Comparison of Diagnostic Mammography-Guided Biopsy and Digital Breast Tomosynthesis-Guided Biopsy of Suspicious Breast Calcifications: Results in 1354 Biopsies.

BACKGROUND. Studies have shown improved targeting and sampling of noncalcified lesions (asymmetries, masses, and architectural distortion) with digital breast tomosynthesis (DBT)-guided biopsy in comparison with digital mammography (DM)-guided stereotactic biopsy. Literature that compares the two techniques specifically for sampling calcifications has been scarce. OBJECTIVE. The purpose of this study was to compare the performance and outcomes of DM- and DBT-guided biopsy of suspicious calcifications. METHODS. This retrospective study included 1310 patients (mean age, 58 ± 12 [SD] years) who underwent a total of 1354 9-gauge vacuum-assisted core biopsies of suspicious calcifications performed at a single institution from May 22, 2017, to December 31, 2021. The decision to use a DM-guided or DBT-guided technique was made at the discretion of the radiologist performing the biopsy. Procedure time, the number of exposures during the procedure, and the histopathologic outcomes were recorded. The two techniques were compared using a two-sample t test for continuous variables and a chi-square test for categoric variables. Additional tests were performed using generalized estimating equations to control for the effect of the individual radiologist performing the biopsy. RESULTS. A total of 348 (26%) biopsies used DM guidance, and 1006 (74%) used DBT guidance. The mean procedure time was significantly lower for DBT-guided biopsy (14.9 ± 8.0 [SD] minutes) than for DM-guided biopsy (24.7 ± 14.3 minutes) (p < .001). The mean number of exposures was significantly lower for DBT-guided biopsy (4.1 ± 1.0 [SD] exposures) than for DM-guided biopsy (9.1 ± 3.3 exposures) (p < .001). The differences in procedure time and number of exposures remained significant (both p < .001) when controlling for the effect of the radiologist performing the biopsy. There were no significant differences (all p > .05) between DM-guided and DBT-guided biopsy in terms of the malignancy rate on initial biopsy (20% vs 19%), the rate of high-risk lesion upgrading (14% vs 22%), or the final malignancy rate (23% vs 22%). CONCLUSION. DBT-guided biopsy of suspicious calcifications can be performed with shorter procedure time and fewer exposures compared with DM-guided biopsy, without a significant difference in rates of malignancy or high-risk lesion upgrading. CLINICAL IMPACT. The use of a DBT-guided, rather than a DM-guided, biopsy technique for suspicious calcifications can potentially reduce patient discomfort and radiation exposure without affecting clinical outcomes.

High-risk lesions in the breast diagnosed by MRI-guided core biopsy: upgrade rates and features associated with malignancy.

PURPOSE: This study assessed the upgrade rates of high-risk lesions (HRLs) in the breast diagnosed by MRI-guided core biopsy and evaluated imaging and clinical features associated with upgrade to malignancy. METHODS: This IRB-approved, retrospective study included MRI-guided breast biopsy exams yielding HRLs from August 1, 2011, to August 31, 2020. HRLs included atypical ductal hyperplasia (ADH), lobular carcinoma in situ (LCIS), atypical lobular hyperplasia (ALH), radial scar, and papilloma. Only lesions that underwent excision or at least 2 years of MRI imaging follow-up were included. For each HRL, patient history, imaging features, and outcomes were recorded. RESULTS: Seventy-two lesions in 65 patients were included in the study, with 8/72 (11.1%) of the lesions upgraded to malignancy. Upgrade rates were 16.7% (2/12) for ADH, 100% (1/1) for pleomorphic LCIS, 40% (2/5) for other LCIS, 0% (0/19) for ALH, 0% (0/18) for papilloma, and 0% (0/7) for radial scar/complex sclerosing lesion. Additionally, two cases of marked ADH bordering on DCIS and one case of marked ALH bordering on LCIS, were upgraded. Lesions were more likely to be upgraded if they presented as T2 hypointense (versus isotense, OR 6.46, 95% CI 1.27-32.92) or as linear or segmental non-mass enhancement (NME, versus focal or regional, p = 0.008). CONCLUSION: Our data support the recommendation that ADH and LCIS on MRI-guided biopsy warrant surgical excision due to high upgrade rates. HRLs that present as T2 hypointense, or as linear or segmental NME, should be viewed with suspicion as these were associated with higher upgrade rates to malignancy.

Developing Asymmetries without Sonographic Correlate at Digital Breast Tomosynthesis.

Background Digital breast tomosynthesis (DBT) has improved the accuracy of mammography, including resolving many breast asymmetries as overlapping breast tissue. The pathologic outcomes of persistent developing asymmetries visualized at DBT are not well established. Purpose To characterize the outcomes and the predictors of malignancy for developing asymmetries visualized at DBT without a sonographic correlate. Materials and Methods This retrospective study included all tomosynthesis-guided biopsies of developing asymmetries performed at a single institution from May 2017 through January 2020. A reader study including three breast imaging radiologists determined interrater agreement and inclusion into the study. Electronic medical records were used to extract patient characteristics, imaging characteristics, and pathologic diagnoses. The Wilcoxon rank sum test, Fisher exact test, and χ2 test were used to analyze correlations of patient and imaging characteristics with likelihood of malignancy. Results The reader study included 95 DBT examinations with moderate interrater reliability (Fleiss κ = 0.45). There was majority reader agreement in 85 of the 95 DBT examinations (89%) of 83 women (median age, 56 years; interquartile range, 47-69 years), and this finalized the study data set. At pathologic examination, most asymmetries (68 of 85, 80%) were benign, with common diagnoses being fibrocystic change (n = 20), stromal fibrosis (n = 10), and fat necrosis (n = 10). The overall malignancy rate was 20% (17 of 85 asymmetries; 95% CI: 12, 29); 15 of the 17 malignancies (88%) were invasive cancers. Malignancies were more common in women with a personal history of breast cancer (35% vs 10%, P = .02). Conclusion In 85 developing asymmetries visualized at digital breast tomosynthesis without a sonographic correlate, there was a 20% (95% CI: 12, 29) malignancy rate, which was higher than the rates of malignancy for a developing asymmetry detected at digital mammography. © RSNA, 2021 See also the editorial by Skaane in this issue.

COVID-19 Vaccine-Related Axillary Adenopathy on Breast Imaging: Follow-Up Recommendations and Histopathologic Findings.

This study describes 94 patients who presented with suspected COVID-19 vaccine-related axillary adenopathy on breast imaging. All biopsies recommended within 12 weeks of the second vaccine dose were benign. Among women not recommended for biopsy, the median interval between the second vaccine dose and ultrasound follow-up was 15.9 weeks. Three biopsies yielding malignant diagnoses were recommended 12.0-13.1 weeks after the second vaccine dose. Lengthening imaging follow-up to 12-16 weeks after the second dose may reduce unnecessary biopsy recommendations.

Comparison of Outcomes for One-View Asymmetries Recalled From Digital Breast Tomosynthesis Versus Full-Field Digital Mammography Screening Examinations.

BACKGROUND. Recall rates are lower for digital breast tomosynthesis (DBT) than for full-field digital mammography (FFDM). This difference could have important implications with respect to one-view asymmetries given that missed cancers are often visible on one view. OBJECTIVE. The purpose of this study is to compare the outcomes of one-view asymmetries recalled from DBT versus FFDM screening examinations and to determine predictors of malignancy among recalled asymmetries. METHODS. This retrospective study first determined recall rates associated with one-view asymmetries for screening mammography performed using DBT and FFDM from July 14, 2016, through July 14, 2020. Further analyses included patients recalled for a one-view asymmetry who completed subsequent diagnostic workup and all recommended follow-up. Patient and cancer characteristics were extracted from the electronic health record. RESULTS. The recall rate associated with asymmetries was lower for DBT screening (2.5% [3169/128,755]) than for FFDM screening (3.4% [815/23,898]) (p < .001). Further analyses of patients who completed diagnostic workup and subsequent follow-up included 3119 patients (mean age, 57 years) for DBT screening and 811 patients (mean age, 56 years) for FFDM screening. Distribution of final BI-RADS categories from subsequent diagnostic workup was not different between the two modalities (p > .99). The frequency of malignancy was not different between asymmetries recalled from DBT (1.7% [54/3119]) and FFDM (1.7% [14/811]) (p > .99). Malignant asymmetries identified on FFDM versus DBT were more frequently associated with architectural distortion on diagnostic workup (35.7% [5/14] vs 9.3% [5/54]) (p < .001) and were more commonly invasive ductal carcinoma (92.9% vs 57.4%) and less commonly invasive lobular carcinoma (0.0% vs 24.1%) (p = .05). In multivariable analysis, independent predictors of malignancy among recalled asymmetries from DBT were age (for 55-69 years, odds ratio [OR] = 2.40 [p = .04]; for ≥ 70 years, OR = 7.93 [p < .001]; reference, < 55 years) and breast density (not dense, OR = 2.47 [p = .001]; reference, dense breasts). CONCLUSION. Recalled asymmetries were less frequent for DBT than for FFDM. The malignancy rate was low for both modalities (1.7%). Age 55 years old and older and lower breast density predicted malignancy for DBT-recalled asymmetries. CLINICAL IMPACT. Our results support the use of DBT to reduce unnecessary recalls without altering PPV for asymmetry-associated malignancies. Patient factors should be considered when assessing whether a potential asymmetry on DBT screening represents overlapping fibroglandular tissue or a suspicious finding that requires diagnostic workup.

Presentation and characteristics of breast cancer in young women under age 40.

PURPOSE: Although uncommon, breast cancer is the leading cause of cancer death in young women. There are limited studies on the presentation and characteristics of breast cancer in women under age 40. METHODS: This is a retrospective study investigating patient demographics, clinical presentations, imaging findings, and cancer characteristics of a cohort of 145 women under age 40 with breast cancer. RESULTS: Our cohort had more aggressive cancer subtypes than reported in older women; 33.1% triple negative, 80% high Ki-67, and 21.3% with stage 3+ disease. Most were referred from primary care or obstetrician/gynecologist, though 5.5% initially presented from the emergency department and another 2.1% were incidental findings. 16.6% of patients presented while pregnant or breastfeeding. Most patients presented with breast related symptoms. Of the 9.1% of patients diagnosed through our high-risk screening program, 84.6% of the cancers were identified on mammography or simultaneously with mammography and MRI. Most breast cancers presented with typically worrisome imaging (82.6%), though several cancers presented with findings that were typically benign. CONCLUSIONS: We recommend prompt breast imaging for young women presenting with breast-related symptoms or an incidental breast finding, as younger patients have more aggressive cancer subtypes and are of a higher grade at presentation compared to older women. We also recommend vigilance when distinguishing suspicious symptoms from pregnancy-related breast changes to minimize delays in diagnosis. Additionally, it is important to identify patients who qualify for high risk screening, since cancers in screening patients were found at a lower grade than those presenting with symptoms.

Diagnostic Versus Screening Mammography Recommendations for Postlumpectomy Imaging Surveillance of Patients With Breast Cancer.

Among 707 women who were recommended to undergo annual diagnostic mammography (DM) surveillance after lumpectomy for breast cancer, 94.9%, 90.4%, and 84.3% of women presented for DM at years 1, 2, and 3 after lumpectomy. A total of 18.8%, 11.0%, and 9.9% of women received additional views at years 1, 2, and 3, compared with the 10.1% institutional screening recall rate. The postlumpectomy year 3 cancer detection rate of 11.7 cancers per 1000 DM examinations was below DM benchmarks. These preliminary findings suggest that returning to screening mammography may be acceptable after 1 year of postlumpectomy DM follow-up.

Tomosynthesis-Guided Vacuum-Assisted Breast Biopsy of Architectural Distortion Without a Sonographic Correlate: A Retrospective Review.

BACKGROUND. Digital breast tomosynthesis-guided vacuum-assisted breast biopsy (DBT VAB) allows biopsy of findings seen better or exclusively on digital breast tomosynthesis (DBT), including architectural distortion. Although architectural distortion with an associated sonographic mass correlate has a high risk of malignancy, limited data describe the radiologic-pathologic correlation of tomosynthesis-detected architectural distortion without a sonographic correlate. OBJECTIVE. This study evaluates the malignancy rate of architectural distortions without a sonographic correlate that undergo DBT VAB and provides radiologic-pathologic correlation for benign, high-risk, and malignant entities that are associated with architectural distortion. METHODS. We retrospectively reviewed imaging, as well as pathology slides and/or reports, for DBT VABs performed for architectural distortion without a sonographic correlate at a single institution between June 1, 2017, and January 15, 2020. According to the correlative histopathology, cases were categorized as benign, high risk, or malignant, and specific histopathologic diagnoses were summarized. RESULTS. During the study period, 142 patients (mean age, 59 years) underwent DBT VAB for 151 unique architectural distortions without a sonographic correlate. DBT VAB revealed a malignant diagnosis in 27 (18%), a high-risk lesion in 50 (33%), and a benign diagnosis in 74 (49%). Two cases of atypical ductal hyperplasia were upgraded to malignancy, resulting in a final malignancy rate of 19% (n = 29/151). Most malignant lesions were invasive carcinomas (83%, n = 24/29); most invasive carcinomas were of lobular subtype (54%, n = 13/24). Most high-risk lesions were radial scars/complex sclerosing lesions (62%, n = 31/50). Most benign results represented fibrocystic change (66%, n = 49/74). A subset (11%, n = 8/74) of benign results were considered discordant and subsequently excised, with none representing malignancy. CONCLUSION. The final malignancy rate of 19% in architectural distortion without a sonographic correlate justifies a recommendation for biopsy using DBT VAB. CLINICAL IMPACT. Our results highlight the utility of DBT VAB in the era of DBT. The detailed radiologic-pathologic correlations will assist radiologists in assessing concordance when performing DBT VAB for architectural distortions and provide a reference for future patient management.

Outcomes of Foci on Breast MRI: Features Associated With Malignancy.

OBJECTIVE. The objective of this study was to determine the outcomes of foci seen on breast MRI and to evaluate imaging features associated with malignancy. MATERIALS AND METHODS. In this institutional review board-approved retrospective study, we reviewed 200 eligible foci in 179 patients that were assigned BI-RADS category of 3 or 4 from December 2004 to August 2018. Clinical and imaging features of all eligible foci were collected, and associations with malignant outcomes were evaluated. Malignancy rates were also calculated. RESULTS. Of 200 eligible foci, 64 were assigned BI-RADS category 3 and 136 were assigned BI-RADS category 4. The malignancy rate was 1.6% (1/64) among BI-RADS 3 foci and 17.6% (24/136) for BI-RADS 4 foci. The majority of malignant foci represented invasive breast cancer (68.0%, 17/25). Focus size and washout kinetics were significantly associated with malignant outcome (p < 0.05). CONCLUSION. Despite the high prevalence of foci on breast MRI, data are limited to guide their management. Foci should not be disregarded, because foci undergoing biopsy had a malignancy rate of 17.6%, with the majority of malignant foci representing invasive cancer. Larger size and washout kinetics were associated with malignancy in our study and should raise the suspicion level for a focus on breast MRI.

Breast MRI biopsy cancellation due to lesion nonvisualization.

It is a clinical dilemma when a finding reported as suspicious on a breast MRI is not visualized at the time of a scheduled MRI-guided breast biopsy. We retrospectively reviewed all canceled MRI-guided biopsies at our institution between 6/1/2009 and 9/20/2019 and found a cancellation rate of 6.9% (72/1051). In one case, a mastectomy was performed after the canceled biopsy revealing a focus of DCIS in the same quadrant as the original finding (malignancy rate 2.1%). Our results support the current practice of 6-month follow-up MRI recommendation after a canceled MRI-guided biopsy for lesion nonvisualization.

Appropriateness of Information Provided by ChatGPT Regarding Breast Pathologic Diagnoses.

A multidisciplinary physician team rated information provided by ChatGPT regarding breast pathologic diagnoses. ChatGPT responses were mostly appropriate regarding accuracy, consistency, definitions provided, and clinical significance conveyed. Responses were scored lower in terms of management recommendations provided, primarily related to low agreement with recommendations for high-risk lesions.

Imaging Appearance and Clinical Impact of Preoperative Breast MRI in Pregnancy-Associated Breast Cancer.

OBJECTIVE: The purpose of this study is to describe the imaging features of pregnancy-associated breast cancer (PABC) on breast MRI and to consider the impact of preoperative MRI on patient management. MATERIALS AND METHODS: A retrospective review of medical records from January 1994 to May 2014 identified 183 women who presented with a new diagnosis of breast cancer during pregnancy or within 1 year postpartum. MR images were available for 53 of these patients, all of whom were included in the study. Clinical history and available breast images were reviewed. The clinical impact of preoperative breast MRI was also recorded. RESULTS: Of the 53 women, nine (17%) presented during pregnancy and 44 (83%) presented during the first year postpartum. The sensitivity of MRI was 98% (52/53). Among the 53 patients, the most common findings of PABC on MRI included a solitary mass (29 patients [55%]), nonmass enhancement (12 patients [23%]), and multiple masses (eight patients [15%]). For 12 patients (23%), MRI showed a pathologically proven larger tumor size or greater extent of disease than did mammography or ultrasound, with an additional eight patients (15%) having findings suspicious for greater extent of disease but having unavailable pathologic data. Breast MRI changed surgical management for 15 patients (28%), with four patients (8%) requiring a larger lumpectomy, seven (13%) no longer being considered candidates for lumpectomy, two (4%) having contralateral disease, and two (4%) having unsuspected metastasis. CONCLUSION: Breast MRI had a high sensitivity for PABC in our study population. MRI may play an important role in PABC because it changed the surgical management of 28% of patients.

Clinical Outcomes of Benign Concordant MRI-Guided Breast Biopsies.

INTRODUCTION: MRI-guided biopsy is the standard of care for breast imaging findings seen only by MRI. Although a non-zero false-negative rate of MRI-guided breast biopsy has been reported by multiple studies, there are varied practice patterns for imaging follow-up after a benign concordant MRI guided biopsy. This study assessed the outcomes of benign concordant MRI-guided biopsies at a single institution. PATIENTS AND METHODS: This IRB-approved, retrospective study included patients with MRI-guided biopsies of breast lesions from November 1, 2014, to August 31, 2020. Only image-concordant breast lesions with benign histopathology and those follow up with MRI imaging or excision were included in the study. RESULTS: Out of 275 lesions in 216 patients that met the inclusion criteria, 274 lesions were followed with MRI (range, 5-79 months; average, 25.5 months) and showed benign or stable features upon follow-up. One out of 275 lesions (0.4%), a 6 mm focal nonmass enhancement, was ultimately found to represent malignancy after initial MRI-guided biopsy yielded fibrocystic changes. The lesion was stable at a 6-month follow-up MRI but increased in size at 18 months. Repeat biopsy by ultrasound guidance yielded invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS). CONCLUSION: Breast MRI-guided biopsy has a low false-negative rate. Our single malignancy from a total of 275 lesions gives a false negative rate of 0.4%. This data also supports a longer follow-up interval than the commonly performed 6-month follow-up, in order to assess for interval change.

Clinical and Imaging Features of MRI Screen-Detected Breast Cancer.

BACKGROUND: Supplemental screening with breast MRI is recommended annually for patients who have greater than 20% lifetime risk for breast cancer. While there is robust data regarding features of mammographic screen-detected breast cancers, there is limited data regarding MRI-screen-detected cancers. PATIENTS AND METHODS: Screening breast MRIs performed between August 1, 2016 and July 30, 2022 identified 50 screen-detected breast cancers in 47 patients. Clinical and imaging features of all eligible cancers were recorded. RESULTS: During the study period, 50 MRI-screen detected cancers were identified in 47 patients. The majority of MRI-screen detected cancers (32/50, 64%) were invasive. Pathology revealed ductal carcinoma in situ (DCIS) in 36% (18/50), invasive ductal carcinoma (IDC) in 52% (26/50), invasive lobular carcinoma in 10% (5/50), and angiosarcoma in 2% (1/50). The majority of patients (43/47, 91%) were stage 0 or 1 at diagnosis and there were no breast cancer-related deaths during the follow-up periods. Cancers presented as masses in 50% (25/50), nonmass enhancement in 48% (25/50), and a focus in 2% (1/50). DCIS was more likely to present as nonmass enhancement (94.4%, 17/18), whereas invasive cancers were more likely to present as masses (75%, 24/32) (P < .001). All cancers that were stage 2 at diagnosis were detected either on a baseline exam or more than 4 years since the prior MRI exam. CONCLUSION: MRI screen-detected breast cancers were most often invasive cancers. Cancers detected by MRI screening had an excellent prognosis in our study population. Invasive cancers most commonly presented as a mass.

Self-scheduling of Screening Mammograms Using an Online Patient Portal: Initial 8-year Experience at a Multisite Academic Institution.

OBJECTIVE: The goal of this study was to determine patient factors associated with the use of self-scheduling of screening mammograms (SMs) using an online portal. METHODS: All SMs scheduled at our multisite academic institution from January 1, 2015, to December 31, 2022, were included. The frequency of self-scheduling via an online portal was calculated per year. Univariate and multivariate logistic regression models with generalized estimating equation were used to estimate associations between patient characteristics and scheduling format after accounting for correlations between mammograms performed on the same woman. RESULTS: During the study period, 250,369 SMs were performed in 74,860 unique patients (mean age 59 ± 12 years). Of these, 36,200 (14.5%) were self-scheduled via the online portal. Self-scheduling increased each year, from 3.7% in 2015 to 36.9% in 2022. Younger age, non-Black race, being an English speaker, and being from a nondisadvantaged zip code were significant predictors of self-scheduling on univariate and multivariate logistic regression. Age <50 years versus age ≥70 years was the patient characteristic that most strongly predicted the likelihood of self-scheduling (adjusted odds ratio 5.4, 95% confidence interval 5.2-5.6). CONCLUSIONS: Over 8 years (2015-2022), utilization of self-scheduling for screening mammography using an online patient portal increased from 3.7% to 36.9%. Age < 50 years was the patient characteristic that most strongly predicted likelihood of self-scheduling.

Patient Utilization of Weekend and Evening Appointments for Screening Mammography: An 8-Year Observational Cohort Study.

OBJECTIVE: To characterize the patient population using weekend and evening appointments for screening mammography versus standard appointment times across four outpatient facilities in our academic health system. METHODS: In this institutional review board-approved retrospective cohort study, there were 203,101 screening mammograms from 67,323 patients who had a screening mammogram performed at outpatient centers at a multisite academic institution from January 1, 2015, to December 31, 2022. Screening appointments were defined as "standard appointment time" (between 8 am and 5 pm on Monday through Friday) or "weekend or evening appointment time" (scheduled after 5 pm on Monday through Friday or at any time on a Saturday or Sunday). Associations between appointment group and patient characteristics were analyzed using univariate and multivariate logistic regression. RESULTS: Most screening mammograms (n = 185,436, 91.3%) were performed at standard times. The remainder (n = 17,665, 8.7%) were performed during weekends or evenings. As we created additional weekend and evening appointments after the coronavirus disease 2019 pandemic, the annual percentage of all screening mammograms performed on evenings and weekends increased. On multivariate analysis, when compared with standard appointment times, we found that patients who were younger than age 50 (P < .001), a race other than non-Hispanic White (P < .001), non-English speakers (P < .001), and from less advantaged zip codes (P < .03) were more likely to use weekend and evening appointment times compared with those aged 70 and above, non-Hispanic White patients, English speakers, and those from the most advantaged zip codes. CONCLUSIONS: Weekend and evening appointment availability for screening mammograms might improve screening access for all patients, particularly for those younger than age 50, those of races other than non-Hispanic White, and those from less advantaged zip codes.

Cross-site Validation of AI Segmentation and Harmonization in Breast MRI.

This work aims to perform a cross-site validation of automated segmentation for breast cancers in MRI and to compare the performance to radiologists. A three-dimensional (3D) U-Net was trained to segment cancers in dynamic contrast-enhanced axial MRIs using a large dataset from Site 1 (n = 15,266; 449 malignant and 14,817 benign). Performance was validated on site-specific test data from this and two additional sites, and common publicly available testing data. Four radiologists from each of the three clinical sites provided two-dimensional (2D) segmentations as ground truth. Segmentation performance did not differ between the network and radiologists on the test data from Sites 1 and 2 or the common public data (median Dice score Site 1, network 0.86 vs. radiologist 0.85, n = 114; Site 2, 0.91 vs. 0.91, n = 50; common: 0.93 vs. 0.90). For Site 3, an affine input layer was fine-tuned using segmentation labels, resulting in comparable performance between the network and radiologist (0.88 vs. 0.89, n = 42). Radiologist performance differed on the common test data, and the network numerically outperformed 11 of the 12 radiologists (median Dice: 0.85-0.94, n = 20). In conclusion, a deep network with a novel supervised harmonization technique matches radiologists' performance in MRI tumor segmentation across clinical sites. We make code and weights publicly available to promote reproducible AI in radiology.

Can breast MRI predict pathologic response following neoadjuvant chemotherapy for breast cancer? A retrospective cohort study.

PURPOSE: For patients treated with neoadjuvant chemotherapy (NAC) for breast cancer, it is standard of care to perform pre- and post-NAC imaging to evaluate response to therapy prior to surgery. In this study we assess outcome metrics of magnetic resonance imaging (MRI) following NAC. METHODS: We conducted a retrospective analysis of patients with invasive breast cancer who underwent a breast MRI before and after NAC between 2016 and 2021 at a single, multisite academic institution. All breast MRI studies were characterized as either radiologic complete response (rCR) or non-rCR. Corresponding surgical pathology reports were reviewed and categorized as pathologic complete response (pCR) or non-pCR. We defined a positive test as having residual enhancement on MRI (non-rCR) and a positive outcome as having residual disease on final surgical pathology (non-pCR). RESULTS: There were 225 patients included in the study (mean age 52 ± 12 years). Breast cancer receptor distribution was HR+/HER2- (n = 71, 32%), HR+/HER2+ (n = 51, 23%), HR-/HER2- (n = 72, 32%), and HR-/HER2+ (n = 31, 14%). In total, 78 (35%) had rCR and 77 (34%) had pCR; 43 (19%) had both rCR and pCR. The overall accuracy rate was 69% (156/225), sensitivity 76% (113/148), specificity 56% (43/77), positive predictive value 77% (113/147), and negative predictive value 55% (43/78). The PPV was significantly associated with receptor status (p = 0.004). No patient or imaging characteristics were associated with sensitivity. CONCLUSION: Breast MRI only moderately predicts pathologic response for invasive breast cancer treated with NAC (overall accuracy 69%). PPV is significantly associated with receptor status.

Solitary Dilated Ducts Revisited: Malignancy Rate and Implications for Management.

RATIONALE AND OBJECTIVES: A solitary dilated duct (SDD) is a single asymmetrically dilated breast duct with diameter more than 2 mm. The Breast Imaging Reporting and Data System (BI-RADS) fifth edition recommends additional imaging and biopsy for SDDs without demonstrated benign etiology, however management of this rare entity remains controversial. This study describes practice patterns, malignancy rate, and features associated with high-risk/malignant SDDs to better stratify patients requiring biopsy versus follow-up. MATERIALS AND METHODS: This IRB-approved retrospective study identified mammographic, sonographic and MRI exams utilizing the term "solitary dilated duct" at a multisite academic institution between 1/1/2010 and 12/31/2020. Clinical and imaging features, BI-RADS assessments, and outcomes were analyzed. Univariate and multivariate analyses identified predictors of high-risk/malignant histology. RESULTS: SDDs identified in 49 women (mean age 56.1 years) were assessed as BI-RADS 4/5 (31/49, 63%), BI-RADS 3 (9/49, 18%), or BI-RADS 2 (9/49, 18%). Most sampled lesions were benign (16/31, 52%) and the remaining were high-risk (15/31, 48%, all papillary lesions). The only papilloma with atypia on core biopsy upgraded to grade 2 DCIS on excision (malignancy rate 1/49, 2%). All anechoic SDDs were benign (n=13), and all benign SDDs lacked internal vascularity. SDDs with associated masses were associated with malignant/high-risk outcomes on multivariate analysis (p < .001). CONCLUSION: The BI-RADS fifth edition recommends biopsy for SDDs without demonstrated benign etiology. In our 11-year study period, practice patterns were variable with a low malignancy rate of 2%. Our findings suggest that anechoic SDDs may be followed, and SDDs with associated masses or internal vascularity require biopsy.