MammoSite therapy uses a small, soft balloon attached to a thin catheter (tube). This balloon in placed inside the lumpectomy cavity. To deliver the required therapy, a tiny radioactive seed is placed within the balloon by a computer-controlled machine.
During 10 treatments over 5 days, the seed is placed in the balloon and therapeutic radiation is delivered to the area surrounding the lumpectomy cavity. After each treatment, the seed is removed, but the balloon catheter remains for the next treatment.
After 5 days of treatment, the balloon catheter is removed, and the area is closed with a small bandage. Most women say that they feel little or no discomfort either during the treatment or when the device is removed.