Multicriteria Optimization in Brachytherapy

Brachytherapy treatments have increased in complexity over the years by integrating intensity modulation through both dwell-time and dwell-position. Multicatheter interstitial implants and a new generation of sophisticated applicators combined with interstitial needles have become commonplace in clinical practice. This has increased the demand for refined adaptive planning methods based either on real-time imaging (eg, ultrasound-based prostate high-dose-rate [HDR] brachytherapy) or daily imaging with image fusion, such as magnetic resonance imaging/computed tomography for gynecologic brachytherapy. Many modern brachytherapy treatment plans require finding the best possible dose distributions for clinical geometries involving 1 or more targets, sometimes with different levels of dose coverage, and multiple organs at risk (OARs) to protect using hundreds of possible source positions via dozens of possible channels.