Q: What is partial breast irradiation and what are its advantages in the treatment of breast cancer?

A: Partial breast irradiation (PBI) is a newer form of breast radiation treatment for women who have early stage breast cancer and have chosen lumpectomy (removal of the tumor only) as their primary surgical approach. PBI treats only the area where the tumor was removed from the breast and not the entire breast. This technique spares much of the normal tissue of the body including the unaffected breast itself, the lungs and, many times, the heart. The techniques used are quite complex and should only be performed in a facility that is not only technically capable, but also has doctors with significant experience in this type of treatment. By using partial breast irradiation, doctors are able to avoid potential side effects such as severe skin reaction during treatment and the more important long-term side effects of scar tissue formation in the heart, lungs and other organs. A number of preliminary clinical trials have shown that PBI may be as effective as whole breast irradiation, but more proof is needed. A large, national clinical trial based here is ongoing and the results may prove that PBI is as effective as treatment of the whole breast. Before choosing such treatments women should speak to their radiation oncologist to find out more of the details of this exciting and innovative treatment.

Have a brief question? Write to "Dear Doctor," Allegheny County Medical Society, 713 Ridge Avenue, Pittsburgh, PA 15212 or e-mail acms@acms.org. Individual responses will not be provided. This column acts as an overview; see your physician for diagnosis.