It has been nearly eight years since the world’s first digital breast tomosynthesis (DBT) mammography technology was introduced to market to address the limitations of conventional 2-D imaging, and since then, there have been various technological advancements made to DBT. Today, more than half of certified facilities (4,500-plus) have DBT units, according to the U.S. Food and Drug Administration (FDA), officially making DBT the gold standard of care for breast screening. This progress speaks to the widespread positive impact that DBT has had, and continues to have, on both clinicians and patients. As October kicks off Breast Cancer Awareness Month, it’s most appropriate for the radiology industry to reflect upon the evolution of DBT since its inception, its many benefits and where it is headed in the future.
Past and Present
Like most technological advancements in healthcare, DBT was first developed to improve its predecessor, traditional 2-D mammography. Two-dimensional imaging, clinicians and medical device manufacturers noticed, had limitations because overlapping tissue in the breast may hide lesions or cause benign areas to appear suspicious. As a result, radiologists were sometimes overlooking some breast cancer diagnoses, and conversely, calling back patients for additional examination who were in fact cancer-free. Upon its introduction to the market, DBT was a major breakthrough because it allowed radiologists to look at thin, high-resolution image slices intended to provide clear renditions of structures in the breast and their spatial relationship with the surrounding breast tissue, thus giving radiologists a more accurate depiction of the breasts’ architecture. Over the years, various manufacturers have made DBT systems and subsequent upgrades to refine their precision, greatly expanding the market.
DBT has not only evolved from a technical perspective, but it has also made great strides when it comes to healthcare policies that give more women access to this technology. In January 2015, for example, Medicare announced it would completely cover DBT. Similarly, in January 2018, Texas implemented legislation mandating that all commercial insurers cover the cost of DBT mammography exams in the state. Today, more than 85 percent of women have access to DBT mammograms thanks to policy changes that occurred. These advances reinforce the idea that this technology has truly replaced 2-D mammography as the standard of care. Additionally, these policy changes reflect exactly just how critical DBT has become in the breast screening process since it came to market. The fact that legislators are so committed to giving women in their community access to this technology is a testament to how much evidence there is that DBT is not only effective, but superior technology for breast cancer screening.
The biggest benefit that DBT has demonstrated to date is its improved accuracy compared to 2-D mammography — a major value given that accuracy is the most crucial factor for early cancer detection. According to a 2014 study that was published in the Journal of the American Medical Association (JAMA), for example, there was a 41 percent increase in the detection of invasive breast cancers and a 29 percent increase in the detection of all breast cancers using DBT compared to traditional mammograms. Similarly, JAMA published a study in 2016 that determined, “Digital breast tomosynthesis screening outcomes are sustainable, with significant recall reduction, increasing cancer cases per recalled patients, and a decline in interval cancers.” Since then, DBT has further proven itself to be an advantageous breast screening tool, especially for women with dense breasts. This is a huge feat given that many women — more than 40 percent of women in the U.S. between the ages of ages 40 and 74 — have heterogeneously dense or extremely dense breasts, according to the American Cancer Society (ACS). Thus, not only has DBT evolved from being a new technology to a device that is clinically proven to be more accurate compared to 2-D mammography, but it has also grown to be a key imaging modality for the many women who have dense breasts. As a result, DBT’s credibility has continued to grow as studies reveal its critical value to breast cancer screening: Its incredible precision makes it a true life-saver.
As more clinical evidence continues to reveal DBT’s superiority, the existing facilities that only use traditional 2-D mammography will fall farther behind. Additionally, as more studies uncover the many factors that can contribute to breast cancer risks and affect screening outcomes, such as breast density, the way DBT is used and how it can be most effective for patients will continue to shift. No two patients are exactly alike, and as medicine as a whole further tailors to that idea so, too, will DBT. Until then, at a minimum, DBT’s trajectory to date has demonstrated that this technology plays an important role in breast cancer screening today and will continue to do so for years to come.
Tracy Accardi is global vice president of research and development, breast and skeletal solutions, at Hologic, Inc.