Radiation dose and risk in screening mammography.

Screening mammography has not yet become a standard procedure. There are great variations in image quality and radiation dose. Mean glandular dose has become the most frequently used description of radiation dose in screening mammography. Because of the low energy x-ray beam required for the procedure, the use of mean glandular dose as the radiation exposure indicator may cause a misunderstanding of the dose-risk relationship and result in confusion about radiation exposure and the risk of induced neoplasm. Data are presented to show that increases in both maximum glandular dose and imparted energy are greater than the increases in mean glandular dose with comparable increases in breast thickness. In the future, an indication of total imparted energy should replace the use of mean glandular dose as the standard for describing radiation dose in screening mammography.