Role of high dose rate brachytherapy in the treatment of prostate cancer.

High dose rate (HDR) brachytherapy in intermediate and high-risk prostate cancer patients has started in the late eighties in Europe and the United States, as a boost combined with external beam radiation therapy, as an attractive method for dose escalation. The results of the first dose-escalation study performed at William Beaumont Hospital has established the safety and efficacy of this combined treatment approach. Likewise, this landmark study enabled a paradigm shift in the radiobiology of prostate cancer, demonstrating that the alpha/beta of prostate cancer was much lower than previously believed to be and therefore the sensitivity of this tumor model to higher-than-conventional doses per fraction led to a dramatic increase of hypofractionated treatment regimens, the object of significant clinical research efforts, currently under way. The excellent toxicity profile and clinical outcome of HDR boost combined treatment prompted investigators to expand HDR brachytherapy indications to low/intermediate prostate cancer patients as the sole treatment modality. The results, toxicity and a brief review of the literature for both HDR boost and HDR monotherapy will be presented.