Breast tomosynthesis

Retrieval of 3D information in X-ray dark-field imaging with a large field of view

X-ray dark-field imaging is a widely researched imaging technique, with many studies on samples of very different dimensions and at very different resolutions. However, retrieval of three-dimensional (3D) information for human thorax sized objects has not yet been demonstrated. We present a method, similar to classic tomography and tomosynthesis, to obtain 3D information in X-ray dark-field imaging. Here, the sample is moved through the divergent beam of a Talbot-Lau interferometer. Projections of features at different distances from the source seemingly move with different velocities over the detector, due to the cone beam geometry. The reconstruction of different focal planes exploits this effect. We imaged a chest phantom and were able to locate different features in the sample (e.g. the ribs, and two sample vials filled with water and air and placed in the phantom) to corresponding focal planes. Furthermore, we found that image quality and detectability of features is sufficient for image reconstruction with a dose of 68 μSv at an effective pixel size of [Formula: see text]. Therefore, we successfully demonstrated that the presented method is able to retrieve 3D information in X-ray dark-field imaging.

Comparing the diagnostic efficacy of full field digital mammography with digital breast tomosynthesis using BIRADS score in a tertiary cancer care hospital

Introduction

Breast cancer is one of the leading cancers in females worldwide, and its incidence has been rising at an exponential pace in the last 10 years even in India. Mammography has been the mainstay for detection of breast cancer over decades and has gradually advanced from screen film to full-field digital mammography. Recently, tomosynthesis has evolved as an advanced imaging investigation for early diagnosis of breast lesions in both diagnostic and screening settings.

Aim of Study

To compare and evaluate the impact of digital breast tomosynthesis (DBT) compared to full-field digital mammography (FFDM) in the interpretation of BIRADS score in both diagnostic and screening settings.

Settings and Design

A 1-year prospective longitudinal study was conducted in the Department of Radio-diagnosis in our institute using Hologic Selenia Dimensions for mammography as well as tomosynthesis.

Materials and Methods

One hundred women known or suspected (opportunistic screening) for breast cancer were evaluated either with FFDM alone or both FFDM and DBT. Sensitivity, specificity, positive predictive value, negative predictive value, and P value were used to assess the various diagnostic criteria in our study.

Results

Addition of DBT to FFDM results in a statistically significant increase in the sensitivity, specificity, and positive predictive value, and a statistically significant decrease in the false positive rates. Similar results were noted in both diagnostic and screening cases. It was observed that, in most cases, i.e. a total of 47, DBT did not change the BIRADS scoring; however, its addition increased the diagnostic confidence. BIRADS was upgraded and downgraded in 14 and 31 cases, respectively, with the addition of DBT to FFDM. New lesions were seen with addition of DBT to FFDM in 8 cases.

Conclusion

Addition of DBT to FFDM results in increase in sensitivity, specificity, positive predictive value, and a statistically significant decrease in false positive rates in both diagnostic and screening cases. As addition of tomosynthesis results in a significant decrease in recall rate, it should be added, at least, in all screening mammography programs.

Is contralateral breast ultrasound worthwhile in preoperative staging of breast cancer?

BACKGROUND

Women with invasive breast cancer are at higher risk of contralateral synchronous cancer. This study aimed at determining if contralateral breast ultrasound (CBUS) examination should be routinely performed in the preoperative evaluation of breast cancer patients.

METHODS

This is a retrospective study of preoperative CBUS examinations performed between January 2012 and April 2015. The charts of patients presenting for biopsy of a Breast Imaging Reporting and Data System (BIRADS) 5 lesion and who had undergone a concomitant contralateral breast US examination were reviewed. Index tumor, lymph node status, American College of Radiology (ACR) breast density on mammogram, total scanning time, and results of CBUS were recorded.

RESULTS

Of the 3007 patients who underwent breast biopsies during the study period, 360 patients met the inclusion criteria. Index mass size was 19 ± 10 mm. CBUS examination led to 76 biopsies, of which 12 were positive in 11 patients. Detection rate for mammographically occult contralateral invasive cancers was 3.1% (11/360). Contralateral lesion size was 13 ± 10 mm. Breast density was rated ACR C/D for nine women and ACR B for two. In the ACR C/D subgroup (82%), the contralateral cancer detection rate was 4.1%. Average additional scanning time spent required to perform CBUS examination was 3.1 ± 4.9 min. Patients diagnosed with contralateral invasive breast cancer underwent surgery and/or chemotherapy. The treatment strategy was changed in all 11 patients after the detection of a second primary cancer.

CONCLUSION

Preoperative CBUS is effective and most beneficial with women presenting ACR C/D breast density. Given its impact on decreasing future morbidity, its routine use should be considered to improve quality healthcare for women diagnosed with breast cancer.

Breast tomosynthesis for the clarification of mammographic BI-RADS 3 lesions can decrease follow-up examinations and enables immediate cancer diagnosis

Background The limited sensitivity of mammography in case of a high breast density often produces unclear or false-positive findings, so-called BI-RADS 3 lesions, which have to be followed up to prove benignity. Digital breast tomosynthesis (DBT) was developed to reduce such summation effects. Purpose To evaluate the influence of an additional DBT on the management of mammographic BI-RADS 3 findings and whether DBT can decrease the time to definitive diagnosis or not. Material and Methods We analyzed 87 patients with a mammographic non-calcified BI-RADS 3 lesion who underwent an additional DBT of the affected breast. A follow-up two-dimensional (2D) examination or a histological result of the lesion had to be available. The images were analyzed especially for the BI-RADS category and incremental diagnostic accuracy. Moreover, the inter-reader reliability and the radiation dose were evaluated. Results The BI-RADS category has been changed by the addition of DBT: 57.1% were assessed as BI-RADS 1 or 2, 4.6% as BI-RADS 4, and only 38.3% remained as BI-RADS 3. The intraclass correlation coefficient for the three readers showed a good agreement for inter-reader reliability. No false-negative examination was found in the follow-ups. Nine lesions were biopsied (seven benign, two malignant). Both malignant lesions were suspicious in the DBT (BI-RADS 4). A significant higher glandular dose was necessary for the DBT. Conclusion DBT has the potential to reduce the recall-rate of BI-RADS 3 lesions and to find and diagnose malignant lesions earlier than 2D mammography alone.

Mammography: an update of the EUSOBI recommendations on information for women

Abstract

This article summarises the information to be offered to women about mammography. After a delineation of the aim of early diagnosis of breast cancer, the difference between screening mammography and diagnostic mammography is explained. The need to bring images and reports from the previous mammogram (and from other recent breast imaging examinations) is highlighted. Mammography technique and procedure are described with particular attention to discomfort and pain experienced by a small number of women who undergo the test. Information is given on the recall during a screening programme and on the request for further work-up after a diagnostic mammography. The logic of the mammography report and of classification systems such as R1-R5 and BI-RADS is illustrated, and brief but clear information is given about the diagnostic performance of the test, with particular reference to interval cancers, i.e., those cancers that are missed at screening mammography. Moreover, the breast cancer risk due to radiation exposure from mammography is compared to the reduction in mortality obtained with the test, and the concept of overdiagnosis is presented with a reliable estimation of its extent. Information about new mammographic technologies (tomosynthesis and contrast-enhanced spectral mammography) is also given. Finally, frequently asked questions are answered.

Key Points

• Direct digital mammography should be preferred to film-screen or phosphor plates.

• Screening (in asymptomatic women) should be distinguished from diagnosis (in symptomatic women).

• A breast symptom has to be considered even after a negative mammogram.

• Digital breast tomosynthesis increases cancer detection and decreases the recall rate.

• Contrast-enhanced spectral mammography can help in cancer detection and lesion characterisation.

Digital Breast Tomosynthesis: State of the Art

This topical review on digital breast tomosynthesis (DBT) is provided with the intent of describing the state of the art in terms of technology, results from recent clinical studies, advanced applications, and ongoing efforts to develop multimodality imaging systems that include DBT. Particular emphasis is placed on clinical studies. The observations of increase in cancer detection rates, particularly for invasive cancers, and the reduction in false-positive rates with DBT in prospective trials indicate its benefit for breast cancer screening. Retrospective multireader multicase studies show either noninferiority or superiority of DBT compared with mammography. Methods to curtail radiation dose are of importance. (©) RSNA, 2015.

Accuracy of Digital Breast Tomosynthesis for Depicting Breast Cancer Subgroups in a UK Retrospective Reading Study (TOMMY Trial)

PURPOSE

To compare the diagnostic performance of two-dimensional (2D) mammography, 2D mammography plus digital breast tomosynthesis (DBT), and synthetic 2D mammography plus DBT in depicting malignant radiographic features.

MATERIALS AND METHODS

In this multicenter, multireader, retrospective reading study (the TOMMY trial), after written informed consent was obtained, 8869 women (age range, 29-85 years; mean, 56 years) were recruited from July 2011 to March 2013 in an ethically approved study. From these women, a reading dataset of 7060 cases was randomly allocated for independent blinded review of (a) 2D mammography images, (b) 2D mammography plus DBT images, and (c) synthetic 2D mammography plus DBT images. Reviewers had no access to results of previous examinations. Overall sensitivities and specificities were calculated for younger women and those with dense breasts.

RESULTS

Overall sensitivity was 87% for 2D mammography, 89% for 2D mammography plus DBT, and 88% for synthetic 2D mammography plus DBT. The addition of DBT was associated with a 34% increase in the odds of depicting cancer (odds ratio [OR] = 1.34, P = .06); however, this level did not achieve significance. For patients aged 50-59 years old, sensitivity was significantly higher (P = .01) for 2D mammography plus DBT than it was for 2D mammography. For those with breast density of 50% or more, sensitivity was 86% for 2D mammography compared with 93% for 2D mammography plus DBT (P = .03). Specificity was 57% for 2D mammography, 70% for 2D mammography plus DBT, and 72% for synthetic 2D mammography plusmDBT. Specificity was significantly higher than 2D mammography (P < .001in both cases) and was observed for all subgroups (P < .001 for all cases).

CONCLUSION

The addition of DBT increased the sensitivity of 2D mammography in patients with dense breasts and the specificity of 2D mammography for all subgroups. The use of synthetic 2D DBT demonstrated performance similar to that of standard 2D mammography with DBT. DBT is of potential benefit to screening programs, particularly in younger women with dense breasts. (©) RSNA, 2015.

Breast cancer screening: an evidence-based update

Routine screening mammography is recommended by most groups issuing breast cancer screening guidelines, especially for women 50 years of age and older. However, both the potential benefits and risks of screening should be discussed with individual patients to allow for shared decision making regarding their participation in screening, age of commencement and conclusion, and interval of mammography screening.

The TOMMY trial: a comparison of TOMosynthesis with digital MammographY in the UK NHS Breast Screening Programme--a multicentre retrospective reading study comparing the diagnostic performance of digital breast tomosynthesis and digital mammography with digital mammography alone

BACKGROUND

Digital breast tomosynthesis (DBT) is a three-dimensional mammography technique with the potential to improve accuracy by improving differentiation between malignant and non-malignant lesions.

OBJECTIVES

The objectives of the study were to compare the diagnostic accuracy of DBT in conjunction with two-dimensional (2D) mammography or synthetic 2D mammography, against standard 2D mammography and to determine if DBT improves the accuracy of detection of different types of lesions.

STUDY POPULATION

Women (aged 47-73 years) recalled for further assessment after routine breast screening and women (aged 40-49 years) with moderate/high of risk of developing breast cancer attending annual mammography screening were recruited after giving written informed consent.

INTERVENTION

All participants underwent a two-view 2D mammography of both breasts and two-view DBT imaging. Image-processing software generated a synthetic 2D mammogram from the DBT data sets.

RETROSPECTIVE READING STUDY

In an independent blinded retrospective study, readers reviewed (1) 2D or (2) 2D + DBT or (3) synthetic 2D + DBT images for each case without access to original screening mammograms or prior examinations. Sensitivities and specificities were calculated for each reading arm and by subgroup analyses.

RESULTS

Data were available for 7060 subjects comprising 6020 (1158 cancers) assessment cases and 1040 (two cancers) family history screening cases. Overall sensitivity was 87% [95% confidence interval (CI) 85% to 89%] for 2D only, 89% (95% CI 87% to 91%) for 2D + DBT and 88% (95% CI 86% to 90%) for synthetic 2D + DBT. The difference in sensitivity between 2D and 2D + DBT was of borderline significance (p = 0.07) and for synthetic 2D + DBT there was no significant difference (p = 0.6). Specificity was 58% (95% CI 56% to 60%) for 2D, 69% (95% CI 67% to 71%) for 2D + DBT and 71% (95% CI 69% to 73%) for synthetic 2D + DBT. Specificity was significantly higher in both DBT reading arms for all subgroups of age, density and dominant radiological feature (p < 0.001 all cases). In all reading arms, specificity tended to be lower for microcalcifications and higher for distortion/asymmetry. Comparing 2D + DBT to 2D alone, sensitivity was significantly higher: 93% versus 86% (p < 0.001) for invasive tumours of size 11-20 mm. Similarly, for breast density 50% or more, sensitivities were 93% versus 86% (p = 0.03); for grade 2 invasive tumours, sensitivities were 91% versus 87% (p = 0.01); where the dominant radiological feature was a mass, sensitivities were 92% and 89% (p = 0.04) For synthetic 2D + DBT, there was significantly (p = 0.006) higher sensitivity than 2D alone in invasive cancers of size 11-20 mm, with a sensitivity of 91%.

CONCLUSIONS

The specificity of DBT and 2D was better than 2D alone but there was only marginal improvement in sensitivity. The performance of synthetic 2D appeared to be comparable to standard 2D. If these results were observed with screening cases, DBT and 2D mammography could benefit to the screening programme by reducing the number of women recalled unnecessarily, especially if a synthetic 2D mammogram were used to minimise radiation exposure. Further research is required into the feasibility of implementing DBT in a screening setting, prognostic modelling on outcomes and mortality, and comparison of 2D and synthetic 2D for different lesion types.

STUDY REGISTRATION

Current Controlled Trials ISRCTN73467396.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 4. See the HTA programme website for further project information.

Update on new technologies in digital mammography

Despite controversy regarding mammography's efficacy, it continues to be the most commonly used breast cancer-screening modality. With the development of digital mammography, some improved benefit has been shown in women with dense breast tissue. However, the density of breast tissue continues to limit the sensitivity of conventional mammography. We discuss the development of some derivative digital technologies, primarily digital breast tomosynthesis, and their strengths, weaknesses, and potential patient impact.

Digital breast tomosynthesis versus full-field digital mammography: comparison of the accuracy of lesion measurement and characterization using specimens

BACKGROUND

Digital breast tomosynthesis (DBT) is one of the new techniques being developed to overcome the inherent limitations of mammography caused by superimposed structures in a 2D projection.

PURPOSE

To compare the diagnostic performances of digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) for lesion characterization and size measurement using breast specimens.

MATERIAL AND METHODS

Out of 156 women scheduled for surgery, we included in our study 114 women, each of whom had a single, breast lesion. Three breast radiologists independently evaluated the DBT and FFDM performance regarding the breast specimens obtained during surgery. Each reader measured the lesion size, and then categorized the probability of malignancy using the American College of Radiology Breast Imaging Reporting and Data system (BI-RADS). After both reading sessions, the readers selected the preferred modality of either FFDM or DBT in lesion characterization. We also analyzed the radiologists' evaluation performance in patients with dense versus fatty breasts when using DBT and FFDM.

RESULTS

The imaging findings of 84 cancers and 30 benign lesions, all of which had been pathologically proven, were reviewed. The size evaluation determined by DBT was more accurately correlated with that found by pathology (P = 0.001 for fatty breasts and <0.001 for dense breasts) than that determined by FFDM. The correlation coefficients of DBT and FFDM to the pathologically determined lesion size were 0.90 and 0.89, respectively (P < 0.001). Compared with the pathologically determined lesion size, the size determined by both imaging modalities was overestimated. Overall, assessment of the probability of malignancy by DBT and FFDM did not differ significantly (P = 0.07); however, in dense breast, DBT was more strongly correlated with the pathology determination than FFDM (P = 0.03).

CONCLUSION

DBT may be superior to FFDM for determining the preoperative size measurement of breast lesions irregardless of their parenchymal density. Particularly in dense breasts, DBT was more useful for differentiating the lesion malignancy rate.

'In vivo' average glandular dose evaluation: one-to-one comparison between digital breast tomosynthesis and full-field digital mammography

We analysed 300 patients X rayed with digital breast tomosynthesis (DBT), full-field digital mammography (FFDM) and 'COMBO' (single view both in FFDM and DBT in a single breast compression)-Hologic Selenia Dimension-W/Rh-Ag-Al: three different anode-filter combinations-automatic exposure control modalities. Examination parameter data collection (EPDC) and 'in vivo' dosimetry using metal oxide semiconductor field effect transistor (MOSFET) were utilised to determine and compare entrance skin air kerma (ESAK) and average glandular dose (AGD) from a radioprotection viewpoint in the DBT and COMBO modalities. MOSFET has been tested to be introduced in clinical routine. EPDC of DBT underlines increase in ESAK and AGD compared with FFDM (p < 0.05). The mean percentage increase was 34 % (+17 %) in ESAK and 46 % (+16 %) in AGD. In the COMBO modality, the mean percentage increase in ESAK was 162 % (+41 %) and in AGD was 202 % (+61 %). Differences between MOSFET measurement and calculated values were <8 % for breasts thicker than 30 mm; otherwise, the errors are >15 %. DBT increases ESAK and AGD, due to the 3D acquisition modality. MOSFET may be considered in DBT as a routine check.

Digital breast tomosynthesis versus mammography and breast ultrasound: a multireader performance study

OBJECTIVES

To compare the diagnostic performance of single-view breast tomosynthesis (BT) with that of dual-view mammography (MX); to assess the benefit of adding the craniocaudal (CC) mammographic view to BT, and of adding BT to MX plus breast ultrasound, considered to be the reference work-up.

METHODS

One hundred and fifty-five consenting patients with unresolved mammographic and/or ultrasound findings or breast symptoms underwent conventional work-up plus mediolateral oblique-view BT of the affected breast. The final study set in 130 patients resulted in 55 malignant and 76 benign and normal cases. Seven breast radiologists rated the cases through five sequential techniques using a BIRADS-based scale: MX, MX + ultrasound, MX + ultrasound + BT, BT, BT + MX(CC). Multireader, multicase receiver operating characteristic (ROC) analysis was performed and performance of the techniques was assessed from the areas under ROC curves. The performance of BT and of BT + MX(CC) was tested versus MX; the performance of MX + ultrasound + BT tested versus MX + ultrasound.

RESULTS

Tomosynthesis was found to be non-inferior to mammography. BT + MX(CC) did not appear to be superior to MX, and MX + ultrasound + BT not superior to MX + ultrasound.

CONCLUSIONS

Overall, none of the five techniques tested outperformed the others. Further clinical studies are needed to clarify the role of BT as a substitute for traditional work-up in the diagnostic environment.

KEY POINTS

• Digital breast tomosynthesis is a new adjunct to mammography and breast ultrasound. • We compared the diagnostic performance of these investigations in an experimental observer study. • Single-view breast tomosynthesis was confirmed as non-inferior to dual-view mammography. • None of the investigations (or combinations) tested outperformed the others. • Further prospective studies are needed to clarify precise role of tomosynthesis for diagnostic application.

Digital tomosynthesis: a new future for breast imaging?

The aim of this article is to review the major limitations in current mammography and to describe how these may be addressed by digital breast tomosynthesis (DBT). DBT is a novel imaging technology in which an x-ray fan beam sweeps in an arc across the breast, producing tomographic images and enabling the production of volumetric, three-dimensional (3D) data. It can reduce tissue overlap encountered in conventional two-dimensional (2D) mammography, and thus has the potential to improve detection of breast cancer, reduce the suspicious presentations of normal tissues, and facilitate accurate differentiation of lesion types. This paper reviews the latest studies of this new technology. Issues including diagnostic efficacy, reading time, radiation dose, and level of compression; cost and new innovations are considered.

Breast mass characterization using 3-dimensional automated ultrasound as an adjunct to digital breast tomosynthesis: a pilot study

OBJECTIVES

The purpose of this study was to retrospectively evaluate the effect of 3-dimensional automated ultrasound (3D-AUS) as an adjunct to digital breast tomosynthesis (DBT) on radiologists' performance and confidence in discriminating malignant and benign breast masses.

METHODS

Two-view DBT (craniocaudal and mediolateral oblique or lateral) and single-view 3D-AUS images were acquired from 51 patients with subsequently biopsy-proven masses (13 malignant and 38 benign). Six experienced radiologists rated, on a 13-point scale, the likelihood of malignancy of an identified mass, first by reading the DBT images alone, followed immediately by reading the DBT images with automatically coregistered 3D-AUS images. The diagnostic performance of each method was measured using receiver operating characteristic (ROC) curve analysis and changes in sensitivity and specificity with the McNemar test. After each reading, radiologists took a survey to rate their confidence level in using DBT alone versus combined DBT/3D-AUS as potential screening modalities.

RESULTS

The 6 radiologists had an average area under the ROC curve of 0.92 for both modalities (range, 0.89-0.97 for DBT and 0.90-0.94 for DBT/3D-AUS). With a Breast Imaging Reporting and Data System rating of 4 as the threshold for biopsy recommendation, the average sensitivity of the radiologists increased from 96% to 100% (P > .08) with 3D-AUS, whereas the specificity decreased from 33% to 25% (P > .28). Survey responses indicated increased confidence in potentially using DBT for screening when 3D-AUS was added (P < .05 for each reader).

CONCLUSIONS

In this initial reader study, no significant difference in ROC performance was found with the addition of 3D-AUS to DBT. However, a trend to improved discrimination of malignancy was observed when adding 3D-AUS. Radiologists' confidence also improved with DBT/3DAUS compared to DBT alone.

Digital breast tomosynthesis (DBT): initial experience in a clinical setting

BACKGROUND

Digital breast tomosynthesis (DBT) is a promising new technology. Some experimental clinical studies have shown positive results, but the future role and indications of this new technique, whether in a screening or clinical setting, need to be evaluated.

PURPOSE

To compare digital mammography and DBT in a side-by-side feature analysis for cancer conspicuity, and to assess whether there is a potential additional value of DBT to standard state-of-the-art conventional imaging work-up with respect to detection of additional malignancies.

MATERIAL AND METHODS

The study had ethics committee approval. A total of 129 women underwent 2D digital mammography including supplementary cone-down and magnification views and breast ultrasonography if indicated, as well as digital breast tomosynthesis. The indication for conventional imaging in the clinical setting included a palpable lump in 30 (23%), abnormal mammographic screening findings in 54 (42%), and surveillance in 45 (35%) of the women. The women were examined according to present guidelines, including spot-magnification views, ultrasonography, and needle biopsies, if indicated. The DBT examinations were interpreted several weeks after the conventional imaging without knowledge of the conventional imaging findings. In a later session, three radiologists performed a side-by-side feature analysis for cancer conspicuity in a sample of 50 cases.

RESULTS

State-of-the-art conventional imaging resulted in needle biopsy of 45 breasts, of which 20 lesions were benign and a total of 25 cancers were diagnosed. The remaining 84 women were dismissed with a normal/definitely benign finding and without indication for needle biopsy. The subsequent DBT interpretation found suspicious findings in four of these 84 women, and these four women had to be called back for repeated work-up with knowledge of the tomosynthesis findings. These delayed work-ups resulted in two cancers (increasing the cancer detection by 8%) and two false-positive findings. The side-by-side feature analysis showed higher conspicuity scores for tomosynthesis compared to conventional 2D for cancers presenting as spiculated masses and distortions.

CONCLUSION

Tomosynthesis is a promising new technique. Our preliminary clinical experience shows that there is a potential for increasing the sensitivity using this new technique, especially for cancers manifesting as spiculated masses and distortions.