The Impact of Mammographic, Radiologist, and Patient Factors on the Likelihood of Probably Benign (BI-RADS 3) Assessment at Diagnostic Mammography.

OBJECTIVE: To evaluate the association of mammographic, radiologist, and patient factors on BI-RADS 3 assessment at diagnostic mammography in patients recalled from screening mammography. METHODS: This Institutional Review Board-approved retrospective study of consecutive unique diagnostic mammography examinations in asymptomatic patients recalled from screening mammography March 5, 2014, to December 31, 2019, was conducted in a single large United States health care institution. Mammographic features (mass, calcification, distortion, asymmetry), breast density, prior examination, and BI-RADS assessment were extracted from reports by natural language processing. Patient age, race, and ethnicity were extracted from the electronic health record. Radiologist years in practice, recall rate, and number of interpreted diagnostic mammograms were calculated. A mixed effect logistic regression model evaluated factors associated with likelihood of BI-RADS 3 compared with other BI-RADS assessments. RESULTS: A total of 12 080 diagnostic mammography examinations were performed during the study period, yielding 2010 (16.6%) BI-RADS 3 and 10 070 (83.4%) other BI-RADS assessments. Asymmetry (odds ratio [OR] = 6.49, P <.001) and calcification (OR = 5.59, P <.001) were associated with increased likelihood of BI-RADS 3 assessment; distortion (OR = 0.20, P <.001), dense breast parenchyma (OR = 0.82, P <.001), prior examination (OR = 0.63, P = .01), and increasing patient age (OR = 0.99, P <.001) were associated with decreased likelihood. Mass, patient race or ethnicity, and radiologist factors were not significantly associated with BI-RADS 3 assessment. Malignancy rate for BI-RADS 3 lesions was 1.6%. CONCLUSION: Asymmetry and calcifications had an increased likelihood of BI-RADS 3 assessment at diagnostic evaluation with low likelihood of malignancy, while radiologist features had no association.

High Peritumoral and Intratumoral T2 Signal Intensity in HER2-Positive Breast Cancers on Preneoadjuvant Breast MRI: Assessment of Associations With Histopathologic Characteristics.

BACKGROUND. Intratumoral necrosis and peritumoral edema are features of aggressive breast cancer that may present as high T2 signal intensity (T2 SI). Implications of high T2 SI in HER2-positive cancers are unclear. OBJECTIVE. The purpose of this study was to assess associations with histopathologic characteristics of high peritumoral T2 SI and intratumoral T2 SI of HER2-positive breast cancer on MRI performed before initiation of neoadjuvant therapy. METHODS. This retrospective study included 210 patients (age, 24-82 years) with 211 HER2 breast cancers who, from January 1, 2015, to July 30, 2022, underwent breast MRI before receiving neoadjuvant therapy. Two radiologists independently assessed cancers for high peritumoral T2 SI and high intratumoral T2 SI on fat-suppressed T2-weighted imaging and classified patterns of high peritumoral T2 SI (adjacent to tumor vs prepectoral extension). A third radiologist resolved discrepancies. Multivariable logistic regression analyses were performed to identify associations of high peritumoral and intratumoral T2 SI with histopathologic characteristics (associated ductal carcinoma in situ, hormone receptor status, histologic grade, lymphovascular invasion, and axillary lymph node metastasis). RESULTS. Of 211 HER2-positive cancers, 81 (38.4%) had high peritumoral T2 SI, and 95 (45.0%) had high intratumoral T2 SI. A histologic grade of 3 was independently associated with high peritumoral T2 SI (OR = 1.90; p = .04). Otherwise, none of the five assessed histopathologic characteristics were independently associated with high intratumoral T2 SI or high peritumoral T2 SI (p > .05). Cancers with high T2 SI adjacent to the tumor (n = 29) and cancers with high T2 SI with prepectoral extension (n = 52) showed no significant difference in frequency for any of the histopathologic characteristics (p > .05). Sensitivities and specificities for predicting the histopathologic characteristics ranged from 35.6% to 43.7% and from 59.7% to 70.7%, respectively, for high peritumoral T2 SI, and from 37.3% to 49.6% and from 49.3% to 62.7%, respectively, for high intratumoral T2 SI. Interreader agreement was almost perfect for high peritumoral T2 SI (Gwet agreement coefficient [AC] = 0.93), high intratumoral T2 SI (Gwet AC = 0.89), and a pattern of high peritumoral T2 SI (Gwet AC = 0.95). CONCLUSION. The only independent association between histopathologic characteristics and high T2 SI of HER2-positive breast cancer was observed between a histologic grade of 3 and high peritumoral T2 SI. CLINICAL IMPACT. In contrast with previously reported findings in broader breast cancer subtypes, peritumoral and intratumoral T2 SI had overall limited utility as prognostic markers of HER2-positive breast cancer.

Experience of a single healthcare system with screening mammography before and after COVID-19 shutdown.

PURPOSE: To evaluate COVID-19's longitudinal impact on screening mammography volume trends. METHODS: HIPAA-compliant, IRB-approved, single institution, retrospective study of screening mammogram volumes before (10/21/2016-3/16/2020) and greater than two years after (6/17/2020-11/30/2022) a state-mandated COVID-19 shutdown (3/17/2020-6/16/2020) were reviewed. A segmented quasi-poisson linear regression model adjusting for seasonality and network and regional population growth compared volume trends before and after the shutdown of each variable: age, race, language, financial source, risk factor for severe COVID-19, and examination location. RESULTS: Adjusted model demonstrated an overall increase of 65 screening mammograms per month before versus a persistent decrease of 5 mammograms per month for >2 years after the shutdown (p < 0.0001). In subgroup analysis, downward volume trends were noted in all age groups <70 years (age < 50: +9/month before vs. -7/month after shutdown; age 50-60: +17 vs. -7; and age 60-70: +21 vs. -2; all p < 0.001), those identifying as White (+55 vs. -8, p < 0.0001) and Black (+4 vs. +1, p = 0.009), all financial sources (Medicare: +22 vs. -3, p < 0.0001; Medicaid: +5 vs. +2, p = 0.006; private insurance/self-pay: +38 vs. -4, p < 0.0001), women with at least one risk factor for severe COVID-19 (+30 vs. -48, p < 0.0001), and screening mammograms performed at a hospital-based location (+48 vs. -14, p = 0.0001). CONCLUSION: The screening mammogram volume trend more than two years after the COVID-19 shutdown has continued to decline for most patient populations. Findings highlight the need to identify additional areas for education and outreach.

Patients characteristics related to screening mammography cancellation and rescheduling rates during the COVID-19 pandemic.

PURPOSE: To identify patient characteristics associated with screening mammography cancellations and rescheduling during the COVID-19 pandemic. METHODS: Scheduled screening mammograms during three time periods were retrospectively reviewed: state-mandated shutdown (3/17/2020-6/16/2020) during which screening mammography was cancelled, a period of 2 months immediately after screening mammography resumed (6/17/2020-8/16/2020), and a representative period prior to COVID-19 (6/17/2019-8/16/2019). Relative risk of cancellation before COVID-19 and after reopening was compared for age, race/ethnicity, insurance, history of chronic disease, and exam location, controlling for other collected variables. Risk of failure to reschedule was similarly compared between all 3 time periods. RESULTS: Overall cancellation rate after reopening was higher than before shutdown (7663/16595, 46% vs 5807/15792, 37%; p < 0.001). Relative risk of cancellation after reopening increased with age (1.20 vs 1.27 vs 1.36 for ages at 25th, 50th, and 75th quartile or 53, 61, and 70 years, respectively, p < 0.001). Relative risk of cancellation was also higher among Medicare patients (1.41) compared to Medicaid and those with other providers (1.26 and 1.21, respectively, p < 0.001) and non-whites compared to whites (1.34 vs 1.25, p = 0.03). Rescheduling rate during shutdown was higher than before COVID-19 and after reopening for all patients (10,658/13593, 78%, 3569/5807, 61%, and 4243/7663, respectively, 55%, p < 0.001). Relative risk of failure to reschedule missed mammogram was higher in hospitals compared to outpatient settings both during shutdown and after reopening (0.62 vs 0.54, p = 0.005 and 1.29 vs 1.03, p < 0.001, respectively). CONCLUSION: Minority race/ethnicity, Medicare insurance, and advanced age were associated with increased risk of screening mammogram cancellation during COVID-19.

Computer-aided heterogeneity analysis in breast MR imaging assessment of ductal carcinoma in situ: Correlating histologic grade and receptor status.

PURPOSE: To identify breast MR imaging biomarkers to predict histologic grade and receptor status of ductal carcinoma in situ (DCIS). MATERIALS AND METHODS: Informed consent was waived in this Health Insurance Portability and Accountability Act-compliant Institutional Review Board-approved study. Case inclusion was conducted from 7332 consecutive breast MR studies from January 1, 2009, to December 31, 2012. Excluding studies with benign diagnoses, studies without visible abnormal enhancement, and pathology containing invasive disease yielded 55 MR-imaged pathology-proven DCIS seen on 54 studies. Twenty-eight studies (52%) were performed at 1.5 Tesla (T); 26 (48%) at 3T. Regions-of-interest representing DCIS were segmented for precontrast, first and fourth postcontrast, and subtracted first and fourth postcontrast images on the open-source three-dimensional (3D) Slicer software. Fifty-seven metrics of each DCIS were obtained, including distribution statistics, shape, morphology, Renyi dimensions, geometrical measure, and texture, using the 3D Slicer HeterogeneityCAD module. Statistical correlation of heterogeneity metrics with DCIS grade and receptor status was performed using univariate Mann-Whitney test. RESULTS: Twenty-four of the 55 DCIS (44%) were high nuclear grade (HNG); 44 (80%) were estrogen receptor (ER) positive. Human epidermal growth factor receptor-2 (HER2) was amplified in 10/55 (18%), nonamplified in 34/55 (62%), unknown/equivocal in 8/55 (15%). Surface area-to-volume ratio showed significant difference (P < 0.05) between HNG and non-HNG DCIS. No metric differentiated ER status (0.113 < p ≤ 1.000). Seventeen metrics showed significant differences between HER2-positive and HER2-negative DCIS (0.016 < P < 0.050). CONCLUSION: Quantitative heterogeneity analysis of DCIS suggests the presence of MR imaging biomarkers in classifying DCIS grade and HER2 status. Validation with larger samples and prospective studies is needed to translate these results into clinical applications. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1748-1759.

MR imaging assessment of the breast after breast conservation therapy: distinguishing benign from malignant lesions.

Dynamic contrast material-enhanced magnetic resonance (MR) imaging has emerged as a valuable tool in evaluation of women who have undergone lumpectomy and whole-breast radiation therapy for breast cancer. Early diagnosis of local recurrence by means of close clinical and imaging follow-up is an important component of a breast-conserving strategy, as it may improve survival. In the post-breast conservation therapy (BCT) breast, resolving edema, fat necrosis, a small focal area of non-masslike enhancement (NMLE), and thin linear NMLE at the lumpectomy site can all be expected findings. In contrast, masslike enhancement or NMLE of ductal or segmental distribution can indicate recurrence. Therefore, at MR imaging of the post-BCT breast, it is important to identify lesions that are benign or appropriate for short-interval imaging surveillance to minimize unnecessary intervention, as well as to discern suspicious lesions and optimize the diagnosis of recurrence.