Background Breast Parenchymal Signal During Menstrual Cycle on Diffusion-Weighted MRI: A Prospective Study in Healthy Premenopausal Women.

OBJECTIVE: To prospectively investigate the influence of the menstrual cycle on the background parenchymal signal (BPS) and apparent diffusion coefficient (ADC) of the breast on diffusion-weighted MRI (DW-MRI) in healthy premenopausal women. MATERIALS AND METHODS: Seven healthy premenopausal women (median age, 37 years; range, 33-49 years) with regular menstrual cycles participated in this study. DW-MRI was performed during each of the four phases of the menstrual cycle (four examinations in total). Three radiologists independently assessed the BPS visual grade on images with b-values of 800 sec/mm² (b800), 1200 sec/mm² (b1200), and a synthetic 1500 sec/mm² (sb1500). Additionally, one radiologist conducted a quantitative analysis to measure the BPS volume (%) and ADC values of the BPS (ADCBPS) and fibroglandular tissue (ADCFGT). Changes in the visual grade, BPS volume (%), ADCBPS, and ADCFGT during the menstrual cycle were descriptively analyzed. RESULTS: The visual grade of BPS in seven women varied from mild to marked on b800 and from minimal to moderate on b1200 and sb1500. As the b-value increased, the visual grade of BPS decreased. On b800 and sb1500, two of the seven volunteers showed the highest visual grade in the early follicular phase (EFP). On b1200, three of the seven volunteers showed the highest visual grades in EFP. The BPS volume (%) on b800 and b1200 showed the highest value in three of the six volunteers with dense breasts in EFP. Three of the seven volunteers showed the lowest ADCBPS in the EFP. Four of the seven volunteers showed the highest ADCBPS in the early luteal phase (ELP) and the lowest ADCFGT in the late follicular phase (LFP). CONCLUSION: Most volunteers did not exhibit specific BPS patterns during their menstrual cycles. However, the highest BPS and lowest ADCBPS were more frequently observed in EFP than in the other menstrual cycle phases, whereas the highest ADCBPS was more common in ELP. The lowest ADCFGT was more frequent in LFP.

Automated Versus Handheld Breast Ultrasound for Evaluating Axillary Lymph Nodes in Patients With Breast Cancer.

OBJECTIVE: Automated breast ultrasound (ABUS) is a relevant imaging technique for early breast cancer diagnosis and is increasingly being used as a supplementary tool for mammography. This study compared the performance of ABUS and handheld ultrasound (HHUS) in detecting and characterizing the axillary lymph nodes (LNs) in patients with breast cancer. MATERIALS AND METHODS: We retrospectively reviewed the medical records of women with recently diagnosed early breast cancer (≤ T2) who underwent both ABUS and HHUS examinations for axilla (September 2017-May 2018). ABUS and HHUS findings were compared using pathological outcomes as reference standards. Diagnostic performance in predicting any axillary LN metastasis and heavy nodal-burden metastases (i.e., ≥ 3 LNs) was evaluated. The ABUS-HHUS agreement for visibility and US findings was calculated. RESULTS: The study included 377 women (53.1 ± 11.1 years). Among 385 breast cancers in 377 patients, 101 had axillary LN metastases and 30 had heavy nodal burden metastases. ABUS identified benign-looking or suspicious axillary LNs (average, 1.4 ± 0.8) in 246 axillae (63.9%, 246/385). According to the per-breast analysis, the sensitivity, specificity, positive and negative predictive values, and accuracy of ABUS in predicting axillary LN metastases were 43.6% (44/101), 95.1% (270/284), 75.9% (44/58), 82.6% (270/327), and 81.6% (314/385), respectively. The corresponding results for HHUS were 41.6% (42/101), 95.1% (270/284), 75.0% (42/56), 82.1% (270/329), and 81.0% (312/385), respectively, which were not significantly different from those of ABUS (P ≥ 0.53). The performance results for heavy nodal-burden metastases were 70.0% (21/30), 89.6% (318/355), 36.2% (21/58), 97.3% (318/327), and 88.1% (339/385), respectively, for ABUS and 66.7% (20/30), 89.9% (319/355), 35.7% (20/56), 97.0% (319/329), and 88.1% (339/385), respectively, for HHUS, also not showing significant difference (P ≥ 0.57). The ABUS-HHUS agreement was 95.9% (236/246; Cohen's kappa = 0.883). CONCLUSION: Although ABUS showed limited sensitivity in diagnosing axillary LN metastasis in early breast cancer, it was still useful as the performance was comparable to that of HHUS.

Digital Breast Tomosynthesis Plus Ultrasound Versus Digital Mammography Plus Ultrasound for Screening Breast Cancer in Women With Dense Breasts.

OBJECTIVE: To compare the outcomes of digital breast tomosynthesis (DBT) screening combined with ultrasound (US) with those of digital mammography (DM) combined with US in women with dense breasts. MATERIALS AND METHODS: A retrospective database search identified consecutive asymptomatic women with dense breasts who underwent breast cancer screening with DBT or DM and whole-breast US simultaneously between June 2016 and July 2019. Women who underwent DBT + US (DBT cohort) and DM + US (DM cohort) were matched using 1:2 ratio according to mammographic density, age, menopausal status, hormone replacement therapy, and a family history of breast cancer. The cancer detection rate (CDR) per 1000 screening examinations, abnormal interpretation rate (AIR), sensitivity, and specificity were compared. RESULTS: A total of 863 women in the DBT cohort were matched with 1726 women in the DM cohort (median age, 53 years; interquartile range, 40-78 years) and 26 breast cancers (9 in the DBT cohort and 17 in the DM cohort) were identified. The DBT and DM cohorts showed comparable CDR (10.4 [9 of 863; 95% confidence interval {CI}: 4.8-19.7] vs. 9.8 [17 of 1726; 95% CI: 5.7-15.7] per 1000 examinations, respectively; P = 0.889). DBT cohort showed a higher AIR than the DM cohort (31.6% [273 of 863; 95% CI: 28.5%-34.9%] vs. 22.4% [387 of 1726; 95% CI: 20.5%-24.5%]; P < 0.001). The sensitivity for both cohorts was 100%. In women with negative findings on DBT or DM, supplemental US yielded similar CDRs in both DBT and DM cohorts (4.0 vs. 3.3 per 1000 examinations, respectively; P = 0.803) and higher AIR in the DBT cohort (24.8% [188 of 758; 95% CI: 21.8%-28.0%] vs. 16.9% [257 of 1516; 95% CI: 15.1%-18.9%; P < 0.001). CONCLUSION: DBT screening combined with US showed comparable CDR but lower specificity than DM screening combined with US in women with dense breasts.

Microcalcifications and Peritumoral Edema Predict Survival Outcome in Luminal Breast Cancer Treated with Neoadjuvant Chemotherapy.

Background Little is known regarding findings at imaging associated with survival in patients with luminal breast cancer treated with neoadjuvant chemotherapy (NAC). Purpose To determine the relationship between imaging (MRI, US, and mammography) and clinical-pathologic variables in predicting distant metastasis-free survival (DMFS) and overall survival (OS) in patients with luminal breast cancer treated with NAC. Materials and Methods In this retrospective study, consecutive women with luminal breast cancer who underwent NAC followed by surgery were identified from the breast cancer registries of two hospitals. Women from one hospital between January 2003 and July 2015 were classified into the development cohort, and women from the other hospital between January 2007 and July 2015 were classified into the validation cohort. MRI scans, US scans, and mammograms before and after NAC (hereafter, referred to as pre- and post-NAC, respectively) and clinical-pathologic data were reviewed. Peritumoral edema was defined as the water-like high signal intensity surrounding the tumor on T2-weighted MRI scans. The prediction model was developed in the development cohort by using Cox regression and then tested in the validation cohort. Results The development cohort consisted of 318 women (68 distant metastases, 54 deaths) and the validation cohort consisted of 165 women (37 distant metastases, 14 deaths) (median age, 46 years in both cohorts). Post-NAC MRI peritumoral edema, age younger than 40 years, clinical N2 or N3, and lymphovascular invasion were associated with worse DMFS (all, P < .05). Pre-NAC mammographic microcalcifications, post-NAC MRI peritumoral edema, age older than 60 years, and clinical T3 or T4 were associated with worse OS (all, P < .05). The prediction model showed good discrimination ability (C index, 0.67-0.75 for DMFS and 0.70-0.77 for OS) and stratified prognosis into low-risk and high-risk groups (10-year DMFS rates, 79% vs 21%, respectively; and 10-year OS rates, 95%-96% vs 63%-67%, respectively) in the validation cohort. Conclusion MRI features and clinical-pathologic variables were identified that were associated with prolonged survival of patients with luminal breast cancer treated with neoadjuvant chemotherapy. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Kataoka in this issue.

The Usefulness of Ultrasound Surveillance for Axillary Recurrence in Women With Personal History of Breast Cancer.

PURPOSE: To evaluate the axillary recurrence rate and usefulness of axillary ultrasound (AUS) during supplementary whole-breast ultrasound (US) screening in women with a personal history of breast cancer (PHBC). METHODS: A retrospective database search identified consecutive asymptomatic women who underwent postoperative supplemental whole-breast US screening, including that of the bilateral axillae, after negative findings on mammography between January and June 2017. Using the pathologic data or at least 1-year follow-up data as reference standards, the axillary recurrence rate, cancer detection rate (CDR), interval axillary recurrence rate per 1,000 screenings, sensitivity, specificity, and abnormal interpretation rate (AIR) were estimated. RESULTS: From the data of 4,430 women (mean age, 55.0 ± 10.1 years) analyzed in this study, there were five axillary recurrence cases (1.1/1,000) in the median follow-up period of 57.2 months. AUS showed a CDR of 0.2 (1/4,430; 95% confidence interval [CI], 0.01-1.3) and an interval axillary recurrence rate of 0.9 (4/4,402; 95% CI, 0.2-2.3) per 1,000 examinations. The sensitivity and specificity were 20.0% (1/5; 95% CI, 0.5-71.6), and 99.4% (4,398/4,425; 95% CI, 99.1-99.6), respectively, while the AIR was 0.6% (28/4,430; 95% CI, 0.4-0.9%). CONCLUSION: In asymptomatic women with a PHBC and negative findings on mammography, axillary recurrence after breast cancer and axillary treatment was uncommon, and the supplemental AUS screening yielded 0.2 cancers per 1,000 examinations.

Imaging Protocol and Criteria for Evaluation of Axillary Lymph Nodes in the NAUTILUS Trial.

Axillary ultrasonography (US) is the most commonly used imaging modality for nodal evaluation in patients with breast cancer. No Axillary Surgical Treatment in Clinically Lymph Node-Negative Patients after Ultrasonography (NAUTILUS) is a prospective, multicenter, randomized controlled trial investigating whether sentinel lymph node biopsy (SLNB) can be safely omitted in patients with clinically and sonographically node-negative T1-2 breast cancer treated with breast-conserving therapy. In this trial, a standardized imaging protocol and criteria were established for the evaluation of axillary lymph nodes. Women lacking palpable lymph nodes underwent axillary US to dismiss suspicious nodal involvement. Patients with a round hypoechoic node with effaced hilum or indistinct margins were excluded. Patients with T1 tumors and a single node with a cortical thickness ≥ 3 mm underwent US-guided biopsy. Finally, patients with negative axillary US findings were included. The NAUTILUS axillary US nodal assessment criteria facilitate the proper selection of candidates who can omit SLNB. Trial Registration: ClinicalTrials.gov Identifier: NCT04303715.

Diagnostic Performance of Artificial Intelligence-Based Computer-Aided Diagnosis for Breast Microcalcification on Mammography.

The present study evaluated the diagnostic performance of artificial intelligence-based computer-aided diagnosis (AI-CAD) compared to that of dedicated breast radiologists in characterizing suspicious microcalcification on mammography. We retrospectively analyzed 435 unilateral mammographies from 420 patients (286 benign; 149 malignant) undergoing biopsy for suspicious microcalcification from June 2003 to November 2019. Commercial AI-CAD was applied to the mammography images, and malignancy scores were calculated. Diagnostic performance was compared between radiologists and AI-CAD using the area under the receiving operator characteristics curve (AUC). The AUCs of radiologists and AI-CAD were not significantly different (0.722 vs. 0.745, p = 0.393). The AUCs of the adjusted category were 0.726, 0.744, and 0.756 with cutoffs of 2%, 10%, and 38.03% for AI-CAD, respectively, which were all significantly higher than those for radiologists alone (all p < 0.05). None of the 27 cases downgraded to category 3 with a cutoff of 2% were confirmed as malignant on pathological analysis, suggesting that unnecessary biopsies could be avoided. Our findings suggest that the diagnostic performance of AI-CAD in characterizing suspicious microcalcification on mammography was similar to that of the radiologists, indicating that it may aid in making clinical decisions regarding the treatment of breast microcalcification.

Addition of Screening Breast US to Digital Mammography and Digital Breast Tomosynthesis for Breast Cancer Screening in Women at Average Risk.

Background Digital breast tomosynthesis (DBT) with or without digital mammography (DM) is the primary method of breast cancer screening. However, the sufficiency of DBT screening for women at average risk and the need for supplemental whole-breast US needs further investigation. Purpose To evaluate the added value of supplemental US screening following combined DM/DBT. Materials and Methods A retrospective database search identified consecutive asymptomatic women who underwent DM/DBT and radiologist-performed screening breast US simultaneously between March 2016 and December 2018. The cancer detection rate (CDR) per 1000 screening examinations, sensitivity, specificity, and abnormal interpretation rate of DM/DBT and DM/DBT combined with US were compared. Results A total of 1003 women (mean age, 56 years ± 8.6 [standard deviation]) were included. Among them, 12 cancers (mean invasive tumor size, 14 mm; range, 6-33 mm) were diagnosed. With DM/DBT and DM/DBT combined with US, the CDRs were 9.0 per 1000 screening examinations (nine of 1003 women; 95% CI: 4.1, 17) and 12 per 1000 screening examinations (12 of 1003 women; 95% CI: 6.2, 21), respectively, and the abnormal interpretation rates were 7.8% (78 of 1003 women; 95% CI: 6.2, 9.6) and 24% (243 of 1003 women; 95% CI: 22, 27). In women with negative findings at DM/DBT, supplementary US yielded a CDR of 3.2 per 1000 examinations (three of 925 women; 95% CI: 0.7, 9.4), sensitivity of 100% (three of three women; 95% CI: 29, 100), specificity of 82% (760 of 922 women; 95% CI: 80, 85), and abnormal interpretation rate of 18% (165 of 925 women; 95% CI: 15, 21). The three additional US-detected cancers were identified in women with dense breasts; no benefit was observed in women with nondense breasts. Conclusion The addition of breast US to digital mammography and digital breast tomosynthesis yielded an additional 0.7-9.4 cancers per 1000 women at average risk, with a substantial increase in the abnormal interpretation rate. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Rahbar in this issue.

Utility and Diagnostic Performance of Automated Breast Ultrasound System in Evaluating Pure Non-Mass Enhancement on Breast Magnetic Resonance Imaging.

OBJECTIVE: To compare the utility and diagnostic performance of automated breast ultrasound system (ABUS) with that of hand-held ultrasound (HHUS) in evaluating pure non-mass enhancement (NME) lesions on breast magnetic resonance imaging (MRI). MATERIALS AND METHODS: One hundred twenty-six consecutive MRI-visible pure NME lesions of 122 patients with breast cancer were assessed from April 2016 to March 2017. Two radiologists reviewed the preoperative breast MRI, ABUS, and HHUS images along with mammography (MG) findings. The NME correlation rate and diagnostic performance of ABUS were compared with that of HHUS, and the imaging features associated with ABUS visibility were analyzed. RESULTS: Among 126 pure NME lesions, 100 (79.4%) were malignant and 26 (20.6%) were benign. The overall correlation rate was 87.3% (110/126) in ABUS and 92.9% (117/126) in HHUS. The sensitivity and specificity were 87% and 50% for ABUS and 92% and 42.3% for HHUS, respectively, with no significant differences (p = 0.180 and 0.727, respectively). Malignant NME was more frequently visualized than benign NME lesions on ABUS (93% vs. 65.4%, p = 0.001). Significant factors associated with the visibility of ABUS were the size of NME lesions on MRI (p < 0.001), their distribution pattern (p < 0.001), and microcalcifications on MG (p = 0.027). CONCLUSION: ABUS evaluation of pure NME lesions on MRI in patients with breast cancer is a useful technique with high visibility, especially in malignant lesions. The diagnostic performance of ABUS was comparable with that of conventional HHUS in evaluating NME lesions.

Prediction of pathologic complete response using image-guided biopsy after neoadjuvant chemotherapy in breast cancer patients selected based on MRI findings: a prospective feasibility trial.

PURPOSE: Accurate prediction of pathologic complete response (pCR) in breast cancer using magnetic resonance imaging (MRI) and ultrasound (US)-guided biopsy may aid in selecting patients who forego surgery for breast cancer. We evaluated the accuracy of US-guided biopsy aided by MRI in predicting pCR in the breast after neoadjuvant chemotherapy (NAC). METHODS: After completion of NAC, 40 patients with near pCR (either tumor size ≤ 0.5 cm or lesion-to-background signal enhancement ratio (L-to-B SER) ≤ 1.6 on MRI) and no diffused residual microcalcifications were prospectively enrolled at a single institution. US-guided multiple core needle biopsy (CNB) or vacuum-assisted biopsy (VAB) of the tumor bed, followed by standard surgical excision, was performed. Matched biopsy and surgical specimens were compared to assess pCR. The negative predictive value (NPV), accuracy, and false-negative rate (FNR) were analyzed. RESULTS: pCR was confirmed in 27 (67.5%) surgical specimens. Preoperative biopsy had an NPV, accuracy, and FNR of 87.1%, 90.0%, and 30.8%, respectively. NPV for hormone receptor-negative and hormone receptor-positive tumors were 83.3% and 100%, respectively. Obtaining at least 5 biopsy cores based on tumor size ≤ 0.5 cm and an L-to-B SER of ≤ 1.6 on MRI (27 patients) resulted in 100% NPV and accuracy. No differences in accuracy were noted between CNB and VAB (90% vs. 90%). CONCLUSIONS: Investigation using stringent MRI criteria and ultrasound-guided biopsy could accurately predict patients with pCR after NAC. A larger prospective clinical trial evaluating the clinical safety of breast surgery omission after NAC in selected patients will be conducted based on these findings.

Ultrafast Dynamic Contrast-Enhanced Breast MRI: Lesion Conspicuity and Size Assessment according to Background Parenchymal Enhancement.

OBJECTIVE: To evaluate the clinical utility of ultrafast dynamic contrast-enhanced (DCE)-MRI compared to conventional DCE-MRI by studying lesion conspicuity and size according to the level of background parenchymal enhancement (BPE). MATERIALS AND METHODS: This study included 360 women (median age, 54 years; range, 26-82 years) with 361 who had undergone breast MRI, including both ultrafast and conventional DCE-MRI before surgery, between January and December 2017. Conspicuity was evaluated using a five-point score. Size was measured as the single maximal diameter. The Wilcoxon signed-rank test was used to compare median conspicuity score. To identify factors associated with conspicuity, multivariable logistic regression was performed. Absolute agreement between size at MRI and histopathologic examination was assessed using the intraclass correlation coefficient (ICC). RESULTS: The median conspicuity scores were 5 at both scans, but the interquartile ranges were significantly different (5-5 at ultrafast vs. 4-5 at conventional, p < 0.001). Premenopausal status (odds ratio [OR] = 2.2, p = 0.048), non-mass enhancement (OR = 4.1, p = 0.001), moderate to marked BPE (OR = 7.5, p < 0.001), and shorter time to enhancement (OR = 0.9, p = 0.043) were independently associated with better conspicuity at ultrafast scans. Tumor size agreement between MRI and histopathologic examination was similar for both scans (ICC = 0.66 for ultrafast vs. 0.63 for conventional). CONCLUSION: Ultrafast DCE-MRI could improve lesion conspicuity compared to conventional DCE-MRI, especially in women with premenopausal status, non-mass enhancement, moderate to marked BPE or short time to enhancement.

Time-to-enhancement at ultrafast breast DCE-MRI: potential imaging biomarker of tumour aggressiveness.

OBJECTIVES: This study was conducted in order to investigate whether there is a correlation between the time-to-enhancement (TTE) in ultrafast MRI and histopathological characteristics of breast cancers. METHODS: Between January and August 2017, 274 consecutive breast cancer patients (mean age, 53.5 years; range, 25-80 years) who underwent ultrafast MRI and subsequent surgery were included for analysis. Ultrafast MRI scans were acquired using TWIST-VIBE or 4D TRAK-3D TFE sequences. TTE and maximum slope (MS) were derived from the ultrafast MRI. The repeated measures ANOVA, Mann-Whitney U test and Kruskal-Wallis H test were performed to compare the median TTE, MS and SER according to histologic type, histologic grade, ER/PR/HER2 positivity, level of Ki-67 and tumour subtype. For TTE calculation, intraclass correlation coefficient (ICC) was used to evaluate interobserver variability. RESULTS: The median TTE of invasive cancers was shorter than that of in situ cancers (p < 0.001). In invasive cancers, large tumours showed shorter TTE than small tumours (p = 0.001). High histologic/nuclear grade cancers had shorter TTE than low to intermediate grade cancers (p < 0.001 and p < 0.001). HER2-positive cancers showed shorter TTE than HER2-negative cancers (p = 0.001). The median TTE of cancers with high Ki-67 was shorter than that of cancers with low Ki-67 (p < 0.001). ICC between two readers showed moderate agreement (0.516). No difference was found in the median MS or SER values according to the clinicopathologic features. CONCLUSIONS: The median TTE of breast cancer in ultrafast MRI was shorter in invasive or aggressive tumours than in in situ cancer or less aggressive tumours, respectively. KEY POINTS: • Invasive breast tumours show a shorter TTE in ultrafast DCE-MRI than in situ cancers. • A shorter TTE in ultrafast DCE-MRI is associated with breast tumours of a large size, high histologic or nuclear grade, PR negativity, HER2 positivity and high Ki-67 level.

Evaluation of TP53/PIK3CA mutations using texture and morphology analysis on breast MRI.

PURPOSE: Somatic mutations in TP53 and PIK3CA genes, the two most frequent genetic alternations in breast cancer, are associated with prognosis and therapeutic response. This study predicted the presence of TP53 and PIK3CA mutations in breast cancer by using texture and morphology analyses on breast MRI. MATERIALS AND METHODS: A total of 107 breast cancers (dataset A) from The Cancer Imaging Archive (TCIA) consisting of 40 TP53 mutation cancer and 67 cancers without TP53 mutation; 35 PIK3CA mutations cancer and 72 without PIK3CA mutation. 122 breast cancer (dataset B) from Seoul National University Hospital containing 54 TP53 mutation cancer and 68 without mutations were used in this study. At first, the tumor area was segmented by a region growing method. Subsequently, gray level co-occurrence matrix (GLCM) texture features were extracted after ranklet transform, and a series of features including compactness, margin, and ellipsoid fitting model were used to describe the morphological characteristics of tumors. Lastly, a logistic regression was used to identify the presence of TP53 and PIK3CA mutations. The classification performances were evaluated by accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Taking into account the trade-offs of sensitivity and specificity, the overall performances were evaluated by using receiver operating characteristic (ROC) curve analysis. RESULTS: The GLCM texture feature based on ranklet transform is more capable of recognizing TP53 and PIK3CA mutations than morphological feature, especially for the TP53 mutation that achieves statistically significant. The area under the ROC curve (AUC) for TP53 mutation dataset A and dataset B achieved 0.78 and 0.81 respectively. For PIK3CA mutation, the AUC of ranklet texture feature was 0.70. CONCLUSION: Texture analysis of segmented tumor on breast MRI based on ranklet transform is potential in recognizing the presence of TP53 mutation and PIK3CA mutation.

Detection of noncalcified breast cancer in patients with extremely dense breasts using digital breast tomosynthesis compared with full-field digital mammography.

OBJECTIVE: To evaluate the tumour visibility and diagnostic performance of digital breast tomosynthesis (DBT) in patients with noncalcified T1 breast cancer. METHODS: Medical records of 106 females with noncalcified T1 invasive breast cancer who underwent DBT and full-field digital mammography (FFDM) between January 2012 and December 2014 were retrospectively reviewed. To assess tumour visibility (score 1-3), all DBT and FFDM images were reviewed by two radiologists blinded to clinicopathological information. A reference standard was established by an unblinded consensus review of all images. Clinicopathological and imaging variables were analysed based on tumour visibility. After adding 159 negative controls, the diagnostic performance of DBT + FFDM was compared with that of FFDM. RESULTS: The tumour visibility was significantly higher through DBT + FFDM (2.5 vs 1.8; p = 0.002) than FFDM alone. Breast composition was the independent variable for tumour visibility through DBT + FFDM (extremely dense; odds ratio, 0.02; p < 0.001). Sensitivity (p = 0.642), specificity (p = 0.463), positive-predictive value (p = 0.078), and negative-predictive value (p = 0.072) of DBT + FFDM were not significantly superior to those of FFDM in 55 females with extremely dense breast composition, whereas specificity (p = 0.002) and positive-predictive value (p < 0.001) were significantly higher in 210 females with other breast compositions. CONCLUSION: Addition of DBT to FFDM showed no significant increase in the tumour visibility and diagnostic performance in patients with noncalcified T1 cancer in extremely dense breasts. ADVANCES IN KNOWLEDGE: Addition of DBT to FFDM did not further improve the detection of noncalcified early breast cancers in females with extremely dense breasts.

Dynamic Contrast-enhanced Breast MRI for Evaluating Residual Tumor Size after Neoadjuvant Chemotherapy.

Purpose To investigate the accuracy of dynamic contrast material-enhanced (DCE) breast MRI for determining residual tumor size after neoadjuvant chemotherapy (NAC). Materials and Methods For this retrospective study, 487 consecutive women (mean age, 47.0 years ± 10.3 [standard deviation]; range, 24-78 years) underwent preoperative DCE MRI following NAC and subsequent surgeries between 2008 and 2011. Tumor size was measured at early-phase, conventional delayed-phase, and late delayed-phase MRI (90, 360, and 590 seconds after contrast material injection, respectively). At histopathologic examination, total tumor size (both invasive and in situ) and the size of invasive tumor alone were separately recorded. Absolute agreement between tumor size at MRI and histopathologic examination was assessed by using intraclass correlation coefficient (ICC) analysis. Factors affecting size discrepancy were assessed by using multiple linear regression analysis. Results Compared with tumor size at histopathologic examination, total tumor sizes showed higher agreement at conventional delayed-phase MRI than at early-phase MRI (ICC, 0.76 vs 0.56; P ˂ .001) and comparable agreement at conventional and late delayed-phase MRI (ICC, 0.76 vs 0.74; P = .55). Lobular histologic features and tumor subtype were independently associated with greater size discrepancy (P ˂ .001). Lobular cancers were underestimated in size compared with ductal cancers (mean size discrepancy, -2.8 cm ± 3.2 vs -0.3 cm ± 1.8; P = .004). Estrogen receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative cancers were underestimated compared with HER2-positive cancers (-0.8 cm ± 2.0 vs -0.3 cm ± 1.7, P = .006) and triple-negative cancers (-0.8 cm ± 2.0 vs 0.3 cm ± 1.7, P ˂ .001). Conclusion Delayed-phase MRI is more accurate than early-phase MRI for evaluating residual breast tumor size after neoadjuvant chemotherapy. Lobular or estrogen receptor-positive/human epidermal growth factor receptor 2-negative cancers are underestimated in size at MRI compared with ductal or other subtypes. © RSNA, 2018 Online supplemental material is available for this article.

Neoadjuvant Chemotherapy and Surgery for Breast Cancer: Preoperative MRI Features Associated with Local Recurrence.

Purpose To investigate the MRI and clinical-pathologic features associated with local-regional recurrence (LRR) in patients who had undergone breast-conserving surgery (BCS) following neoadjuvant chemotherapy (NAC). Materials and Methods In this retrospective, single-institution study between October 2003 and September 2015, 548 consecutive women, consisting of 468 down-staged and 80 preplanned BCS patients (mean age, 45.7 years; range, 22-75 years), underwent preoperative MRI and BCS following NAC. The rate and site of LRR, preoperative MRI features including Breast Imaging Reporting and Data System lexicon, and clinical-pathologic features (age, stage, tumor subtype, histologic grade, lymphovascular invasion, adjuvant chemotherapy, and endocrine therapy) were analyzed with the Cox proportional hazards model to identify independent factors associated with LRR-free survival (LRFS). Results Of the 548 women, 23 (4.2%) had LRR at a median follow-up of 23.1 months. In Cox regression analysis, younger age (ie, ≤ 40 years) (hazard ratio = 2.932; 95% confidence interval [CI]: 1.233, 6.969; P = .015) or the presence of nonmass enhancement on preoperative MR images (hazard ratio = 3.220; 95% CI: 1.274, 8.140; P = .014) was associated with worse LRFS. LRR was more frequently observed in the same quadrant as the original tumor in the down-staged BCS group than in the preplanned BCS group (80.0% [16 of 20] vs 33.3% [one of three]; P = .021). Conclusion Age of 40 years or younger or the presence of nonmass enhancement on preoperative MR images tends to be associated with worse local-regional recurrence-free survival, and local-regional recurrence frequently occurs in the same quadrant as the original tumor in breast cancer patients who undergo breast-conserving surgery following neoadjuvant chemotherapy. © RSNA, 2018.

Computer-aided prediction model for axillary lymph node metastasis in breast cancer using tumor morphological and textural features on ultrasound.

BACKGROUND AND OBJECTIVES: Axillary lymph node (ALN) status is a key indicator in assessing and determining the treatment strategy for patients with newly diagnosed breast cancer. Previous studies suggest that sonographic features of a primary tumor have the potential to predict ALN status in the preoperative staging of breast cancer. In this study, a computer-aided prediction (CAP) model as well as the tumor features for ALN metastasis in breast cancers were developed using breast ultrasound (US) images. METHODS: A total of 249 malignant tumors were acquired from 247 female patients (ages 20-84 years; mean 55 ±â€¯11 years) to test the differences between the non-metastatic (130) and metastatic (119) groups based on various features. After applying semi-automatic tumor segmentation, 69 quantitative features were extracted. The features included morphology and texture of tumors inside a ROI of breast US image. By the backward feature selection and linear logistic regression, the prediction model was constructed and established to estimate the likelihood of ALN metastasis for each sample collected. RESULTS: In the experiments, the texture features showed higher performance for predicting ALN metastasis compared to morphology (Az, 0.730 vs 0.667). The difference, however, was not statistically significant (p-values > 0.05). Combining the textural and morphological features, the accuracy, sensitivity, specificity, and Az value achieved 75.1% (187/249), 79.0% (94/119), 71.5% (93/130), and 0.757, respectively. CONCLUSIONS: The proposed CAP model, which combines textural and morphological features of primary tumor, may be a useful method to determine the ALN status in patients with breast cancer.

Contrast-enhanced MRI after neoadjuvant chemotherapy of breast cancer: lesion-to-background parenchymal signal enhancement ratio for discriminating pathological complete response from minimal residual tumour.

OBJECTIVES: To retrospectively investigate whether the lesion-to-background parenchymal signal enhancement ratio (SER) on breast MRI can distinguish pathological complete response (pCR) from minimal residual cancer following neoadjuvant chemotherapy (NAT), and compare its performance with the conventional criterion. METHODS: 216 breast cancer patients who had undergone NAT and MRI and achieved pCR or minimal residual cancer on surgical histopathology were included. Clinical-pathological features, SER and lesion size on MR images were analysed. Multivariate logistic regression, ROC curve and McNemar's test were performed. RESULTS: SER on early-phase MR images was independently associated with pCR (odds ratio [OR], 0.286 [95% CI: 0.113-0.725], p = .008 for Reader 1; OR, 0.306 [95% CI: 0.111-0.841], p = .022 for Reader 2). Compared with the conventional criterion, SER ≤1.6 increased AUC (0.585-0.599 vs. 0.709-0.771, p=.001-.033) and specificity (21.9-27.4% vs. 80.8-86.3%, p <.001) in identifying pCR. SER ≤1.6 and/or size ≤0.2 cm criterion showed the highest specificity of 90.4%. CONCLUSION: SER on early-phase MR images was independently associated with pCR, and showed improved AUC and specificity compared to the conventional criterion. The combined criterion of SER and size could be used to select candidates to avoid surgery in a future study. KEY POINTS: • Compared with conventional criterion, SER ≤ 1.6 criterion increased AUC and specificity. • Simple measurement of signal intensity could differentiate pCR from minimal residual cancer. • SER ≤1.6 and/or size≤0.2cm criterion showed the highest specificity of 90.4 %. • The combined criterion could be used for a study to avoid surgery.

Association between US features of primary tumor and axillary lymph node metastasis in patients with clinical T1-T2N0 breast cancer.

Background Most patients with early-stage breast cancer have clinically negative lymph nodes (LNs). However, 15-20% of patients have axillary nodal metastasis based on the sentinel LN biopsy. Purpose To assess whether ultrasound (US) features of a primary tumor are associated with axillary LN metastasis in patients with clinical T1-T2N0 breast cancer. Material and Methods This retrospective study included 138 consecutive patients (median age = 51 years; age range = 27-78 years) who underwent breast surgery with axillary LN evaluation for clinically node-negative T1-T2 breast cancer. Three radiologists blinded to the axillary surgery results independently reviewed the US images. Tumor distance from the skin and distance from the nipple were determined based on the US report. Association between US features of a breast tumor and axillary LN metastasis was assessed using a multivariate logistic regression model after controlling for clinicopathologic variables. Results Of the 138 patients, 28 (20.3%) had nodal metastasis. At univariate analysis, tumor distance from the skin ( P = 0.019), tumor size on US ( P = 0.023), calcifications ( P = 0.036), architectural distortion ( P = 0.001), and lymphovascular invasion ( P = 0.049) were associated with axillary LN metastasis. At multivariate analysis, shorter skin-to-tumor distance (odds ratio [OR] = 4.15; 95% confidence interval [CI] = 1.01-16.19; P = 0.040) and masses with associated architectural distortion (OR = 3.80; 95% CI = 1.57-9.19; P = 0.003) were independent predictors of axillary LN metastasis. Conclusion US features of breast cancer can be promising factors associated with axillary LN metastasis in patients with clinically node-negative early-stage breast cancer.