Two Breast Cancer Radiotherapies Similar

Whole breast irradiation, or WBI, and 3-D conformal partial breast irradiation, or PBI, have risks and benefits that may be equivalent, a U.S. study says.

Lead investigator Dr. Laura Vallow of the Mayo Clinic Jacksonville and colleagues analyzed radiation plans for 25 patients enrolled in a clinical trial and calculated what radiation to the lung would be if WBI or PBI was used. PBI uses radiation to a small sector of the breast through multiple beams over a period of days, but the radiation can pass through the breast to the heart and lungs. WBI radiates the entire breast over week, but can expose much of the heart and lungs to long periods of lower dose radiation, Vallow said.

For 14 of the same patients who had a lumpectomy in their left breast, the study investigators calculated radiation to normal heart tissue. They found PBI and WBI delivered about the same amount of radiation to the heart of patients whose tumor was located in the middle of the breast, but for breast tumors closer to the armpit, PBI did not affect normal heart tissue, Vallow said.

The findings were presented at the annual meeting of the American Society for Therapeutic Radiation and Oncology in Los Angeles.