Combination of one-view digital breast tomosynthesis with one-view digital mammography versus standard two-view digital mammography: per lesion analysis

ACR Appropriateness Criteria® Monitoring Response to Neoadjuvant Systemic Therapy for Breast Cancer: 2022 Update

Imaging plays a vital role in managing patients undergoing neoadjuvant chemotherapy, as treatment decisions rely heavily on accurate assessment of response to therapy. This document provides evidence-based guidelines for imaging breast cancer before, during, and after initiation of neoadjuvant chemotherapy. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Imaging of the Axilla

This publication reviews the current evidence supporting the imaging approach of the axilla in various scenarios with broad differential diagnosis ranging from inflammatory to malignant etiologies. Controversies on the management of axillary adenopathy results in disagreement on the appropriate axillary imaging tests. Ultrasound is often the appropriate initial imaging test in several clinical scenarios. Clinical information (such as age, physical examinations, risk factors) and concurrent complete breast evaluation with mammogram, tomosynthesis, or MRI impact the type of initial imaging test for the axilla. Several impactful clinical trials demonstrated that selected patient's population can received sentinel lymph node biopsy instead of axillary lymph node dissection with similar overall survival, and axillary lymph node dissection is a safe alternative as the nodal staging procedure for clinically node negative patients or even for some node positive patients with limited nodal tumor burden. This approach is not universally accepted, which adversely affect the type of imaging tests considered appropriate for axilla. This document is focused on the initial imaging of the axilla in various scenarios, with the understanding that concurrent or subsequent additional tests may also be performed for the breast. 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.

PERFORMANCE COMPARISON OF SYSTEMS WITH FULL-FIELD DIGITAL MAMMOGRAPHY, DIGITAL BREAST TOMOSYNTHESIS AND CONTRAST-ENHANCED SPECTRAL MAMMOGRAPHY

The purpose is to compare full-field digital mammography (FFDM), digital breast tomosynthesis (DBT) and contrast-enhanced spectral mammography (CESM) technologies on three mammography systems in terms of image quality and patient dose. Two Senographe Essential with DBT and CESM (denoted S1 and S2) and one Selenia Dimensions (S3) with FFDM and DBT were considered. Dosimetry methods recommended in the European protocol were used. Image quality was tested with CDMAM in FFDM and DBT and with ideal observer method in FFDM. Mean values of mean glandular dose (MGD) from whole patient samples on S1, S2 and S3 were as follows: FFDM 1.65, 1.84 and 2.23 mGy; DBT 2.03, 1.96 and 2.87 mGy; CESM 2.65 and 3.16 mGy, respectively. S3 exhibited better low-contrast detectability for the smallest sized discs of CDMAM and ideal observer in FFDM, and for the largest sized discs in DBT, at similar dose levels.

Do automated breast ultrasound and tomosynthesis have an effective role in dense breast evaluation?

Background

Mammography plays a great role in reducing breast cancer mortality as it is the standard method of breast imaging and screening. But the accuracy of mammography performance reduces in cancer detection in women with dense breast due to the summation of images and overlapping of breast tissue. ABUS and tomosynthesis both recently help to detect breast cancer in dense breasted women. This prospective study was done in the female imaging unit and approved by its research and ethical committee; all the patients did an informed consent during the period from October 2018 to March 2019. The study was conducted on 38 patients with 38 lesions subjected to digital mammography, tomosynthesis and automated breast ultrasound (ABUS), who all had dense breast in mammography.

Results

Automated breast ultrasound (ABUS) showed 100% in all sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) as well as accuracy, while the digital mammography tomosynthesis showed 100% in specificity, 87.5% in sensitivity, 100% in PPV, 82.4% in NPV and 92.1% accuracy.

Conclusion

Automated breast ultrasound (ABUS) together with tomosynthesis makes a revolution in breast screening and detecting cancer in women with dense breasts.

Malignancy Upgrade Rates of Radial Sclerosing Lesions at Breast Cancer Screening

Purpose To determine the upgrade rate for biopsy-proven radial scars and radial sclerosing lesions (RS). Materials and Methods In this retrospective study, radiology and pathology databases from two tertiary breast centers were searched to identify patients with biopsy-confirmed RS between March 1, 2012, and December 31, 2017, during which all mammography was performed with digital breast tomosynthesis (DBT). Adjunct modalities such as MRI or US are performed at our centers to better characterize lesions identified at DBT. Patient demographics, imaging, needle and excisional biopsies, and follow-up data were collected at the patient level. Clopper-Pearson interval estimate for upgrade was calculated for 95% confidence using PropCIs package with R version 4.1.0 (R Foundation for Statistical Computing) (1). Results During the study period, a total of 155 885 DBT examinations were performed. From these examinations, 146 biopsy-proven RS were identified in 142 women (median age, 58 years; age range, 26-87 years). A total of 80.1% (117 of 146) of all RS did not have associated atypia or malignancy, and 19.9% (29 of 146) had associated atypia at initial biopsy. A total of 66.7% (78 of 117) of RS without atypia or malignancy were surgically excised, 25.6% (30 of 117) were followed (median, 3 years; range, 1-7 years) with benign findings on imaging, and 7.7% (nine of 117) were lost to follow-up. The rate of malignancy upgrade was 0.9% (one of 117 [95% CI: 0.02, 4.7]); one RS without concurrent atypia or malignancy demonstrated invasive carcinoma at surgical excision. Conclusion RS without atypia had a low upgrade rate. Keywords: Mammography, Breast © RSNA, 2021.

Comparison of two-view versus single-view digital breast tomosynthesis and 2D-mammography in breast cancer surveillance imaging

PURPOSE

Limited work has been performed for the implementation of digital breast tomosynthesis (DBT) in breast cancer surveillance imaging. The aim of this study was to investigate the differences between two different DBT implementations in breast cancer surveillance imaging, for patients with a personal history of breast cancer.

METHOD

The DBT implementations investigated were: (1) 2-view 2D digital mammography and 2-view DBT (2vDM&2vDBT) (2) 1-view (cranial-caudal) DM and 1-view (mediolateral-oblique) DBT (1vDM&1vDBT). Clinical performance of these two implementations was assessed retrospectively using observer studies with 118 sets of real patient images, from a single imaging centre, and six observers. Sensitivity, specificity and area under the curve (AUC) using the Jack-knife alternative free-response receiver operating characteristics (JAFROC) analysis were evaluated.

RESULTS

Results suggest that the two DBT implementations are not significantly different in terms of sensitivity, specificity and AUC. When looking at the two main different lesion types, non-calcifications and calcifications, and two different density levels, no difference in the performance of the two DBT implementations was found.

CONCLUSIONS

Since 1vDM&1vDBT exposes the patient to half the dose of 2vDM&2vDBT, it might be worth considering 1vDM&1vDBT in breast cancer surveillance imaging. However, larger studies are required to conclude on this matter.

Reader performances in breast lesion characterization via DBT: One or two views and which view?

PURPOSE

To compare the performance in breast lesion characterization of one-view mediolateral (MLO) digital mammography plus digital breast tomosynthesis (DM-DBT) versus one-view craniocaudal (CC) DM-DBT versus two-view DM-DBT.

MATERIALS AND METHODS

The institutional review board approved this retrospective study conducted on 138 women from the population of a previous prospective multicenter study, with 69 consecutive patients with benign or high-risk lesions and 69 randomized patients with breast cancer, all confirmed at pathology. Four radiologists (two senior and two junior) blinded to the clinical, mammographic and pathological data independently reviewed the MLO DM-DBT views, the CC DM-DBT views and the MLO + CC DM-DBT views using the American College of Radiology Breast Imaging-Reporting and Data System criteria for index lesion characterization. Areas under the receiver were calculated and compared for each reader and imaging protocol.

RESULTS

No significant differences in breast cancer characterization were observed between single MLO and CC views for all the readers. The added value of a second view was statistically significant for characterization in pooled data and for junior readers but not for senior readers (p ranging from 0.15 to 0.57 depending on the view and the senior reader). Finally, in 4 breast cancer cases, lesions were only detectable on the CC DM-DBT view in two cases and on the MLO DM-DBT view in the two other cases.

CONCLUSION

Our results support the use of two-view DM-DBT for breast lesion characterization when the readers are inexperienced. There is no significant difference between CC and MLO views when diagnosis is performed with one view.

Is there any added value to substitute the 2D digital MLO projection for a MLO tomosynthesis projection and its synthetic view when a 2D standard digital mammography is used in a one-stop-shop immediate reading mammography screening?

OBJECTIVES

Breast cancer screening consists of batch interpretation of two-view (cranio-caudal CC- and medio-lateral oblique MLO) digital mammography (DM) per breast. The DM-MLO view was substituted by an MLO-digital breast tomosynthesis (DBT) and its synthetic (2D-synthetic mammography (SM)-MLO) view. The performance of this hybrid protocol was evaluated in a one-stop-shop screening visit, providing immediate reading and additional work up.

METHODS

Retrospective, observational review, comparing the cancer detection rate (CDR), breast US rates, and biopsy rates in 13,048 women screened with DM from June 2015 to November 2016 and 8639 women screened with SM-DBT/DM from January 2017 to July 2018. Chi-square tests or Fisher's exact tests were used to compare proportions between the two screening imaging methods.

RESULTS

SM + DBT/DM significantly increased the overall CDR (10.8‰) versus DM (7.5‰) (p = 0.0120) with more invasive lobular carcinoma (14% versus 4%) (p = 0.0357) detected and overall more invasive cancers among women with breast density type B (p = 0.0411) and those aged between 60 and 70 (p = 0.0306). This was achieved at the expense of additional sonographic examinations performed (33.5% in DBT group versus 26.7% in DM group) (p < 0.0001), more BI-RADS category III assigned (1.8% in SM-DBT/DM group versus 1.5% in DM group) (p = 0.0443) and more biopsy rates (3.0 % in SM-DBT/DM group versus 1.7% in DM group) (p < 0.0001).

CONCLUSIONS

Hybrid mammographic protocol replacing 2D-MLO by DBT-MLO and SM-MLO views in a one-stop-shop screening visit improved CDR, at the expense of more sonographic examinations, biopsies, and BI-RADS III lesions. Breast US alone detected 9.2% of all breast cancers in this cohort.

KEY POINTS

• Hybrid protocol including MLO (DBT + SM) with 2D DM CC may improve CDR compared to standard 4 views 2D DM in a screening program providing immediate interpretation. • Adding screening breast US, when perceived necessary, in the same visit of a screening mammography, increases cancer detection rate of 9.2%. • Based on our results, hybrid protocol including DBT + SM in MLO plane and DM in CC plane could be safely implemented as a transition towards DBT and SM alone, without any compromise in the cancer detection ability. Our results may vary according to the properties of machines from different vendors.

ACR Appropriateness Criteria® Imaging After Mastectomy and Breast Reconstruction

Mastectomy may be performed to treat breast cancer or as a prophylactic approach in women with a high risk of developing breast cancer. In addition, mastectomies may be performed with or without reconstruction. Reconstruction approaches differ and may be autologous, involving a transfer of tissue (skin, subcutaneous fat, and muscle) from other parts of the body to the chest wall. Reconstruction may also involve implants. Implant reconstruction may occur as a single procedure or as multistep procedures with initial use of an adjustable tissue expander allowing the mastectomy tissues to be stretched without compromising blood supply. Ultimately, a full-volume implant will be placed. Reconstructions with a combination of autologous and implant reconstruction may also be performed. Other techniques such as autologous fat grafting may be used to refine both implant and flap-based reconstruction. This review of imaging in the setting of mastectomy with or without reconstruction summarizes the literature and makes recommendations based on available evidence. 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.

A Review of Breast Pain: Causes, Imaging Recommendations, and Treatment

Over two-thirds of women will experience breast pain in their lifetime. As one of the leading breast symptoms for which women seek medical attention, breast pain is suspected to be underreported and under-studied. Cyclical breast pain is related to hormonal changes. Noncyclical breast pain is independent of the menstrual cycle and can be idiopathic and related to chronic pain syndromes, infections, ill-fitting bras, musculoskeletal abnormalities, pregnancy, perimenopause, and postsurgical causes. Breast pain can also present in transgender patients and may require additional considerations as to the underlying cause. Imaging of mastalgia depends upon the suspected etiology. Inappropriate imaging for breast pain is associated with significant utilization of health care resources. Cyclical breast pain does not require an imaging work-up. The work-up of focal, noncyclical breast pain includes ultrasound for women aged younger than 40 years, and mammography and ultrasound for women aged 40 years and older. Management of breast pain is often supportive, as most breast pain resolves spontaneously. If pain persists, imaging and management should follow a step-wise approach. If conservative measures fail, second-line therapy is topical nonsteroidal anti-inflammatory drugs. If breast pain is severe and resistant to conservative methods, additional third-line therapies can be added by breast care specialists with specific knowledge of the potential deleterious side effects of these medications. While the causes of mastalgia are overwhelmingly benign, breast pain can significantly impact quality of life, and the breast radiologist should be familiar with causes, management, and treatment recommendations from a multidisciplinary approach.

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.

ACR Appropriateness Criteria® Breast Pain

Breast pain is a common complaint. However, in the absence any accompanying suspicious clinical finding (eg, lump or nipple discharge), the association with malignancy is very low (0%-3.0%). When malignancy-related, breast pain tends to be focal (less than one quadrant) and persistent. Pain that is clinically insignificant (nonfocal [greater than one quadrant], diffuse, or cyclical) requires no imaging beyond what is recommended for screening. In cases of pain that is clinically significant (focal and noncyclical), imaging with mammography, digital breast tomosynthesis (DBT), and ultrasound are appropriate, depending on the patient's age. 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.

A new breast tomosynthesis imaging method: Continuous Sync-and-Shoot - technical feasibility and initial experience

Background

Digital breast tomosynthesis (DBT) is gaining popularity in breast imaging. There are several different technical approaches for conducting DBT imaging.

Purpose

To determine optimal imaging parameters, test patient friendliness, evaluate the initial diagnostic performance, and describe diagnostic advances possible with the new Continuous Sync-and-Shoot method.

Material and Methods

Thirty-six surgical breast specimens were imaged with digital mammography (DM) and a prototype of a DBT system (Planmed Oy, Helsinki, Finland). We tested the patient friendliness of the sync-and-shoot movement without radiation exposure in eight volunteers. Different imaging parameters were tested with 20 specimens to identify the optimal combination: angular range 30°, 40°, and 60°; pixel binning; Rhodium (Rh) and Silver (Ag) filtrations; and different kV and mAs values. Two breast radiologists evaluated 16 DM and DBT image pairs and rated six different image properties. Imaging modalities were compared with paired t-test.

Results

The Continuous Sync-and-Shoot method produced diagnostically valid images. Five out of eight volunteers felt no/minimal discomfort, three experienced mild discomfort from the tilting movement of the detector, with the motion being barely recognized. The combination of 30°, Ag filtering, and 2 × 2 pixel binning produced the best image quality at an acceptable dose level. DBT was significantly better in all six evaluated properties (P < 0.05). Mean Dose_DBT/Dose_DM ratio was 1.22 (SD = 0.42).

Conclusion

The evaluated imaging method is feasible for imaging and analysing surgical breast specimens and DBT is significantly better than DM in image evaluation.

ACR Appropriateness Criteria® Monitoring Response to Neoadjuvant Systemic Therapy for Breast Cancer

Patients with locally advanced invasive breast cancers are often treated with neoadjuvant chemotherapy prior to definitive surgical intervention. The primary aims of this approach are to: 1) reduce tumor burden thereby permitting breast conservation rather than mastectomy; 2) promptly treat possible metastatic disease, whether or not it is detectable on preoperative staging; and 3) potentially tailor future chemotherapeutic decisions by monitoring in-vivo tumor response. Accurate radiological assessment permits optimal management and planning in this population. However, assessment of tumor size and response to treatment can vary depending on the modality used, the measurement technique (such as single longest diameter, 3-D measurements, or calculated tumor volume), and varied response of different tumor subtypes to neoadjuvant chemotherapy (such as concentric shrinkage or tumor fragmentation). As discussed in further detail, digital mammography, digital breast tomosynthesis, US and MRI represent the key modalities with potential to help guide patient management. 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.

ACR Appropriateness Criteria® Evaluation of Nipple Discharge

Appropriate imaging evaluation of nipple discharge depends the nature of the discharge. Imaging is not indicated for women with physiologic nipple discharge. For evaluation of pathologic nipple discharge, multiple breast imaging modalities are rated for evidence-based appropriateness under various scenarios. For women age 40 or older, mammography or digital breast tomosynthesis (DBT) should be the initial examination. Ultrasound is usually added as a complementary examination, with some exceptions. For women age 30 to 39, either mammogram or ultrasound may be used as the initial examination on the basis of institutional preference. For women age 30 or younger, ultrasound should be the initial examination, with mammography/DBT added when ultrasound shows suspicious findings or if the patient is predisposed to developing breast cancer. For men age 25 or older, mammography/DBT should be performed initially, with ultrasound added as indicated, given the high incidence of breast cancer in men with pathologic nipple discharge. Although MRI and ductography are not usually appropriate as initial examinations, each may be useful when the initial standard imaging evaluation is negative. 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.

Characterization of Breast Masses in Digital Breast Tomosynthesis and Digital Mammograms: An Observer Performance Study

RATIONALE AND OBJECTIVES

This study aimed to compare Breast Imaging Reporting and Data System (BI-RADS) assessment of lesions in two-view digital mammogram (DM) to two-view wide-angle digital breast tomosynthesis (DBT) without DM.

MATERIALS AND METHODS

With Institutional Review Board approval and written informed consent, two-view DBTs were acquired from 134 subjects and the corresponding DMs were collected retrospectively. The study included 125 subjects with 61 malignant (size: 3.9-36.9 mm, median: 13.4 mm) and 81 benign lesions (size: 4.8-43.8 mm, median: 12.0 mm), and 9 normal subjects. The cases in the two modalities were read independently by six experienced Mammography Quality Standards Act radiologists in a fully crossed counterbalanced manner. The readers were blinded to the prevalence of malignant, benign, or normal cases and were asked to assess the lesions based on the BI-RADS lexicon. The ratings were analyzed by the receiver operating characteristic methodology.

RESULTS

Lesion conspicuity was significantly higher (P << .0001) and fewer lesion margins were considered obscured in DBT. The mean area under the receiver operating characteristic curve for the six readers increased significantly (P = .0001) from 0.783 (range: 0.723-0.886) for DM to 0.911 (range: 0.884-0.936) for DBT. Of the 366 ratings for malignant lesions, 343 on DBT and 278 on DM were rated as BI-RADS 4a and above. Of the 486 ratings for benign lesions, 220 on DBT and 206 on DM were rated as BI-RADS 4a and above. On average, 17.8% (65 of 366) more malignant lesions and 2.9% (14 of 486) more benign lesions would be recommended for biopsy using DBT. The inter-radiologist variability was reduced significantly.

CONCLUSION

With DBT alone, the BI-RADS assessment of breast lesions and inter-radiologist reliability were significantly improved compared to DM.

The role of digital breast tomosynthesis in the breast assessment clinic: a review

Mammography has long been considered as the primary technique in breast cancer detection and assessment. Despite low specificity, mammography has been preferred over other contemporary techniques such as magnetic resonance imaging (MRI), computed tomography (CT) and ultrasonography (US) due to superior sensitivity and significant health economic benefits. The development of a new technique, a limited angle cone beam pseudo-three-dimensional tomosynthesis, digital breast tomosynthesis (DBT), has gained momentum. Several preliminary studies and ongoing trials are showing evidence of the benefits of DBT in improving lesion visibility, accuracy of cancer detection and observer performance. This raises the possibility of adoption of DBT in the breast cancer assessment clinic, wherein confirming or dismissing the presence of malignancy (at the potential site identified during screening) is of utmost importance. Identification of suspected malignancy in terms of lesion characteristics and location is also essential in assessment. In this literature review, we evaluate the role of DBT for use in breast cancer assessment and its future in biopsy.

New diagnostic tools for breast cancer

Imaging plays a major role in the diagnosis, treatment, and follow-up of breast cancer. Findings that require further assessment will be detected both at screening and curative mammography. Most findings that are further worked up tend to yield benign diagnoses. Consequently, there is an ongoing search for new tools to reduce recalls and unnecessary biopsies while maintaining or improving cancer detection rates. The clinically most promising methods in this respect are described and discussed in this review.

ACR Appropriateness Criteria® Stage I Breast Cancer: Initial Workup and Surveillance for Local Recurrence and Distant Metastases in Asymptomatic Women

Women and health care professionals generally prefer intensive follow-up after a diagnosis of breast cancer. However, there are no survival differences between women who obtain intensive surveillance with imaging and laboratory studies compared with women who only undergo testing because of the development of symptoms or findings on clinical examinations. American Society of Clinical Oncology and National Comprehensive Cancer Network guidelines state that annual mammography is the only imaging examination that should be performed to detect a localized breast recurrence in asymptomatic patients; more imaging may be needed if the patient has locoregional symptoms (eg, palpable abnormality). Women with other risk factors that increase their lifetime risk for breast cancer may warrant evaluation with breast MRI. Furthermore, the quality of life is similar for women who undergo intensive surveillance compared with those who do not. There is little justification for imaging to detect or rule out metastasis in asymptomatic women with newly diagnosed stage I breast cancer. 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.

Imaging features and conspicuity of invasive lobular carcinomas on digital breast tomosynthesis

OBJECTIVE

To review the imaging features of invasive lobular carcinoma (ILC) seen on digital breast tomosynthesis (DBT) in comparison with invasive ductal carcinoma (IDC), and to evaluate whether DBT could improve conspicuity and tumour size assessment of ILC in comparison with digital mammography (DM).

METHODS

Institutional review board with waiver of informed consent was obtained for this retrospective study. Patients with ILC or IDC who underwent DBT and DM at the time of diagnosis were included. DM and DBT images were reviewed in consensus by two breast radiologists in order to assess imaging features, conspicuity and maximum tumour diameter of ILC and IDC. Pathology on the surgical specimen was considered the standard of reference for assessment of tumour size.

RESULTS

43 patients (20 patients with ILC and 23 patients with IDC) were included. On DBT, compared with IDC, ILC presented less frequently as masses (40% vs 78%) (p = 0.01) and more frequently as isolated distortion (20% vs 0%) (p = 0.03). ILC presented more often as asymmetries (60%) than masses (20%) on DM (p = 0.02) but not on DBT (35% vs 40%; p = 1.00). Conspicuity of ILC was significantly higher on DBT than on DM (p = 0.002), while the difference between the two techniques was not significant for IDC (p = 0.2). Regarding ILC, concordance in tumour size measurement between DBT and pathology was fair (intraclass correlation coefficient = 0.24).

CONCLUSION

ILC rarely presented as dense masses but frequently demonstrated architectural distortion on DBT. DBT increased lesion conspicuity but failed to accurately assess tumour size of ILC. Advances in knowledge: (1) This study describes specific features of ILC on DBT. (2) It shows that DBT can improve conspicuity of ILC.

Replacing single-view mediolateral oblique (MLO) digital mammography (DM) with synthesized mammography (SM) with digital breast tomosynthesis (DBT) images: Comparison of the diagnostic performance and radiation dose with two-view DM with or without MLO-DBT

OBJECTIVES

To evaluate the diagnostic performance and radiation dose of single view cranio-caudal (CC) digital mammography (DM) plus mediolateral oblique (MLO) digital breast tomosynthesis (DBT) combined with synthesized mammography (SM) in comparison with two-view DM with or without DBT.

MATERIAL AND METHODS

This study was approved by our institutional review board, and informed consent was obtained from 130 women. Paired two-view DM and single MLO-DBT with SM images were acquired, and four independent retrospective reading sessions of different combinations of DM, SM and DBT were performed for the presence of malignant tumors using jackknife alternative free-response receiver operator curve (JAFROC) methods. The diagnostic performances and average glandular dose (AGD) were compared between different combinations of DM, SM and DBT.

RESULTS

Of 159 lesions in 130 patients, 27 were malignant. When using MLO-DBT with SM instead of MLO-DM, a significantly higher sensitivity (P=0.016) and specificity (P=0.012) were noted than with two-view DM, and comparable figure of merit (FOM), sensitivity, and specificity to two-view DM with DBT were noted. The mean AGD of CC-DM plus MLO-DBT with SM was 5.78mGy±1.06 per patient, which was significantly lower than that with two-view DM with MLO-DBT (8.45mGy±1.32; P <0.001) and slightly higher than that with two-view DM (5.30mGy±0.63).

CONCLUSIONS

The combined use of CC-DM plus MLO-DBT with SM showed higher sensitivity and specificity to two-view DM with a smaller AGD increment and comparable diagnostic performance to that of two-view DM with MLO-DBT with a significantly lower mean AGD.

Strategies to Increase Cancer Detection: Review of True-Positive and False-Negative Results at Digital Breast Tomosynthesis Screening

Digital breast tomosynthesis (DBT) represents a valuable addition to breast cancer screening by decreasing recall rates while increasing cancer detection rates. The increased accuracy achieved with DBT is due to the quasi-three-dimensional format of the reconstructed images and the ability to "scroll through" breast tissue in the reconstructed images, thereby reducing the effect of tissue superimposition found with conventional planar digital mammography. The margins of both benign and malignant lesions are more conspicuous at DBT, which allows improved lesion characterization, increased reader confidence, and improved screening outcomes. However, even with the improvements in accuracy achieved with DBT, there remain differences in breast cancer conspicuity by mammographic view. Early data suggest that breast cancers may be more conspicuous on craniocaudal (CC) views than on mediolateral oblique (MLO) views. While some very laterally located breast cancers may be visualized on only the MLO view, the increased conspicuity of cancers on the CC view compared with the MLO view suggests that DBT screening should be performed with two-view imaging. Even with the improved conspicuity of lesions at DBT, there may still be false-negative studies. Subtle lesions seen on only one view may be discounted, and dense and/or complex tissue patterns may make some cancers occult or extremely difficult to detect. Therefore, radiologists should be cognizant of both perceptual and cognitive errors to avoid potential pitfalls in lesion detection and characterization. ^©RSNA, 2016 Online supplemental material is available for this article.

Detection and characterization of breast lesions in a selective diagnostic population: diagnostic accuracy study for comparison between one-view digital breast tomosynthesis and two-view full-field digital mammography

OBJECTIVE

To compare the performance of one-view digital breast tomosynthesis (DBT) and two-view full-field digital mammography (FFDM) in the detection and characterization of breast lesions in a selective diagnostic population.

METHODS

A total of 598 breasts of 319 diagnostic patients were prospectively enrolled. Participants underwent bilateral one-view, mediolateral oblique (MLO) DBT and two-view, craniocaudal and MLO FFDM. The sensitivity and specificity of these methods and their classification into correct Breast Imaging-Reporting and Data System (BI-RADS) categories were compared. These methods were also compared in patients subgrouped by mammographic parenchymal density. Receiver operating characteristic (ROC) curve analysis was performed using the probability of cancer scores.

RESULTS

DBT had higher overall sensitivity than FFDM (88.7% vs 80.7%, p = 0.001). Subgroup analyses showed that DBT had significantly higher sensitivity in assessing dense breasts and invasive cancers than FFDM. The BI-RADS category assessment was significantly better for DBT than for FFDM. The differences between the two modalities in specificity (94.1% and 93.2% for FFDM and DBT) were not significant (p = 0.664). The area under the ROC curves using the probability of cancer scores were 0.93 [95% confidence interval (CI), 0.91-0.95] for FFDM and 0.96 (95% CI, 0.94-0.97) for DBT (p = 0.005). ROC curve analysis indicated that most of the increased performance of DBT was due to dense breasts.

CONCLUSION

A beneficial effect on the detection and characterization of breast lesions was found for one-view DBT compared with two-view FFDM in a selective diagnostic population. Improvements were especially enhanced in females with dense breasts. These results need to be examined in studies using large-scale consecutive sampling of a diagnostic population.

ADVANCES IN KNOWLEDGE

In this study, using selective diagnostic study cases, one-view DBT offered improved reader performance compared with two-view FFDM for detection and characterization of breast cancers.

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.

Monte Carlo simulation for the estimation of the glandular breast dose for a digital breast tomosynthesis system

Digital breast tomosynthesis (DBT) is a screening and diagnostic modality that acquires images of the breast at multiple angles during a short scan. The Selenia Dimensions (Hologic, Bedford, Mass) DBT system can perform both full-field digital mammography and DBT. The system acquires 15 projections over a 15° angular range (from -7.5° to +7.5°). An important factor in determining the optimal imaging technique for breast tomosynthesis is the radiation dose. In breast imaging, the radiation dose of concern is that deposited in the glandular tissue of the breast because this is the tissue that has a risk of developing cancer. The concept of the normalised mean glandular dose (DgN) has been introduced as the metric for the dose in breast imaging. The DgN is difficult to measure. The Monte Carlo techniques offer an alternative method for a realistic estimation of the radiation dose. The purpose of this work was to use the Monte Carlo code MCNPX technique to generate monoenergetic glandular dose data for estimating the breast tissue dose in tomosynthesis for arbitrary spectra as well as to observe the deposited radiation dose by projection on the glandular portion of the breast in a Selenia Dimensions DBT system. A Monte Carlo simulation of the system was developed to compute the DgN in a craniocaudal view. Monoenergetic X-ray beams from 10 to 49 keV in 1-keV increments were used. The simulation utilised the assumption of a homogeneous breast composition and three compositions (0 % glandular, 50 % glandular and 100 % glandular). The glandular and adipose tissue compositions were specified according ICRU Report 44. A skin layer of 4 mm was assumed to encapsulate the breast on all surfaces. The breast size was varied using the chest wall-to-nipple distance (CND) and compressed breast thickness (t). In this work, the authors assumed a CND of 5 cm and the thicknesses ranged from 2 to 8 cm, in steps of 2 cm. The fractional energy absorption increases (up to 44.35 % between 0 % glandular and 100 % glandular) with the increase in the glandular fraction due to changing the composition and increasing the density. Low-energy photon absorption occurred in the first tissue layer. The DgN decreases with increasing the compressed breast thickness. The graphs show that between 15 and 30 keV provides the greatest contribution to the dose and that the glandular dose is almost constant as a function of the projection angle. The results may be useful for optimising tomosynthesis procedures and evaluating the dose distribution in the projections in a craniocaudal view.

[Clinical practice guidelines: Benign breast tumor--Aims, methods and organization]

Conversely to breast cancer, few data and guidelines are available to explore and manage benign breast disorders. Therefore, the Collège national des gynécologues et obstétriciens français (CNGOF - French College of Gynaecologists and Obstetricians) decided to establish clinical practice guidelines for benign breast tumour (BBT). CNGOF appointed a committee with responsibility for selecting experts, compiling questions and summarizing the recommendations. The summary of valid scientific data for each question analyzed by the experts included a level of evidence, based on the quality of the data available and defined accordingly rating scheme developed by the Haute Autorité de santé (French National Authority for Health).

"Off Label" Use of FDA-Approved Devices and Digital Breast Tomosynthesis

OBJECTIVE

The purpose of this article is to clarify for radiologists the meaning of U.S. Food and Drug Administration (FDA) approval with respect to Digital Breast Tomosynthesis (DBT).

CONCLUSION

DBT is a major improvement over 2D mammography in the detection of cancers (sensitivity) and the reduction in recalls resulting from screening (specificity). Most imaging systems that have been approved by the FDA are used "off label" for breast imaging. Although the FDA determines which claims a manufacturer can make for a device, physicians may use approved devices, such as DBT, off label to provide better patient care.

Digital Breast Tomosynthesis guided Near Infrared Spectroscopy: Volumetric estimates of fibroglandular fraction and breast density from tomosynthesis reconstructions

A multimodality system combining a clinical prototype digital breast tomosynthesis with its imaging geometry modified to facilitate near-infrared spectroscopic imaging has been developed. The accuracy of parameters recovered from near-infrared spectroscopy is dependent on fibroglandular tissue content. Hence, in this study, volumetric estimates of fibroglandular tissue from tomosynthesis reconstructions were determined. A kernel-based fuzzy c-means algorithm was implemented to segment tomosynthesis reconstructed slices in order to estimate fibroglandular content and to provide anatomic priors for near-infrared spectroscopy. This algorithm was used to determine volumetric breast density (VBD), defined as the ratio of fibroglandular tissue volume to the total breast volume, expressed as percentage, from 62 tomosynthesis reconstructions of 34 study participants. For a subset of study participants who subsequently underwent mammography, VBD from mammography matched for subject, breast laterality and mammographic view was quantified using commercial software and statistically analyzed to determine if it differed from tomosynthesis. Summary statistics of the VBD from all study participants were compared with prior independent studies. The fibroglandular volume from tomosynthesis and mammography were not statistically different (p=0.211, paired t-test). After accounting for the compressed breast thickness, which were different between tomosynthesis and mammography, the VBD from tomosynthesis was correlated with (r =0.809, p<0.001), did not statistically differ from (p>0.99, paired t-test), and was linearly related to, the VBD from mammography. Summary statistics of the VBD from tomosynthesis were not statistically different from prior studies using high-resolution dedicated breast computed tomography. The observation of correlation and linear association in VBD between mammography and tomosynthesis suggests that breast density associated risk measures determined for mammography are translatable to tomosynthesis. Accounting for compressed breast thickness is important when it differs between the two modalities. The fibroglandular volume from tomosynthesis reconstructions is similar to mammography indicating suitability for use during near-infrared spectroscopy.

Digital breast tomosynthesis at screening assessment: are two views always necessary?

OBJECTIVE

The current recommendation from the UK National Health Service Breast Screening Programme is that digital breast tomosynthesis (DBT) can be used for further assessment of possible screen-detected soft-tissue abnormalities in place of spot compression views and when used should be performed in two projections. The aim of the study was to assess whether two-view DBT is necessary if the abnormality is seen only in one view on initial full-field digital mammography (FFDM).

METHODS

617 cases with possible masses, distortions and asymmetrical densities visualized only in one view on screening FFDM were included. All of these females underwent two-view DBT, clinical examination and ultrasound. The FFDM and DBT findings on each view were compared and correlated with the histological diagnosis.

RESULTS

586 of 617 cases had normal or benign findings on further assessment, and no additional information was obtained on the other DBT view. There were 31 confirmed cancers. In 26 cases (84%), the cancer was seen on the corresponding DBT view. No cancer was seen on the other DBT view alone. Five cancers (16%) were not seen on either view on DBT owing to technical reasons. No cancers would have been missed if only the corresponding DBT view was performed.

CONCLUSION

Two-view DBT may not be necessary when used for further assessment of possible screen-detected soft-tissue abnormalities. Larger studies should be undertaken to investigate this further.

ADVANCES IN KNOWLEDGE

One-view DBT may be adequate in assessing soft-tissue abnormalities seen only on one FFDM view.

Digital breast tomosynthesis: observer performance of clustered microcalcification detection on breast phantom images acquired with an experimental system using variable scan angles, angular increments, and number of projection views

PURPOSE

To investigate the dependence of microcalcification cluster detectability on tomographic scan angle, angular increment, and number of projection views acquired at digital breast tomosynthesis ( DBT digital breast tomosynthesis ).

MATERIALS AND METHODS

A prototype DBT digital breast tomosynthesis system operated in step-and-shoot mode was used to image breast phantoms. Four 5-cm-thick phantoms embedded with 81 simulated microcalcification clusters of three speck sizes (subtle, medium, and obvious) were imaged by using a rhodium target and rhodium filter with 29 kV, 50 mAs, and seven acquisition protocols. Fixed angular increments were used in four protocols (denoted as scan angle, angular increment, and number of projection views, respectively: 16°, 1°, and 17; 24°, 3°, and nine; 30°, 3°, and 11; and 60°, 3°, and 21), and variable increments were used in three (40°, variable, and 13; 40°, variable, and 15; and 60°, variable, and 21). The reconstructed DBT digital breast tomosynthesis images were interpreted by six radiologists who located the microcalcification clusters and rated their conspicuity.

RESULTS

The mean sensitivity for detection of subtle clusters ranged from 80% (22.5 of 28) to 96% (26.8 of 28) for the seven DBT digital breast tomosynthesis protocols; the highest sensitivity was achieved with the 16°, 1°, and 17 protocol (96%), but the difference was significant only for the 60°, 3°, and 21 protocol (80%, P < .002) and did not reach significance for the other five protocols (P = .01-.15). The mean sensitivity for detection of medium and obvious clusters ranged from 97% (28.2 of 29) to 100% (24 of 24), but the differences fell short of significance (P = .08 to >.99). The conspicuity of subtle and medium clusters with the 16°, 1°, and 17 protocol was rated higher than those with other protocols; the differences were significant for subtle clusters with the 24°, 3°, and nine protocol and for medium clusters with 24°, 3°, and nine; 30°, 3°, and 11; 60°, 3° and 21; and 60°, variable, and 21 protocols (P < .002).

CONCLUSION

With imaging that did not include x-ray source motion or patient motion during acquisition of the projection views, narrow-angle DBT digital breast tomosynthesis provided higher sensitivity and conspicuity than wide-angle DBT digital breast tomosynthesis for subtle microcalcification clusters.