Modern brachytherapy.

Brachytherapy consists of placing radioactive sources within, or directly adjacent to a tumor, and is a means of delivering highly targeted and conformal radiation. While its history dates back to the origins of the field, in recent years brachytherapy treatment paradigms have been evolving considerably. This has been driven primarily by advancements in imaging, which allow for precise placement of sources and applicators under image guidance, and volume-based optimization to ensure adequate tumor coverage while sparing adjacent normal tissue. There has been a shift towards high-dose-rate (HDR) brachytherapy for many of the disease sites treated with brachytherapy. Simultaneously, with increasingly conformal treatment, there has been a shift towards utilization of higher doses per fraction, over fewer fractions, for specific disease sites where hypofractionation is believed to confer a radiobiological benefit. Here we review recent data and trends for those disease sites and conditions that are commonly treated with brachytherapy, including prostate, gynecologic, breast, head and neck, and skin cancers and salvage of recurrent disease.