Clinical performance of Siemens digital breast tomosynthesis versus standard supplementary mammography for the assessment of screen-detected soft-tissue abnormalities: a multi-reader study

Mammographic features of benign breast lesions and risk of subsequent breast cancer in women attending breast cancer screening

OBJECTIVES

To evaluate the mammographic features in women with benign breast disease (BBD) and the risk of subsequent breast cancer according to their mammographic findings.

METHODS

We analyzed data from a Spanish cohort of women screened from 1995 to 2015 and followed up until December 2017 (median follow-up, 5.9 years). We included 10,650 women who had both histologically confirmed BBD and mammographic findings. We evaluated proliferative and nonproliferative BBD subtypes, and their mammographic features: architectural distortion, asymmetries, calcifications, masses, and multiple findings. The adjusted hazard ratios (aHR) and 95% confidence intervals (95% CI) for breast cancer were estimated using a Cox proportional hazards model. We plotted the adjusted cumulative incidence curves.

RESULTS

Calcifications were more frequent in proliferative disease with atypia (43.9%) than without atypia (36.8%) or nonproliferative disease (22.2%; p value < 0.05). Masses were more frequent in nonproliferative lesions (59.1%) than in proliferative lesions without atypia (35.1%) or with atypia (30.0%; p value < 0.05). Multiple findings and architectural distortion were more likely in proliferative disease (16.1% and 4.7%) than in nonproliferative disease (12.8% and 1.9%). Subsequent breast cancer occurred in 268 (2.5%) women. Compared with women who had masses, the highest risk of subsequent breast cancer was found in those with architectural distortions (aHR, 2.21; 95% CI, 1.16-4.22), followed by those with multiple findings (aHR, 1.89; 95% CI, 1.34-2.66), asymmetries (aHR, 1.66; 95% CI, 0.84-3.28), and calcifications (aHR, 1.60; 95% CI, 1.21-2.12).

CONCLUSION

BBD subtypes showed distinct mammographic findings. The risk of subsequent breast cancer was high in those who have shown architectural distortion, multiple findings, asymmetries, and calcifications than in women with masses.

KEY POINTS

• The presence of mammographic findings in women attending breast cancer screening helps clinicians to assess women with benign breast disease (BBD). • Calcifications were frequent in BBDs with atypia, which are the ones with a high breast cancer risk, while masses were common in low-risk BBDs. • The excess risk of subsequent breast cancer in women with BBD was higher in those who showed architectural distortion compared to those with masses.

Digital breast tomosynthesis compared to diagnostic mammographic projections (including magnification) among women recalled at screening mammography: a systematic review for the European Commission Initiative on Breast Cancer (ECIBC)

Background

Diagnostic mammography projections (DxMM) have been traditionally used in the assessment of women recalled after a suspicious screening mammogram. Digital breast tomosynthesis (DBT) reduces the tissue overlap effect, thus improving image assessment. Some studies have suggested DBT might replace DxMM with at least equivalent performance.

Objective

To evaluate the replacement of DxMM with DBT in women recalled at screening.

Methods

We searched PubMed, EMBASE, and the Cochrane Library databases to identify diagnostic paired cohort studies or RCTs comparing DBT vs DxMM, published in English that: reported accuracy outcomes, recruited women recalled for assessment at mammography screening, and included a reference standard. Subgroup analysis was performed over lesion characteristics. We provided pooled accuracy estimates and differences between tests using a quadrivariate model. We assessed the certainty of the evidence using the GRADE approach.

Results

We included ten studies that reported specificity and sensitivity. One study included 7060 women while the remaining included between 52 and 738 women. DBT compared with DxMM showed a pooled difference for the sensitivity of 2% (95% CI 1%–3%) and a pooled difference for the specificity of 6% (95%CI 2%–11%). Restricting the analysis to the six studies that included women with microcalcification lesions gave similar results. In the context of a prevalence of 21% of breast cancer (BC) in recalled women, DBT probably detects 4 (95% CI 2–6) more BC cases and has 47 (95%CI 16–87) fewer false‐positive results per 1000 assessments. The certainty of the evidence was moderate due to risk of bias.

Conclusion

The evidence in the assessment of screen‐recalled findings with DBT is sparse and of moderate certainty. DBT probably has higher sensitivity and specificity than DxMM. Women, health care providers and policymakers might value as relevant the reduction of false‐positive results and related fewer invasive diagnostic procedures with DBT, without missing BC cases.

Breast Cancer Screening and Diagnosis: A Synopsis of the European Breast Guidelines

DESCRIPTION

The European Commission Initiative for Breast Cancer Screening and Diagnosis guidelines (European Breast Guidelines) are coordinated by the European Commission's Joint Research Centre. The target audience for the guidelines includes women, health professionals, and policymakers.

METHODS

An international guideline panel of 28 multidisciplinary members, including patients, developed questions and corresponding recommendations that were informed by systematic reviews of the evidence conducted between March 2016 and December 2018. GRADE (Grading of Recommendations Assessment, Development and Evaluation) Evidence to Decision frameworks were used to structure the process and minimize the influence of competing interests by enhancing transparency. Questions and recommendations, expressed as strong or conditional, focused on outcomes that matter to women and provided a rating of the certainty of evidence.

RECOMMENDATIONS

This synopsis of the European Breast Guidelines provides recommendations regarding organized screening programs for women aged 40 to 75 years who are at average risk. The recommendations address digital mammography screening and the addition of hand-held ultrasonography, automated breast ultrasonography, or magnetic resonance imaging compared with mammography alone. The recommendations also discuss the frequency of screening and inform decision making for women at average risk who are recalled for suspicious lesions or who have high breast density.

Digital breast tomosynthesis for breast cancer detection: a diagnostic test accuracy systematic review and meta-analysis

OBJECTIVES

No consensus exists on digital breast tomosynthesis (DBT) utilization for breast cancer detection. We performed a diagnostic test accuracy systematic review and meta-analysis comparing DBT, combined DBT and digital mammography (DM), and DM alone for breast cancer detection in average-risk women.

METHODS

MEDLINE and EMBASE were searched until September 2018. Comparative design studies reporting on the diagnostic accuracy of DBT and/or DM for breast cancer detection were included. Demographic, methodologic, and diagnostic accuracy data were extracted. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. Accuracy metrics were pooled using bivariate random-effects meta-analysis. The impact of multiple covariates was assessed using meta-regression.

PROSPERO ID

CRD 42018111287.

RESULTS

Thirty-eight studies reporting on 488,099 patients (13,923 with breast cancer) were included. Eleven studies were at low risk of bias. DBT alone, combined DBT and DM, and DM alone demonstrated sensitivities of 88% (95% confidence interval [CI] 83-92), 88% (CI 83-92), and 79% (CI 75-82), as well as specificities of 84% (CI 76-89), 81% (CI 73-88), and 79% (CI 71-85), respectively. The greater sensitivities of DBT alone and combined DBT and DM compared to DM alone were preserved in the combined meta-regression models accounting for other covariates (p = 0.003-0.006). No significant difference in diagnostic accuracy between DBT alone and combined DBT and DM was identified (p = 0.175-0.581).

CONCLUSIONS

DBT is more sensitive than DM, while the addition of DM to DBT provides no additional diagnostic benefit. Consideration of these findings in breast cancer imaging guidelines is recommended.

KEY POINTS

• Digital breast tomosynthesis with or without additional digital mammography is more sensitive in detecting breast cancer than digital mammography alone in women at average risk for breast cancer. • The addition of digital mammography to digital breast tomosynthesis provides no additional diagnostic benefit in detecting breast cancer compared to digital breast tomosynthesis alone. • The specificity of digital breast tomosynthesis with or without additional digital mammography is no different than digital mammography alone in the detection of breast cancer.

The role of digital breast tomosynthesis in breast cancer screening: a manufacturer- and metrics-specific analysis

Aim

Digital Breast Tomosynthesis (DBT), with or without Digital Mammography (DM) or Synthetic Mammography (SM), has been introduced or is under consideration for its introduction in breast cancer screening in several countries, as it has been shown that it has advantages over DM. Despite this there is no agreement on how to implement DBT in screening, and in many cases there is a lack of official guidance on the optimum usage of each commercially available system. The aim of this review is to carry out a manufacturer-specific summary of studies on the implementation of DBT in breast cancer screening.

Methods

An exhaustive literature review was undertaken to identify clinical observer studies that evaluated at least one of five common metrics: sensitivity, specificity, area under the curve (AUC) of the receiver-operating characteristics (ROC) analysis, recall rate and cancer detection rate. Four common DBT implementation methods were discussed in this review: (1) DBT, (2) DM with DBT, (3) 1-view DBT with or without 1-view DM or 2-view DM and (4) DBT with SM.

Results

A summary of 89 studies, selected from a database of 677 studies, on the assessment of the implementation of DBT in breast cancer screening is presented in tables and discussed in a manufacturer- and metric-specific approach. Much more studies were carried out using some DBT systems than others. For one implementation method of DBT by one manufacturer there is a shortage of studies, for another implementation there are conflicting results. In some cases, there is a strong agreement between studies, making the advantages and disadvantages of each system clear.

Conclusion

The optimum implementation method of DBT in breast screening, in terms of diagnostic benefit and patient radiation dose, for one manufacturer does not necessarily apply to other manufacturers.

Masses in the era of screening tomosynthesis: Is diagnostic ultrasound sufficient?

METHODS:

All masses recalled from screening digital breast tomosynthesis between July 1, 2017 and December 31, 2017 that were sent either to diagnostic mammography or ultrasound were compared. Size, shape, margins, visibility on ultrasound, diagnostic assessment and pathology of all masses along with breast density were evaluated.

RESULTS:

102/212 digital breast tomosynthesis screen-detected masses were worked up with diagnostic mammography initially and 110/212 were worked up with ultrasound directly. There was no significant difference in ultrasound visibility of masses sent to diagnostic mammography first with those sent to ultrasound first (p = 0.42). 4 (4%) masses sent to mammogram first and 2 (2%) masses sent to ultrasound first were not visualized. There was a significant difference in size between masses that were visualized under ultrasound versus those that were not (p = 0.01), when masses in both groups were assessed cumulatively.

CONCLUSIONS:

98% of digital breast tomosynthesis screen-detected masses sent to ultrasound directly were adequately assessed without diagnostic mammography.

ADVANCES IN KNOWLEDGE:

There is potential for avoiding a diagnostic mammogram for evaluation of majority of digital breast tomosynthesis screen-detected masses.

Use of single-view digital breast tomosynthesis (DBT) and ultrasound vs. additional views and ultrasound for the assessment of screen-detected abnormalities: German multi-reader study

Background Data on the value of digital breast tomosynthesis (DBT) for further assessment of screen-detected lesions are still limited. Purpose To compare screening mammography, single-view DBT and ultrasound-information (TS) vs. screening mammography, additional views and ultrasound-information (AV) for assessment of screen-detected abnormalities. Material and Methods The use of wide-angle DBT for screen-detected, soft-tissue abnormalities requiring additional views was investigated: 241 cases (206 benign and 35 malignant lesions), verified by histology or two-year follow-up, were read by ten readers as TS and as AV sets, yielding 2410 diagnoses for each set. Readings were randomly sequenced. Results The mean interval between readings was nine weeks (random sequence). Evaluation was breast-based. Overall, in terms of area under receiver operating characteristic (AUC; varying degree of suspicion cutoff), TS and AV readings showed similar performance: for TS, AUC was 0.889 (95% confidence interval [CI] = 0.871-0.907) and for AV, AUC was 0.903 (95% CI = 0.886-0.921). TS readings had slightly higher sensitivity than AV readings (96.9% vs. 95.4%) but lower specificity (50% vs. 58.1%) and more variations between reader performance; absolute false negatives (FN) were reduced in 8/16 readers, equal in 5/16, and increased in only 3/16. Conclusion This study broadly confirms previous data showing equivalence of DBT to AV. However, bias against TS may have occurred since the region of interest was not indicated in the TS set as compared to its obvious identification on the AV set by the selected spot views. A key finding is that reader experience with DBT may be more important than so far reported.

Digital breast tomosynthesis (3D mammography) for breast cancer screening and for assessment of screen-recalled findings: review of the evidence

INTRODUCTION

Digital breast tomosynthesis (DBT) addresses some of the limitations of digital mammography (DM) by reducing the effect of overlapping tissue. Emerging data have shown that DBT increases breast cancer (BC) detection and reduces recall in BC screening programs. Studies have also suggested that DBT improves assessment of screen-recalled findings. Areas covered: Studies of DBT for population BC screening and those for assessment of screen-detected findings were reviewed to provide an up-to-date summary of the evidence on DBT in the screening setting. A systematic literature search was conducted for each of the topics; study-specific information and/or quantitative data on detection or accuracy were extracted and collated in tables. Expert commentary: The evidence on DBT for BC screening reinforces that DBT integrated with DM increases cancer detection rates compared to DM alone, although the extent of improved detection varied between studies. The effect of DBT on recall rates was heterogeneous with substantial reductions evident noticeably in retrospective comparative studies. The evidence on DBT for workup was sparse and those studies had limitations related to design and methods. Even though the majority showed improved specificity using DBT compared with conventional imaging, there was little evidence on how DBT impacts assessment outcomes.

Digital breast tomosynthesis (DBT): recommendations from the Italian College of Breast Radiologists (ICBR) by the Italian Society of Medical Radiology (SIRM) and the Italian Group for Mammography Screening (GISMa)

This position paper, issued by ICBR/SIRM and GISMa, summarizes the evidence on DBT and provides recommendations for its use. In the screening setting, DBT in adjunct to digital mammography (DM) increased detection rate by 0.5-2.7‰ and decreased false positives by 0.8-3.6% compared to DM alone in observational and double-testing experimental studies. The reduction in recall rate could be less prominent in those screening programs which already have low recall rates with DM. The increase in radiation exposure associated with DM/DBT protocols has been solved by the introduction of synthetic mammograms (sDM) reconstructed from DBT datasets. Thus, whenever possible, sDM/DBT should be preferred to DM/DBT. However, before introducing DBT as a routine screening tool for average-risk women, we should wait for the results of randomized controlled trials and for a statistically significant and clinically relevant reduction in the interval cancer rate, hopefully associated with a reduction in the advanced cancer rate. Otherwise, a potential for overdiagnosis and overtreatment cannot be excluded. Studies exploring this issue are ongoing. Screening of women at intermediate risk should follow the same recommendations, with particular protocols for women with previous BC history. In high-risk women, if mammography is performed as an adjunct to MRI or in the case of MRI contraindications, sDM/DBT protocols are suggested. Evidence exists in favor of DBT usage in women with clinical symptoms/signs and asymptomatic women with screen-detected findings recalled for work-up. The possibility to perform needle biopsy or localization under DBT guidance should be offered when DBT-only findings need characterization or surgery.

Value of Digital Breast Tomosynthesis versus Additional Views for the Assessment of Screen-Detected Abnormalities - a First Analysis

BACKGROUND

The purpose of this study was to countercheck the equivalence of single-view digital breast tomosynthesis (DBT) or DBT with additional views (DBT+AV) compared to traditional standard assessment by additional views (AV) in patients with a screen-detected abnormality.

PATIENTS AND METHODS

Patients with a screen-detected abnormality were consecutively invited to obtain 1 single-view wide-angle DBT in addition to the indicated AV. The study was approved by the local ethics committee and by the Federal Office for Radiation Protection.

RESULTS

This study is based on 311 lesions in 285 patients with a follow-up of > 2 years and/or biopsy. Counting BI-RADS 0 and 3 as positive calls, the sensitivity/specificity of DBT+AV versus DBT only versus AV only were 96.4/54.3%, 96.4/56.6%, and 90.9/42.2%, respectively. The specificities and BI-RADS classifications differed significantly (p < 0.01). AV appeared unnecessary in 88.8% of the cases.

CONCLUSION

DBT appeared to be at least equivalent to AV for assessing indeterminate screen-detected lesions and could replace AV for most lesions. To obtain the extra information appears possible without increasing the overall radiation dose. Subsequent blinded reader studies are ongoing.