Effect of Mammographic Screening Modality on Breast Density Assessment: Digital Mammography versus Digital Breast Tomosynthesis

Abstract

ammographic breast density reflects the relative amounts of fat versus fibroglandular tissues in the breast (1) and is an established risk factor for breast cancer (2). Women with the highest level of breast density have four to six times the risk for breast cancer compared with women with the lowest levels of density (3), and high density is associated with larger and more aggressive tumors (4). Moreover, breast density can affect the sensitivity of mammography because of masking of tumors (5). As of December 2018, over 70% of states in the United States passed legislation mandating that women be notified of their breast density. In some states, women with high breast density are advised to both discuss the implication of their density with their health care provider and consider supplemental screening methods (6). The most commonly used breast density assessment is the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) (1). The BI-RADS system includes four categories of breast density (a, almost entirely fatty; b, scattered areas of fibroglandular density; c, hetereogeneously dense; and, d, extremely dense). According to most state notification laws, women assigned the latter two breast density categories are considered to have dense breasts whereas the first two density categories are considered nondense. In many states, having dense breast parenchyma prompts supplemental screening, most often with breast US. Studies show a strong relationship of high BI-RADS breast density categories to cancer risk (2), risk of masking (5), and high-risk benign breast disease (7).

Comparison of breast density assessment between human eye and automated software on digital and synthetic mammography: Impact on breast cancer risk

“…12.9% of the patients in our study who were rated as having dense breast by DM were rated as having non-dense breast on SM. This result is in line with other authors who reported that density differed from one imaging modality to another, with more breasts classified as non-dense on SM [20,52,53]. In this most recent study, 26% of the patients rated as having dense breast on DM were rated as having non-dense breast on SM [20].…”

“…In addition, the development of synthetic mammography (SM) from digital breast tomosynthesis adds another factor of variability with fewer cases of dense breast detected on SM than on digital mammography (DM) [20,21].…”

Accuracy in tumor size measurements: Comparison of digital mammography, digital breast tomosynthesis and synthetic mammography

“…In the current study we found that correlation analyses were quite similar for dense and non-dense breasts with all mammographic imaging techniques. Therefore, our findings are in line with the results of Khalayleh et al It has been reported that breast density assignments may vary with mammographic imaging technique and there is a trend of downgrading breast density when DM is replaced with SM [22]. Therefore, since we assigned breast densities based on DM, the impact of breast density on tumor size measurements could potentially be different if breast densities were assigned with SM.…”

Average glandular dose in paired digital mammography and digital breast tomosynthesis acquisitions in a population based screening program: effects of measuring breast density, air kerma and beam quality

“…Potential changes of the BI-RADS density classification using BDT has been investigated in several studies, with conflicting results. Three large screening studies (including 24.756, 78.810 and 15.571 women) showed that women screened using DBT had a lower likelihood of being classified with dense breasts compared to those screened with DM alone (208,209), with even lower likelihood was found for women screened using DBT and synthetic mammograms, compared to those screened using DBT and DM (208)(209)(210). A smaller reader study comparing DBT and DM density assessment found similar results (211).…”