City of Hope’s digital mammography systems may not herald an end to the threat of breast cancer, but for certain women, they just may be able to detect breast tumors a little bit easier.
That means that physicians might find more cancers when they are at an earlier, more treatable stage — and women may gain some much-needed peace of mind.
City of Hope has replaced its previous film-based systems with two Hologic Selenia full-field digital mammography systems. Radiologists now provide screening and diagnostic mammography using the systems at the Rita Cooper Finkel and J. William Finkel Women’s Health Center.
“When they’re getting their mammograms, women won’t experience anything different from their previous screenings. It uses the same X-ray process and breast compression. But digital mammography allows us to adjust what we see on the screen and enhance the image,” said radiologist Sally Shaw, M.D., chief of the Breast Imaging Section in the Division of Diagnostic Radiology.
In traditional film mammography, X-rays pass through breast tissue and create images on photographic film. In digital mammography, computer hardware replaces film and converts the X-rays into electrical signals, which then immediately transform into an image on a computer monitor — without waiting for film processing.
But high-tech equipment offers little benefit unless it translates into real results for patients. For certain women, Shaw noted, research shows that digital mammography does.
Early studies comparing digital and film mammography showed them to be equivalent in finding breast cancer. However, a large, multi-institutional study published in 2005 in the
New England Journal of Medicine — the Digital Mammographic Imaging Screening Trial — found that while overall digital and film mammography were equivalent, digital mammography offered superior detection in certain, selected groups of women.
Digital systems uncovered cancer better than traditional film mammography in these groups: women with dense breast tissue, women in their 40s and those just going through menopause. “Women who fall into these groups may want to seek it out,” Shaw said.
City of Hope radiologists also will use a computer-aided detection system to perform a second reading of mammography images. The system points out potentially suspicious areas, especially areas of calcification, allowing radiologists to focus and examine such areas even more closely to rule out cancer.
Digital mammography will enable physicians to quickly share images electronically with other experts throughout City of Hope, even across the campus. It also allows staff to easily store and retrieve year-to-year mammograms, eliminating the risk of misplaced films.
Radiology researchers continually look for ways to make X-ray technology even more effective for breast cancer detection, Shaw said. Breast tomosynthesis, for example, is on the horizon. This method uses X-rays to create images of thin slices of the breast, creating a three-dimensional view of tissues and helping radiologists look at breast tissue that might otherwise be obscured.
Researchers also are investigating whether injecting a contrast agent during mammography may boost mammography’s ability to spotlight cancers; and an up-and-coming strategy called dual-energy subtraction might help unveil otherwise obscured lesions, as well. Digital mammography provides a platform for such advances.
Medical advances offer no benefits if patients do not use them, though. Mammography’s benefit in saving lives has been proven regardless of whether images are viewed on film or on the computer. As Shaw urged, “The most important thing is to get your mammogram regularly.”
Best care for the breast
The American Cancer Society offers these guidelines for screening mammograms in women:
|20-39||Have a clinical breast exam by a health-care professional every three years.|
|40 and older|
|Have a clinical breast examination by a health-care professional every year.|
Have a screening mammogram every year.
Women also should talk to their doctors about the value of regular breast self-exam and report any changes in the breasts immediately. Screening recommendations also may differ for women with a family history of breast cancer, so health-care professionals encourage women to discuss the recommendations with their physicians.