Rapid review: Estimates of incremental breast cancer detection from tomosynthesis (3D-mammography) screening in women with dense breasts

How long does it take to read a mammogram? Investigating the reading time of digital breast tomosynthesis and digital mammography

PURPOSE

To analyse digital breast tomosynthesis (DBT) reading times in the screening setting, compared to 2D full-field digital mammography (FFDM), and investigate the impact of reader experience and professional group on interpretation times.

METHOD

Reading time data were recorded in the PROSPECTS Trial, a prospective randomised trial comparing DBT plus FFDM or synthetic 2D mammography (S2D) to FFDM alone, in the National Health Service (NHS) breast screening programme, from January 2019-February 2023. Time to read DBT+FFDM or DBT+S2D and FFDM alone was calculated per case and reading times were compared between modalities using dependent T-tests. Reading times were compared between readers from different professional groups (radiologists and radiographer readers) and experience levels using independent T-tests. The learning curve effect of using DBT in screening on reading time was investigated using a Kruskal-Wallis test.

RESULTS

Forty-eight readers interpreted 1,242 FFDM batches (34,210 FFDM cases) and 973 DBT batches (13,983 DBT cases). DBT reading time was doubled compared to FFDM (2.09 ± 0.64 min vs. 0.98 ± 0.30 min; p < 0.001), and DBT+S2D reading was longer than DBT + FFDM (2.24 ± 0.62 min vs. 2.04 ± 0.46 min; p = 0.006). No difference was identified in reading time between radiologists and radiographers (2.06 ± 0.71 min vs. 2.14 ± 0.46 min, respectively; p = 0.71). Readers with five or more years of experience reading DBT were quicker than those with less experience (1.86 ± 0.56 min vs. 2.37 ± 0.65 min; p = 0.008), and DBT reading time decreased after less than 9 months accrued screening experience (p = 0.01).

CONCLUSIONS

DBT reading times were double those of FFDM in the screening setting, but there was a short learning curve effect with readers showing significant improvements in reading times within the first nine months of DBT experience.

CLINICALTRIALS

gov Identifier: NCT03733106.

ACR Appropriateness Criteria® Supplemental Breast Cancer Screening Based on Breast Density

Mammography remains the only validated screening tool for breast cancer, however, there are limitations to mammography. One of the limitations of mammography is the variable sensitivity based on breast density. Supplemental screening may be considered based on the patient's risk level and breast density. For average-risk women with nondense breasts, the sensitivity of digital breast tomosynthesis (DBT) screening is high; additional supplemental screening is not warranted in this population. For average-risk women with dense breasts, given the decreased sensitivity of mammography/DBT, this population may benefit from additional supplemental screening with contrast-enhanced mammography, screening ultrasound (US), breast MRI, or abbreviated breast MRI. In intermediate-risk women, there is emerging evidence suggesting that women in this population may benefit from breast MRI or abbreviated breast MRI. In intermediate-risk women with dense breasts, given the decreased sensitivity of mammography/DBT, this population may benefit from additional supplemental screening with contrast-enhancedmammography or screening US. There is strong evidence supporting screening high-risk women with breast MRI regardless of breast density. Contrast-enhanced mammography, whole breast screening US, or abbreviated breast MRI may be also considered. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Supplemental Screening for Patients at Intermediate and High Risk for Breast Cancer

The sensitivity of mammography is more limited in patients with dense breasts and some patients at higher risk for breast cancer. Patients with intermediate or high risk for breast cancer may begin screening earlier and benefit from supplemental screening techniques beyond standard 2-dimensional mammography. A patient's individual risk factors for developing breast cancer, their breast density, and the evidence supporting specific modalities for a given clinical scenario help to determine the need for supplemental screening and the modality chosen. Additional factors include the availability of supplemental screening techniques at an individual institution, cost, insurance coverage, and state-specific breast density legislation.

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

PURPOSE

To evaluate the agreement between automatic assessment software of breast density based on artificial intelligence (AI) and visual assessment by a senior and a junior radiologist, as well as the impact on the assessment of breast cancer risk (BCR) at 5 years.

MATERIALS AND METHODS

We retrospectively included 311 consecutive women (mean age, 55.6±8.5 [SD]; range: 40-74 years) without a personal history of breast cancer who underwent routine mammography between January 1, 2019 and February 28, 2019. Mammographic breast density (MBD) was independently evaluated by a junior and a senior reader on digital mammography (DM) and synthetic mammography (SM) using BI-RADS (5th edition) and by an AI software. For each MBD, BCR at 5 years was estimated per woman by the AI software. Interobserver agreement for MBD between the two readers and the AI software were evaluated by quadratic κ coefficients. Reproducibility of BCR was assessed by intraclass correlation coefficient (ICC).

RESULTS

Agreement for MBD assessment on DM and SM was almost perfect between senior and junior radiologists (κ=0.88 [95% CI: 0.84-0.92] and κ=0.86 [95% CI: 0.82-0.90], respectively) and substantial between the senior radiologist and AI (κ=0.79; 95% CI: 0.73-0.84). There was substantial agreement between DM and SM for the senior radiologist (κ=0.79; 95% CI: 0.74-0.84). BCR evaluation at 5 years was highly reproducible between the two radiologists on DM and SM (ICC=0.98 [95% CI: 0.97-0.98] for both), between BCR evaluation based on DM and SM evaluated by the senior (ICC=0.96; 95% CI: 0.95-0.97) or junior radiologist (ICC=0.97; 95% CI: 0.96-0.98) and between the senior radiologist and AI (ICC=0.96; 95% CI: 0.95-0.97).

CONCLUSION

This preliminary study demonstrates a very good agreement for BCR evaluation based on the evaluation of MBD by a senior radiologist, junior radiologist and AI software.

Comparative analysis between synthetic mammography reconstructed from digital breast tomosynthesis and full-field digital mammography for breast cancer detection and visibility

•

2D synthetic mammography images from the DBT dataset do not require additional radiation exposure.

•

We compare observer performance between 2DSM and FFDM for breast cancer detection and visibility.

•

Diagnostic performances of 2DSM and FFDM images were comparable for detecting breast cancers.

•

2DSM may eliminate the need for additional FFDM during DBT-based imaging.

Purpose

To compare observer performance between synthetic mammography (2DSM) and full-field digital mammography (FFDM) for breast cancer detection and visibility.

Method

A retrospective analysis was conducted on 136 histopathologically proven cases of breast cancer in patients who underwent FFDM and digital breast tomosynthesis (DBT). 2DSM images were reconstructed from DBT data, and 2DSM and FFDM images were reviewed and evaluated for mammographic features, probability of malignancy (BI-RADS classification), and lesion conspicuity. DBT images were not reviewed. Statistical differences in cancer detection rates between 2DSM and FFDM images were analyzed using the McNemar test, agreement on BI-RADS assessment between 2DSM and FFDM was assessed using Cohen’s kappa test, and the Wilcoxon’s signed rank test was used to compare visibility scores.

Results

Mean cancer detection rates with 2DSM and FFDM images were 84.6 % and 87.8 %, respectively. In subgroup analyses, differences in breast density, tumor size, and presence of calcifications were not statistically significant. Agreement between 2DSM and FFDM images for BI-RADS classification was graded as good with Cohen’s k-coefficient of 0.78 ± 0.05. Visibility scores in both modalities of images were similar for all lesions combined; however, 2DSM had significantly better visibility scores for calcified cancers (p < 0.01), and in dense breast tissue (p < 0.01).

Conclusions

Diagnostic performances of 2DSM and FFDM images were comparable for detecting breast cancers, and it is possible that 2DSM may eliminate the need for additional FFDM during DBT-based imaging due to advances in image reconstruction methods.

Double reading of diffusion-weighted magnetic resonance imaging for breast cancer detection

PURPOSE

To estimate the performance of diffusion-weighted imaging (DWI) for breast cancer detection.

METHODS

Consecutive breast magnetic resonance imaging examinations performed from January to September 2016 were retrospectively evaluated. Examinations performed before/after neoadjuvant therapy, lacking DWI sequences or reference standard were excluded; breasts after mastectomy were also excluded. Two experienced breast radiologists (R1, R2) independently evaluated only DWI. Final pathology or > 1-year follow-up served as reference standard. Mc Nemar, χ², and κ statistics were applied.

RESULTS

Of 1,131 examinations, 672 (59.4%) lacked DWI sequence, 41 (3.6%) had no reference standard, 30 (2.7%) were performed before/after neoadjuvant therapy, and 10 (0.9%) had undergone bilateral mastectomy. Thus, 378 women aged 49 ± 11 years (mean ± standard deviation) were included, 51 (13%) with unilateral mastectomy, totaling 705 breasts. Per-breast cancer prevalence was 96/705 (13.6%). Per-breast sensitivity was 83/96 (87%, 95% confidence interval 78-93%) for both R1 and R2, 89/96 (93%, 86-97%) for double reading (DR) (p = 0.031); per-lesion DR sensitivity for cancers ≤ 10 mm was 22/31 (71%, 52-86%). Per-breast specificity was 562/609 (93%, 90-94%) for R1, 538/609 (88%, 86-91%) for R2, and 526/609 (86%¸ 83-89%) for DR (p < 0.001). Inter-observer agreement was substantial (κ = 0.736). Acquisition time varied from 3:00 to 6:22 min:s. Per-patient median interpretation time was 46 s (R1) and 51 s (R2).

CONCLUSIONS

DR DWI showed a 93% sensitivity and 88% specificity, with 71% sensitivity for cancers ≤ 10 mm, pointing out a potential for DWI as stand-alone screening method.

Detection of noncalcified breast cancer in patients with extremely dense breasts using digital breast tomosynthesis compared with full-field digital mammography

OBJECTIVE

To evaluate the tumour visibility and diagnostic performance of digital breast tomosynthesis (DBT) in patients with noncalcified T1 breast cancer.

METHODS

Medical records of 106 females with noncalcified T1 invasive breast cancer who underwent DBT and full-field digital mammography (FFDM) between January 2012 and December 2014 were retrospectively reviewed. To assess tumour visibility (score 1-3), all DBT and FFDM images were reviewed by two radiologists blinded to clinicopathological information. A reference standard was established by an unblinded consensus review of all images. Clinicopathological and imaging variables were analysed based on tumour visibility. After adding 159 negative controls, the diagnostic performance of DBT + FFDM was compared with that of FFDM.

RESULTS

The tumour visibility was significantly higher through DBT + FFDM (2.5 vs 1.8; p = 0.002) than FFDM alone. Breast composition was the independent variable for tumour visibility through DBT + FFDM (extremely dense; odds ratio, 0.02; p < 0.001). Sensitivity (p = 0.642), specificity (p = 0.463), positive-predictive value (p = 0.078), and negative-predictive value (p = 0.072) of DBT + FFDM were not significantly superior to those of FFDM in 55 females with extremely dense breast composition, whereas specificity (p = 0.002) and positive-predictive value (p < 0.001) were significantly higher in 210 females with other breast compositions.

CONCLUSION

Addition of DBT to FFDM showed no significant increase in the tumour visibility and diagnostic performance in patients with noncalcified T1 cancer in extremely dense breasts.

ADVANCES IN KNOWLEDGE

Addition of DBT to FFDM did not further improve the detection of noncalcified early breast cancers in females with extremely dense breasts.

Agreement between digital breast tomosynthesis and pathologic tumour size for staging breast cancer, and comparison with standard mammography

PURPOSE

Tomosynthesis is proposed to improve breast cancer assessment and staging. We compared tomosynthesis and mammography in estimating the size of newly-diagnosed breast cancers.

METHODS

All pathologically-confirmed cancers detected in the STORM-2 trial (90 cancers, 85 women) were retrospectively measured on tomosynthesis by two independent readers. One reader also measured cancers on mammography. Relative mean differences (MDs) and 95% limits of agreement (LOA) with pathology were estimated for tomosynthesis and mammography within a single reader (Analysis 1) and between two readers (Analysis 2).

RESULTS

Where cancers were detected and hence measured by both tests, tomosynthesis overestimated pathologic size relative to mammography (Analysis 1: MD 5% versus 1%, Analysis 2: 7% versus 3%; P = 0.10 both analyses). There was similar, large measurement variability for both tests (LOA range: -60% to +166%). Overestimation by tomosynthesis was attributable to the subgroup with dense breasts (MDs = 12-13% versus 4% for mammography). There was low average bias for both tests in the low-density subgroup (MDs = 0-4%). LOA were larger in dense breasts for both tomosynthesis and mammography (P ≤ 0.02 all comparisons). Cancers detected only by tomosynthesis were more frequently in dense breasts (60-68%): for those tumours size was estimated with increased measurement variability (LOA ranging from -75% to +293%).

CONCLUSIONS

On average, tomosynthesis overestimates pathologic tumour size in women with dense breasts; that difference is more likely to impact management in women with larger tumours. The main advantage of tomosynthesis appears to be detecting mammographically-occult cancers; however tomosynthesis less accurately measured those cancers in dense breasts (large measurement variability).

The impact of legislation mandating breast density notification - Review of the evidence

Breast density (BD) is an independent risk factor for breast cancer and reduces the sensitivity of mammography. The enactment of BD legislation in a majority of states in the USA mandating notification of risks associated with BD directly to women undergoing mammography has catapulted interest in BD among women, physicians, and policymakers. We therefore report a descriptive review of the evidence on the impact of enactment of BD legislation. Based on 22 eligible studies, we identified four broad themes of research: studies of the impact on screening rates, most showing increased utilisation of supplemental screening; studies exploring the effect on women, radiologists, or primary physicians (reporting heterogeneous effects on knowledge, awareness, perceptions, attitudes and behaviour; and changes in practice); few studies assessing the population impact (effect on screening outcomes or breast cancer stage); and studies of costs highlighting the economic burden from supplemental screening. Given that many of the studies were retrospective single institution studies (comparing pre- and post-legislation) or small surveys with a paucity of population-level studies, we highlight areas meriting additional research. The information described in this review can inform research priorities where BD legislation has been introduced and can be used to guide world-wide policy or practice decisions where BD legislation may be under debate or contemplation.

Systematic review of agreement between tomosynthesis and pathologic tumor size for newly diagnosed breast cancer and comparison with other imaging tests

INTRODUCTION

Tomosynthesis is proposed to improve breast cancer assessment and staging as a complementary role to its detection capability. We examine the accuracy of tomosynthesis in measuring tumor size relative to pathology and compared with other tests.

AREAS COVERED

A systematic literature search identified studies of tomosynthesis in estimating the size of newly diagnosed breast cancers. Descriptive analyses were performed due to heterogeneity in patients, technology, and methods between studies. Eight studies were eligible (678 patients). Mean differences (MDs) between measurements (tomosynthesis-pathology) were generally small; overestimation (MDs of 1-3 mm) and underestimation (-1 mm) were reported. Limits of agreement (LOA) ranged between ±10 mm and ±28 mm. MDs did not differ in high and low breast densities. Large underestimation (-11 mm) and wide LOA (±41 mm) were reported for invasive lobular carcinoma. MDs and LOA were lower for tomosynthesis than mammography, but differences between tests were small.

EXPERT COMMENTARY

Although tomosynthesis is a promising technology for assessing breast cancer size, few studies in that context had limitations (small sample sizes, heterogeneous populations, and technologies). Studies using current technology and appropriate statistical methods are required to establish the magnitude of improvement in measurement accuracy, and patients for whom the test may be of most benefit.

Digital breast tomosynthesis for breast cancer screening and diagnosis in women with dense breasts - a systematic review and meta-analysis

BACKGROUND

This study aimed to systematically review and to meta-analyse the accuracy of digital breast tomosynthesis (DBT) versus digital mammography (DM) in women with mammographically dense breasts in screening and diagnosis.

METHODS

Two independent reviewers identified screening or diagnostic studies reporting at least one of four outcomes (cancer detection rate-CDR, recall rate, sensitivity and specificity) for DBT and DM in women with mammographically dense breasts. Study quality was assessed using QUADAS-2. Meta-analysis of CDR and recall rate used a random effects model. Summary ROC curve summarized sensitivity and specificity.

RESULTS

Sixteen studies were included (five diagnostic; eleven screening). In diagnosis, DBT increased sensitivity (84%-90%) versus DM alone (69%-86%) but not specificity. DBT improved CDR versus DM alone (RR: 1.16, 95% CI 1.02-1.31). In screening, DBT + DM increased CDR versus DM alone (RR: 1.33, 95% CI 1.20-1.47 for retrospective studies; RR: 1.52, 95% CI 1.08-2.11 for prospective studies). Recall rate was significantly reduced by DBT + DM in retrospective studies (RR: 0.72, 95% CI 0.64-0.80) but not in two prospective studies (RR: 1.12, 95% CI 0.76-1.63).

CONCLUSION

In women with mammographically dense breasts, DBT+/-DM increased CDR significantly (versus DM) in screening and diagnosis. In diagnosis, DBT+/-DM increased sensitivity but not specificity. The effect of DBT + DM on recall rate in screening dense breasts varied between studies.

Interest of systematic tomosynthesis (3D mammography) with synthetic 2D mammography in breast cancer screening

Full field digital mammography (FFDM) is the current pillar of breast cancer screening program. However, the emerging technique digital breast tomosynthesis (DBT) has demonstrated a significant increase in the sensibility of cancer detection in several large cohort trials. DBT is particularly helpful for young patients, dense breasts and soft masses due to its ability to reduce overlapping of tissue. In such a population of women, radiologists are more confident and the recall rates are reduced together with a higher positive predictive value. To reduce the breast absorbed doses of screened women and facilitate the workflow, a synthetized two-dimensional (2D) digital mammography (sDM) is obtained from DBT to replace the FFDM. No significant differences regarding detection of anomalies have been reported with respect to FFDM. These results validate a modern strategy for breast cancer screening supported by two views of DBT with sDM. In terms of mean absorbed doses, this strategy is around 1.5 mGy/view and almost equivalent to FFDM. In Europe, major limitations to such evolution are public health policies especially agreements and reimbursement for the technique being used in organized screening.

Screening Mammography and Digital Breast Tomosynthesis: Controversies

Breast cancer screening with mammography reduces breast cancer mortality; however, diverging recommendations regarding screening have caused controversy. The emerging technology of digital breast tomosynthesis (DBT) may soon become the mainstay of breast cancer screening. We present recommendations for breast cancer screening based on guidelines. A PubMed literature review was performed and the results from five large clinical studies comparing the efficacy of digital mammography alone versus digital mammography with DBT are examined. We emphasize the importance of annual screening to reduce breast cancer mortality. Our review of the literature demonstrates that DBT increases cancer detection rates and reduces callbacks. Additional research is needed to determine whether the increased cancer detection rates are associated with a decrease in mortality.

Comparison of synthetic mammography, reconstructed from digital breast tomosynthesis, and digital mammography: evaluation of lesion conspicuity and BI-RADS assessment categories

PURPOSE

To compare the interpretive performance of synthetic mammography (SM), reconstructed from digital breast tomosynthesis (DBT), and full-field digital mammography (FFDM) in a diagnostic setting, covering different conditions of breast density and mammographic signs.

METHODS

A retrospective analysis was conducted on 231 patients, who underwent FFDM and DBT (from which SM images were reconstructed) between September 2014-September 2015. The study included 250 suspicious breast lesions, all biopsy proven: 148 (59.2%) malignant and 13 (5.2%) high-risk lesions were confirmed by surgery, 89 (35.6%) benign lesions had radiological follow-up. Two breast radiologists, blinded to histology, independently reviewed all cases. Readings were performed with SM alone, then with FFDM, collecting data on: probability of malignancy for each finding, lesion conspicuity, mammographic features and dimensions of detected lesions.

RESULTS

Agreement between readers was good for BI-RADS classification (Cohen's k-coefficient = 0.93 ± 0.02) and for lesion dimension (Wilcoxon's p = 0.76). Visibility scores assigned to SM and FFDM for each lesion were similar for non-dense and dense breasts, however, there were significant differences (p = 0.0009) in distribution of mammographic features subgroups. SM and FFDM had similar sensitivities in non-dense (respectively 94 vs. 91%) and dense breasts (88 vs. 80%) and for all mammographic signs (93 vs. 87% for asymmetric densities, 96 vs. 75% for distortion, 92 vs. 85% for microcalcifications, and both 94% for masses). Based on all data, there was a significant difference in sensitivity for SM (92%) vs. FFDM (87%), p = 0.02, whereas the two modalities yielded similar results for specificity (SM: 60%, FFDM: 62%, p = 0.21).

CONCLUSIONS

SM alone showed similar interpretive performance to FFDM, confirming its potential role as an alternative to FFDM in women having tomosynthesis, with the added advantage of halving the patient's dose exposure.

Comparative diagnostic accuracy of 18F-FDG PET/CT for breast cancer recurrence

In the last decades, in addition to conventional imaging techniques and magnetic resonance imaging (MRI), ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has been shown to be relevant in the detection and management of breast cancer recurrence in doubtful cases in selected groups of patients. While there are no conclusive data indicating that imaging tests, including FDG PET/CT, produce a survival benefit in asymptomatic patients, FDG PET/CT can be useful for identifying the site of relapse when traditional imaging methods are equivocal or conflicting and for identifying or confirming isolated loco-regional relapse or isolated metastatic lesions. The present narrative review deals with the potential role of FDG PET in these clinical settings by comparing its accuracy and impact with conventional imaging modalities such as CT, ultrasound, bone scan, ¹⁸F-sodium fluoride PET/CT (¹⁸F-NaF PET/CT) as well as MRI. Patient-focused perspectives in terms of patients' satisfaction and acceptability are also discussed.

Overview of tomosynthesis (3D mammography) for breast cancer screening

This review of the evidence on digital breast tomosynthesis, a 3D-mammography technology, for breast cancer (BC) screening describes two types of studies. Prospective trials comparing tomosynthesis (combined with 2D mammography) with 2D mammography alone in the same participants were based on double-reading practice in mostly biennial screening. These showed incremental BC detection attributed to use of tomosynthesis ranging from 2.2 to 2.7 per 1000 screens. Retrospective studies reported the difference in BC detection between women screened with tomosynthesis (2D plus 3D mammography) or with 2D mammography alone, using single-reading and mostly annual screening. Differences in cancer detection ranged between 0.2 and 2.1 per 1000 screens favoring tomosynthesis. The impact of using tomosynthesis on recall was heterogeneous; however, significant reduction in recall rates was observed among the retrospective studies.