The MammoSite breast brachytherapy device: targeted delivery of breast brachytherapy.

The MammoSite breast brachytherapy device was designed to overcome the logistic difficulties presented by external beam radiation therapy and the technical difficulties of multicatheter-based interstitial brachytherapy. The device consists of a silicone balloon connected to a catheter which contains an inflation channel and a port for passage of a high-dose-rate brachytherapy source. The American Brachytherapy Society and American Society of Breast Surgeons have published partial breast irradiation patient selection guidelines. Initial reports have shown a favorable cosmetic outcome in the majority of patients. The MammoSite applicator has also been associated with minimal side effects. The NSABP B-39/RTOG 0413 trial will randomize patients to either whole breast irradiation or partial-breast irradiation consisting of interstitial brachytherapy, MammoSite brachytherapy, or 3D conformal radiation. This national randomized trial has the potential to provide a definitive answer regarding the benefits of partial-breast irradiation, and therefore lead to more women undergoing breast conserving therapy.