Two Greater Des Moines medical practices are now using technology that has been shown to improve the rate of breast cancer detection in many women.

Since February, Iowa Radiology and The Iowa Clinic P.C. have installed digital mammography machines. Although the technology has been available for a few years, it started getting more attention last fall after The New England Journal of Medicine published the results of a study by the National Cancer Institute comparing digital and film mammography.

The NCI study compiled results from nearly 50,000 women with no symptoms of breast cancer who had both digital and film mammograms on the same day. The digital process proved to be 15 percent more accurate than film in detecting breast cancer in women in three categories: those under 50 years of age, those who have very dense breast tissue and those who are pre-menopausal.

“The digital mammography machines have been on the market for a little while, but the cost has been a limiting factor for a long time,” said Dr. Jill Westercamp, the director of breast imaging at Iowa Radiology. “But when The [New England] Journal of Medicine came out with the study, we decided that now was the time to invest in the technology because it offers a significant advantage for women.”

Both digital and film mammography use X-rays to capture images of a woman’s breast. In film mammography, which has been used for more than 35 years, a receptor on the machine takes a picture of the breast and that image is transferred to film. In digital mammography, the machine records an image and sends it directly to a computer. The digital process eliminates the loss of resolution or quality that occurs when converting the image to film.

According to the NCI, fewer than 10 percent of all U.S. breast imaging centers offer digital mammography, but Westercamp expects that number to climb in response to the NCI study. “This is a really hot topic right now,” she said.

In early February, The Iowa Clinic started using its new digital mammography machines at its West Des Moines office and one of its offices downtown. Those offices have two machines, which were manufactured by General Electric Co. Dr. Gary Haynes, an Iowa Clinic radiologist, says the recent study about the benefits of digital mammography also prompted the clinic to order them.

West Des Moines-based Iowa Radiology purchased three Lorad digital mammography machines for $1.5 million. The machines were installed the third week of February, and following staff training, they were put into use at the beginning of last month.

Westercamp and Haynes said their practices plan to switch all mammogram examinations over to digital.

“We don’t want to tell some women that they can’t have access to the newest technology,” Westercamp said.

The University of Iowa Hospitals and Clinics in Iowa City and Buena Vista Regional Medical Center in Storm Lake had the technology before it became available in Greater Des Moines this year.

Westercamp and Haynes say the digital machines have several advantages over the older film-based systems, the main one being better penetration of dense breast tissue. About 40 percent of women have dense breast tissue, according to the National Cancer Institute.

“The problem with film mammography is that when women have very dense breast tissue, it’s very difficult for the X-ray beam to penetrate through the tissue, so we have a difficult time seeing what might be hiding in the dense tissue,” Haynes said.

Because the image of the breast is stored digitally, doctors can manipulate the image on a computer to focus on areas that look suspicious, Haynes said. “We can use electronic zooming tools to better look at calcifications and various subtle changes in the tissue,” he said. “It’s nice to actually be able to manipulate the image, as opposed to the old film screen, where you can only look at it on the light box.”

Also, because images are stored electronically, it eliminates the problem of lost X-ray films, and doctors can share the images more easily with each other over e-mail to get second opinions.

From the patients’ perspective, the digital mammography examination is similar to a traditional mammogram in how the breast is compressed and positioned in the machine, but one difference they will notice is that the whole process takes less time with the digital technology, Westercamp said.

“The technologist can see the images right away to say they look good from a technical standpoint,” she said. “We now know the quality of the image instantly, whereas with the film version, the technologist has to leave the patient to go develop the films, which takes about 10 minutes.”

One difference with the digital process that won’t be apparent to patients is that it uses less radiation than film mammography, Westercamp said. In order to capture images of dense breast tissue on film, a higher amount of radiation was needed to penetrate the breast tissue.

Breast cancer is the most common non-skin cancer and the second leading cause of cancer-related death in the United States. But death rates from breast cancer have been declining since the 1990s, which is attributed to earlier detection and improved treatment. Westercamp expects digital mammography to be another step forward in cancer detection that will save more lives.

“The technology for mammograms has been getting better and better over the past 40 years, which has helped decrease the mortality rate for breast cancer,” Westercamp said. “The goal is to be able to find these cancers earlier. Digital technology will hopefully help us get past some of the limitations of film mammography.”