Both MammoSite and Contura are catheter balloon devices for partial breast intracavity brachytherapy, a type of accelerated partial breast radiation treatment after the tumor has been removed with a lumpectomy for early-stage breast cancer. A balloon with catheters is surgically inserted into the lumpectomy cavity and inflated to create space between the radioactive sources and the lumpectomy cavity so that tumocidal radiation dose can be delivered to the residual cancer cells while sparing surrounding normal tissues. The treatment typically lasts for 5 days with 1-2 treatments a day. Since the radiation dose is focused on lumpectomy cavity, this procedure has fewer side effects than the standard six or seven week course of external beam radiation. MammoSite uses a single-lumen balloon catheter radiation while Contura is a multi-lumen balloon device, which usually has better skin sparing but requires a thicker catheter. The breast surgeon and radiation oncologist will work together to decide which device is best for the patient.