There are several types of APBI. At Stanford, we focus on two types: Intraoperative Radiotherapy (IORT) and external beam 3-dimensional conformal radiotherapy (3D-CRT). APBI using IORT is done during surgery at the time of the lumpectomy procedure. Radiation is delivered directly to the area where the tumor was removed, using a specialized radiation machine in the operating room. No further radiation is needed. External Beam 3D-CRT APBI is delivered after surgery using the same machine as we use for whole breast radiation, but instead targets the tissue around where the tumor was removed. This treatment is given twice a day for five days.