Digital mammography does not appear provide improvements over traditional film X-rays in the ability to detect cases of breast cancer.
The technology does, however, offer other benefits, including slightly lower radiation doses for patients, that may prompt its increasing use despite its much higher costs.
In digital mammography the pictures are stored directly in a computer system, where they can be enhanced, magnified or shared.
The digital devices were first approved for marketing in the United States in 2000.
Three large trials of the technology have been completed, with several thousand women receiving digital mammograms in each.
No statistically significant differences in detection rates were observed between the x-ray and the new digital technology. The patients in each group experienced identical positioning and compression of the breast.
A new large clinical trial sponsored by the National Cancer Institute has been completed.
Nearly 50,000 women in the United States and Canada received both types of mammograms and were asked to return one year later for follow-up exams to determine whether digital mammography detects breast cancer more accurately than X-rays.
Digital mammography systems cost at least three times as much as film systems. In addition to reducing radiation, they can also facilitate the use of computer-aided detection systems and can be easily transmitted for second opinions, according to the report.
" Many health care professionals predict that screen-film mammography will eventually be replaced by full-field digital mammography once it is proven that the image quality and diagnostic accuracy of both technologies are at least equivalent," says the ECRI report.
ECRI is a nonprofit health services research agency that produces systematic evidence reviews on medical devices, drugs, biotechnologies, procedures, and behavioral health services.
According to ECRI, the current body of evidence that suggests that digital mammography may be able to reduce recall rates, and possibly necessary follow-up procedures, which could offset some of its higher initial costs. But more evidence is needed to confirm these potential benefits.
Breast cancer is the most common malignancy in women and the third most frequent cancer throughout the world. More than 1 million new cases were diagnosed worldwide in 2002, and incidence rates are increasing at about 5 percent a year.
Source: Center for the Advancement of Health, 2005