Synthesized Mammography: The New Standard of Care When Screening for Breast Cancer with Digital Breast Tomosynthesis?

doi:10.1016/j.acra.2017.12.015

Academic Radiology

Volume 25, Issue 8, August 2018, Pages 973-976

https://doi.org/10.1016/j.acra.2017.12.015 Get rights and content

Rationale and Objectives

This study aims to evaluate the screening performance of digital breast tomosynthesis (DBT) combined with synthesized mammography (SM) vs combined with full-field digital mammography (FFDM).

Materials and Methods

We retrospectively reviewed all screening studies utilizing FFDM + DBT (n = 7845) and SM + DBT (n = 14,776) between April 1, 2013, and February 15, 2016. Recall rate, biopsy rate, positive predictive value 1 (PPV1), positive predictive value 3 (PPV3), and cancer detection rate (CDR) were compared between the two groups. A generalized linear mixed model specifying the reading radiologist as the random effect and controlling for age was used to compare clinical outcomes between the two groups.

Results

The overall recall rate was significantly lower in the SM + DBT cohort compared to the FFDM + DBT cohort (7.06% vs 7.63%, P = .04). There was no difference in biopsy rate, PPV1, PPV3, or CDR between the two groups.

Conclusions

When DBT is performed for screening, the use of SM rather than acquiring an additional FFDM has no significant effect on biopsy rate, PPV1, PPV3, or CDR. We found a decrease in recall rate in the SM + DBT group, which may be related to the learning curve of interpreting DBT. These findings support the use of SM for patients undergoing screening with DBT.

Introduction

Digital breast tomosynthesis (DBT) is a relatively recent advancement in breast imaging that decreases recall rate and improves invasive cancer detection rate (CDR) 1, 2, 3, 4, 5, 6. The US Food and Drug Administration (FDA) initially approved DBT as a screening adjunct to be used in combination with standard full-field digital mammography (FFDM). The primary reasons that DBT was only approved in combination with FFDM were that some findings, such as microcalcifications, are thought to not be well visualized on DBT 7, 8, and the standard FFDM examination allows easier comparison to previous examinations.

The disadvantage of combination FFDM and DBT is an approximate twofold increase in radiation dose (9), although the total dose still falls within radiation dose limits set forth by the Mammographic Quality and Standards Act (3 mGy). Concerns regarding increased radiation dose led to the advancement of synthesized two-dimensional mammography (SM). SM is a technique that generates two-dimensional images from the DBT dataset, eliminating the need for a separately acquired FFDM examination and thereby decreasing the radiation dose to the patient (10). The FDA approved replacing FFDM with a specific SM technique (Selenia Dimensions 3D System with C-View Software Module, sponsored by Hologic, Inc., Marlborough, MA) for screening mammography in May 2013.

There have been limited studies comparing SM + DBT to FFDM + DBT. In 2009, one small study using a first version of SM + DBT demonstrated lower sensitivity and similar specificity compared to FFDM + DBT (11). Since then, a few reader studies and prospective studies have shown overall comparable results between the two techniques 12, 13, 14. For example, in 2014, Zuley et al. published a retrospective observer performance study of 123 cases concluding that SM was comparable in performance to FFDM. Recently, the first study was published evaluating implementation of SM + DBT in a screening population compared to historic screening outcomes of FFDM + DBT (15). Results showed decreased recall rate and radiation dose in the SM + DBT group while maintaining CDR. The purpose of this study was to further validate the use of SM in women being screened with DBT by comparing the performance metrics of SM + DBT to FFDM + DBT in screening asymptomatic women at a large multisite academic center.

Section snippets

Materials and Methods

This was an Health Insurance Portability and Accountability Act compliant, institutional review board approved study with a waiver of informed consent. We retrospectively evaluated outcome metrics of two cohorts of patients undergoing breast cancer screening with DBT at multiple sites of a single institution. The first cohort included patients screened with DBT and FFDM from April 1, 2013, to February 14, 2015 (n = 7845) and the second included patients screened with DBT and SM from February

Results

A total of 7845 asymptomatic women underwent screening with FFDM + DBT between April 4, 2013, and February 14, 2015, and a total of 14,776 asymptomatic women underwent screening with SM + DBT between February 15, 2015, and February 15, 2016. After excluding screening recalls for technical issues (n = 32 in the FFDM + DBT group and n = 54 in the SM + DBT group), a total of 7813 studies were included in the first cohort and 14,722 in the second cohort. From recall recommendation, 2 patients were

Discussion

Breast cancer screening with combined FFMD + DBT decreases recall rate and improves CDR 1, 2, 3, 4, 5, 6 but also increases radiation dose (9). In this study, we found that replacing FFDM with SM in an asymptomatic population being screened with DBT does not affect biopsy rate, PPV1, PPV3, or CDR, and decreased recall rate.

We found similar biopsy rates, PPV1, PPV3, and CDR between the cohort screened with FFDM + DBT and the cohort screened with SM + DBT. This supports a previous study, which

Acknowledgments

The authors have no disclosures of possible conflict of interest and/or commercial involvement. The authors are grateful for the support of Jennifer Kline in data acquisition.

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Screening outcomes following implementation of digital breast tomosynthesis in a general-population screening program
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Cited by (13)

Prospective Comparison of Synthesized Mammography with DBT and Full-Field Digital Mammography with DBT Uncovers Recall Disagreements That may Impact Cancer Detection
2022, Academic Radiology
Citation Excerpt :
Mammography follow-up detected five new breast cancers (1 IDC, 2 IDC+DCIS, 1 ILC, 1 DCIS) in five patients: one patient at 8 months (imaging prompted by new bloody nipple discharge and palpable mass) and four patients at 11–15 months postinitial screening (early or late for annual screening), in whom prior SM+DBT or FFDM+DBT interpretations prompted no recall. Our study demonstrated no statistical difference in RR, PPV1, and CDR, similar to multiple other studies (8,9,12–24). A few prospective studies comparing the performance of SM+DBT and FFDM+DBT had mixed results: some showing similar performance, while others showed lower sensitivity for SM+DBT than for FFDM+DBT but comparable specificity for the two imaging modalities (8,13,22).
Synthesized mammography with digital breast tomosynthesis (SM+DBT) and full-field digital mammography with DBT were prospectively evaluated for recall rate (RR), cancer detection rate (CDR), positive predictive value 1 (PPV1), lesion recall differences, and disagreements in recall for additional imaging.
From December 15, 2015 to January 15, 2017, after informed consent was obtained for this Health Insurance Portability and Accountability Act compliant study, each enrolled patient's SM+DBT and FFDM+DBT were interpreted sequentially by one of eight radiologists. RR, CDR, PPV1, and imaging findings (asymmetry, focal asymmetry, mass, architectural distortion, and calcifications) recalled were reviewed.
For SM+DBT and FFDM+DBT in 1022 patients, RR was 7.3% and 7.9% (SM+DBT vs. FFDM+DBT: diff= −0.6%; 90% CI= −1.4%, 0.1%); CDR was 6.8 and 7.8 per 1000 (SM+DBT vs. FFDM+DBT: diff= −1.0, 95% CI= −5.5, 2.8, p = 0.317); PPV1 was 9.3% and 9.9% (relative positive predictive value for SM+DBT vs. FFDM+DBT: 0.95, 95% CI: 0.73–1.22, p = 0.669). FFDM+DBT detected eight cancers; SM+DBT detected seven (missed 1 cancer with calcifications). SM+DBT and FFDM+DBT disagreed on patient recall for additional imaging in 19 patients, with majority (68%, 13/19 patients) in the recall of patients for calcifications. For calcifications, SM+DBT recalled six patients that FFDM+DBT did not recall, and FFDM+DBT recalled seven patients that SM+DBT did not recall, even though the total number of calcifications finding recalled was similar overall for both SM+DBT and FFDM+DBT.
Disagreement in recall of patients for calcifications may impact cancer detection by SM+DBT, warranting further investigation.
Breast cancer screening using synthesized two-dimensional mammography: A systematic review and meta-analysis
2021, Breast
Citation Excerpt :
Due to that the SM image is created from the DBT dataset, vendor differences in DBT acquisition result in vendor-specific DBT images and subsequently varying synthesized results [15]. Most studies used Hologic Selenia Dimensions with improved version of the reconstructed synthesized image processing software (C-View) [28,30,33,38–41]. In addition, the radiologists in the RCT had insufficient experience in screen reading of DBT, so the radiologists may have not yet achieved optimal screen reading capabilities with DBT at the startup of the study [19].
We conducted a systematic review and meta-analysis to compare the screening performance of synthesized mammography (SM) plus digital breast tomosynthesis (DBT) with digital mammography (DM) plus DBT or DM alone.
Medline, Embase, Web of Science, and the Cochrane Library databases were searched from January 2010 to January 2021. Eligible population-based studies on breast cancer screening comparing SM/DBT with DM/DBT or DM in asymptomatic women were included. A random-effect model was used in this meta-analysis. Data were summarized as risk differences (RDs), with 95 % confidence intervals (CIs).
Thirteen studies involving 1,370,670 participants were included. Compared with DM/DBT, screening using SM/DBT had similar breast cancer detection rate (CDR) (RD = −0.1/1000 screens, 95 % CI = −0.4 to 0.2, p = 0.557, I² = 0 %), but lower recall rate (RD = −0.56 %, 95 % CI = −1.03 to −0.08, p = 0.022, I² = 90 %) and lower biopsy rate (RD = −0.33 %, 95 % CI = −0.56 to −0.10, p = 0.005, I² = 78 %). Compared with DM, SM/DBT improved CDR (RD = 2.0/1000 screens, 95 % CI = 1.4 to 2.6, p < 0.001, I² = 63 %) and reduced recall rate (RD = −0.95 %, 95 % CI = −1.91 to −0.002, p = 0.049, I² = 99 %). However, SM/DBT and DM had similar interval cancer rate (ICR) (RD = 0.1/1000 screens, 95 % CI = −0.6 to 0.8, p = 0.836, I² = 71 %) and biopsy rate (RD = −0.05 %, 95 % CI = −0.35 to 0.24, p = 0.727, I² = 93 %).
Screening using SM/DBT has similar breast cancer detection but reduces recall and biopsy when compared with DM/DBT. SM/DBT improves CDR when compared with DM, but they have little difference in ICR. SM/DBT could replace DM/DBT in breast cancer screening to reduce radiation dose.
The threshold detectable mass diameter for 2D-mammography and digital breast tomosynthesis
2019, Physica Medica
Citation Excerpt :
A potential solution may lie in the use of synthetic imaging, which provides the generation of a synthesised 2D image from DBT data (and thus eliminating the use of 2D-mammography), and is available from some manufacturers. There are on-going studies on the use of synthetic imaging in screening [40–43] and the identification of its strengths and weaknesses [44]. This study also provided a comparison between an existing narrow angle DBT and a wide angle DBT system when the same image receptor and X-ray spectrum are used.
Digital breast tomosynthesis (DBT) is currently under consideration for replacement of, or combined use with 2D-mammography in national breast screening programmes. To investigate the potential benefits that DBT can bring to screening, the threshold detectable lesion diameters were measured for different forms of DBT in comparison to 2D-mammography. The aim of this study was to compare the threshold detectable mass diameters obtained with narrow angle (15°/15 projections) and wide angle (50°/25 projections) DBT in comparison to 2D-mammography. Simulated images of 60 mm thick compressed breasts were produced with and without masses using a set of validated image modelling tools for 2D-mammography and DBT. Image processing and reconstruction were performed using commercial software. A series of 4-alternative forced choice (4AFC) experiments was conducted for signal detection with the masses as targets. The threshold detectable mass diameter was found for each imaging modality with a mean glandular dose of 2.5 mGy. The resulting values of the threshold diameter for 2D-mammography (10.2 ± 1.4 mm) were found to be larger (p < 0.001) than those for narrow angle DBT (6.0 ± 1.1 mm) and wide angle DBT (5.6 ± 1.2 mm). There was no significant difference between the threshold diameters for wide and narrow angle DBT. Implications for the introduction of DBT alone or in combination with 2D-mammography in breast cancer screening are discussed.
Insights into innovative breast imaging techniques
2019, Clinical Imaging
Digital breast tomosynthesis: Image acquisition principles and artifacts
2019, Clinical Imaging
Digital breast tomosynthesis (DBT) is a new technology that is being used more frequently for both breast cancer screening and diagnostic purposes and its utilization is likely to continue to increase over time. The major benefit of tomosynthesis over 2D-mammography is that it allows radiologists to view breast tissue using a three-dimensional dataset and improves diagnostic accuracy by facilitating differentiation of potentially malignant lesions from overlap of normal tissue. In addition, image processing techniques allow reconstruction of two dimensional synthesized mammograms (SM) from DBT data, which eliminates the need for acquiring two dimensional full field digital mammography (FFDM) in addition to tomosynthesis and thereby reduces the radiation dose. DBT systems incorporate a moveable x-ray tube, which moves in a prescribed way over a limited angular range to obtain three-dimensional data of patients' breasts, and utilize reconstruction algorithms. The limited angular range for DBT leads to incomplete sampling of the object, and a movable x-ray tube prolongs the imaging time, both of which make DBT and SM susceptible to artifacts. Understanding the etiology of these artifacts should help radiologists in reducing the number of artifacts and in differentiating a true finding from one related to an artifact, thus potentially decreasing recall rates and false positive rates. This is becoming especially important with increased incorporation of DBT in practices around the world. The goal of this article is to review the physics principles behind DBT systems and use these principles to explain the origin of artifacts that can limit diagnostic evaluation.
Combinations of Digital Breast Tomosynthesis and Full-field Digital Mammography for Different Density Types of Breasts
2024, Current Medical Imaging

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View full text

Original InvestigationSynthesized Mammography: The New Standard of Care When Screening for Breast Cancer with Digital Breast Tomosynthesis?

Rationale and Objectives

Materials and Methods

Results

Conclusions

Introduction

Section snippets

Materials and Methods

Results

Discussion

Acknowledgments

Lancet Oncol

Lancet Oncol

Acad Radiol

Breast

Assessing radiologist performance using combined digital mammography and breast tomosynthesis compared with digital mammography alone: results of a multicenter, multireader trial

Radiology

Diagnostic accuracy and recall rates for digital mammography and digital mammography combined with one-view and two-view tomosynthesis: results of an enriched reader study

AJR Am J Roentgenol

Screening outcomes following implementation of digital breast tomosynthesis in a general-population screening program

J Natl Cancer Inst

Prospective trial comparing full-field digital mammography (FFDM) versus combined FFDM and tomosynthesis in a population-based screening programme using independent double reading with arbitration

Eur Radiol

Detection and classification of calcifications on digital breast tomosynthesis and 2D digital mammography: a comparison

AJR Am J Roentgenol

Original Investigation
Synthesized Mammography: The New Standard of Care When Screening for Breast Cancer with Digital Breast Tomosynthesis?