The Use of Breast Imaging to Screen Women at High Risk for Cancer

ACR Appropriateness Criteria® Female Breast Cancer Screening: 2023 Update

Early detection of breast cancer from regular screening substantially reduces breast cancer mortality and morbidity. Multiple different imaging modalities may be used to screen for breast cancer. Screening recommendations differ based on an individual's risk of developing breast cancer. Numerous factors contribute to breast cancer risk, which is frequently divided into three major categories: average, intermediate, and high risk. For patients assigned female at birth with native breast tissue, mammography and digital breast tomosynthesis are the recommended method for breast cancer screening in all risk categories. In addition to the recommendation of mammography and digital breast tomosynthesis in high-risk patients, screening with breast MRI is recommended. 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.

Molecular Breast Imaging and Positron Emission Mammography

There is growing interest in application of functional imaging modalities for adjunct breast imaging due to their unique ability to evaluate molecular/pathophysiologic changes, not visible by standard anatomic breast imaging. This has led to increased use of nuclear medicine dedicated breast-specific single photon and coincidence imaging systems for multiple indications, such as supplemental screening, staging of newly diagnosed breast cancer, evaluation of response to neoadjuvant treatment, diagnosis of local disease recurrence in the breast, and problem solving. Studies show that these systems maybe especially useful for specific subsets of patients, not well served by available anatomic breast imaging modalities.

Imaging of breast cancer-beyond the basics

Imaging of breast cancer is the backbone of breast cancer screening, diagnosis, preoperative/treatment assessment and follow-up. The main modalities are mammography, ultrasound and magnetic resonance imaging, each with its own advantages and disadvantages. New emerging technologies have also enabled each modality to improve on their weaknesses. Imaging-guided biopsies have allowed for accurate diagnosis of breast cancer, with low complication rates. The purpose of this article is to review the common modalities for breast cancer imaging in current practice with emphasis on the strengths and potential weaknesses, discuss the selection of the best imaging modality for the specific clinical question or patient population, and explore new technologies / future directions of breast cancer imaging.

Factors Associated With Breast Cancer Screening Behaviors Among Women With Dense Breasts

OBJECTIVE

We sought to identify patient factors associated with patient-reported screening behaviors in women with dense breasts.

METHODS

An IRB-approved survey study of women with dense breasts presenting for annual screening mammography at an outpatient imaging center was previously conducted from March 2017 to February 2018. The survey included questions regarding mammographic screening frequency and recent participation in supplemental screening. These survey data were combined post hoc with clinical and demographic data and socioeconomic data imputed from census data. Logistic regression was used to identify patient factors associated with reported screening behaviors.

RESULTS

Surveys were completed by 508 women (median age, 59.0 years; range, 31.0-86.0 years) with dense breasts. Multivariable analysis demonstrated an independent association of undergoing mammographic screening annually with a history of discussing breast density with a doctor (adjusted odds ratio [AOR], 2.60; P = 0.019). Undergoing supplemental screening in the previous three years was independently associated with younger age (AOR, 1.59; P = 0.004), strong family history of breast cancer (AOR, 3.84; P = 0.027), higher perceived personal risk for breast cancer (AOR, 3.47; P = 0.004), and increased concern about radiation associated with screening examinations (AOR, 3.31; P = 0.006).

CONCLUSION

Women with dense breasts who had discussed breast density with a doctor were more likely to report undergoing annual screening mammography, while younger women and women with a strong family history of breast cancer, higher perceived personal risk for breast cancer, or greater concern about radiation were more likely to report recently undergoing supplemental screening.

Does MRI have added value in ultrasound-detected BIRADS-3 breast masses in candidates for assisted reproductive therapy?

Background

Ultrasound-detected breast lesions with probably benign features are a great challenge for clinicians, especially in breasts with dense composition. We aimed to investigate the finding of two radiologic modalities on these lesions.

Methods

This retrospective cross-sectional study recruited patients including (1) candidates of assisted reproductive therapy (ART), (2) patients with prior high-risk lesions, and (3) the "suspected" BIRADS-3 masses referring to masses that US BIRADS-3 was not compatible with the clinical breast exam. The degree of agreement in diagnosing BIRADS-3 lesions between two modalities of magnetic resonance imaging (MRI) and ultrasonography (US), and comparison of the lesions in US and MRI were the study variables.

Results

A total number of 123 lesions in 67 patients with a median age of 38 (IQR: 11, range: 17-67). In the examination by MRI, 107 (87.0 %) lesions were BIRADS-3 indicating the agreement level between these two modalities. The median size of the lesions in US was 9 mm (IQR: 5, range: 3-43) and 9 mm (IQR: 10, range: 4-46) in MRI. The measured size of the lesions between the two modalities was highly correlated (Spearman correlation coefficient: 0.889, P-value < 0.001). MRI evaluation revealed two cases of deep lesions which were missed in the US imaging.

Conclusions

This study found relatively high agreement values between US and MRI in detecting BIRADS-3 breast lesions in candidates for ART or patients with prior high-risk lesions. Also, MRI could downgrade about one-tenth of the cases to a lower BIRADS level and resolved the need for closer follow-up.

Body mass index, breast density, and the risk of breast cancer development in relation to the menopausal status; results from a population-based screening program in a native African-Arab country

Background

Risk factors are traits or behaviors that have an influence on the development of breast cancer (BC). Awareness of the prevalent risk factors can guide in developing prevention interventions.

Purpose

To evaluate the correlation between the breast density, body mass index, and the risk of breast cancer development in relation to the menopausal status in a native African-Arab population.

Material and methods

The study included 30,443 screened females who were classified into cancer and non-cancer groups and each group was further sub-classified into pre- and postmenopausal groups. The breast density (BD) was reported and subjectively classified according to the 2013 ACR BI-RADS breast density classification. The weight and height were measured, and the body mass index (BMI) was calculated and classified according to the WHO BMI classification.

Results

A statistically significant difference was calculated between the mean BMI in the cancer and non-cancer groups (p: .027) as well as between the pre- and postmenopausal groups (p < .001). A positive statistically insignificant correlation was calculated between the breast density and the risk of breast cancer in the premenopausal group (OR: 1.062, p: .919) and a negative highly significant correlation was calculated in the postmenopausal group (OR: 0.234, p < .001).

Conclusion

BMI and BD are inversely associated with each other. The current studied population presented unique ethnic characteristics, where a decreased BD and an increased BMI were found to be independent risk factors for developing breast cancer.

Classification of Breast Cancer Lesions in Ultrasound Images by Using Attention Layer and Loss Ensemble in Deep Convolutional Neural Networks

The reliable classification of benign and malignant lesions in breast ultrasound images can provide an effective and relatively low-cost method for the early diagnosis of breast cancer. The accuracy of the diagnosis is, however, highly dependent on the quality of the ultrasound systems and the experience of the users (radiologists). The use of deep convolutional neural network approaches has provided solutions for the efficient analysis of breast ultrasound images. In this study, we propose a new framework for the classification of breast cancer lesions with an attention module in a modified VGG16 architecture. The adopted attention mechanism enhances the feature discrimination between the background and targeted lesions in ultrasound. We also propose a new ensembled loss function, which is a combination of binary cross-entropy and the logarithm of the hyperbolic cosine loss, to improve the model discrepancy between classified lesions and their labels. This combined loss function optimizes the network more quickly. The proposed model outperformed other modified VGG16 architectures, with an accuracy of 93%, and also, the results are competitive with those of other state-of-the-art frameworks for the classification of breast cancer lesions. Our experimental results show that the choice of loss function is highly important and plays a key role in breast lesion classification tasks. Additionally, by adding an attention block, we could improve the performance of the model.

Glandular Tissue Component and Breast Cancer Risk in Mammographically Dense Breasts at Screening Breast US

Background Breast density at mammography is an established risk factor for breast cancer, but it cannot be used to distinguish between glandular and fibrous tissue. Purpose To evaluate the association between the glandular tissue component (GTC) at screening breast US and the risk of future breast cancer in women with dense breasts and the association between the GTC and lobular involution. Materials and Methods Screening breast US examinations performed in women with no prior history of breast cancer and with dense breasts with negative findings from mammography from January 2012 to December 2015 were retrospectively identified. The GTC was reported as being minimal, mild, moderate, or marked at the time of the US examination. In women who had benign breast biopsy results, the degree of lobular involution in normal background tissue was categorized as not present, mild, moderate, or complete. The GTC-related breast cancer risk in women with a cancer diagnosis or follow-up after 6 months was estimated by using Cox proportional hazards regression. Cumulative logistic regression was used to evaluate the association between the GTC and lobular involution. Results Among 8483 women (mean age, 49 years ± 8 [standard deviation]), 137 developed breast cancer over a median follow-up time of 5.3 years. Compared with a minimal or mild GTC, a moderate or marked GTC was associated with an increased cancer risk (hazard ratio, 1.5; 95% CI: 1.05, 2.1; P = .03) after adjusting for age and breast density. The GTC had an inverse association with lobular involution; women with no, mild, or moderate involution had greater odds (odds ratios of 4.9 [95% CI: 1.5, 16.6], 2.6 [95% CI: 0.95, 7.2], and 1.8 [95% CI: 0.7, 4.6], respectively) of a moderate or marked GTC than those with complete involution (P = .004). Conclusion The glandular tissue component was independently associated with the future breast cancer risk in women with dense breasts and reflects the lobular involution. It should be considered for risk stratification during screening breast US. © RSNA, 2021 Online supplemental material is available for this article.

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.

Mammographic density and breast cancer screening

Mammographic density, which is determined by the relative amounts of fibroglandular tissue and fat in the breast, varies between women. Mammographic density is associated with a range of factors, including age and body mass index. The description of mammographic density has been transformed by the digitalization of mammography, which has allowed automation of the assessment of mammographic density, rather than using visual inspection by a radiologist. High mammographic density is important because it is associated with reduced sensitivity for the detection of breast cancer at the time of mammographic screening. High mammographic density is also associated with an elevated risk of developing breast cancer. Mammographic density appears to be on the causal pathway for some breast cancer risk factors, but not others. Mammographic density needs to be considered in the context of a woman's background risk of breast cancer. There is intense debate about the use of supplementary imaging for women with high mammographic density. Should supplementary imaging be used in women with high mammographic density and a clear mammogram? If so, what modalities of imaging should be used and in which women? Trials are underway to address the risks and benefits of supplementary imaging.

Surveillance for second breast cancer events in women with a personal history of breast cancer using breast MRI: a systematic review and meta-analysis

PURPOSE

Women with personal history of breast cancer (PHBC) are currently recommended to receive annual mammography for surveillance of breast cancer recurrence or new primary. However, given issues in accuracy with mammography, there is a need for evolving evidence-based surveillance recommendations with supplemental imaging. In this systematic review, we compiled and compared existing studies that describe the test performance of surveillance breast MRI among women with PHBC.

METHODS

We searched PubMed and EMBASE using MeSH terms for studies (2000-2019) that described the diagnostic characteristics of breast MRI in women with PHBC. Search results were reviewed and included based on PICOTS criteria; quality of included articles was assessed using QUADAS-2. Meta-analysis of single proportions was conducted for diagnostic characteristics of breast MRI, including tests of heterogeneity.

RESULTS

Our review included 11 articles in which unique cohorts were studied, comprised of a total of 8338 women with PHBC and 12,335 breast MRI done for the purpose of surveillance. We predict intervals (PI) for cancer detection rate per 1000 examinations (PI 9-15; I² = 10%), recall rate (PI 5-31%; I² = 97%), sensitivity (PI 58-95%; I² = 47%), specificity (PI 76-97%; I² = 97%), and PPV3 (PI 16-40%; I² = 44%).

CONCLUSIONS

Studies addressing performance of breast MRI are variable and limited in population-based studies. The summary of evidence to date is insufficient to recommend for or against use of breast MRI for surveillance among women with PHBC.

Design and clinical validation of a software program for automated measurement of mammographic breast density

Background

Mammographic breast density is an important predictor of breast cancer, but its measurement has limitations related to subjectivity of visual evaluation or to difficult access for automatic volumetric measurement methods. Herein, we describe the design and clinical validation of Aguida, a software program for automated quantification of breast density from flat mammography images.

Materials and methods

The software program was developed in MatLab. After image segmentation separating the background from the breast image, the operator positions a cursor defining a region of interest on the pectoralis major muscle from the mediolateral oblique view. Then, in the craniocaudal view, the threshold for separation of the dense tissue is based on the optical density of the pectoral muscle, and the proportion of dense tissue is calculated by the program. Mammograms obtained from 2 different occasions in 291 women were used for clinical evaluation.

Results

The intraclass correlation coefficient (ICC) between breast density measurements by the software and by a radiologist was 0.96, with a bias of only 0.67 percentage points and a 95% limit of agreement of 13.5 percentage points; the ICC was 0.94 in the interobserver reliability assessment by two radiologists with different experience; and the ICC was 0.98 in the intraobserver reliability assessment. The distribution among the density classes was close to the values obtained with the volumetric software.

Conclusions

Measurement of breast density with the Aguida program from flat mammography images showed high agreement with the visual determination by radiologists, and high inter- and intra-observer reliability.

Risk-Based Screening Mammography for Women Aged <40: Outcomes From the National Mammography Database

OBJECTIVE

There is insufficient large-scale evidence for screening mammography in women <40 years at elevated risk. This study compares risk-based screening of women aged 30 to 39 with risk factors versus women aged 40 to 49 without risk factors in the National Mammography Database (NMD).

METHODS

This retrospective, HIPAA-compliant, institutional review board-exempt study analyzed data from 150 NMD mammography facilities in 31 states. Patients were stratified by 5-year age intervals, availability of prior mammograms, and specific risk factors for breast cancer: family history of breast cancer, personal history of breast cancer, and dense breasts. Four screening performance metrics were calculated for each age and risk group: recall rate (RR), cancer detection rate (CDR), and positive predictive values for biopsy recommended (PPV₂) and biopsy performed (PPV₃).

RESULTS

Data from 5,986,131 screening mammograms performed between January 2008 and December 2015 in 2,647,315 women were evaluated. Overall, mean CDR was 3.69 of 1,000 (95% confidence interval: 3.64-3.74), RR was 9.89% (9.87%-9.92%), PPV₂ was 20.1% (19.9%-20.4%), and PPV₃ was 28.2% (27.0%-28.5%). Women aged 30 to 34 and 35 to 39 had similar CDR, RR, and PPVs, with the presence of the three evaluated risk factors associated with significantly higher CDR. Moreover, compared with a population currently recommended for screening mammography in the United States (aged 40-49 at average risk), incidence screening (at least one prior screening examination) of women aged 30 to 39 with the three evaluated risk factors has similar cancer detection rates and recall rates.

DISCUSSION

Women with one or more of these three specific risk factors likely benefit from screening commencing at age 30 instead of age 40.

BRCA Mutation Carriers: Breast and Ovarian Cancer Screening Guidelines and Imaging Considerations

Patients who carry the BRCA1 and BRCA2 gene mutations have an underlying genetic predisposition for breast and ovarian cancers. These deleterious genetic mutations are the most common genes implicated in hereditary breast and ovarian cancers. This monograph summarizes the evidence behind current screening recommendations, reviews imaging protocols specific to this patient population, and illustrates some of the imaging nuances of breast and ovarian cancers in this clinical setting.

Underutilization of Supplemental Magnetic Resonance Imaging Screening Among Patients at High Breast Cancer Risk

BACKGROUND

Women at high lifetime breast cancer risk may benefit from supplemental breast magnetic resonance imaging (MRI) screening, in addition to routine mammography screening for earlier cancer detection.

MATERIALS AND METHODS

We performed a cross-sectional study of 422,406 women undergoing routine mammography screening across 86 Breast Cancer Surveillance Consortium (BCSC) facilities during calendar year 2012. We determined availability and use of on-site screening breast MRI services based on woman-level characteristics, including >20% lifetime absolute risk using the National Cancer Institute risk assessment tool. Multivariate analyses were performed to determine sociodemographic characteristics associated with on-site screening MRI use.

RESULTS

Overall, 43.9% (2403/5468) of women at high lifetime risk attended a facility with on-site breast MRI screening availability. However, only 6.6% (158/2403) of high-risk women obtained breast MRI screening within a 2-year window of their screening mammogram. Patient factors associated with on-site MRI screening use included younger (<40 years) age (odds ratio [OR] = 2.39, 95% confidence interval [CI]: 1.34-4.21), family history (OR = 1.72, 95% CI: 1.13-2.63), prior breast biopsy (OR = 2.09, 95% CI: 1.22-3.58), and postsecondary education (OR = 2.22, 95% CI: 1.04-4.74).

CONCLUSIONS

While nearly half of women at high lifetime breast cancer risk undergo routine screening mammography at a facility with on-site breast MRI availability, supplemental breast MRI remains widely underutilized among those who may benefit from earlier cancer detection. Future studies should evaluate whether other enabling factors such as formal risk assessment and patient awareness of high lifetime breast cancer risk can mitigate the underutilization of supplemental screening breast MRI.

Deciphering the Breast Density Inform Law Movement: Implications for Practice

Although dense breast tissue is a normal and routine finding on screening mammography, dense breast tissue is associated with an independent increased risk for breast cancer. It is well known that screening mammography has a decreased sensitivity for cancer detection in women with dense breasts. Over the past decade, there has been increased interest generated among patients, physicians, and legislators regarding how best to screen dense-breasted women culminating in 2009 with the passage of a breast density notification law in Connecticut. Since that time, over half the United States has passed similar notification laws. Despite this, controversy remains as to the optimal supplemental screening modality to complement mammography as each imaging modality (digital breast tomosynthesis, whole breast ultrasound, magnetic resonance imaging, contrast-enhanced mammography, and molecular breast imaging) has variable benefits and limitations.

Molecular Breast Imaging in Breast Cancer Screening and Problem Solving

In the United States, legislative actions in over 28 states require radiologists to notify women who undergo breast screening mammography of their breast density. This has led to increased public interest in supplemental screening, but radiologists have not come to a consensus on a supplemental screening modality. In choosing between the most common options, whole-breast ultrasonography (US) and magnetic resonance (MR) imaging, one must weigh the benefits and drawbacks of each modality, as increased cancer detection may be accompanied by increased examination costs and biopsy rates. There has been recent interest in molecular breast imaging (MBI) for supplemental screening because of its high sensitivity, as well as its high specificity. This article describes how MBI fits into clinical practice alongside digital breast tomosynthesis (DBT), targeted US, and MR imaging. The authors describe their approach to breast cancer screening, which uses DBT as the primary imaging modality. DBT is complemented by automated density calculations and supplemented with functional imaging techniques, including MR imaging or MBI, for women with dense breasts. An algorithm based on the patient's breast cancer risk is used to determine if either MR imaging or MBI for supplemental screening is appropriate. MBI is also used as a problem-solving tool for the evaluation of clinical indications following complex mammography or US, or for unexplained physical findings. This article describes aspects related to implementing MBI in clinical practice, including the clinical workflow, patient management, radioactive tracer administration, and procedure reimbursement. ^© RSNA, 2017.

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.

Breast Density Legislation in New England: A Survey Study of Practicing Radiologists

RATIONALE AND OBJECTIVES

This study aimed to assess radiologists' knowledge about breast density legislation as well as perceived practice changes resulting from the enactment of breast density legislation.

MATERIALS AND METHODS

This is an institutional review board-exempt anonymous email survey of 523 members of the New England Roentgen Ray Society. In addition to radiologist demographics, survey questions addressed radiologist knowledge of breast density legislation, knowledge of breast density as a risk factor for breast cancer, recommendations for supplemental screening, and perceived practice changes resulting from density notification legislation.

RESULTS

Of the 523 members, 96 responded, yielding an 18% response rate. Seventy-three percent of respondents practiced in a state with breast density legislation. Sixty-nine percent felt that breast density notification increased patient anxiety about breast cancer, but also increased patient (74%) and provider (66%) understanding of the effect of breast density on mammographic sensitivity. Radiologist knowledge of the relative risk of breast cancer when comparing breasts of different density was variable.

CONCLUSIONS

Considerable confusion and controversy regarding breast density persists, even among practicing radiologists.

Risk-based Breast Cancer Screening: Implications of Breast Density

The approach to breast cancer screening has changed over time from a general approach to a more personalized, risk-based approach. Women with dense breasts, one of the most prevalent risk factors, are now being informed that they are at increased risk of developing breast cancer and should consider supplemental screening beyond mammography. This article reviews the current evidence regarding the impact of breast density relative to other known risk factors, the evidence regarding supplemental screening for women with dense breasts, supplemental screening options, and recommendations for physicians having shared decision-making discussions with women who have dense breasts.

Managing hereditary breast cancer risk in women with and without ovarian cancer

Current guidelines recommend that all women with ovarian cancer undergo germline genetic testing for BRCA1/2. Increasingly, genetic testing is being performed via panels that include other genes that confer a high or moderate risk of breast cancer. In addition, many women with a family history of breast or ovarian cancer are not found to have a mutation, but may have increased risk of breast cancer for which surveillance and risk reduction strategies are indicated. This review discusses how to assess and manage an increased risk of breast cancer through surveillance, preventive medications, and risk-reducing surgery. Assessing and managing the increased risk of breast cancer in BRCA1/2 mutation carriers after a diagnosis of ovarian cancer can be challenging. For the first few years after an ovarian cancer diagnosis, BRCA1/2 mutation carriers have a relatively low risk of breast cancer, and their prognosis is largely determined by the ovarian cancer. However, if these women remain in remission after two years, the risk of breast cancer becomes comparable with, and in some cases exceeds, their risk of ovarian cancer recurrence. For these women, breast cancer surveillance and risk reduction becomes important to their overall health. Specifically, for BRCA1/2 carriers who are diagnosed with early-stage ovarian cancer, we recommend regular breast cancer surveillance and consideration of risk reduction with medication and/or prophylactic mastectomy. For women with advanced ovarian cancer who do not achieve remission, breast cancer surveillance or prophylaxis is not of value. However, among carriers with more favorable advanced disease, it is reasonable to initiate breast cancer surveillance. Patients with less favorable advanced stage disease who achieve sustained remission (>2-5years) should also consider more aggressive strategies for breast cancer screening and prevention. For mutation carriers who remain in remission after five years, prophylactic mastectomy can be considered.

Dense Breast Notification and Supplemental Screening: A Survey of Current Strategies and Sentiments

Dense breast parenchyma obscures breast lesions and has been shown to be an independent risk factor for development of breast cancer. An ever-increasing number of states have approved laws requiring patient notification of dense breast tissue. Reviews of supplemental screening imaging modalities are available, but there is no consensus and little discussion regarding what radiologists are specifically doing to manage patients with dense breasts. Our goal was to survey breast imagers facing these issues in an effort to simplify dense breast management. A survey was administered via email to the Society of Breast Imaging member directory, designed to collect information regarding current practices in dense breast notification and supplemental screening. There were 223 surveys completed to entirety, including 38% from respondents in states without mandatory breast density reporting laws and 62% from states with reporting laws. A majority of respondents from both groups, 60% and 51% in those without and with laws, respectively, felt they lacked adequate resources to offer or sustain supplemental screening. In those offering supplemental imaging, the modalities offered varied widely as did the manner of offering a supplemental exam. Levels of satisfaction, concerns, and standard practices of respondents were also queried. Strategizing optimal imaging approaches and algorithms to handle dense breast management issues is important to maintain efficiency in breast imaging departments. Sharing current ideas and practices may facilitate a smoother workflow in mandatory dense breast reporting and supplemental imaging, allowing breast imagers to correct or prevent systems-based flaws.

What we need to know about dense breasts: implications for breast cancer screening

High breast density and its relationship to the risk of breast cancer has become a hot topic in the medical literature and in the lay press, especially in the United States, where it has brought about changes in the legal framework that require radiologists to inform clinicians and patients about breast density. Radiologists, who are mainly responsible for this information, need to know the scientific evidence and controversies regarding this subject. The discussion is centered on the real importance of the risk, the limitation that not having standardized methods of measurement represents, and the possible application of complementary screening techniques (ultrasound, magnetic resonance imaging, or tomosynthesis) for which clear recommendations have yet to be established. We need controlled studies that evaluate the application of these techniques in women with dense breasts, including the possibility that they can lead to overdiagnosis.

The Economic and Social Value of an Image Exchange Network: A Case for the Cloud

As the health care environment continually changes, radiologists look to the ACR's Imaging 3.0^® initiative to guide the search for value. By leveraging new technology, a cloud-based image exchange network could provide secure universal access to prior images, which were previously siloed, to facilitate accurate interpretation, improved outcomes, and reduced costs. The breast imaging department represents a viable starting point given the robust data supporting the benefit of access to prior imaging studies, existing infrastructure for image sharing, and the current workflow reliance on prior images. This concept is scalable not only to the remainder of the radiology department but also to the broader medical record.

Gold silver alloy nanoparticles (GSAN): an imaging probe for breast cancer screening with dual-energy mammography or computed tomography

Earlier detection of breast cancer reduces mortality from this disease. As a result, the development of better screening techniques is a topic of intense interest. Contrast-enhanced dual-energy mammography (DEM) is a novel technique that has improved sensitivity for cancer detection. However, the development of contrast agents for this technique is in its infancy. We herein report gold-silver alloy nanoparticles (GSAN) that have potent DEM contrast properties and improved biocompatibility. GSAN formulations containing a range of gold : silver ratios and capped with m-PEG were synthesized and characterized using various analytical methods. DEM and computed tomography (CT) phantom imaging showed that GSAN produced robust contrast that was comparable to silver alone. Cell viability, reactive oxygen species generation and DNA damage results revealed that the formulations with 30% or higher gold content are cytocompatible to Hep G2 and J774A.1 cells. In vivo imaging was performed in mice with and without breast tumors. The results showed that GSAN produce strong DEM and CT contrast and accumulated in tumors. Furthermore, both in vivo imaging and ex vivo analysis indicated the excretion of GSAN via both urine and feces. In summary, GSAN produce strong DEM and CT contrast, and has potential for both blood pool imaging and for breast cancer screening.

The inter-observer variability of breast density scoring between mammography technologists and breast radiologists and its effect on the rate of adjuvant ultrasound

PURPOSE

This study assesses the inter-observer variability of mammographic breast density scoring (BDS) between technologists and radiologists and evaluates the effect of technologist patient referral on the load of adjuvant ultrasounds.

MATERIALS AND METHODS

In this IRB approved study, a retrospective analysis of 503 prospectively acquired, random mammograms was performed between January and March 2014. Each mammogram was evaluated for BDS independently and blindly by both the performing technologist and the interpreting radiologist. Statistical calculation of the Spearman correlation coefficient and weighted kappa were obtained to evaluate the inter-observer variability between technologists and radiologists and to examine whether it relates to the technologist's seniority or women's age. The effect on the load of adjuvant ultrasounds was evaluated.

RESULTS

10 mammography technologists and 7 breast radiologists participated in this study. BDS agreement levels between technologists and radiologists were in the fair to moderate range (kappa values: 0.3-0.45, Spearman coefficient values: 0.59-0.65). The technologists markedly over-graded the density compared to the radiologists in all the subsets evaluated. Comparison between low and high-density groups demonstrated a similar trend of over-grading by technologists, who graded 51% of the women as having dense breasts (scores 3-4) compared to 27% of the women graded as such by the radiologists. This trend of over grading breast density by technologists was unrelated to the women's age or to the technologists' seniority.

CONCLUSION

Mammography technologists over-grade breast density. Technologists' referral to an adjuvant ultrasound leads to redundant ultrasound studies, unnecessary breast biopsies, costs and increased patient anxiety.

Missed Breast Cancer: What Can We Learn?

Multiple studies have shown that screening mammography helps to reduce mortality and morbidity from advanced breast cancer. However mammography does have its own limitations, and unfortunately, there are a fair number of false-negative mammograms. We are all aware that the sensitivity of mammography is inversely proportional to the breast density. With many states passing mandatory breast density reporting legislation, there has been an emphasis on using additional and alternative screening methods such as whole breast ultrasound and screening magnetic resonance imaging. Many cancers are simply not detected on mammography, even in retrospect. However, many of the breast cancers are actually visible retrospectively on the prior mammogram. It is these small and often subtle cancers that are perceptible but often missed, that provide a valuable learning opportunity. Studying the imaging findings of cancers that went undetected is a good learning exercise for the radiologist to identify common patterns and mistakes that lead to a missed cancer. This allows the radiologist to improve mammographic sensitivity and overall diagnostic accuracy. This article discusses some of the limitations of mammography, common sources of error which may lead to an undetected cancer, and also discuss a few pearls to prevent these common errors.

Breast Cancer Induced by X-Ray Mammography Screening? A Review Based on Recent Understanding of Low-Dose Radiobiology

Screening mammography offers the possibility of discovering malignant diseases at an early stage, which is consequently treated early, thereby reducing the mortality rate. However, ionizing radiation as used in low-dose X-ray mammography may be associated with a risk of radiation-induced carcinogenesis. In the context of the harmful effects of ionizing radiation, this article reviewed novel radiobiological data and provided a simulation of the relative incidence of radiation-induced breast cancer due to screening against a background baseline incidence in a population of 100,000 individuals. The use of modern digital mammographic technology was assumed, giving rise to a glandular dose of 2.5 mGy from a 2-view per breast image. Assuming no latency time, this led to a ratio of induced incidence rate over baseline incidence rate of about 1.6‰ for biennial screening in women aged 50-74 years, although it cannot be excluded that the dose and dose rate effectiveness factor values relying on new radiobiological insights may lower this number to about 0.7‰. This carcinogenic risk is considered small in relation to the potential beneficial effects of screening, especially as latency time was not taken into consideration. However, individuals who are known to be carriers of risk-increasing genetic variations and/or have an inherited disposition of breast cancer should avoid ionizing radiation as much as possible and should be referred to ultrasound or magnetic resonance imaging. In addition, a significant, but difficult to quantify, risk of cancer is present for individuals who suffer from hypersusceptibility to ionizing radiation.

Abbreviated screening protocol for breast MRI: a feasibility study

RATIONALE AND OBJECTIVES

To compare the performance of two shortened breast magnetic resonance imaging (MRI) protocols to a standard MRI protocol for breast cancer screening.

MATERIALS AND METHODS

In this Health Insurance Portability and Accountability Act compliant, institutional review board-approved pilot study, three fellowship-trained breast imagers evaluated 48 breast MRIs (24 normal, 12 benign, and 12 malignant) selected from a high-risk screening population. MRIs were presented in three viewing protocols, and a final Breast Imaging-Reporting and Data System assessment was recorded for each case. The first shortened protocol (abbreviated 1) included only fat-saturated precontrast T2-weighted, precontrast T1-weighted, and first pass T1-weighted postcontrast sequences. The second shortened protocol (abbreviated 2) included the abbreviated 1 protocol plus the second pass T1-weighted postcontrast sequence. The third protocol (full), reviewed after a 1-month waiting period, included a nonfat-saturated T1-weighted sequence, fat-saturated T2-weighted, precontrast T1-weighted, and three or four dynamic postcontrast sequences. Interpretation times were recorded for the abbreviated 1 and full protocols. Sensitivity and specificity were compared via a chi-squared analysis. This pilot study was designed to detect a 10% difference in sensitivity with a power of 0.8.

RESULTS

There was no significant difference in sensitivity between the abbreviated 1 (86%; P = .22) or abbreviated 2 (89%; P = .38) protocols and the full protocol (95%). There was no significant difference in specificity between the abbreviated 1 (52%; P = 1) or abbreviated 2 (45%; P = .34) protocols and the full protocol (52%). The abbreviated 1 and full protocol interpretation times were similar (2.98 vs. 3.56 minutes).

CONCLUSIONS

In this pilot study, reader performance comparing two shortened breast MRI protocols to a standard protocol in a screening cohort were similar, suggesting that a shortened breast MRI protocol may be clinically useful, warranting further investigation.

Breast cancer screening in the era of density notification legislation: summary of 2014 Massachusetts experience and suggestion of an evidence-based management algorithm by multi-disciplinary expert panel

Stemming from breast density notification legislation in Massachusetts effective 2015, we sought to develop a collaborative evidence-based approach to density notification that could be used by practitioners across the state. Our goal was to develop an evidence-based consensus management algorithm to help patients and health care providers follow best practices to implement a coordinated, evidence-based, cost-effective, sustainable practice and to standardize care in recommendations for supplemental screening. We formed the Massachusetts Breast Risk Education and Assessment Task Force (MA-BREAST) a multi-institutional, multi-disciplinary panel of expert radiologists, surgeons, primary care physicians, and oncologists to develop a collaborative approach to density notification legislation. Using evidence-based data from the Institute for Clinical and Economic Review, the Cochrane review, National Comprehensive Cancer Network guidelines, American Cancer Society recommendations, and American College of Radiology appropriateness criteria, the group collaboratively developed an evidence-based best-practices algorithm. The expert consensus algorithm uses breast density as one element in the risk stratification to determine the need for supplemental screening. Women with dense breasts and otherwise low risk (<15% lifetime risk), do not routinely require supplemental screening per the expert consensus. Women of high risk (>20% lifetime) should consider supplemental screening MRI in addition to routine mammography regardless of breast density. We report the development of the multi-disciplinary collaborative approach to density notification. We propose a risk stratification algorithm to assess personal level of risk to determine the need for supplemental screening for an individual woman.

The Potential Impact of Risk-Based Screening Mammography in Women 40-49 Years Old

OBJECTIVE

The purpose of this study was to determine the prevalence of very strong family history and extremely dense tissue in women 40-49 years old with breast cancer detected on screening mammography.

MATERIALS AND METHODS

All cancers detected by screening mammography at our institution between January 1997 and November 2012 in 40- to 49-year-old women were retrospectively identified. Those with a personal history of breast cancer were excluded. Family history, breast density, type of malignancy, hormone receptor status, and lymph node status were recorded.

RESULTS

One hundred thirty-six cases of breast cancer were identified on screening mammography in 40- to 49-year-old women; 50% were invasive cancers, and 50%, ductal carcinoma in situ. Very strong family history was absent in 88%, and extremely dense breast tissue was absent in 86%. Seventy-six percent of patients had neither very strong family history nor extremely dense breasts, including 79% of the cases of invasive cancers, of which 25% had axillary nodal involvement and 89% were estrogen receptor positive.

CONCLUSION

Very strong family history and extremely dense breast tissue were absent in most 40- to 49-year-old women with breast cancer detected at screening mammography. These cancers were frequently invasive (often with nodal metastases) and treatable (hormone receptor positive). Reducing the number of women to be screened in this age group by using this risk-based approach would reduce the number of screen-detected cancers by more than 75%, thereby precluding the benefit of mortality reduction. Even using a risk-based strategy with an expanded definition of high risk that included any first-degree family history, extremely dense tissue, or both, 66% of malignancies would still be missed.

Availability of Advanced Breast Imaging at Screening Facilities Serving Vulnerable Populations

OBJECTIVE

Among vulnerable women, unequal access to advanced breast imaging modalities beyond screening mammography may lead to delays in cancer diagnosis and unfavourable outcomes. We aimed to compare on-site availability of advanced breast imaging services (ultrasound, magnetic resonance imaging [MRI], and image-guided biopsy) between imaging facilities serving vulnerable patient populations and those serving non-vulnerable populations.

SETTING

73 imaging facilities across five Breast Cancer Surveillance Consortium regional registries in the United States during 2011 and 2012.

METHODS

We examined facility and patient characteristics across a large, national sample of imaging facilities and patients served. We characterized facilities as serving vulnerable populations based on the proportion of mammograms performed on women with lower educational attainment, lower median income, racial/ethnic minority status, and rural residence.We performed multivariable logistic regression to determine relative risks of on-site availability of advanced imaging at facilities serving vulnerable women versus facilities serving non-vulnerable women.

RESULTS

Facilities serving vulnerable populations were as likely (Relative risk [RR] for MRI = 0.71, 95% Confidence Interval [CI] 0.42, 1.19; RR for MRI-guided biopsy = 1.07 [0.61, 1.90]; RR for stereotactic biopsy = 1.18 [0.75, 1.85]) or more likely (RR for ultrasound = 1.38 [95% CI 1.09, 1.74]; RR for ultrasound-guided biopsy = 1.67 [1.30, 2.14]) to offer advanced breast imaging services as those serving non-vulnerable populations.

CONCLUSIONS

Advanced breast imaging services are physically available on-site for vulnerable women in the United States, but it is unknown whether factors such as insurance coverage or out-of-pocket costs might limit their use.

Screening magnetic resonance imaging recommendations and outcomes in patients at high risk for breast cancer

The purpose of this study was to determine magnetic resonance imaging (MRI) screening recommendations and the subsequent outcomes in women with increased risk for breast cancer evaluated by oncology subspecialists at an academic center. Patients evaluated between 1/1/2007 and 3/1/2011 under diagnosis codes for family history of breast or ovarian cancer, genetic syndromes, lobular carcinoma in situ or atypical hyperplasia were included. Patients with a history of breast cancer were excluded. Retrospective review of prospectively acquired demographics, lifetime risk of breast cancer, and screening recommendations were obtained from the medical record. Retrospective review of the results of prospectively interpreted breast imaging examinations and image-guided biopsies were analyzed. 282 women were included. The majority of patients were premenopausal with a median age of 43. Most (69%) were referred due to a family history of breast or ovarian cancers. MRI was recommended for 84% of patients based on a documented lifetime risk >20%. Most women referred for MRI screening (88%) were compliant with this recommendation. A total of 299 breast MRI examinations were performed in 146 patients. Biopsy was performed for 32 (11%) exams and 10 cancers were detected for a positive predictive value (PPV) of 31% (based on biopsy performed) and an overall per exam cancer yield of 3.3%. Three cancers were detected in patients who did not undergo screening MRI. The 13 cancers were Stage 0-II; all patients were without evidence of disease with a median follow-up of 22 months. In a cohort of women seen by breast subspecialty providers, screening breast MRI was recommended according to guidelines, and used primarily in premenopausal women with a family history or genetic predisposition to breast cancer. Adherence to MRI screening recommendations was high and cancer yield from breast MRI was similar to that in clinical trials.

The evolution of breast imaging: past to present

The practice of breast imaging has transitioned through a wide variety of technologic advances from the early days of direct-exposure film mammography to xeromammography to screen-film mammography to the current era of full-field digital mammography and digital breast tomosynthesis. Along with these technologic advances, organized screening, federal regulations based on the Mammography Quality Standards Act, and the development of the American College of Radiology Breast Imaging Reporting and Data System have helped to shape the specialty of breast imaging. With the development of breast ultrasonography and breast magnetic resonance imaging, both complementary to mammography, additional algorithms for diagnostic workup and screening high-risk subgroups of women have emerged. A substantial part of breast imaging practice these days also involves breast interventional procedures-both percutaneous biopsy to obtain tissue diagnosis and localization procedures to guide surgical excision. This article reviews the evolution of breast imaging starting from a historical perspective and progressing to the present day.

Understanding patient options, utilization patterns, and burdens associated with breast cancer screening

Despite ongoing awareness, educational campaigns, and advances in technology, breast cancer screening remains a complex topic for women and for the health care system. Lack of consensus among organizations developing screening guidelines has caused confusion for patients and providers. The psychosocial factors related to breast cancer screening are not well understood. The prevailing algorithm for screening results in significant rates of patient recall for further diagnostic imaging or procedures, the majority of which rule out breast cancer rather than confirming it. For women, the consequences of the status quo range from unnecessary stress to additional out-of-pocket expenses to indirect costs that are more difficult to quantify. A more thoughtful approach to breast cancer screening, coupled with a research agenda that recognizes the indirect and intangible costs that women bear, is needed to improve cost and quality outcomes in this area.