Innovative technologies in radiation therapy: brachytherapy.

Brachytherapy has changed dramatically in the last decade, with the widespread introduction of high-dose rate afterloading systems having greater flexibility of source loading patterns and smaller sources enabling new anatomic sites to be considered. This has been harnessed to the major developments in cross-sectional imaging and dosimetry planning systems to enable highly conformal radiotherapy to be delivered accurately and reliably by brachytherapy. There has been a major change in the distribution of sites treated, the majority being prostate, gynecologic, and breast treatments, whereas an emerging role as a simple but effective palliative treatment in bronchus, esophagus, and rectal cancers has also been recognized.