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The heterogeneous group of B3 lesions in the breast harbors lesions with different malignant potential and progression risk. As several studies about B3 lesions have been published since the last Consensus in 2018, the 3rd International Consensus Conference discussed the six most relevant B3 lesions (atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), radial scar (RS), papillary lesions (PL) without atypia, and phyllodes tumors (PT)) and made recommendations for diagnostic and therapeutic approaches. Following a presentation of current data of each B3 lesion, the international and interdisciplinary panel of 33 specialists and key opinion leaders voted on the recommendations for further management after core-needle biopsy (CNB) and vacuum-assisted biopsy (VAB). In case of B3 lesion diagnosis on CNB, OE was recommended in ADH and PT, whereas in the other B3 lesions, vacuum-assisted excision was considered an equivalent alternative to OE. In ADH, most panelists (76%) recommended an open excision (OE) after diagnosis on VAB, whereas observation after a complete VAB-removal on imaging was accepted by 34%. In LN, the majority of the panel (90%) preferred observation following complete VAB-removal. Results were similar in RS (82%), PL (100%), and FEA (100%). In benign PT, a slim majority (55%) also recommended an observation after a complete VAB-removal. VAB with subsequent active surveillance can replace an open surgical intervention for most B3 lesions (RS, FEA, PL, PT, and LN). Compared to previous recommendations, there is an increasing trend to a de-escalating strategy in classical LN. Due to the higher risk of upgrade into malignancy, OE remains the preferred approach after the diagnosis of ADH., (© 2023. The Author(s).)

Background: Prediction of histological tumor size by post-neoadjuvant therapy (NAT) ultrasound and magnetic resonance imaging (MRI) was evaluated in different breast cancer subtypes., Methods: Imaging was performed after 12-week NAT in patients enrolled into three neoadjuvant WSG ADAPT subtrials. Imaging performance was analyzed for prediction of residual tumor measuring ≤10 mm and summarized using positive (PPV) and negative (NPV) predictive values., Results: A total of 248 and 588 patients had MRI and ultrasound, respectively. Tumor size was over- or underestimated by < 10 mm in 4.4% and 21.8% of patients by MRI and in 10.2% and 15.8% by ultrasound. Overall, NPV (proportion of correctly predicted tumor size ≤10 mm) of MRI and ultrasound was 0.92 and 0.83; PPV (correctly predicted tumor size > 10 mm) was 0.52 and 0.61. MRI demonstrated a higher NPV and lower PPV than ultrasound in hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-positive and in HR-/HER2+ tumors. Both methods had a comparable NPV and PPV in HR-/HER2- tumors., Conclusions: In HR+/HER2+ and HR-/HER2+ breast cancer, MRI is less likely than ultrasound to underestimate while ultrasound is associated with a lower risk to overestimate tumor size. These findings may help to select the most optimal imaging approach for planning surgery after NAT., Trial Registration: Clinicaltrials.gov , NCT01815242 (registered on March 21, 2013), NCT01817452 (registered on March 25, 2013), and NCT01779206 (registered on January 30, 2013).

Objectives: To evaluate whether multiparametric breast-MRI, obtained before the initiation of neoadjuvant systemic therapy (NST) for operable breast cancer, predicts which cancer will achieve a pathological complete response (pCR) after the completion of NST., Methods: This was an IRB-approved retrospective study on 31 consecutive patients (median age, 56 years) with operable invasive breast cancer (median size: 22 mm; triple-negative: 11/31 [35%], HER2-positive: 7/31 [23%], triple-positive: 13/31 [42%]) who underwent multiparametric DCE-MRI before the initiation of NST. The MRI protocol consisted of high-resolution dynamic contrast-enhanced MRI (DCE-MRI), T2-TSE, and DWI (b-values 0, 100, 800 s/mm 2 ). The results of surgical pathology after the completion of NST served as a standard of reference. Patient characteristics (age and menopausal status), pathological tumor characteristics (type, stage, nuclear grade, ER/PR and HER2 receptor status, and Ki-67 staining), and MRI characteristics (size, morphology, T2 signal intensity, enhancement kinetics, and ADC values) before NST were evaluated and compared between patients achieving pCR vs. non-pCR., Results: Among 31 patients, 17 achieved pCR (55%) and 14 non-pCR (45%). No correlation was observed between patient- or tumor pathology-derived characteristics and pCR vs. non-pCR. Among MRI-derived tumor characteristics, tumor growth orientation parallel to Cooper's ligaments (p = 0.002) and wash-out rates (p = 0.019) correlated with pCR. Pre-NST ADC values were lower in patients achieving pCR (P = 0.086)., Conclusions: A tumor growth pattern parallel with Cooper's ligaments and a fast wash-out rate on pre-treatment multiparametric MRI are predictive of pCR and more closely associated with pCR than ADC values., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Although annual MRI screening has improved early diagnosis of hereditary breast cancer, fast growth rates of BRCA1-associated cancers can still lead to interval cancers and/or node-positive disease. Using MRI with shorter screening intervals helps to effectively avoid both interval cancers and node-positive stages, whereas there is no role for mammography in these women.See related article by Guindalini et al., p. 1786., (©2018 American Association for Cancer Research.)

Purpose To compare the diagnostic performance of radiomic analysis (RA) and a convolutional neural network (CNN) to radiologists for classification of contrast agent-enhancing lesions as benign or malignant at multiparametric breast MRI. Materials and Methods Between August 2011 and August 2015, 447 patients with 1294 enhancing lesions (787 malignant, 507 benign; median size, 15 mm ± 20) were evaluated. Lesions were manually segmented by one breast radiologist. RA was performed by using L1 regularization and principal component analysis. CNN used a deep residual neural network with 34 layers. All algorithms were also retrained on half the number of lesions (n = 647). Machine interpretations were compared with prospective interpretations by three breast radiologists. Standard of reference was histologic analysis or follow-up. Areas under the receiver operating curve (AUCs) were used to compare diagnostic performance. Results CNN trained on the full cohort was superior to training on the half-size cohort (AUC, 0.88 vs 0.83, respectively; P = .01), but there was no difference for RA and L1 regularization (AUC, 0.81 vs 0.80, respectively; P = .76) or RA and principal component analysis (AUC, 0.78 vs 0.78, respectively; P = .93). By using the full cohort, CNN performance (AUC, 0.88; 95% confidence interval: 0.86, 0.89) was better than RA and L1 regularization (AUC, 0.81; 95% confidence interval: 0.79, 0.83; P < .001) and RA and principal component analysis (AUC, 0.78; 95% confidence interval: 0.76, 0.80; P < .001). However, CNN was inferior to breast radiologist interpretation (AUC, 0.98; 95% confidence interval: 0.96, 0.99; P < .001). Conclusion A convolutional neural network was superior to radiomic analysis for classification of enhancing lesions as benign or malignant at multiparametric breast MRI. Both approaches were inferior to radiologists' performance; however, more training data will further improve performance of convolutional neural network, but not that of radiomics algorithms. © RSNA, 2018 Online supplemental material is available for this article.

Background: Breast magnetic resonance imaging (MRI) has been reported to frequently result in false-positive diagnoses, limiting its positive predictive value (PPV). However, for PPV calculation, all nonmalignant tissue changes are equally considered false-positive, although the respective prognostic importance, and thus patient management implications, of different pathologies may well differ. We investigated the pathology of false-positive diagnoses made by MRI compared with radiographic (digital mammography/tomosynthesis [DM/DBT]) screening., Methods: We conducted an institutional review board-approved prospective analysis of 710 consecutive asymptomatic women at average risk for breast cancer who underwent vacuum biopsy with or without surgical biopsy for screen-detected DM/DBT (n = 344) or MRI (n = 366) findings. We compared the frequency of false-positive biopsies (given by PPV3), as well as the types of nonmalignant tissue changes that caused the respective false-positive biopsies. In an order of increasing relative risk of subsequent breast cancer, pathologies of false-positive biopsies were categorized as nonproliferative, simple proliferative, complex proliferative, or atypical proliferative (including lobular carcinoma in situ/lobular intraepithelial neoplasia). The Mann-Whitney U test was used to compare distributions., Results: Histology yielded nonmalignant tissue in 202 of 366 biopsies done for positive MRI studies and 195 of 344 biopsies for positive DM/DBT studies, respectively, yielding a similar PPV3 percentages of 44.8% (164 of 202) and 43.3% (149 of 202) for both methods. However, the distribution of tissue types that caused false-positive diagnoses differed significantly (p < 0.0001). On the basis of MRI, high-risk atypical proliferative changes (40.1%; 81 of 202) were most common, followed by complex proliferative changes (23.8%; 48 of 202). In DM/DBT, low-risk, nonproliferative changes were the dominant reason for false-positive diagnoses (49.7%; 97 of 195), followed by simple proliferative changes (25.2%; 51 of 195). Low-risk nonproliferative changes resulted in false-positive diagnoses based on MRI as infrequently as did high-risk atypical proliferative changes based on DM/DBT (18.8% [38 of 202] vs. 18.0% [35 of 195]). The likelihood of a false-positive diagnosis including atypias was twice as high in women undergoing biopsy for MRI findings (81 of 202; 40%) as for those with DM/DBT findings (35 of 195; 18%)., Conclusions: The prognostic importance, and thus the clinical implications, of false-positive diagnoses made on the basis of breast MRI vs. radiographic screening differed significantly, with a reversed prevalence of high- and low-risk lesions. This should be taken into account when discussing the rate of false-positive diagnoses (i.e., PPV levels of MRI vs. radiographic screening). Current benchmarks that rate the utility of breast cancer screening programs (i.e., cancer detection rates and PPVs) do not reflect these substantial biological differences and the different prognostic implications.

Purpose To (a) compare the diagnostic accuracy of breast magnetic resonance (MR) imaging with that of conventional imaging (digital mammography and breast ultrasonography) in the identification of ductal carcinoma in situ (DCIS) components of biopsy-proven invasive breast cancer before surgery and (b) investigate the surgical outcome (positive margin rates and mastectomy rates) of women with breast cancer who underwent preoperative MR imaging combined with MR-guided needle biopsy and/or MR-guided lesion localization or bracketing where appropriate. Materials and Methods The authors performed a prospective two-center study of 593 consecutive patients with biopsy-proven invasive breast cancer who underwent breast MR imaging in addition to conventional imaging. MR-guided vacuum biopsy and MR-guided lesion bracketing were performed for DCIS components visible at MR imaging alone. The accuracy of breast MR imaging was compared with that of conventional imaging, and surgical outcomes (positive margin and mastectomy rates) were investigated. Results Surgical-pathologic assessment demonstrated DCIS components in 139 of the 593 women (23.4%). The sensitivity of MR imaging for the diagnosis of DCIS components pre-operatively (84.9%; 118 of 139) was significantly higher than that of conventional imaging (36.7%; 51 of 139) (P < .0001); more than half of DCIS components (51.1%; 71 of 139) were detected only with MR imaging. The sensitivity advantage of MR imaging over conventional imaging increased with increasing relative size of DCIS components, as follows: The sensitivity of MR imaging versus conventional imaging for small, marginal DCIS components was 56.8% (21 of 37) versus 29.7% (11 of 37); the sensitivity for extensive DCIS components was 91.7% (55 of 60) versus 41.7% (25 of 60); the sensitivity for large, predominant DCIS components was 100.0% (42 of 42) versus 35.7% (15 of 42). Moreover, the sensitivity advantage of MR imaging over conventional imaging increased with increasing nuclear grade of DCIS components, as follows: The sensitivity of MR imaging versus conventional imaging for low-grade DCIS components was 74.0% (20 of 27) versus 40.7% (11 of 27); the sensitivity for intermediate-grade DCIS components was 84.1% (53 of 63) versus 34.9% (22 of 63); the sensitivity for high-grade DCIS components was 91.8% (45 of 49) versus 36.7% (18 of 49) (P < .05-.001 for all). Positive margin rates were low overall (3.7% [95% Clopper Pearson confidence interval [CI]: 2.3%, 5.6%]) and did not differ significantly between the 139 women with DCIS components (5.0% [95% CI: 2.0%, 10.1%]) compared with the 454 women without such components (3.3% [95% CI: 1.9%, 5.4%]). The same was true for mastectomy rates (10.8% [95% CI: 6.2%, 17.2%] vs 8.1% [95% CI: 5.8%, 11.1%]). Conclusion Breast MR imaging improves depiction of DCIS components of invasive breast cancers before surgery and is associated with positive margin and mastectomy rates that are low irrespective of the presence or absence of DCIS components. © RSNA, 2017.

Purpose To investigate the utility and accuracy of breast magnetic resonance (MR) imaging as a supplemental screening tool in women at average risk for breast cancer and to investigate the types of cancer detected with MR imaging screening. Materials and Methods This prospective observational study was conducted at two academic breast centers in women aged 40-70 years without breast cancer-associated risk factors (lifetime risk <15%). Between January 2005 and December 2013, women with at least minimal residual breast tissue (American College of Radiology categories A-D) and normal conventional imaging findings (screening mammography with or without screening ultrasonography [US]) were invited to undergo supplemental MR imaging screening. Outcome measures were supplemental cancer detection rates, interval cancer rates, and biologic profiles of MR imaging-detected additional cancers, as well as specificity and positive predictive value (PPV) of MR imaging screening. Tissue diagnoses or 2 years of follow-up were used to establish the reference standard. Results A total of 2120 women were recruited and underwent 3861 screening MR imaging studies, covering an observation period of 7007 women-years. Breast MR imaging depicted 60 additional breast cancers (ductal carcinoma in situ, n = 20; invasive carcinoma, n = 40) for an overall supplemental cancer detection rate of 15.5 per 1000 cases (95% confidence interval [CI]: 11.9, 20.0). Forty-eight additional cancers were detected with MR imaging at initial screening (supplemental cancer detection rate, 22.6 per 1000 cases). During the 1741 subsequent screening rounds, 12 of 13 incident cancers were found with MR imaging alone (supplemental cancer detection rate, 6.9 per 1000 cases). One cancer was diagnosed with all three methods (mammography, US, and MR imaging), and none were diagnosed with mammography only or US only. Cancers diagnosed with MR imaging were small (median, 8 mm), node negative in 93.4% of cases, and dedifferentiated (high-grade cancer) in 41.7% of cases at prevalence screening and 46.0% of cases at incidence screening. No interval cancers were observed. MR imaging screening offered high specificity (97.1%; 95% CI: 96.5, 97.6) and high PPV (35.7%; 95% CI: 28.9, 43.1). Conclusion In women at average risk for breast cancer, MR imaging screening improves early diagnosis of prognostically relevant breast cancer. © RSNA, 2017 Online supplemental material is available for this article.

Objective: Magnetic resonance (MR)-guided vacuum-biopsy is technically demanding and may fail depending on target-lesion size or breast size, and location of lesions within the breast. We developed an MR-guided vacuum-assisted biopsy protocol that collects larger amounts of tissue, aiming at an at least partial or complete ablation of the target-lesion, just as it is intended during surgical (excisional) biopsy. Rationale is to avoid biopsy failures (false-negative results due to undersampling) by collecting larger amounts of tissue. We report on our experience with MR-guided vacuum-assisted large-volume breast biopsy (VALB) (MR-guided VALB) with regard to clinical success and complication rates., Materials: Institutional review board-approved analysis of 865 patients with 1414 MR imaging (MRI)-only breast lesions who underwent tissue sampling under MRI guidance. Magnetic resonance-guided VALB was performed on a 1.5 T-system with a 9G system. Per target lesion, we collected at least 24 samples, with the biopsy notch directed toward the position of the target until on postbiopsy control imaging the target lesion appeared completely or at least greatly removed. The standard-of-reference was established by at least 24-months follow-up (for benign biopsy results), or results of surgical histology (for malignant or borderline results). We investigated the technical success rates as a function of factors that usually interfere with MR-guided vacuum biopsy., Results: Target lesions were located in the central versus peripheral parts of the breast in 66.6% (941/1414) versus 33.6% (473/1414), occurred in large, intermediate, or small breasts in 22.7% (321/1414), 56.4% (797/1414), or 20.9% (296/1414), corresponded to nonmass enhancement (NME) versus mass enhancement (ME) in 64.0% (905/1414) vs. 36.0% (509/1414), with an average size of 23 mm for NME versus 9 mm for ME, respectively. Primary technical failures, that is, inability to reach the target lesion occurred in 0.2% of patients (2/865) and 0.1% of target lesions (2/1414). Successful biopsy, that is, an MR-guided VALB diagnosis matching with the standard of reference, was achieved in 99.5% (859/863) of patients and 99.7% (1408/1412) target lesions that had been amenable to MR-guided VALB. In 0.5% of patients (4/863) and 0.3% of target lesions (4/1412), a radiologic-pathologic mismatch suggested a false-negative biopsy, confirmed by secondary excisional biopsy. The likelihood of failure was independent of the lesion's location in the breast, breast size, target lesion size, or target lesion type (NME vs ME). None of the patients with benign MR-guided VALB diagnoses developed breast cancer at the biopsy site during follow-up of 2 years. None of the patients developed major complications., Conclusion: Magnetic resonance-guided VALB is a safe procedure that is associated with a high success rate (99.7%) that is independent of the size, type, or location of a target lesion, or the size of the breast, and is associated with a very low complication rate.

Purpose: To prospectively investigate the influence of taxane-containing neoadjuvant chemotherapy (T-NACT) versus non-taxane-containing NACT (NT-NACT) on the contrast material enhancement of breast cancers, benign enhancing lesions (BELs), and background parenchymal enhancement (BPE) at dynamic contrast-enhanced magnetic resonance (MR) imaging., Materials and Methods: This institutional review board-approved study was performed in 62 patients with invasive breast cancer who underwent multiagent NACT with (n = 49) or without (n = 13) taxanes between 2008 and 2011. Written informed consent was obtained. Patients underwent dynamic contrast-enhanced MR imaging according to a standardized protocol before and 2 weeks after completing NACT. The percentage reduction of enhancement of breast cancers, BELs, and BPEs was calculated for patients undergoing NT-NACT versus those undergoing T-NACT. Final surgical pathologic results served as standard of reference. Changes in mean enhancement of breast cancers, BELs, and BPEs between the regimens were compared by using the Student t test for unpaired samples; for intraindividual comparison, the Student t test for paired samples was used., Results: Similar rates of complete pathologic response were observed after T-NACT and NT-NACT (28 [57.2%] of 49 vs eight [61.5%] of 13). T-NACT was associated with an almost complete suppression of enhancement in not only breast cancers but also BELs and BPE in the same patients, with an average reduction of enhancement of -89.9% ± 9.3, -90.2% ± 11.8, and -91.2% ± 7.5, respectively. After T-NACT, cancers with partial (n = 21) or complete (n = 28) pathologic response exhibited a similar reduction of enhancement (-81.8% ± 17.5 vs -93.9% ± 2.3; P = .22). The reduction of enhancement of cancers after NT-NACT was significantly less pronounced than that after T-NACT (-41.1% ± 22.8 vs 88.1% ± 13.9; P < .0001), and effects on enhancement of BELs and BPE were significantly less pronounced compared with effects on enhancement of cancers in the same women (P < .0001). MR imaging led to an overestimation of response (yielded false-negative results for residual disease) in 66.7% (14 of 21) of patients after T-NACT, versus in 20% (one of five) of patients after NT-NACT., Conclusion: The reduction of enhancement observed in breast cancers after T-NACT is, in part, unrelated to their oncologic response. MR imaging-detectable effects of taxanes represent a combination of specific antimitotic and nonspecific antiangiogenic effects. This impacts the accuracy with which dynamic contrast-enhanced MR imaging helps predict complete pathologic response to T-NACT. (©) RSNA, 2015 Online supplemental material is available for this article.

Purpose: To use digital breast tomosynthesis (DBT)-guided vacuum-assisted biopsy (VAB) to sample target lesions identified at full-field digital screening mammography and compare clinical performance with that of prone stereotactic (PS) VAB., Materials and Methods: In this institutional review board-approved study, 205 patients with 216 mammographic findings suspicious for cancer were scheduled to undergo mammography-guided VAB. Written informed consent was obtained. PS VAB was performed in 159 patients with 165 target lesions. DBT VAB was performed in 46 consecutive patients with 51 target lesions. Tissue-sampling methods and materials (9-gauge needles) were the same with both systems. For calcifications, specimen radiographs were obtained, and for masses or architectural distortions, control mammography or DBT was performed to confirm adequate target lesion sampling. χ(2) and Student t tests were used to compare biopsy time, and the Fisher exact test was used to compare lesion type distribution for DBT versus PS VAB., Results: Technical success was achieved in 51 of 51 lesions (100%) with DBT VAB versus 154 of 165 lesions (93%) with PS VAB. In one of 11 lesions in which PS VAB failed, DBT VAB was performed successfully. Mean time to complete VAB was 13 minutes ± 3.7 for DBT VAB versus 29 minutes ± 10.1 for PS VAB (P < .0001). Reidentifying and targeting lesions during PS VAB took longer than it did during DBT VAB (P < .0001). Tissue sampling took about the same time for PS VAB and DBT VAB (P = .067). Significantly more "low-contrast" (ie, uncalcified) target lesions were biopsied with DBT VAB (13 of 51 lesions) versus PS VAB (nine of 165 lesions) (P < .0002). No major complications were observed with either system. One patient who underwent DBT VAB in the sitting position and one patient who underwent PS VAB developed self-limiting vasovagal reactions., Conclusion: Clinical performance of DBT VAB was significantly superior to PS VAB. Because DBT VAB allows use of the full detector size for imaging and provides immediate lesion depth information without requiring triangulation, it facilitates target lesion reidentification and sampling of even low-contrast targets, such as uncalcified masses.

Purpose: To investigate the utility of magnetic resonance (MR) imaging according to different types of Breast Imaging Reporting and Data System (BI-RADS) category 4 findings from screening mammography and/or screening ultrasonography (US)., Materials and Methods: This institutional review board-approved prospective study included 340 patients in whom 353 lesions were detected at screening mammography or US and were rated BI-RADS category 4 after appropriate conventional work-up. Written informed consent was obtained from all patients. Women underwent standard dynamic contrast material-enhanced MR imaging for further assessment. Women with negative or benign MR findings who did not proceed to biopsy underwent intensified follow-up for at least 18 months. Pure clustered microcalcifications were followed up for at least 24 months., Results: Of the 353 study findings, 66 (18.7%) were finally shown to be true-positive (23 cases of ductal carcinoma in situ [DCIS], 43 invasive cancers) and 287 (81.3%) were false-positive. Assessment of MR imaging findings led to a correct diagnosis of no breast cancer in 264 of the 287 false-positive findings (92%) and helped confirm the presence of breast cancer in 63 of 66 malignancies. The false-negative rate for pure clustered microcalcifications was 12% (three of 25 cases) because of three nonenhancing low-grade DCIS cases; in turn, MR imaging depicted additional invasive cancers in three women with false-positive findings from mammography and US. For mammographic findings other than pure clustered microcalcifications, MR imaging increased the positive predictive value (PPV) from 17.5% (21 of 120 cases; 95% confidence interval [CI]: 10.7%, 24.3%) to 78% (21 of 27 cases; 95% CI: 62.1%, 93.5%), with a false-negative rate of 0%. For all US findings, MR imaging increased the PPV from 12.9% (20 of 155 cases; 95% CI: 7.6%, 18.2%) to 69% (20 of 29 cases; 95% CI: 52.2%, 85.8%), again with a false-negative rate of 0%. MR imaging resulted in false-positive findings that led to MR imaging-guided biopsy in five of the 340 patients (1.5%)., Conclusion: MR imaging is useful for the noninvasive work-up of lesions classified as BI-RADS category 4 at mammography or US and can help avoid 92% of unnecessary biopsies. The false-negative rate was 0% for all US findings and for all mammographic findings except pure clustered microcalcifications. Additional invasive cancers were identified in three women with false-positive findings from mammography and US., (© RSNA, 2014.)

Purpose: We investigated whether an abbreviated protocol (AP), consisting of only one pre- and one postcontrast acquisition and their derived images (first postcontrast subtracted [FAST] and maximum-intensity projection [MIP] images), was suitable for breast magnetic resonance imaging (MRI) screening., Methods: We conducted a prospective observational reader study in 443 women at mildly to moderately increased risk who underwent 606 screening MRIs. Eligible women had normal or benign digital mammograms and, for those with heterogeneously dense or extremely dense breasts (n = 427), normal or benign ultrasounds. Expert radiologists reviewed the MIP image first to search for significant enhancement and then reviewed the complete AP (consisting of MIP and FAST images and optionally their nonsubtracted source images) to characterize enhancement and establish a diagnosis. Only thereafter was the regular full diagnostic protocol (FDP) analyzed., Results: MRI acquisition time for FDP was 17 minutes, versus 3 minutes for the AP. Average time to read the single MIP and complete AP was 2.8 and 28 seconds, respectively. Eleven breast cancers (four ductal carcinomas in situ and seven invasive cancers; all T1N0 intermediate or high grade) were diagnosed, for an additional cancer yield of 18.2 per 1,000. MIP readings were positive in 10 (90.9%) of 11 cancers and allowed establishment of the absence of breast cancer, with a negative predictive value (NPV) of 99.8% (418 of 419). Interpretation of the complete AP, as with the FDP, allowed diagnosis of all cancers (11 [100%] of 11). Specificity and positive predictive value (PPV) of AP versus FDP were equivalent (94.3% v 93.9% and 24.4% v 23.4%, respectively)., Conclusion: An MRI acquisition time of 3 minutes and an expert radiologist MIP image reading time of 3 seconds are sufficient to establish the absence of breast cancer, with an NPV of 99.8%. With a reading time < 30 seconds for the complete AP, diagnostic accuracy was equivalent to that of the FDP and resulted in an additional cancer yield of 18.2 per 1,000., (© 2014 by American Society of Clinical Oncology.)

Purpose: To investigate whether mammographic breast densities and the respective degree of MRI background enhancement would correlate. Mammographic breast density is coded to communicate how likely a cancer is obscured by parenchyma. Similarly, background enhancement in breast MRI could obscure enhancing cancer tissue., Materials and Methods: A total of 468 women underwent standard full-field digital mammography and dynamic contrast-enhanced breast MRI in our institution. Mammographic breast density was scored according to the American College of Radiology-classification; background enhancement in MRI was scored on a 4-point scale from absent to severe. Breast "density classes" were retrospectively compared by analyzing the differences between scores for mammography and MRI. Statistical correlation was calculated using the Spearman coefficient., Results: Scores matched in 19% of women (90/468) but differed in 81% (378/468). A deviation by 1 point was observed in 33% (157/468), by 2 points in 38% (179/468), by 3 in 9% (42/468). Scores for background enhancement were lower than mammographic scores in 371/468 (79.3%), equivalent in 90/468 (19.2%), and higher in 7/468 (1.5%)., Conclusion: Mammographic breast density does not correlate with the degree of background enhancement in MRI. In the majority of women, scores for background enhancement in MRI will be lower than the respective mammographic density scores., (© 2014 Wiley Periodicals, Inc.)

Purpose: To prospectively investigate the effects of two antihormonal medications, tamoxifen and aromatase inhibitor (AI), on the degree of background enhancement in breast magnetic resonance (MR) imaging., Materials and Methods: This institutional review board-approved study was performed in 40 postmenopausal women (mean age, 63 years; range, 49-78 years) with unilateral breast cancer between January 2005 and December 2010. Informed consent was obtained from all participants. All patients underwent breast MR imaging before starting any medication, under tamoxifen, and after switching to an AI. Qualitative and quantitative degrees of benign parenchymal enhancement were investigated before treatment, under tamoxifen, and under AI. Data were analyzed by using the Wilcoxon singed-rank test and Student t test for matched pairs., Results: Before treatment, the distribution of background enhancement MR-American College of Radiology (ACR) categories 1, 2, 3, and 4 was 20%, 35%, 33%, and 13%, respectively. With tamoxifen, background enhancement was suppressed, with a distribution of 80%, 15%, 5%, and 0% for MR-ACR categories 1, 2, 3, and 4, respectively. With AI, background enhancement recovered in part, with a distribution of 25%, 53%, 23%, and 0% for categories 1, 2, 3, and 4, respectively. In all 40 women, background enhancement rates were highest before treatment (mean, 51.3% ± 33.3 [standard deviation]). By using tamoxifen, background enhancement rates were significantly reduced (mean, 8.4% ± 9.2), and rose again after the switch to an AI (mean, 22.9% ± 19.1 [P < .001]). Prevalence of benign enhancing foci was 65% (26 of 40) at baseline, 12.5% (five of 40) with tamoxifen, and 40% (16 of 40) with AI., Conclusion: The effects of tamoxifen and AI on benign parenchymal enhancement differ. Whereas tamoxifen leads to a virtually complete suppression of enhancement, the effects of AI are less pronounced. Accordingly, whereas enhancement is unusual and deserves a more careful work-up in a patient in whom tamoxifen is used, this is not necessarily true for women in whom AIs are used. Online supplemental material is available for this article., (RSNA, 2013)

Purpose: Accelerated partial breast irradiation (APBI) after breast-conserving therapy is currently under investigation in prospective randomized studies. Multifocality and multicentricity are exclusion criteria for APBI. Preoperative breast magnetic resonance imaging (MRI) can detect ipsilateral and contralateral invasive tumor foci or ductal carcinoma in situ in addition to conventional diagnostic methods (clinical examination, mammography, and ultrasonography). The objective of this retrospective study was to evaluate the impact of preoperative MRI on patient selection for APBI., Methods and Materials: From 2002 to 2007, a total of 579 consecutive, nonselected patients with newly diagnosed early-stage breast cancer received preoperative breast MRI in addition to conventional imaging studies at the Bonn University Breast Cancer Center. In retrospect, 113 patients would have met the criteria for APBI using conventional imaging workup (clinical tumor size ≤3 cm; negative axillary lymph node status; unifocal disease; no evidence of distant metastases; no invasive lobular carcinoma, ductal and lobular carcinoma in situ, or Paget's disease). We analyzed the amount of additional ipsilateral and contralateral tumor foci detected by MRI., Results: MRI detected additional tumor foci in 8.8% of patients eligible for APBI (11 tumor foci in 10 of 113 patients), either ipsilateral (n = 7, 6.2%) or contralateral (n = 4, 3.5%). In 1 patient, MRI helped detect additional tumor focus both ipsilaterally and contralaterally., Conclusions: Preoperative breast MRI is able to identify additional tumor foci in a clinically relevant number of cases in this highly selected group of patients with low-risk disease and may be useful in selecting patients for APBI., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to evaluate two systems of MRI-guided vacuum-assisted biopsy and to investigate the influence of the choice of system on the choice of biopsy mode in the care of patients with lesions found only at MRI., Materials and Methods: Over a period of 3 years, a total 349 patients underwent MRI-guided tissue sampling of 475 lesions found only at MRI. The lesions were sampled by needle localization plus excisional biopsy or by vacuum-assisted biopsy. Two different systems were used for MRI-guided vacuum-assisted biopsy. During the first half of the study period, a handheld system was used, and during the second half, a console system was used. The procedural advantages and disadvantages, size of lesions biopsied, and time needed for vacuum-assisted biopsy were recorded. The distribution of the type of intervention (needle localization or vacuum-assisted biopsy) used to manage MRI-only lesions during the two study periods also was assessed., Results: The average diameter of lesions sampled with vacuum-assisted biopsy was 19.2 mm with the handheld system and 10.4 mm with the console system (p < 0.039). The average biopsy time was 69 minutes for the handheld system and 39 minutes for the console system (p < 0.005). Of the total of 170 MRI-only lesions biopsied with the handheld system, 121 (71%) were sampled by localization and 49 (29%) by vacuum-assisted biopsy. Of the total 305 MRI-only lesions biopsied with the console system, 38 (12%) were sampled by localization and 267 (88%) by vacuum-assisted biopsy., Conclusion: Because of the procedural advantages of use of the console-based system, smaller lesions were biopsied in less time and with higher operator confidence. This result translated into a major shift in the care of patients with MRI-only lesions away from lesion localization toward increased use of MRI-guided vacuum-assisted biopsy.

Purpose: We investigated the respective contribution (in terms of cancer yield and stage at diagnosis) of clinical breast examination (CBE), mammography, ultrasound, and quality-assured breast magnetic resonance imaging (MRI), used alone or in different combination, for screening women at elevated risk for breast cancer., Methods: Prospective multicenter observational cohort study. Six hundred eighty-seven asymptomatic women at elevated familial risk (> or = 20% lifetime) underwent 1,679 annual screening rounds consisting of CBE, mammography, ultrasound, and MRI, read independently and in different combinations. In a subgroup of 371 women, additional half-yearly ultrasound and CBE was performed more than 869 screening rounds. Mean and median follow-up was 29.18 and 29.09 months., Results: Twenty-seven women were diagnosed with breast cancer: 11 ductal carcinoma in situ (41%) and 16 invasive cancers (59%). Three (11%) of 27 were node positive. All cancers were detected during annual screening; no interval cancer occurred; no cancer was identified during half-yearly ultrasound. The cancer yield of ultrasound (6.0 of 1,000) and mammography (5.4 of 1,000) was equivalent; it increased nonsignificantly (7.7 of 1,000) if both methods were combined. Cancer yield achieved by MRI alone (14.9 of 1,000) was significantly higher; it was not significantly improved by adding mammography (MRI plus mammography: 16.0 of 1,000) and did not change by adding ultrasound (MRI plus ultrasound: 14.9 of 1,000). Positive predictive value was 39% for mammography, 36% for ultrasound, and 48% for MRI., Conclusion: In women at elevated familial risk, quality-assured MRI screening shifts the distribution of screen-detected breast cancers toward the preinvasive stage. In women undergoing quality-assured MRI annually, neither mammography, nor annual or half-yearly ultrasound or CBE will add to the cancer yield achieved by MRI alone.

Purpose: Evaluation of the impact of preoperative magnetic resonance imaging (MRI) of the breast on the clinical management of patients with operable breast cancer (BC)., Methods: Retrospective analysis of 160 patients with operable breast cancer (stages Tis through T4), treated from 2002 through 2004. All patients underwent a full mammographic assessment, high frequency breast ultrasound, and breast MRI. The impact of preoperative MRI was evaluated for each patient with regard to changes in the therapeutic procedure. Patient and tumor characteristics were analyzed to identify possible patient subgroups that predominantly would benefit from preoperative MRI., Results: Preoperative MRI affected the clinical management in 44 of 160 patients (27.5%). In 30 cases (18.75%) additional in situ or invasive cancers or a more widespread tumor extent were diagnosed correctly which went undetected by clinical palpation, mammography, and breast ultrasound. In 14 cases (8.75%) additional surgical procedures were performed based on suspicious MRI findings that turned out to be benign in final pathology. Age, menopausal status, breast density, tumor characteristics (type, tumor size, grading), ER-, PR- and HER2-receptor features did not significantly differ between patients in which breast MRI affected the clinical management and patients that experienced no additional information from MRI., Conclusions: Preoperative breast MRI changes surgical management of patients with operable breast cancer. MRI detects additional invasive carcinoma and proves to be a powerful supplement to the conventional work-up in the clinical management of breast cancer. This advantage is independent from patients- and tumor-specific characteristics.

Purpose: To prospectively investigate the imaging (mammographic, ultrasonographic [US], magnetic resonance [MR] imaging) features of invasive and intraductal breast cancers in women at familial risk., Materials and Methods: Ethics committee approval and informed consent were obtained. Breast cancers were identified in women at moderately increased risk, in women at high familial risk, and in documented BRCA1 and BRCA2 mutation carriers. All cancers were investigated with mammography, US, and bilateral dynamic breast MR imaging. Imaging findings of breast cancer in women in the different risk categories were prospectively collected and compared. With the two-sample Wilcoxon signed rank test, imaging features of cancers were compared., Results: Seventy-six breast cancers were identified in 68 women (mean age, 41.3 years). Mammographic breast density had no influence on detectability of cancers. Imaging phenotypes differed among risk categories: 15 (23%) of 64 invasive cancers appeared as fibroadenoma-like masses without calcifications but without fibroadenoma-like internal enhancement or enhancement kinetics at breast MR imaging. Of those, 12 (80%) occurred in women at high risk and documented BRCA1 mutation carriers. A posterior (immediately prepectoral) location was observed in 67% (32 of 48) of all breast cancers in women at high risk and mutation carriers (P < .009). None of the remaining BRCA1-associated invasive cancers exhibited calcifications; intraductal cancers were not observed. In 28 cancers in BRCA2 carriers or women at moderately increased risk, imaging features seemed equivalent to those reported for sporadic cancers; cases of ductal carcinoma in situ were observed, and there was no preference for a posterior location in the breast. At MR imaging, a high percentage (20% [13 of 64]) of invasive cancers appeared as non-masslike enhancement; benign kinetic features were observed in 33% (25 of 76)., Conclusion: Imaging phenotypes of cancers differ among risk categories. If MR imaging is used for screening, high sensitivity rates are achievable only if morphologic and kinetic features are assessed and if non-masslike enhancement is considered. Lesion location is important in regard to malignancy., Supplemental Material: http://radiology.rsnajnls.org/cgi/content/full/246/1/58/DC1., (RSNA, 2008)

Background: Diagnosing breast cancer in its intraductal stage might be helpful to prevent the development of invasive cancer. Our aim was to investigate the sensitivity with which ductal carcinoma in situ (DCIS) is diagnosed by mammography and by breast MRI., Methods: During a 5-year period, 7319 women who were referred to an academic national breast centre received MRI in addition to mammography for diagnostic assessment and screening. Mammograms and breast MRI studies were assessed independently by different radiologists. We investigated the sensitivity of each method of detection and compared the biological profiles of mammography-diagnosed DCIS versus DCIS detected by MRI alone. We also compared the risk profiles of women with mammography-detected DCIS with those of MRI-detected DCIS., Findings: 193 women received a final surgical pathology diagnosis of pure DCIS. Of those, 167 had undergone both imaging tests preoperatively. 93 (56%) of these cases were diagnosed by mammography and 153 (92%) by MRI (p<0.0001). Of the 89 high-grade DCIS, 43 (48%) were missed by mammography, but diagnosed by MRI alone; all 43 cases missed by mammography were detected by MRI. By contrast, MRI detected 87 (98%) of these lesions; the two cases missed by MRI were detected by mammography. Age, menopausal status, personal or family history of breast cancer or of benign breast disease, and breast density of women with MRI-only diagnosed DCIS did not differ significantly from those of women with mammography-diagnosed DCIS., Interpretation: MRI could help improve the ability to diagnose DCIS, especially DCIS with high nuclear grade.

Purpose: To compare the effectiveness of mammography, breast ultrasound, and magnetic resonance imaging (MRI) for surveillance of women at increased familial risk for breast cancer (lifetime risk of 20% or more)., Patients and Methods: We conducted a surveillance cohort study of 529 asymptomatic women who, based on their family history and/or mutational analysis, were suspected or proven to carry a breast cancer susceptibility gene (BRCA). A total of 1,542 annual surveillance rounds were completed with a mean follow-up of 5.3 years. Diagnostic accuracies of the three imaging modalities used alone or in different combinations were compared., Results: Forty-three breast cancers were identified in the total cohort (34 invasive, nine ductal carcinoma-in-situ). Overall sensitivity of diagnostic imaging was 93% (40 of 43 breast cancers); overall node-positive rate was 16%, and one interval cancer occurred (one of 43 cancers, or 2%). In the analysis by modality, sensitivity was low for mammography (33%) and ultrasound (40%) or the combination of both (49%). MRI offered a significantly higher sensitivity (91%). The sensitivity of mammography in the higher risk groups was 25%, compared with 100% for MRI. Specificity of MRI (97.2%) was equivalent to that of mammography (96.8%)., Conclusion: Mammography alone, and also mammography combined with breast ultrasound, seems insufficient for early diagnosis of breast cancer in women who are at increased familial risk with or without documented BRCA mutation. If MRI is used for surveillance, diagnosis of intraductal and invasive familial or hereditary cancer is achieved with a significantly higher sensitivity and at a more favorable stage.

Purpose: To investigate the respective diagnostic accuracies of the different breast imaging modalities, i. e., mammography (Mx), high-frequency breast ultrasound (US), and dynamic contrast-enhanced breast (MRI) regarding the early diagnosis of familial (hereditary) breast cancer., Materials and Methods: A prospective, non-randomized controlled clinical multi-center trial is performed at 4 academic tertiary care centers in Germany (Ulm, Munchen/Grosshadern, Munster and Bonn) for a total period of 4 years, sponsored by the German Cancer Aid. The protocol consists of semiannual clinical visits and breast ultrasound, and annual bilateral two-view Mx, US and MRI. Imaging studies were first analyzed independently, then Mx was read in conjunction with US, followed by Mx combined with MRI, and finally, all three imaging modalities were read in synopsis. We present the concept and first results of this trial., Results: So far, 748 screening rounds are available for analysis in 613 women. A total of 12 breast cancers have been identified, with 11/12 cases in the pTis or pT1/N0 stage. The mean size of detected invasive cancers was 7 mm. A total of 19 benign lesions were biopsied due to false-positive imaging diagnoses. The breast cancer detection rates were: Mx: 5/12 (42 %), US 3/12 (25 %), MRI 10/12 (83 %), and the positive predictive values: Mx 5/17 (29 %), US 3/15 (30 %), and MRI 10/23 (43 %)., Conclusion: The preliminary data suggest that early diagnosis of familial breast cancer is feasible by intensified surveillance, in particular with the addition of MRI.