The lobular neoplasia enigma: management and prognosis in a long follow-up case series.

BACKGROUND: Many oncologists debate if lobular neoplasia (LN) is a risk factor or an obligatory precursor of more aggressive disease. This study has three aims: (i) describe the different treatment options (surgical resection vs observation), (ii) investigate the upgrade rate in surgically treated patients, and (iii) evaluate the long-term occurrences of aggressive disease in both operated and unoperated patients. METHODS: A series of 122 patients with LN bioptic diagnosis and follow-up information were selected. Clinical, radiological, and pathological data were collected from medical charts. At definitive histology, either invasive or ductal carcinoma in situ was considered upgraded lesions. RESULTS: Atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS), and high-grade LN (HG-LN) were diagnosed in 44, 63, and 15 patients, respectively. The median follow-up was 9.5 years. Ninety-nine patients were surgically treated, while 23 underwent clinical-radiological follow-up. An upgrade was observed in 28/99 (28.3%). Age ≥ 54 years (OR 4.01, CI 1.42-11.29, p = 0.009), Breast Imaging-Reporting and Data System (BI-RADS) categories 4-5 (OR 3.76, CI 1.37-10.1, p = 0.010), and preoperatory HG-LN diagnosis (OR 8.76, 1.82-42.27, p = 0.007) were related to upgraded/aggressive disease. During follow-up, 8 patients developed an ipsilateral malignant lesion, four of whom were not initially operated (4/23, 17%). CONCLUSIONS: BI-RADS categories 4-5, HG-LN diagnosis, and age ≥ 54 years were features associated with an upgrade at definitive surgery. Moreover, 17% of unoperated cases developed an aggressive disease, emphasizing that LN patients need close surveillance due to the long-term risk of breast cancer.

Apparent diffusion coefficient in estrogen receptor-positive and lymph node-negative invasive breast cancers at 3.0T DW-MRI: A potential predictor for an oncotype Dx test recurrence score.

PURPOSE: To measure the apparent diffusion coefficient (ADC) values in estrogen receptor-positive (ER+) and axillary lymph node-negative (LN-) invasive breast cancer and investigate the correlation of ADC with Oncotype Dx test recurrence scores (ODxRS). MATERIALS AND METHODS: This was a Health Insurance Portability and Accountability Act (HIPAA)-compliant single-site retrospective study. Patients underwent preoperative 3.0T MRI scans with additional diffusion-weighted imaging sequential scans (b = 0, 600 and b = 0, 1000 s/mm2 ) from January 2011 to 2013. The study population included 31 ER+/LN- invasive breast cancers, which underwent ODxRS genomic testing. ADC600 and ADC1000 parametric maps were generated, and ADC values were calculated from a user-drawn region of interest. ODxRS predicts 10-year recurrence risk in individual patients: low (RS <18), intermediate (RS: 18-30), or high (RS >30). All breast lesions, including subgroups of invasive ductal carcinoma (IDC) lesions and mass-only lesions were dichotomized by RS scores, low-risk versus intermediate/high-risk, and statistical analysis was performed using Mann-Whitney's test (statistical significance at P < 0.05) and receiver operating characteristic (ROC) curves. Multivariate analysis was also performed. RESULTS: Invasive breast cancers, when scored as low-risk by ODxRS, had significantly higher ADC values compared with intermediate/high-risk lesions for both ADC600 (P = 0.007) and ADC1000 (P = 0.008) mean values. This was true both when analyzing only mass-lesions (P = 0.03 and 0.01) or only IDCs (P = 0.001 and 0.009). CONCLUSION: Preliminary findings suggest that lesion ADC values correlate with recurrence risk likelihood stratified using ODxRS. Hence, ADC is a potential surrogate biomarker for tumor aggressiveness. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;47:401-409.

Apparent diffusion coefficient mapping using diffusion-weighted MRI: impact of background parenchymal enhancement, amount of fibroglandular tissue and menopausal status on breast cancer diagnosis.

OBJECTIVES: To investigate the impact of background parenchymal enhancement (BPE), amount of fibroglandular tissue (FGT) and menopausal status on apparent diffusion coefficient (ADC) values in differentiation between malignant and benign lesions. METHODS: In this HIPAA-compliant study, mean ADC values of 218 malignant and 130 benign lesions from 288 patients were retrospectively evaluated. The differences in mean ADC values between benign and malignant lesions were calculated within groups stratified by BPE level (high/low), amount of FGT (dense/non-dense) and menopausal status (premenopausal/postmenopausal). Sensitivities and specificities for distinguishing malignant from benign lesions within different groups were compared for statistical significance. RESULTS: The mean ADC value for malignant lesions was significantly lower compared to that for benign lesions (1.07±0.21 x 10-3 mm2/s vs. 1.53±0.26 x 10-3 mm2/s) (p<0.0001). Using the optimal cut-off point of 1.30 x 10-3 mm2/s, an area under the curve of 0.918 was obtained, with sensitivity and specificity both of 87 %. There was no statistically significant difference in sensitivities and specificities of ADC values between different groups stratified by BPE level, amount of FGT or menopausal status. CONCLUSIONS: Differentiation between benign and malignant lesions on ADC values is not significantly affected by BPE level, amount of FGT or menopausal status. KEY POINTS: • ADC allows differentiation between benign and malignant lesions. • ADC is useful for breast cancer diagnosis despite different patient characteristics. • BPE, FGT or menopause do not significantly affect sensitivity and specificity.

Comparison of synthetic mammography, reconstructed from digital breast tomosynthesis, and digital mammography: evaluation of lesion conspicuity and BI-RADS assessment categories.

PURPOSE: To compare the interpretive performance of synthetic mammography (SM), reconstructed from digital breast tomosynthesis (DBT), and full-field digital mammography (FFDM) in a diagnostic setting, covering different conditions of breast density and mammographic signs. METHODS: A retrospective analysis was conducted on 231 patients, who underwent FFDM and DBT (from which SM images were reconstructed) between September 2014-September 2015. The study included 250 suspicious breast lesions, all biopsy proven: 148 (59.2%) malignant and 13 (5.2%) high-risk lesions were confirmed by surgery, 89 (35.6%) benign lesions had radiological follow-up. Two breast radiologists, blinded to histology, independently reviewed all cases. Readings were performed with SM alone, then with FFDM, collecting data on: probability of malignancy for each finding, lesion conspicuity, mammographic features and dimensions of detected lesions. RESULTS: Agreement between readers was good for BI-RADS classification (Cohen's k-coefficient = 0.93 ± 0.02) and for lesion dimension (Wilcoxon's p = 0.76). Visibility scores assigned to SM and FFDM for each lesion were similar for non-dense and dense breasts, however, there were significant differences (p = 0.0009) in distribution of mammographic features subgroups. SM and FFDM had similar sensitivities in non-dense (respectively 94 vs. 91%) and dense breasts (88 vs. 80%) and for all mammographic signs (93 vs. 87% for asymmetric densities, 96 vs. 75% for distortion, 92 vs. 85% for microcalcifications, and both 94% for masses). Based on all data, there was a significant difference in sensitivity for SM (92%) vs. FFDM (87%), p = 0.02, whereas the two modalities yielded similar results for specificity (SM: 60%, FFDM: 62%, p = 0.21). CONCLUSIONS: SM alone showed similar interpretive performance to FFDM, confirming its potential role as an alternative to FFDM in women having tomosynthesis, with the added advantage of halving the patient's dose exposure.

Breast Cancer: Computer-aided Detection with Digital Breast Tomosynthesis.

PURPOSE: To evaluate a commercial tomosynthesis computer-aided detection (CAD) system in an independent, multicenter dataset. MATERIALS AND METHODS: Diagnostic and screening tomosynthesis mammographic examinations (n = 175; cranial caudal and mediolateral oblique) were randomly selected from a previous institutional review board-approved trial. All subjects gave informed consent. Examinations were performed in three centers and included 123 patients, with 132 biopsy-proven screening-detected cancers, and 52 examinations with negative results at 1-year follow-up. One hundred eleven lesions were masses and/or microcalcifications (72 masses, 22 microcalcifications, 17 masses with microcalcifications) and 21 were architectural distortions. Lesions were annotated by radiologists who were aware of all available reports. CAD performance was assessed as per-lesion sensitivity and false-positive results per volume in patients with negative results. RESULTS: Use of the CAD system showed per-lesion sensitivity of 89% (99 of 111; 95% confidence interval: 81%, 94%), with 2.7 ± 1.8 false-positive rate per view, 62 of 72 lesions detected were masses, 20 of 22 were microcalcification clusters, and 17 of 17 were masses with microcalcifications. Overall, 37 of 39 microcalcification clusters (95% sensitivity, 95% confidence interval: 81%, 99%) and 79 of 89 masses (89% sensitivity, 95% confidence interval: 80%, 94%) were detected with the CAD system. On average, 0.5 false-positive rate per view were microcalcification clusters, 2.1 were masses, and 0.1 were masses and microcalcifications. CONCLUSION: A digital breast tomosynthesis CAD system can allow detection of a large percentage (89%, 99 of 111) of breast cancers manifesting as masses and microcalcification clusters, with an acceptable false-positive rate (2.7 per breast view). Further studies with larger datasets acquired with equipment from multiple vendors are needed to replicate the findings and to study the interaction of radiologists and CAD systems.

Characterisation of microcalcification clusters on 2D digital mammography (FFDM) and digital breast tomosynthesis (DBT): does DBT underestimate microcalcification clusters? Results of a multicentre study.

OBJECTIVES: To compare DBT and FFDM in the classification of microcalcification clusters (MCs) using BI-RADS. METHODS: This Institutional Review Board-approved study was undertaken in three centres. A total of 107 MCs evaluated with both DBT and FFDM were randomised for prospective reading by six experienced breast radiologists and classified using BI-RADS. RESULTS: The benign/malignant ratio of MC was 66/41. Of 11/107 discordant results, DBT classified MCs as R2 whereas FFDM classified them as R3 in 9 and R4 in 2. Three of these (3/107 = 2.8%) were malignant; 8 (7.5%) were nonmalignant and were correctly classified as R2 on DBT but incorrectly classified as R3 on FFDM. Estimated sensitivity and specificity, respectively, were 100% (95% CI: 91% to 100%) and 94.6% (95% CI: 86.7% to 98.5%) for FFDM and 91.1% (95% CI: 78.8% to 97.5%) and 100% (95% CI: 94.8% to 100%) for DBT. Overall intra- and interobserver agreements were 0.75 (95% CI: 0.61-0.84) and 0.73 (95% CI: 0.62-0.78). CONCLUSIONS: Most MCs are scored similarly on FFDM and DBT. Although a minority (11/107) of MCs are classified differently on FFDM (benign MC classified as R3) and DBT (malignant MC classified as R2), this may have clinical relevance. KEY POINTS: • The BI-RADS classification of MC differs for FFDM and DBT in 11/107 cases • DBT assigned lower BI-RADS classes compared to FFDM in 11 clusters • In 4/107 DBT may have missed some malignant and high-risk lesions • In 7/107 the 'underclassification' on DBT was correct, potentially avoiding unnecessary biopsies • DBT may miss a small proportion of malignant lesions.

Digital Breast Tomosynthesis (DBT) to Characterize MRI-Detected Additional Lesions Unidentified at Targeted Ultrasound in Newly Diagnosed Breast Cancer Patients.

OBJECTIVES: Preoperative breast magnetic resonance (MR) often generates additional suspicious findings needing further investigations. Targeted breast ultrasound (US) is the standard tool to characterize MR additional lesions. The purpose of this study is to evaluate the potential role of digital breast tomosynthesis (DBT) to characterize MR detected additional findings, unidentified at targeted breast US. METHODS: This prospective study included women who a) had biopsy-proven, newly diagnosed breast cancers detected at conventional 2D mammography and/or US, referred to breast MR for tumour staging; and b) had DBT if additional MR findings were not detected at targeted ('second look') US. RESULTS: In 520 patients, MR identified 164 (in 114 women, 22%) additional enhancing lesions. Targeted US identified 114/164 (69.5%) of these, whereas 50/164 (30.5%) remained unidentified. DBT identified 32/50 of these cases, increasing the overall characterization of MR detected additional findings to 89.0% (146/164). Using DBT the identified lesions were significantly more likely to be malignant than benign MR-detected additional lesions (p = 0.04). CONCLUSIONS: DBT improves the characterization of additional MR findings not identified at targeted breast US in preoperative breast cancer staging. KEY POINTS: • Targeted US identified 114 of 164 (69.5%) additional enhancing lesions at preoperative breast MRI. • DBT identified a further 32 of the 50 lesions unidentified on targeted US. • DBT improved the characterization of additional MR findings for breast cancer staging.

Breast cancer risk associated with the diagnosis of a microhistological radial scar (RS): retrospective analysis in 10 years of experience.

PURPOSE: To retrospectively assess the risk of breast cancer associated with the radial scar (RS) microhistological diagnosis, also taking into consideration the percutaneous biopsy devices used, as well as the different performances of the mammographic systems (analogical, digital and tomosynthesis) in the radiological diagnosis of RS. MATERIALS AND METHODS: Between March 2002 and November 2011, 80 RSs were identified using the analogical, digital and tomosynthesis mammographic systems. Based on the microhistological examination, the patients were divided into three groups [RS without hyperplasic-proliferative lesions (HPL); RS with HPL; RS with cancer] and we assessed the risk of cancer associated with RS in the first and second group. We evaluated the mammographic features and the BI-RADS categories assigned to RSs, the biopsy devices used and the differences between the pathological examination and the microhistological diagnosis (p < 0.05). RESULTS: Based on the microhistological examination, 51/80 patients were included in the first group (9 of them not subjected to surgery), 25/80 in the second group and 4/80 in the third one. At the final histological examination, there were 7/42 (16.7%) cancers in the first group and 8/25 (32%) in the second group. The largest number of microhistological underestimation occurred in the patients who were subjected to core biopsy (15 cases) (p < 0.05). Tomosynthesis improved (p < 0.05) the identification of the RS. CONCLUSIONS: 22.3% of the RSs was associated with cancer. Given that at microhistological examination 16.7% of the RS without HPL was cancer at pathology, the surgical excision is preferred. Tomosynthesis was useful to detect parenchymal distortions.

Mammotome(®) and EnCor (®): comparison of two systems for stereotactic vacuum-assisted core biopsy in the characterisation of suspicious mammographic microcalcifications alone.

PURPOSE: The authors sought to compare the diagnostic performance of the Mammotome(®) and EnCor(®) vacuum-assisted breast biopsy (VABB) systems in the assessment of suspicious mammographic microcalcifications. MATERIALS AND METHODS: Between January 2011 and July 2012, a total of 169 VABB were performed by stereotactic guidance on a prone table. The Mammotome(®) 11G (S1) or EnCor(®) 10G (S2) probes were used randomly. Sampling time and the number of frustules collected were considered; sensitivity, specificity, diagnostic accuracy, positive and negative predictive value (PPV, NPV) of both procedures were evaluated, considering the final histological examination as reference (B1, B3, B5 lesions underwent surgical excision; B2 lesion were considered confirmed after a negative follow-up of at least 1 year). RESULTS: There were no statistically significant differences between the two groups of patients according to the number of procedures (S1 82/169; S2 87/169), average age, BIRADS category (4a, b), and average size of the lesions. The two systems did not differ statistically for correlation with the final histology (S1 k = 0.94 ± 0.06; S2 k = 0.92 ± 0.08) and underestimation of B3 lesions or in situ (S1 4.5%; S2 4.3%). Sensitivity, specificity, PPV, NPV, diagnostic accuracy of S1 and S2 were also not statistically different. The systems differed only in sampling time (S1 80; S2 63 s), but not in total procedure time. CONCLUSIONS: Our study confirms the effectiveness of VABB in the assessment of microcalcifications and highlights the lack of significant differences between the two systems in terms of diagnostic performance.

Radiological assessment of breast density by visual classification (BI-RADS) compared to automated volumetric digital software (Quantra): implications for clinical practice.

OBJECTIVE: This study was done to assess breast density on digital mammography and digital breast tomosynthesis according to the visual Breast Imaging Reporting and Data System (BI-RADS) classification, to compare visual assessment with Quantra software for automated density measurement, and to establish the role of the software in clinical practice. MATERIALS AND METHODS: We analysed 200 digital mammograms performed in 2D and 3D modality, 100 of which positive for breast cancer and 100 negative. Radiological density was assessed with the BI-RADS classification; a Quantra density cut-off value was sought on the 2D images only to discriminate between BI-RADS categories 1-2 and BI-RADS 3-4. Breast density was correlated with age, use of hormone therapy, and increased risk of disease. RESULTS: The agreement between the 2D and 3D assessments of BI-RADS density was high (K 0.96). A cut-off value of 21% is that which allows us to best discriminate between BI-RADS categories 1-2 and 3-4. Breast density was negatively correlated to age (r = -0.44) and positively to use of hormone therapy (p = 0.0004). Quantra density was higher in breasts with cancer than in healthy breasts. CONCLUSIONS: There is no clear difference between the visual assessments of density on 2D and 3D images. Use of the automated system requires the adoption of a cut-off value (set at 21%) to effectively discriminate BI-RADS 1-2 and 3-4, and could be useful in clinical practice.

Acellular dermal matrix imaging features in breast reconstructive surgery: a pictorial review.

Acellular dermal matrices (ADMs) are biological engineered tissues, which may provide an immunologically inert scaffold in breast reconstruction. Since the literature on imaging features of ADMs is limited, radiologists must be aware of the common imaging appearances of ADM, to differentiate normal conformation from residual or recurrent disease. Our purpose is to review the current role of ADMs in implant-based breast reconstruction, describing the normal imaging findings at ultrasound, mammography, and MRI also considering the possible changes over time. In this pictorial essay, we reviewed imaging features of ADMs described in the literature and we reported our experience in patients who underwent reconstructive surgery with human or animal ADM for newly diagnosed breast cancer.

Accuracy of tumour size assessment in the preoperative staging of breast cancer: comparison of digital mammography, tomosynthesis, ultrasound and MRI.

PURPOSE: Accurate measurement of breast tumour size is fundamental for treatment planning. We compared the accuracy of digital mammography (DM), digital breast tomosynthesis (DBT), ultrasound (US) and magnetic resonance imaging (MRI) for the preoperative evaluation of breast cancer size. MATERIALS AND METHODS: We retrospectively reviewed 149 breast cancers in 110 patients who underwent DM, DBT, US and MRI between January 2010 and December 2011, before definitive surgery. The lesions were measured by two radiologists, without knowledge of the final histological examination, considered the gold standard. For each imaging modality, the maximum tumour size was measured to the nearest millimetre; the measurements were considered concordant if they were within ± 5 mm. Pearson's correlation coefficient was calculated for each imaging modality. RESULTS: The median pathological tumour size was 22.3 mm. MRI and DBT had a level of concordance with pathology of 70% and 66%, respectively, which was higher than that of DM (54%). DBT and MRI measurements had a better correlation with pathological tumour size (R:0.89 and R:0.92, respectively) compared to DM (R:0.83) and US (R:0.77). CONCLUSIONS: DBT and MRI are superior to DM and US in the preoperative assessment of breast tumour size. DBT seems to improve the accuracy of DM, although MRI remains the most accurate imaging modality for breast cancer extension.

Preoperative breast cancer staging with multi-modality imaging and surgical outcomes.

PURPOSE: To compare the rates of mastectomy and re-operation after breast-conserving surgery (BCS) among patients who had different pre-operative multi-modality imaging, hence identifying significant predictors of mastectomy and re-operations within each group. METHOD: Retrospective study of consecutive patients with primary breast cancer treated January 2010 - December 2016, divided in 3 groups, undergoing pre-operative local staging respectively with conventional imaging modalities only (2D mammography, ultrasound (US)), conventional imaging and tomosynthesis (DBT) and/or MRI. The primary outcome was identification of significant predictors of surgical outcomes, within each group. Study variables examined in univariate analysis were age, lesion dimension, breast density, multifocality, tumor size, histology, and if associated with outcomes they were included in binary logistic regression analysis. RESULTS: Amongst 1547 patients, patient and tumor characteristics differed across the three groups, as did mastectomy rates which were 18 % (102/562) for 2D + US, 36 % (154/428) for 2D + DBT + US, 45 % (250/557) for 2D+/-DBT + US + MRI(p < 0.001). Variables strongly associated with mastectomy were larger lesions and multifocality (as was multi-modality group). Re-operation rate showed an opposite trend: 12.2 % (56/459) for 2D + US, 8 % (22/272) for 2D + DBT + US, 6.5 % (20/306) for 2D+/-DBT + US + MRI. Re-operation rate for 2D+/-DBT + US + MRI was lower than for 2D + US (p = 0.01) but similar to 2D + DBT + US (p = 0.58). Patients who had 2D + US and re-operations had significantly larger lesions, more underestimation, higher proportion of invasive carcinoma with in-situ component than those who did not require re-operation. CONCLUSIONS: Patients who had larger tumors and multifocal disease were more frequently staged by adding DBT and/or MRI to conventional imaging (mammography and US) which was associated with more extensive surgical treatment but lower reoperation rates.

Intraoperative breast specimen assessment in breast conserving surgery: comparison between standard mammography imaging and a remote radiological system.

OBJECTIVE: To compare standard specimen mammography (SSM) with remote intraoperative specimen mammography (ISM) assessment in breast conserving-surgery (BCS) based on operative times, intraoperative additional excision (IAE) and re-intervention rates. METHODS AND MATERIALS: We retrospectively compared 129 consecutive patients (136 lesions) who had BCS with SSM at our centre between 11/2011 and 02/2013 with 138 consecutive patients (144 lesions) who underwent BCS with ISM between 08/2014 and 02/2015.SSM or ISM were performed to confirm the target lesions within the excised specimen and margin adequacy. The utility of SMM and ISM was evaluated considering pathology as gold-standard, using χ2 or Fisher's exact tests for comparison of categorical variables, and non-parametric Mann-Whitney test for continuous variables. RESULTS: The two groups did not statistically differ for age (p = 0.20), lesion size (p = 0.29) and morphology (p = 0.82) or tumor histology type (p = 0.65). Intraoperative time was significantly longer (p < 0.00001) for SSM (132 ± 43 min) than for ISM (90 ± 42 min). The proportions requiring IAE did not significantly differ between SSM group (39/136 lesions (40%)) and ISM group (52/144 lesions (57%)) (p = 0.19), overall and in stratified analysis by mammographic features. Re-intervention rates were not statistically different between the two groups [SSM:19/136 (14%), ISM:13/144 (9%); p = 0.27]. CONCLUSION: The introduction of ISM in BCS significantly reduced surgical time but did not change IAE and re-intervention rates, highlighting facilitated communication between surgeons and radiologists. ADVANCES IN KNOWLEDGE: Compared to standard mammography imaging, the use of ISM significantly reduced surgical time.

Lesions of uncertain malignant potential of the breast (B3) on vacuum-assisted biopsy for microcalcifications: Predictors of malignancy.

PURPOSE: To investigate clinical, radiologic and pathologic features of B3 lesions diagnosed on VABB targeting microcalcifications, for identifying predictors of malignancy. METHOD: This retrospective multi-centre study included consecutive VABBs performed over a 10-year period on suspicious microcalcifications not associated with other radiological signs diagnosed as B3 on histology from VABB, with outcomes ascertained by surgical excision. Clinical, demographic, radiological and histological (B3 subcategory) data were collected. For statistical analysis (univariate and binary logistic regression), the primary outcome variable was the upgrade rate to malignancy after surgery. Predictors of upgrade to malignancy were identified from clinical, demographic, radiological and pathological variables (including B3 subcategory). RESULTS: Amongst 447 VABBs, there were 57(12.7 %) upgrades to malignancy at surgical histology (36 DCIS and 21 invasive cancer). At univariate analysis, variables significantly associated with increased risk of upgrade to malignancy were age>55 years (p = 0.01), lesion size>10 mm (p < 0.0001), BI-RADS 4b-c and 5 (p = 0.0001), and fine pleomorphic morphology (p = 0.002) of microcalcifications. Binary logistic regression confirmed as significant independent risk factors age, lesion size and BI-RADS category (p = 0.02, 0.02 and 0.0006 respectively). Amongst subcategories of B3 lesions, lobular neoplasia was significantly(p = 0.04) associated with upgrade, confirmed as an independent risk factor [p = 0.03, OR = 2.3(1.1-4.7)]. Flat epithelial atypia was significantly(p = 0.004) associated with reduced odds of upgrade, but binary logistic regression showed only borderline association [p = 0.052, OR = 0.4(0.2-1.01)]. CONCLUSIONS: Across B3 lesions diagnosed on histology from VABB of suspicious microcalcifications, older age, size>10 mm, BI-RADS category≥ 4b on imaging, and lobular neoplasia were risk factors for upgrade to malignancy. This information can be used to discuss patients' tailored management options.

Background parenchymal enhancement assessment: Inter- and intra-rater reliability across breast MRI sequences.

OBJECTIVE: To evaluate inter- and intra-rater reliability of background parenchymal enhancement (BPE) assessment across breast MRI sequences. MATERIALS AND METHODS: Institutional review board approval was obtained and the requirement for consent was waived. Three radiologists qualitatively categorized BPE on 150 breast MRI using a four-point scale (minimal, mild, moderate or marked) according to BI-RADS category system. According to MR-sequence used for the assessment of BPE, inter-rater and intra-rater reliability across a simulated reading strategy with four options was performed: (1) initial contrast-enhanced (CE) fat-suppressed T1-weighted images (2) initial CE subtracted images (3) maximum-intensity-projection (MIP) of the first CE subtracted images (4) combination of initial CE fat-suppressed T1-weighted, initial CE subtracted and MIP images. Raters repeated BPE assessment of 45 breast MRI four weeks after the initial assessment. Gwet's AC1 index with ordinal weights was used to assess reliabilities. RESULTS: Gwet's index for the reliability among the three raters was 0.68 (0.63-0.74) using initial contrast-enhanced fat-suppressed T1 weighted images, 0.74 (0.69-0.80) using subtracted images, 0.80 (0.76-0.83) using MIP, 0.80 (0.77-0.84) using a combination of the initial contrast-enhanced fat-suppressed T1 weighted, initial contrast-enhanced subtracted and MIP images. Test-retest reliability was 0.81 (0.60-1.00) for rater 1, 0.77 (0.55-0.98) for rater 2, 0.79 (0.59-0.99) for rater 3 using the combination of initial contrast-enhanced fat-suppressed T1 weighted, initial contrast-enhanced subtracted and MIP images. CONCLUSIONS: Overall, the combination of all CE MRI images showed the highest reliability of BPE assessment. However, MIP showed a high reliability with lower reading time compared to the combination of all CE MRI images.

A prospective comparative trial of adjunct screening with tomosynthesis or ultrasound in women with mammography-negative dense breasts (ASTOUND-2).

BACKGROUND: Increased risk of breast cancer (BC) and increased risk of an interval BC at mammography screening are associated with high mammographic density. Adjunct imaging detects additional BCs not detected at mammography screening in women with dense breasts. AIM: The aim is to estimate the incremental cancer detection rate (CDR) and false-positive recall for each of tomosynthesis and ultrasound, as adjunct screening modalities in women with mammography-negative dense breasts. METHODS: A multicentre prospective comparative trial of adjunct screening with tomosynthesis or ultrasound in women with mammography-negative dense breasts (ASTOUND-2) recruited asymptomatic women attending Italian breast screening services. All participants had independently interpreted tomosynthesis and ultrasound. Outcomes were ascertained from excision histopathology or completed assessment. Paired binary data were compared using McNemar's test. RESULTS: We recruited 5300 screening participants with median age of 50 (interquartile range 43-79) years who had negative mammography and dense breasts (April 2015-September 2017). Adjunct screening detected 29 additional BCs (27 invasive, 2 in situ): 12 detected on both tomosynthesis and ultrasound, 3 detected only on tomosynthesis, 14 detected only on ultrasound. Incremental CDR for tomosynthesis (+15 cancers) was 2.83/1000 screens (95% confidence interval [CI]: 1.58-4.67) versus ultrasound (+26 cancers) with an incremental CDR of 4.90/1000 screens (95% CI: 3.21-7.19), P = 0.015. Mean size of these cancers was 14.2 mm (standard deviation: 7.8 mm), and six had nodal metastases. Incremental false-positive recall was 1.22% (95% CI: 0.91%-1.49%) and differed significantly between tomosynthesis (0.30%) and ultrasound (1.0%), P < 0.001. CONCLUSIONS: Ultrasound detected more BCs but caused more false positives than tomosynthesis, underscoring trade-offs in screening outcomes when adjunct imaging is used for screening dense breasts.

Evaluation of background parenchymal enhancement on breast MRI: a systematic review.

OBJECTIVE: To perform a systematic review of the methods used for background parenchymal enhancement (BPE) evaluation on breast MRI. METHODS: Studies dealing with BPE assessment on breast MRI were retrieved from major medical libraries independently by four reviewers up to 6 October 2015. The keywords used for database searching are "background parenchymal enhancement", "parenchymal enhancement", "MRI" and "breast". The studies were included if qualitative and/or quantitative methods for BPE assessment were described. RESULTS: Of the 420 studies identified, a total of 52 articles were included in the systematic review. 28 studies performed only a qualitative assessment of BPE, 13 studies performed only a quantitative assessment and 11 studies performed both qualitative and quantitative assessments. A wide heterogeneity was found in the MRI sequences and in the quantitative methods used for BPE assessment. CONCLUSION: A wide variability exists in the quantitative evaluation of BPE on breast MRI. More studies focused on a reliable and comparable method for quantitative BPE assessment are needed. Advances in knowledge: More studies focused on a quantitative BPE assessment are needed.

Quantitative apparent diffusion coefficient measurement obtained by 3.0Tesla MRI as a potential noninvasive marker of tumor aggressiveness in breast cancer.

PURPOSE: To assess the association between apparent diffusion coefficient (ADC), and histological prognostic parameters in malignant breast lesions. The ability of ADC to identify lesions with the presence of Lymphovascular invasion (LVI) in breast carcinoma was also examined. MATERIALS AND METHODS: This HIPAA-compliant retrospective study consisted of 212 consecutive patients with known cancers who underwent 3.0T MRI between January 2011 and 2013. In this study, a total of 126 malignant lesions in 114 women, who had undergone DWI (b-values of 0 and 1000s/mm(2)) in addition to diagnostic MRI, were included. Patients with less than 0.8cm lesions, or those who underwent neoadjuvant chemotherapy or suboptimal DW images were excluded. Classical prognostic factors [lesion size, histopathological type and grade, lymph node (LN) status and lymphovascular invasion (LVI)], molecular prognostic markers [estrogen receptor (ER), progesterone receptor (PR) and human epidermal grow factor receptor 2 (HER2)] were reviewed and recorded. A region of interest (ROI) was drawn within the lesions to measure ADC values. Statistical analyses were performed by the Wilcoxon rank sum test (statistical significance at P<0.05). Adjusted p values from multiple comparison analysis were also calculated. RESULTS: This study demonstrates an inverse correlation between ADC and LVI in malignant lesions and the ability of ADC to identify aggressiveness in lesions with positive LVI. Tumor size, grade, ER, PR, HER2 and lymph node status did not impact tumor ADC value. However, tumors with LVI showed significantly lower ADC values when compared to tumors without LVI, regardless of the enhancement type, histological grade, histological type, and LN status. CONCLUSION: Our study shows that ADC could be a potential clinical adjunct in the evaluation of prognostic factors related to malignant lesion aggressiveness such as LVI.