Radiobiological rationale and clinical implications of hypofractionated radiation therapy

Recent clinical trials of hypofractionated radiation treatment have provided critical insights into the safety and efficacy of hypofractionation. However, there remains much controversy in the field, both at the level of clinical practice and in our understanding of the underlying radiobiological mechanisms. In this article, we review the clinical literature on hypofractionated radiation treatment for breast, prostate, and other malignancies. We highlight several ongoing clinical trials that compare outcomes of a hypofractionated approach versus those obtained with a conventional approach. Lastly, we outline some of the preclinical and clinical evidence that argue in favor of differential radiobiological mechanisms underlying hypofractionated radiation treatment. Emerging data from the ongoing studies will help to better define and guide the rational use of hypofractionation in future years.