Five years ago, a nationwide breast cancer screening project using mammography was interrupted by a radiation scare. A handful of committees reviewed the project—an American Cancer Society (ACS) and National Cancer Institute-sponsored effort to pick up early, undetected cancers in women aged 35 to 74 years—and recommended against routine mammography for asymptomatic women younger than 50 years. The benefits of screening younger women do not outweigh the risks of causing a few additional breast cancers, the experts said.
Since then, improvements in technology have cut the radiation dose in half—to less than 1 rad for a two-view study of the breast. Nevertheless, a lingering concern about radiation risk among some physicians and patients appears to be partially responsible for a boom in sales of breast ultrasound scanners after just a few years on the market. Although fewer than 100 are in place in the United States, the number is expected