ROCKVILLE, MarylandThe FDA has approved the MammoSite Radiation Therapy System (Proxima Therapeutics, Alpharetta, Georgia), to deliver adjuvant radiation therapy after breast-conserving surgery for patients with early-stage disease. The device is designed to irradiate the surgical site with minimal exposure to surrounding tissue. It consists of a hollow catheter, to which an inflatable balloon is attached. After surgery, the device is implanted, the balloon inflated, and a radiation source is placed in the catheter. The balloon centers the radiation source at the wound site. After a series of treatments, generally extending over several days, the catheter is withdrawn.
FDA approval was based on data from 25 women treated at eight centers. The FDA required Proxima to include a warning in its labeling that clinical trials have not proven MammoSite to be safe and effective as a replacement for whole breast irradiation in women undergoing mammography.