Screening in Women With BRCA Mutations Revisited.

Patients with BRCA1 or BRCA2 gene mutations are at high risk for the development of breast cancer. This article reviews the current evidence for breast cancer screening of patients with BRCA1 or BRCA2 pathogenic gene mutations if they have not undergone prophylactic mastectomy. It will review the current evidence-based imaging recommendations for different modalities and ages of screening initiation in screening this patient population at high risk. Special considerations in transgender BRCA1 and BRCA2 mutation carriers are also discussed.

Evolving Treatment Paradigms for Low-Risk Ductal Carcinoma In Situ: Imaging Needs.

Ductal carcinoma in situ (DCIS) is a nonobligate precursor to invasive cancer that classically presents as asymptomatic calcifications on screening mammography. The increase in DCIS diagnoses with organized screening programs has raised concerns about overdiagnosis, while a patientcentric push for more personalized care has increased awareness about DCIS overtreatment. The standard of care for most new DCIS diagnoses is surgical excision, but nonsurgical management via active monitoring is gaining attention, and multiple clinical trials are ongoing. Imaging, along with demographic and pathologic information, is a critical component of active monitoring efforts. Commonly used imaging modalities including mammography, ultrasound, and MRI, as well as newer modalities such as contrast-enhanced mammography and dedicated breast PET, can provide prognostic information to risk stratify patients for DCIS active monitoring eligibility. Furthermore, radiologists will be responsible for closely surveilling patients on active monitoring and identifying if invasive progression occurs. Active monitoring is a paradigm shift for DCIS care, but the success or failure will rely heavily on the interpretations and guidance of radiologists.

Identifying Good Candidates for Active Surveillance of Ductal Carcinoma In Situ: Insights from a Large Neoadjuvant Endocrine Therapy Cohort.

Ductal carcinoma in situ (DCIS) is a biologically heterogenous entity with uncertain risk for invasive ductal carcinoma (IDC) development. Standard treatment is surgical resection often followed by radiation. New approaches are needed to reduce overtreatment. This was an observational study that enrolled patients with DCIS who chose not to pursue surgical resection from 2002 to 2019 at a single academic medical center. All patients underwent breast MRI exams at 3- to 6-month intervals. Patients with hormone receptor-positive disease received endocrine therapy. Surgical resection was strongly recommended if clinical or radiographic evidence of disease progression developed. A recursive partitioning (R-PART) algorithm incorporating breast MRI features and endocrine responsiveness was used retrospectively to stratify risk of IDC. A total of 71 patients were enrolled, 2 with bilateral DCIS (73 lesions). A total of 34 (46.6%) were premenopausal, 68 (93.2%) were hormone-receptor positive, and 60 (82.1%) were intermediate- or high-grade lesions. Mean follow-up time was 8.5 years. Over half (52.1%) remained on active surveillance without evidence of IDC with mean duration of 7.4 years. Twenty patients developed IDC, of which 6 were HER2 positive. DCIS and subsequent IDC had highly concordant tumor biology. Risk of IDC was characterized by MRI features after 6 months of endocrine therapy exposure; low-, intermediate-, and high-risk groups were identified with respective IDC rates of 8.7%, 20.0%, and 68.2%. Thus, active surveillance consisting of neoadjuvant endocrine therapy and serial breast MRI may be an effective tool to risk-stratify patients with DCIS and optimally select medical or surgical management. Significance: A retrospective analysis of 71 patients with DCIS who did not undergo upfront surgery demonstrated that breast MRI features after short-term exposure to endocrine therapy identify those at high (68.2%), intermediate (20.0%), and low risk (8.7%) of IDC. With 7.4 years mean follow-up, 52.1% of patients remain on active surveillance. A period of active surveillance offers the opportunity to risk-stratify DCIS lesions and guide decisions for operative management.

Outcomes of screening mammography performed prior to fertility treatment in women ages 40-49.

OBJECTIVE: There are currently various conflicting recommendations for breast cancer screening with mammography in women between ages 40-49. There are no specific guidelines for breast cancer screening in women of this age group prior to assisted reproductive technology (ART) for the treatment of infertility. The purpose of our study was to evaluate outcomes of screening mammography, specifically ordered for the purpose of pre-fertility treatment clearance in women aged 40-49 years old. MATERIALS AND METHODS: This was an IRB approved retrospective study of women aged 40-49 presenting for screening mammography prior to ART between January 2010 and October 2018. Clinical history, imaging, and pathology results were gathered from the electronic medical record. Descriptive statistics were performed. RESULTS: Our study cohort consisted of 118 women with a mean age of 42 years (range 40-49). Sixteen of 118 (14%) women were recalled from screening for additional diagnostic work-up. Five of the 16 (31%) were recommended for biopsy (BI-RADS 4 or 5). One of 5 biopsies yielded a malignant result (PPV 20%). Overall cancer detection rate was 0.85% or 8.5 women per 1000 women screened. The single cancer in this cohort was an ER+ PR+ HER2- invasive ductal carcinoma. CONCLUSION: Screening mammography in women 40-49 performed prior to initiation of ART may identify asymptomatic breast malignancy. In accordance with ACR and SBI guidelines to screen women of this age group, women of this age group should undergo screening mammography prior to ART.

Relationship between body mass index and malignancy rates of MRI-guided breast biopsies: impact of clinicodemographic factors.

PURPOSE: To determine the positive predictive value (PPV) of magnetic resonance imaging (MRI)-guided breast biopsy stratified by body mass index (BMI). Secondary endpoints include evaluation of indications for breast MRI and identification of factors associated with malignant biopsy. METHODS: We retrospectively analyzed results of MRI-guided breast biopsies in a consecutive cohort of women at a single institution between 2014 and 2019. The PPV was compared between BMI subgroups and the overall group by the one-sample z-test. Factors associated with malignant biopsy were analyzed using multivariate regression analysis. RESULTS: Among 427 MRI-guided breast biopsies, the PPV was significantly higher in patients with a BMI ≥ 35 compared to BMI < 35 (38.6% versus 24.5%, p = 0.043). This remained true in the 180 biopsies from high-risk screening studies, but there was no difference in PPV by BMI in the 205 biopsies performed to evaluate extent of known disease. Among this cohort who underwent MRI-guided breast biopsy, the underlying indication for MRI was less likely to be high-risk screening in those with a higher BMI or Black or Hispanic race (p = 0.015 and p < 0.001, respectively). For high-risk screening studies, only BMI ≥ 35 was associated with malignant biopsies (OR 37.5, p = 0.003). For evaluation of extent of disease studies, only increased lesion size was a significant predictor of malignant result (OR 1.01, p = 0.04). CONCLUSIONS: Among women who underwent MRI-guided breast biopsy, elevated BMI was associated with increased PPV and malignant biopsies. Patients with a higher BMI or Black or Hispanic race who had MRI-guided biopsy were less likely to be undergoing high-risk screening and more likely to have breast MRI to evaluate extent of known disease.

Accuracy of breast MRI in evaluating nodal status after neoadjuvant therapy in invasive lobular carcinoma.

Neoadjuvant therapy in breast cancer can downstage axillary lymph nodes and reduce extent of axillary surgery. As such, accurate determination of nodal status after neoadjuvant therapy and before surgery impacts surgical management. There are scarce data on the diagnostic accuracy of breast magnetic resonance imaging (MRI) for nodal evaluation after neoadjuvant therapy in patients with invasive lobular carcinoma (ILC), a diffusely growing tumor type. We retrospectively analyzed patients with stage 1-3 ILC who underwent pre-operative breast MRI after either neoadjuvant chemotherapy or endocrine therapy at our institution between 2006 and 2019. Two breast radiologists reviewed MRIs and evaluated axillary nodes for suspicious features. All patients underwent either sentinel node biopsy or axillary dissection. We evaluated sensitivity, specificity, negative and positive predictive values, and overall accuracy of the post-treatment breast MRI in predicting pathologic nodal status. Of 79 patients, 58.2% received neoadjuvant chemotherapy and 41.8% neoadjuvant endocrine therapy. The sensitivity and negative predictive value of MRI were significantly higher in the neoadjuvant endocrine therapy cohort than in the neoadjuvant chemotherapy cohort (66.7 vs. 37.9%, p = 0.012 and 70.6 vs. 40%, p = 0.007, respectively), while overall accuracy was similar. Upstaging from clinically node negative to pathologically node positive occurred in 28.0 and 41.7%, respectively. In clinically node positive patients, those with an abnormal post-treatment MRI had a significantly higher proportion of patients with ≥4 positive nodes on pathology compared to those with a normal MRI (61.1 versus 16.7%, p = 0.034). Overall, accuracy of breast MRI for predicting nodal status after neoadjuvant therapy in ILC was low in both chemotherapy and endocrine therapy cohorts. However, post-treatment breast MRI may help identify patients with a high burden of nodal disease (≥4 positive nodes), which could impact pre-operative systemic therapy decisions. Further studies are needed to assess other imaging modalities to evaluate for nodal disease following neoadjuvant therapy and to improve clinical staging in patients with ILC.

Post-lumpectomy breast calcifications: Can original tumor features assist in determining need for biopsy?

OBJECTIVE: The objective of our study was to determine whether, in the digital era, imaging features of a primary breast tumor can be used to influence the decision to biopsy ipsilateral breast calcifications that occur following surgery in women treated with breast conservation surgery (BCS). MATERIALS AND METHODS: We retrospectively identified women treated with BCS who subsequently developed suspicious calcifications in the treated breast (BI-RADS 4 or 5) from January 2012 - December 2018. Only cases with histopathological diagnosis by stereotactic or surgical biopsy were included. Pathology reports were reviewed, and biopsy results were considered malignant if invasive carcinoma or ductal carcinoma in situ (DCIS) was found. All other results were considered benign. Fisher's exact test was done comparing frequencies of malignancy between those patients whose original tumor had calcifications versus those whose original tumors were not calcified. RESULTS: Of 90 women with suspicious calcifications on a post-BCS mammogram, 65 (72.2%) were biopsy proven benign and 25 (27.8%) were malignant. The original tumor presented without calcifications in 39 patients (43%), and 51 (57%) had calcifications with or without associated mass, focal asymmetry, or architectural distortion. New calcifications were less likely to be malignant if the original tumor presented without calcifications (5/39; 12.8%) as compared to original tumors with calcifications (20/51; 38.5%) [p-value < 0.05]. CONCLUSION: New calcifications after BCS are significantly less likely to be malignant if the original tumor presented without calcifications. However, with a PPV of 12.8%, even calcifications in a patient with a non-calcified primary tumor require biopsy.

Dual-energy three-compartment breast imaging for compositional biomarkers to improve detection of malignant lesions.

Background: While breast imaging such as full-field digital mammography and digital breast tomosynthesis have helped to reduced breast cancer mortality, issues with low specificity exist resulting in unnecessary biopsies. The fundamental information used in diagnostic decisions are primarily based in lesion morphology. We explore a dual-energy compositional breast imaging technique known as three-compartment breast (3CB) to show how the addition of compositional information improves malignancy detection. Methods: Women who presented with Breast Imaging-Reporting and Data System (BI-RADS) diagnostic categories 4 or 5 and who were scheduled for breast biopsies were consecutively recruited for both standard mammography and 3CB imaging. Computer-aided detection (CAD) software was used to assign a morphology-based prediction of malignancy for all biopsied lesions. Compositional signatures for all lesions were calculated using 3CB imaging and a neural network evaluated CAD predictions with composition to predict a new probability of malignancy. CAD and neural network predictions were compared to the biopsy pathology. Results: The addition of 3CB compositional information to CAD improves malignancy predictions resulting in an area under the receiver operating characteristic curve (AUC) of 0.81 (confidence interval (CI) of 0.74-0.88) on a held-out test set, while CAD software alone achieves an AUC of 0.69 (CI 0.60-0.78). We also identify that invasive breast cancers have a unique compositional signature characterized by reduced lipid content and increased water and protein content when compared to surrounding tissues. Conclusion: Clinically, 3CB may potentially provide increased accuracy in predicting malignancy and a feasible avenue to explore compositional breast imaging biomarkers.

The Value of Targeted Ultrasound for the Primary Evaluation of Breast Symptoms in Pregnant Women of All Ages.

OBJECTIVE: Data on breast imaging in symptomatic pregnant women are limited. Our aim was to assess the value of targeted breast US for the primary evaluation of breast symptoms in pregnant women of all ages. METHODS: This IRB-approved retrospective study included all pregnant patients who underwent targeted US for focal breast symptoms at an academic imaging facility over an 18-year period (2000-2018). Clinical, imaging, and pathology results were reviewed. Malignant outcomes were determined by histology. Benign outcomes were confirmed by pathology or ≥2 years of follow-up. Descriptive statistics and 2 × 2 contingency table analyses were performed at the presentation level. RESULTS: The study cohort comprised 178 presentations in 175 pregnant women. Mean age was 34.7 years (standard deviation, 5.2). The majority (153/178, 86.0%) were more than 30 years old. At presentation, 42.1% (75/178) were in the first trimester of pregnancy, 27.0% (48/178) in the second, and 29.8% (53/178) in the third. The most common presenting symptom was a palpable lump (162/178, 91.0%), followed by focal pain (7/178, 3.9%). The vast majority (174/178, 97.8%) of cases were non-malignant. However, targeted US detected all 4 malignancies (cancer detection rate, 22/1000; negative predictive value 136/136, 100%). Sensitivity and specificity were 100% (4/4) and 78.2% (136/174), respectively. CONCLUSION: Benign causes of symptoms in pregnant women were far more common; malignancy was rare, accounting for only 2.2% (4/178) of cases. Targeted breast US detected all malignancies, supporting US as the primary imaging modality for evaluating symptomatic pregnant women, regardless of age.

US as the Primary Imaging Modality in the Evaluation of Palpable Breast Masses in Breastfeeding Women, Including Those of Advanced Maternal Age.

Background Women are increasingly delaying childbearing, and thus lactation, into their 30s and 40s, when mammography would typically be the initial imaging modality to evaluate palpable masses in the general population. Current guidelines recommend US as the first-line imaging modality for palpable masses in pregnant and lactating women, but data regarding breastfeeding women age 30 years and older are near nonexistent. Purpose To evaluate the diagnostic performance of targeted US as the primary imaging modality for the evaluation of palpable masses in lactating women, including those of advanced maternal age. Materials and Methods Lactating women with palpable breast masses evaluated at targeted US over a 17-year period (January 2000 to July 2017) were retrospectively identified. All US evaluations were performed at diagnostic evaluation, and mammography was performed at the discretion of the interpreting radiologist. Breast Imaging Reporting and Data System assessments, imaging, and pathology results were collected. Descriptive statistics and 2 × 2 contingency tables were assessed at the patient level. Results There were 167 women (mean age, 35 years ± 5 [standard deviation]), 101 of whom (60%) were of advanced maternal age (≥35 years). All women underwent targeted US, and 98 (59%) underwent mammography in addition to US. The frequency of malignancy was five of 167 (3.0%). Targeted US demonstrated a sensitivity and specificity of five of five (100%; 95% confidence interval [CI]: 48%, 100%) and 114 of 162 (70%; 95% CI: 63%, 77%), respectively. Negative predictive value, positive predictive value of an abnormal examination, and positive predictive value of biopsy were 114 of 114 (100%; 95% CI: 97%, 100%), five of 53 (9.4%; 95% CI: 3%, 21%), and five of 50 (10%; 95% CI: 3%, 22%), respectively. In the subset of 98 women who underwent mammography in addition to US, mammography depicted seven incidental suspicious findings, which lowered the specificity from 62 of 93 (67%; 95% CI: 56%, 76%) to 57 of 93 (61%; 95% CI: 51%, 71%) (P = .02). Conclusion Targeted US depicted all malignancies in lactating women with palpable masses. Adding mammography increased false-positive findings without any additional cancer diagnoses. © RSNA, 2020 See also the editorial by Newell in this issue.

A case of acute onset gigantomastia in a 20-year-old woman.

Gigantomastia is an abnormal and rare breast condition characterized by excessive breast tissue growth that can result in physical and psychosocial debilitation. While the etiology is not fully understood, it is postulated that abnormal endogenous hormone stimulation plays a contributory role and often requires mastectomy for definitive treatment. Proliferation of all elements is commonly observed, including glands, ducts, stroma, fat, vessels and skin. Pseudoangiomatous stromal hyperplasia (PASH) is an additional benign breast disease defined microscopically by proliferation of mammary stroma. PASH often clinically presents as an incidental finding while evaluating other benign or malignant lesions, or less commonly as a palpable, well-circumscribed breast mass. Uncommon cases have been reported in which PASH presents as a bilateral, diffuse process. In this case presentation, we report a rare case of a 20-year-old woman presenting with acute onset gigantomastia most likely due to diffuse PASH.

Role of Breast MRI in the Evaluation and Detection of DCIS: Opportunities and Challenges.

Historically, breast magnetic resonance imaging (MRI) was not considered an effective modality in the evaluation of ductal carcinoma in situ (DCIS). Over the past decade this has changed, with studies demonstrating that MRI is the most sensitive imaging tool for detection of all grades of DCIS. It has been suggested that not only is breast MRI the most sensitive imaging tool for detection but it may also detect the most clinically relevant DCIS lesions. The role and outcomes of MRI in the preoperative setting for patients with DCIS remains controversial; however, several studies have shown benefit in the preoperative evaluation of extent of disease as well as predicting an underlying invasive component. The most common presentation of DCIS on MRI is nonmass enhancement (NME) in a linear or segmental distribution pattern. Maximizing breast MRI spatial resolution is therefore beneficial, given the frequent presentation of DCIS as NME on MRI. Emerging MRI techniques, such as diffusion-weighted imaging (DWI), have shown promising potential to discriminate DCIS from benign and invasive lesions. Future opportunities including advanced imaging visual techniques, radiomics/radiogenomics, and machine learning / artificial intelligence may also be applicable to the detection and treatment of DCIS. Level of Evidence: 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019. J. Magn. Reson. Imaging 2020;52:697-709.

Outcomes of screening mammography in women less than 40 prior to fertility treatment: a retrospective pilot study.

OBJECTIVE: There are currently no evidence-based guidelines regarding breast cancer screening in women under 40 prior to initiating assisted reproductive technology (ART). The prevalence of abnormal findings on screening mammography in this population is unknown. The purpose of this study was to describe screening mammography outcomes in women less than 40 years old, referred for the indication of pre-ART. MATERIALS, METHODS, PROCEDURES: This is a retrospective review of women less than 40 years old presenting for screening mammography prior to ART between January 2010 and March 2017. Clinical history, breast cancer risk factors, imaging and pathology results were gathered from the electronic medical record. RESULTS: The study included 80 women. Mean patient age was 37 years (range 34-39 years). Sixty-seven (84%) had negative or benign screening (BI-RADS 1 or 2) and 13 (16%) were recalled for diagnostic imaging (BI-RADS 0). Four of 13 (31%) recalled women were given BI-RADS 1 or 2 at diagnostic work-up, 4 (31%) were given a BI-RADS 3, and 5 (38%) were recommended for biopsy (BI-RADS 4). At patient request, 2 of 4 (50%) BI-RADS 3 cases underwent biopsy, for 7 total biopsies. Six (86%) biopsies yielded benign results and 1 (14%) yielded DCIS. Overall cancer yield was 1.3%. CONCLUSION: In women under 40 who plan to undergo ART, screening mammography may identify breast malignancies. This may be of particular importance given many breast cancers are hormone sensitive, and thus fertility treatments may affect tumor growth. Future, larger studies are needed.

Capsular synovial metaplasia mimicking radiographic features of implant-associated anaplastic lymphoma.

Delayed onset breast implant-associated reactions range widely in symptomatology and underlying etiology. With increasing reports of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), findings such as unilateral breast swelling, capsular thickening, and peri-implant fluid raise concern. Synovial metaplasia is a benign histologic finding commonly associated with implant capsules and can be an unusual cause of such symptoms. Though the clinical significance of synovial metaplasia is unknown, it is important to consider this entity in the differential diagnosis for delayed onset breast symptoms, with signs otherwise concerning for BIA-ALCL or infection.

Feasibility of Magnetic Seeds for Preoperative Localization of Axillary Lymph Nodes in Breast Cancer Treatment.

OBJECTIVE. The objective of this study was to evaluate the feasibility of using a magnetic seed system for preoperative localization of axillary lymph nodes in patients with breast cancer. MATERIALS AND METHODS. We performed a retrospective analysis that included patients with breast cancer who underwent preoperative magnetic seed localization of axillary lymph nodes at our institution between January 1, 2017, and January 1, 2019. Magseed (Endomag) is a nonradioactive inducible magnetic seed that is induced to become a magnet when under the influence of its detector in the operating room. Clinical history, prior axillary sampling and clip placement, and procedure details and surgical outcomes were determined from a search of our PACS and electronic medical records. RESULTS. Thirty-five patients (34 women and one man) composed our study cohort. The mean patient age was 56 years (range, 32-78 years). One patient underwent two separate consecutive localizations for two separate operations, and another patient had bilateral lesions, for a total of 37 axillary lymph node localizations. One case of seed misplacement occurred during the ultrasound-guided localization procedure, resulting in immediate placement of a second seed, for a total of 38 Magseeds placed. All seeds were placed under ultrasound guidance. The mean number of days from seed placement to surgery was 5 days (range, 0-31 days). Thirty-seven of 38 Magseeds (97%) were documented to be successfully retrieved in the operating room. CONCLUSION. Magseed localization appears to be a safe, nonradioactive way to accurately localize axillary lymph nodes preoperatively.

Deep learning networks find unique mammographic differences in previous negative mammograms between interval and screen-detected cancers: a case-case study.

BACKGROUND: To determine if mammographic features from deep learning networks can be applied in breast cancer to identify groups at interval invasive cancer risk due to masking beyond using traditional breast density measures. METHODS: Full-field digital screening mammograms acquired in our clinics between 2006 and 2015 were reviewed. Transfer learning of a deep learning network with weights initialized from ImageNet was performed to classify mammograms that were followed by an invasive interval or screen-detected cancer within 12 months of the mammogram. Hyperparameter optimization was performed and the network was visualized through saliency maps. Prediction loss and accuracy were calculated using this deep learning network. Receiver operating characteristic (ROC) curves and area under the curve (AUC) values were generated with the outcome of interval cancer using the deep learning network and compared to predictions from conditional logistic regression with errors quantified through contingency tables. RESULTS: Pre-cancer mammograms of 182 interval and 173 screen-detected cancers were split into training/test cases at an 80/20 ratio. Using Breast Imaging-Reporting and Data System (BI-RADS) density alone, the ability to correctly classify interval cancers was moderate (AUC = 0.65). The optimized deep learning model achieved an AUC of 0.82. Contingency table analysis showed the network was correctly classifying 75.2% of the mammograms and that incorrect classifications were slightly more common for the interval cancer mammograms. Saliency maps of each cancer case found that local information could highly drive classification of cases more than global image information. CONCLUSIONS: Pre-cancerous mammograms contain imaging information beyond breast density that can be identified with deep learning networks to predict the probability of breast cancer detection.

Derived mammographic masking measures based on simulated lesions predict the risk of interval cancer after controlling for known risk factors: a case-case analysis.

PURPOSE: Women with radiographically dense or texturally complex breasts are at increased risk for interval cancer, defined as cancers diagnosed after a normal screening examination. The purpose of this study was to create masking measures and apply them to identify interval risk in a population of women who experienced either screen-detected or interval cancers after controlling for breast density. METHODS: We examined full-field digital screening mammograms acquired from 2006 to 2015. Examinations associated with 182 interval cancers were matched to 173 screen-detected cancers on age, race, exam date and time since last imaging examination. Local Image Quality Factor (IQF) values were calculated and used to create IQF maps that represented mammographic masking. We used various statistics to define global masking measures of these maps. Association of these masking measures with interval cancer vs screen-detected cancer was estimated using conditional logistic regression in a univariate and adjusted model for Breast Imaging-Reporting and Data System (BI-RADS) density. Receiver operator curves were calculated in each case to compare specificity vs sensitivity, and area under those curves were generated. Proportion of screen-detected cancer was estimated for stratifications of IQF features. RESULTS: Several masking features showed significant association with interval compared to screen-detected cancers after adjusting for BI-RADS density (up to P = 2.52E-6), and the 10th percentile of the IQF value (P = 1.72E-3) showed the strongest improvement in the area under the receiver operator curve, increasing from 0.65 using only BI-RADS density to 0.69. The highest masking group had a 32% proportion of screen-detected cancers while the low masking group had a 69% proportion. CONCLUSIONS: We conclude that computer vision methods using model observers may improve quantifying the probability of breast cancer detection beyond using breast density alone.

Combined Benefit of Quantitative Three-Compartment Breast Image Analysis and Mammography Radiomics in the Classification of Breast Masses in a Clinical Data Set.

Purpose To investigate the combination of mammography radiomics and quantitative three-compartment breast (3CB) image analysis of dual-energy mammography to limit unnecessary benign breast biopsies. Materials and Methods For this prospective study, dual-energy craniocaudal and mediolateral oblique mammograms were obtained immediately before biopsy in 109 women (mean age, 51 years; range, 31-85 years) with Breast Imaging Reporting and Data System category 4 or 5 breast masses (35 invasive cancers, 74 benign) from 2013 through 2017. The three quantitative compartments of water, lipid, and protein thickness at each pixel were calculated from the attenuation at high and low energy by using a within-image phantom. Masses were automatically segmented and features were extracted from the low-energy mammograms and the quantitative compartment images. Tenfold cross-validations using a linear discriminant classifier with predefined feature signatures helped differentiate between malignant and benign masses by means of (a) water-lipid-protein composition images alone, (b) mammography radiomics alone, and (c) a combined image analysis of both. Positive predictive value of biopsy performed (PPV3) at maximum sensitivity was the primary performance metric, and results were compared with those for conventional diagnostic digital mammography. Results The PPV3 for conventional diagnostic digital mammography in our data set was 32.1% (35 of 109; 95% confidence interval [CI]: 23.9%, 41.3%), with a sensitivity of 100%. In comparison, combined mammography radiomics plus quantitative 3CB image analysis had PPV3 of 49% (34 of 70; 95% CI: 36.5%, 58.9%; P < .001), with a sensitivity of 97% (34 of 35; 95% CI: 90.3%, 100%; P < .001) and 35.8% (39 of 109) fewer total biopsies (P < .001). Conclusion Quantitative three-compartment breast image analysis of breast masses combined with mammography radiomics has the potential to reduce unnecessary breast biopsies. © RSNA, 2018 Online supplemental material is available for this article.