All forms of accelerated, partial breast irradiation (APBI) deliver radiation within a five day period to a  focused part of the breast.

Intraoperative radiotherapy (IORT) delivers a single dose of radiation to the breast tissue around the lumpectomy cavity during surgery. With this approach, a lead plate is placed beneath the breast tissue to protect the underlying muscle, ribs, heart, and lung, while the skin is moved out of the way of the radiation beam. No additional treatments are given after surgery.

Intracavitary radiotherapy is delivered via a balloon catheter (MammoSite (TM) that is placed in the lumpectomy cavity. The balloon catheter is placed either at the time of surgery under direct vision or after surgery using ultrasound guidance. Radiation is delivered on an outpatient basis twice a day for five days by placing a radioactive seed temporarily into the catheter.  The catheter is removed in the office after the last treatment.

Accelerated, external beam radiotherapy is delivered in the radiation oncology department on an outpatient basis. This treatment is given twice a day over 5 days.

One of the goals of the Stanford trial is to try to match each patient with the accerated radiation technique that appears to be the best for that patient.