of hypofractionation for breast cancer

Hypofractionation (HF) of whole breast irradiation has become a standard treatment regimen because randomized trials continue to demonstrate equivalence in survival and local control compared with conventional fractionation. In 2011, the American Society for Radiation Oncology (ASTRO) adopted clinical guidelines on the proper selection of HF. Nevertheless, utilization remains lower than predicted. We evaluate the effects of clinical directives that serve as default treatment decisions and prospective contouring rounds on the implementation of HF in a large, multicenter radiation oncology department