Partial Breast Irradiation
Accelerated partial breast irradiation, or APBI, is a treatment option for some women with early stage breast cancer. It is a technique used to deliver focused radiation to the area of the lumpectomy. This is typically done using radioactive seeds directly to the lumpectomy area with a catheter (brachytherapy) and is done with twice daily treatments for 1 week. It can also be done without a catheter, with external beam radiation with photon or proton therapy.
APBI, when done with a catheter, is performed about one to four weeks after a lumpectomy. A specialized catheter is inserted into the lumpectomy area by the breast surgeon at the time of surgery. Part of the catheter will remain outside the breast so that it can be connected to deliver radiation. Using computer-guided imaging, your radiation oncologist will carefully plan the radiation treatment specifically for you. The catheter is connected to a machine that delivers radiation through a seed for 5-10 minutes. Then the seed is removed, the catheter is disconnected, and you can go about your normal routine. The catheter is not radioactive and there are no restrictions to being around others. The catheter remains in place during the course of radiation treatments. The process is repeated twice daily (about 6 hours apart) for 10 total treatments. The catheter is then removed in the office and a small dressing is placed.
When compared with standard radiation treatment, APBI can offer significant benefits in some patients. At less than a week, the treatment is far shorter than external beam radiation, which usually lasts four to six weeks. In addition, the radiation dose is concentrated on tissue surrounding the lumpectomy cavity. This can spare normal tissue and critical organs such as the heart and lungs from unnecessary radiation.