Differentiating benign from malignant solid breast masses: value of shear wave elastography according to lesion stiffness combined with greyscale ultrasound according to BI-RADS classification

Magnetic Resonance Elastography of Anterior Mediastinal Tumors

BACKGROUND

Preoperative differentiation of the types of mediastinal tumors is essential. Magnetic resonance (MR) elastography potentially provides a noninvasive method to assess the classification of mediastinal tumor subtypes.

PURPOSE

To evaluate the use of MR elastography in anterior mediastinal masses and to characterize the mechanical properties of tumors of different subtypes.

STUDY TYPE

Prospective.

SUBJECTS

189 patients with anterior mediastinal tumors (AMTs) confirmed by histopathology (62 thymomas, 53 thymic carcinomas, 57 lymphomas, and 17 germ cell tumors).

FIELD STRENGTH/SEQUENCE

A gradient echo-based 2D MR elastography sequence and a diffusion-weighted imaging (DWI) sequence at 3.0 T.

ASSESSMENT

Stiffness and apparent diffusion coefficients (ADC) were measured in AMTs using MR elastography-derived elastograms and DWI-derived ADC maps, respectively. The aim of this study is to identify whether MR elastography can differentiate between the histological subtypes of ATMs.

STATISTICAL TESTS

One-way analysis of variance (ANOVA), two-way ANOVA, Pearson's linear correlation coefficient (r), receiver operating characteristic (ROC) curve analysis; P < 0.05 was considered significant.

RESULTS

Lymphomas had significantly lower stiffness than other AMTs (4.0 ± 0.63 kPa vs. 4.8 ± 1.39 kPa). The mean stiffness of thymic carcinomas was significantly higher than that of other AMTs (5.6 ± 1.41 kPa vs. 4.2 ± 0.94 kPa). Using a cutoff value of 5.0 kPa, ROC analysis showed that lymphomas could be differentiated from other AMTs with an accuracy of 59%, sensitivity of 97%, and specificity of 38%. Using a cutoff value of 5.1 kPa, thymic carcinomas could be differentiated from other AMTs with an accuracy of 84%, sensitivity of 67%, and specificity of 90%. However, there was an overlap in the stiffness values of individual thymomas (4.2 ± 0.71; 3.9-4.5), thymic carcinomas (5.6 ± 1.41; 5.0-6.1), lymphomas (4.0 ± 0.63; 3.8-4.2), and germ cell tumors (4.5 ± 1.79; 3.3-5.6).

DATA CONCLUSION

MR elastography-derived stiffness may be used to evaluate AMTs of various histologies.

LEVEL OF EVIDENCE: 4

TECHNICAL EFFICACY

Stage 2.

Shear wave elastography for solid breast masses evaluation: Quantitative measurement of mean elasticity value and elasticity ratio

Purpose

Shear wave elastography (SWE), an ultrasonographic technique to measure the elasticity of mass lesions to evaluate breast mass. This study aimed to find out the cutoff values identifying breast malignancy using the mean elasticity (E-mean) and elasticity ratio (E-ratio) of breast masses.

Methods

This retrospective study included women underwent SWE and US-guided biopsy of breast masses. During conventional US, the SWE mode was also performed, determining elasticity measurements, E-mean and E-ratio. Histopathological reports were obtained to identify mass status. The optimal and alternative cutoff values for E-mean and E-ratio to determine malignancy were assessed by receiver operating characteristic (ROC) curve analysis and Youden's index score.

Results

Among 147 benign and 93 malignant masses, the median of E-means were 26.20 (IQR 15.70-56.60) and 141.60 (IQR 119.80-154.60) kPa and the median E-ratios were 3.11 (IQR 1.83-5.23) and 9.24 (IQR 6.76-12.44), respectively. Using Youden's index, the optimal cutoff values for E-mean and E-ratio were 90.35 and 5.89, with sensitivity of 87.1 % and 82.8 %, specificity of 89.1 % and 83.7 %, positive predictive value (PPV) of 83.5 % and 76.2 %, negative predictive value (NPV) of 91.6 % and 88.5 %, positive likelihood ratio (LR+) of 8.00 and 5.07, and negative likelihood ratio (LR-) of 0.14 and 0.21, respectively.

Conclusion

This study revealed that SWE is useful in predicting malignancy. With the optimal cutoff values of E-mean and E-ratio at 90.35 kPa and 5.89, the sensitivity was nearly 90 % with E-mean and slightly over 80 % with E-ratio, respectively. These findings could be used in conjunction with conventional US.

Preoperative Role of Superb Microvascular Imaging and Shear-Wave Elastography for Prediction of Axillary Lymph Node Metastasis in Patients With Breast Cancer

ABSTRACT

This study aims to evaluate the role of shearwave elastography (SWE) and superb microvascular imaging (SMI) for preoperative prediction of axillary lymph node metastasis (ALNM) in patients with breast cancer. In a cohort of 214 women with breast cancer, B-Mode ultrasonography (US), SMIvascular-index (SMIvi), and SWE (E-mean, E-ratio) values were recorded before tru-cut biopsy. Axillary fine-needle aspiration biopsy (FNAB) and sentinel lymph node sampling results were collected. Imaging findings and histopathological data were statistically compared. Receiver operating characteristic curve analysis was used to evaluate diagnostic performance. Reverse stepwise logistical regression analysis was conducted. Although ALNM was negative in 111 cases, it was positive in 103 patients. Axillary lymph node metastasis (+) group had larger size ( P < 0.001), higher vascularization (SMIvi: 8.0 ± 6.0 versus 5.0 ± 4.3, P < 0.001), and higher elasticity value (E-mean: 129 ± 31 kPa versus 117.3 ± 40 kPa, P = 0.014). Axillary lymph node metastasis was observed statistically more frequently in Her-2 positive cases ( P = 0.005). There was no significant difference between other B-mode US findings ( P > 0.05), SMI Adler ( P = 0.878), and E-ratio ( P = 0.212). The most appropriate cutoff value for the prediction of ALNM was 23.5 mm for size, 3.8 for SMIvi, and 138.5 kPa for E-mean. The most sensitive (77%) method was the SMIvi measurement, while the most specific (86%) finding was Her-2 positivity. The combined model (being Her-2 positive, >23.5 cm, and >3.8 SMIvi) increased the specificity (78%), PPV (71%), and accuracy (68%). Although the increased size is a previously studied parameter in predicting the risk of ALNM, Her-2 and data obtained by SWE, and SMI can be used to assist conventional US.

Mechanical regulation of mitochondrial morphodynamics in cancer cells by extracellular microenvironment

Recently, it has been recognized that physical abnormalities (e.g. elevated solid stress, elevated interstitial fluid pressure, increased stiffness) are associated with tumor progression and development. Additionally, these mechanical forces originating from tumor cell environment through mechanotransduction pathways can affect metabolism. On the other hand, mitochondria are well-known as bioenergetic, biosynthetic, and signaling organelles crucial for sensing stress and facilitating cellular adaptation to the environment and physical stimuli. Disruptions in mitochondrial dynamics and function have been found to play a role in the initiation and advancement of cancer. Consequently, it is logical to hypothesize that mitochondria dynamics subjected to physical cues may play a pivotal role in mediating tumorigenesis. Recently mitochondrial biogenesis and turnover, fission and fusion dynamics was linked to mechanotransduction in cancer. However, how cancer cell mechanics and mitochondria functions are connected, still remain poorly understood. Here, we discuss recent studies that link mechanical stimuli exerted by the tumor cell environment and mitochondria dynamics and functions. This interplay between mechanics and mitochondria functions may shed light on how mitochondria regulate tumorigenesis.

Biopathologic Characterization and Grade Assessment of Breast Cancer With 3-D Multiparametric Ultrasound Combining Shear Wave Elastography and Backscatter Tensor Imaging

OBJECTIVE

Despite recent improvements in medical imaging, the final diagnosis and biopathologic characterization of breast cancers currently still requires biopsies. Ultrasound is commonly used for clinical examination of breast masses. B-Mode and shear wave elastography (SWE) are already widely used to detect suspicious masses and differentiate benign lesions from cancers. But additional ultrasound modalities such as backscatter tensor imaging (BTI) could provide relevant biomarkers related to tissue organization. Here we describe a 3-D multiparametric ultrasound approach applied to breast carcinomas in the aims of (i) validating the ability of BTI to reveal the underlying organization of collagen fibers and (ii) assessing the complementarity of SWE and BTI to reveal biopathologic features of diagnostic interest.

METHODS

Three-dimensional SWE and BTI were performed ex vivo on 64 human breast carcinoma samples using a linear ultrasound probe moved by a set of motors. Here we describe a 3-D multiparametric representation of the breast masses and quantitative measurements combining B-mode, SWE and BTI.

RESULTS

Our results reveal for the first time that BTI can capture the orientation of the collagen fibers around tumors. BTI was found to be a relevant marker for assessing cancer stages, revealing a more tangent tissue orientation for in situ carcinomas than for invasive cancers. In invasive cases, the combination of BTI and SWE parameters allowed for classification of invasive tumors with respect to their grade with an accuracy of 95.7%.

CONCLUSION

Our results highlight the potential of 3-D multiparametric ultrasound imaging for biopathologic characterization of breast tumors.

Linking cell mechanical memory and cancer metastasis

Metastasis causes most cancer-related deaths; however, the efficacy of anti-metastatic drugs is limited by incomplete understanding of the biological mechanisms that drive metastasis. Focusing on the mechanics of metastasis, we propose that the ability of tumour cells to survive the metastatic process is enhanced by mechanical stresses in the primary tumour microenvironment that select for well-adapted cells. In this Perspective, we suggest that biophysical adaptations favourable for metastasis are retained via mechanical memory, such that the extent of memory is influenced by both the magnitude and duration of the mechanical stress. Among the mechanical cues present in the primary tumour microenvironment, we focus on high matrix stiffness to illustrate how it alters tumour cell proliferation, survival, secretion of molecular factors, force generation, deformability, migration and invasion. We particularly centre our discussion on potential mechanisms of mechanical memory formation and retention via mechanotransduction and persistent epigenetic changes. Indeed, we propose that the biophysical adaptations that are induced by this process are retained throughout the metastatic process to improve tumour cell extravasation, survival and colonization in the distant organ. Deciphering mechanical memory mechanisms will be key to discovering a new class of anti-metastatic drugs.

Prognostic value of metastatic cervical lymph node stiffness in nasopharyngeal carcinoma: A prospective cohort study

OBJECTIVES

Extracellular matrix stiffness plays an important role in tumorigenesis. In this study, we assessed the prognostic value of metastatic cervical lymph node (CLN) stiffness measured using ultrasound shear wave elastography (SWE) in patients with nasopharyngeal carcinoma (NPC).

METHODS

A total of 325 consecutive patients with NPC and CLN metastases were prospectively enrolled in this study. The association between the CLN stiffness and patient characteristics was also evaluated. Survival analysis was performed for 307 patients with stage M0 disease. Distant metastasis-free survival (DMFS) was the primary endpoint. Log-rank test and multivariate analysis were used to explore the prognostic value of CLN stiffness.

RESULTS

Eighteen patients developed distant metastases before treatment (stage M1) and had significantly higher CLN stiffness (Pt-test < 0.001) than the other patients (stage M0). For stage M0 patients, those in the high-stiffness group had lower 3-year DMFS (83.3% vs. 91.7%, P = 0.013) and 3-year progression-free survival (PFS) (78.2% vs. 87.9%, P = 0.015) than those in the low-stiffness group. Multivariate analysis identified CLN stiffness and pretreatment Epstein-Barr virus (EBV) DNA as independent prognostic factors for DMFS and PFS. We further established stiffness-EBV risk stratification based on these two factors. The concordance index, receiver operating characteristic curve, and decision curve analyses showed that our risk stratification outperformed the TNM classification for predicting metastasis.

CONCLUSION

The stiffness of metastatic CLN is closely associated with the prognosis of patients with NPC. SWE can be used as a pretreatment examination for CLN-positive patients. A multicenter study is required to verify our results.

The Diagnostic Role of Shear Wave Elastography and Superb Microvascular Imaging in the Evaluation of Suspicious Microcalcifications

OBJECTIVES

The aim of this study was to investigate the role of superb microvascular imaging (SMI) and shear wave elastography (SWE) in the prediction of malignancy and invasiveness of isolated microcalcifications (MC) that can be visualized by ultrasonography (US).

MATERIAL AND METHODS

Sixty-seven women with MC, who were considered suspicious on mammography were evaluated. Only those lesions that could be visualized by US and presented as non-mass lesion were included. They were evaluated by B-mode US, SMI, and SWE before US-guided core-needle biopsy. B-mode US, SMI (vascular index (SMIvi)), and SWE (E-mean, E-ratio) findings were compared with histopathologic features.

RESULTS

Pathology confirmed 45 malignant (21 invasive and 24 in situ carcinomas) and 22 benign lesions. There was a statistically significant difference between malignant and benign groups in terms of size (P = .015), distortion (P = .028), cystic component (P < .001), E-mean (P < .001), E-ratio (P < .001), and SMIvi (P = .006). For differentiation of invasiveness E-mean (P = .002), E-ratio (P = .002), and SMIvi (P = .030) were statistically significant. According to ROC analysis E-mean (cut-off point at 38 kPa) was the most sensitive (78%) and the most specific (95%) value among four numeric parameters (size, SMI, E-mean, and E-ratio) with AUC = 0.895, PPV = 97%, and NPV = 68% in detecting malignancy. In the evaluation of invasiveness, the most sensitive (71.4%) method was SMI (cut-off point at 3.4) and the most specific (72%) method was E-mean (cut-off point at 91.5 kPa).

CONCLUSION

Our study shows that adding SWE and SMI to the sonographic evaluation of MC would be an advantage for US-guided biopsy. Including suspicious areas according to SMI and SWE in the sampling area can help target the invasive part of the lesion and avoid underestimation of core biopsy.

Development of a nomogram-based model combining intra- and peritumoral ultrasound radiomics with clinical features for differentiating benign from malignant in Breast Imaging Reporting and Data System category 3-5 nodules

Background

The differences in benign and malignant breast tumors are not only within the nodules but also involve changes in the surrounding tissues. Radiomics can reveal many details that are not discernible to the naked eye. This study aimed to distinguish between benign and malignant breast nodules using an ultrasound-based intra- and peritumoral radiomics model.

Methods

This study retrospectively collected the information from 379 patients with Breast Imaging Reporting and Data System (BI-RADS) category 3-5 nodules and clear pathological diagnosis of breast nodules screened by routine ultrasound examination in the Sixth People's Hospital Affiliated to Medical College of Shanghai Jiao Tong University from January 2017 to December 2022. The largest dimension of the lesion on the 2D ultrasound image was selected to outline the area of interest which was conformally and outwardly expanded automatically by 5 mm to extract intra- and peritumor radiomics features. The included cases were randomly divided into training sets and test sets in a ratio of 7:3. The optimal features of the included models were retained by statistical and machine learning methods of dimensionality reduction, and logistic regression was used as the classifier to build an intratumoral model and a combined intratumoral-peritumoral radiomics model, respectively; through single-factor and multifactor logistic regression, the optimal features that could predict benign and malignant breast tumors were screened. The clinical and imaging models were established by selecting independent risk factors as clinical and imaging features through univariate and multifactorial logistic regression.

Results

Among 379 BI-RADS category 3-5 breast nodules, there were 124 malignant nodules and 255 benign nodules; patients were aged 14 to 88 (46.22±15.51) years, and the age differences, radiomics score, and mass diameter between the training and test sets were not statistically significant (P>0.05). The intra- and peritumor radiomics model had an area under the curve (AUC) of 0.840 [95% confidence interval (CI): 0.766-0.914] in the test set. The model with intra- and peritumoral ultrasound radiomics features combined with clinical features had an AUC value of 0.960 (95% CI: 0.920-0.999).

Conclusions

The nomogram, developed using intratumoral and peritumoral radiomics features combined with clinical risk features, demonstrated superior performance in distinguishing between benign and malignant BI-RADS 3-5 lesions.

Linear Regression Modeling Based Scoring System to Reduce Benign Breast Biopsies Using Multi-parametric US with Color Doppler and SWE

RATIONALE AND OBJECTIVES

To develop a simple ultrasound (US) based scoring system to reduce benign breast biopsies.

MATERIALS AND METHODS

Women with BI-RADS 4 or 5 breast lesions underwent shear-wave elastography (SWE) imaging before biopsy. Standard US and color Doppler US (CDUS) parameters were recorded, and the size ratio (SzR=longest/shortest diameter) was calculated. Measured/calculated SWE parameters were minimum (SWVMin) and maximum (SWVMax) shear velocity, velocity heterogeneity (SWVH=SWVMax-SWVMin), velocity ratio (SWVR=SWVMin/SWVMax), and normalized SWVR (SWVRn=(SWVMax-SWVMin)/SWVMin). Linear regression analysis was performed by converting continuous parameters into categorical corresponding equivalents using decision tree analyses. Linear regression models were fitted using stepwise regression analysis and optimal coefficients for the predictors in the models were determined. A scoring model was devised from the results and validated using a different data set from another center consisting of 187 cases with BI-RADS 3, 4, and 5 lesions.

RESULTS

A total of 418 lesions (238 benign, 180 malignant) were analyzed. US and CDUS parameters exhibited poor (AUC=0.592-0.696), SWE parameters exhibited poor-good (AUC=0.607-0.816) diagnostic performance in benign/malignant discrimination. Linear regression models of US+CDUS and US+SWE parameters revealed an AUC of 0.819 and 0.882, respectively. The developed scoring system could have avoided biopsy in 37.8% of benign lesions while missing 1.1% of malignant lesions. The scoring system was validated with a 100% NPV rate with a specificity of 74.6%.

CONCLUSION

The linear regression model using US+SWE parameters performed better than any single parameter alone. The developed scoring method could lead to a significant decrease in benign biopsies.

Predicting the expansion of the lower pole of the breast following smooth breast implant augmentation: A novel shear wave elastography study

OBJECTIVES

This study aimed to educate and demonstrate how the use of shear wave elastography (SWE) can be used to determine the elasticity of patient tissues preoperatively, which can then be used to predict the level of lower pole expansion postoperatively, following breast augmentation surgery.

MATERIALS AND METHODS

This study evaluated 60 breasts in 30 patients that were divided in 3 equal groups (n = 20) according to their predefined elastography criteria measured via SWE (loose, moderate, and tight tissue elasticity). All measurements were taken under maximum stretch between the inferior border of the nipple alveolar complex (NAC) and inframammary fold (IMF) using a measuring tape in millimetres (mm). The follow-up appointments for routine assessments and measurements were done at 3, 6, 12, 18, and 24 months.

RESULTS

The study engaged 38 patients over 4 years, but only 10 patients in each group attended all the appointments. Statistical analysis showed the elastic skin types (loose, moderate, and tight) had significantly different rates of lower pole expansion, and the rate of expansion increased significantly after 6 months postoperatively, whereas prior to 6 months, the rates were comparable (p < 0.05).

DISCUSSION

The results showed that increasingly elastic skin types have a greater rate of lower pole expansion. This is important for the operating surgeon to be aware of as looser skin types will be more prone to lower pole expansion, and thus, a higher surgical IMF suture may be advised to manage patient expectations.

CONCLUSION

This study can be used as a guideline for surgeons, which will allow for a more predictable surgical planning system that will ultimately lead to fewer revisions and risks for patients worldwide.

Diagnostic value of shear wave elastography quantification combined with conventional ultrasound in salivary gland tumors

Background

The histopathological classification of salivary gland tumors is extremely complex. The imaging manifestations of some tumors are nonspecific. It is particularly important to improve the value of ultrasound in the diagnosis of salivary gland tumors. This study aimed to analyze the diagnostic value of different parameters of shear wave elastography (SWE) in the quantitative diagnosis of salivary gland tumors, and to evaluate the value of SWE combined with conventional ultrasound.

Methods

The study was conducted retrospectively. Patients who underwent salivary gland tumor resection from April 2021 to November 2022 in the Ninth People's Hospital, Shanghai Jiaotong University School of Medicine were randomly recruited to the study. A total of 305 masses were divided into an elastography group (150 cases) and a control group (155 cases). The control group underwent conventional ultrasonography, whereas the elastography group underwent conventional ultrasonography and elastography. The Young's modulus E of the mass was quantitatively measured in the elastography group, including maximum cross-sectional area (S), maximum Young's modulus (Emax), mean Young's modulus (Emean), and Young's modulus standard deviation (SD). Pathologic diagnosis was used as the reference standard to determine the cut-off of shear wave elastography of salivary gland tumors, and the diagnostic performance of the 2 groups was compared.

Results

In the elastography group, the diagnostic value of Emax·S (the product of the maximum Young's modulus of the mass and the maximum cross-sectional area of the mass) in the differential diagnosis of malignant tumors (MT) and non-malignant tumors (NMT) was the highest, with a sensitivity and specificity of 72.0% and 80.0%, respectively. The diagnostic value of Emax/D (the quotient of the maximum Young's modulus of the mass and the maximum diameter of the mass) in the differential diagnosis of pleomorphic adenoma (PA) and adenolymphoma (AL) was the highest, with a sensitivity and specificity of 62.3% and 82.4%, respectively. The receiver operating characteristic (ROC) curves for the diagnosis of salivary gland tumors were compared between the elastography group and the control group. The area under the curve (AUC) of the elastography group was 0.915, the sensitivity, specificity, and Youden index were 84.0%, 88.0%, and 0.720, respectively. The AUC of the control group was 0.906, the sensitivity, specificity, and Youden index were 76.0%, 90.0%, and 0.660, respectively, which is the main finding of the study.

Conclusions

SWE can be used as a complementary method for the diagnosis of salivary gland tumors, which has certain value in improving the diagnostic performance. As a result, the sensitivity is improved but the specificity is worsened by addition of SWE to B-mode ultrasound and color Doppler flow imaging (CDFI).

Correlation of shear-wave elastography parameters with the molecular subtype and axillary lymph node status in breast cancer

PURPOSE

To examine correlations between shear-wave elastography (SWE) parameters with molecular subtype and axillary lymph node (LN) status of breast cancer.

METHODS

We retrospectively analyzed 545 consecutive women (mean age, 52.7 ± 10.7 years; range, 26-83) with breast cancer who underwent preoperative breast ultrasound with SWE between December 2019 and January 2021. SWE parameters (E_max, E_mean, and E_ratio) and the histopathologic information from surgical specimens including histologic type, histologic grade, size of invasive cancer, hormone receptor and HER2 status, Ki-67 proliferation index, and axillary LN status were analyzed. The relationships between SWE parameters and histopathologic findings were analyzed using an independent sample t-test, one-way ANOVA test with Tukey's post hoc test, and logistic regression analyses.

RESULTS

Higher stiffness values of SWE were associated with larger lesion size (>20 mm) on ultrasound, high histologic grade, larger invasive cancer size (>20 mm), high Ki-67, and axillary LN metastasis. E_max and E_mean were the lowest in the luminal A-like subtype, and all three parameters were the highest in the triple-negative subtype. Lower value of E_max was independently associated with the luminal A-like subtype (P = 0.04). Higher value of E_mean was independently associated with axillary LN metastasis for tumors ≤ 20 mm (P = 0.03).

CONCLUSION

Increases in the tumor stiffness values on SWE were significantly associated with aggressive histopathologic features of breast cancer. Lower stiffness values were associated with the luminal A-like subtype, and tumors with higher stiffness values were associated with axillary LN metastasis in small breast cancers.

An improved nomogram including elastography for the prediction of non-sentinel lymph node metastasis in breast cancer patients with 1 or 2 sentinel lymph node metastases

Background

The rate of breast-conserving surgery is very low in China, compared with that in developed countries; most breast cancer patients receive mastectomy. It is great important to explore the possibility of omitting axillary lymph node dissection (ALND) in early-stage breast cancer patients with 1 or 2 positive sentinel lymph nodes (SLNs) in China. The aim of this study was to develop a nomogram based on elastography for the prediction of the risk of non-SLN (NSLN) metastasis in early-stage breast cancer patients with 1 or 2 positive SLNs.

Methods

A total of 601 breast cancer patients were initially recruited. According to the inclusion and exclusion criteria, 118 early-stage breast cancer patients with 1 or 2 positive SLNs were finally enrolled and were assigned to the training cohort (n=82) and the validation cohort (n=36), respectively. In the training cohort, the independent predictors were screened by logistic regression analysis and then were used to conducted the nomogram for the prediction of NSLN metastasis in early-stage breast cancer patients with 1 or 2 positive SLNs. The calibration curves, concordance index (C-index), the area under the receiver operating characteristic (ROC) curve (AUC), and Decision curve analysis (DCA) were used to verified the performance of the nomogram.

Results

The multivariable analysis showed that the enrolled patients with positive HER2 expression (OR=6.179, P=0.013), Ki67≥14% (OR=8.976, P=0.015), larger lesion size (OR=1.038, P=0.045), and higher Emean (OR=2.237, P=0.006) were observed to be the independent factors of NSLN metastasis. Based on the above four independent predictors, a nomogram was conducted to predict the risk of the NSLN metastasis in early-stage breast cancer patients with 1 or 2 positive SLNs. The nomogram showed good discrimination in the prediction of NSLN metastasis, with bias-corrected C-index of 0.855 (95% CI, 0.754-0.956) and 0.853 (95% CI, 0.724-0.983) in the training and validation cohorts, respectively. Furthermore, the AUC was 0.877 (95%CI: 0.776- 0.978) and 0.861 (95%CI: 0.732-0.991), respectively, indicating a good performance of the nomogram. The calibration curve suggested a satisfactory agreement between the predictive and actual risk in both the training (χ2 = 11.484, P=0.176, HL test) and validation (χ2 = 6.247, p = 0.620, HL test) cohorts, and the obvious clinical nets were revealed by DCA.

Conclusions

We conducted a satisfactory nomogram model to evaluate the risk of NSLN metastasis in early-stage breast cancer patients with 1 or 2 SLN metastases. This model could be considered as an ancillary tool to help such patients to be selectively exempted from ALND.

Radiotherapy-induced tumor physical microenvironment remodeling to overcome immunotherapy resistance

The clinical benefits of immunotherapy are proven in many cancers, but a significant number of patients do not respond well to immunotherapy. The tumor physical microenvironment (TpME) has recently been shown to affect the growth, metastasis and treatment of solid tumors. The tumor microenvironment (TME) has unique physical hallmarks: 1) unique tissue microarchitecture, 2) increased stiffness, 3) elevated solid stress, and 4) elevated interstitial fluid pressure (IFP), which contribute to tumor progression and immunotherapy resistance in a variety of ways. Radiotherapy, a traditional and powerful treatment, can remodel the matrix and blood flow associated with the tumor to improve the response rate of immune checkpoint inhibitors (ICIs) to a certain extent. Herein, we first review the recent research advances on the physical properties of the TME and then explain how TpME is involved in immunotherapy resistance. Finally, we discuss how radiotherapy can remodel TpME to overcome immunotherapy resistance.

Potential of Lesion-to-Fat Elasticity Ratio Measured by Shear Wave Elastography to Reduce Benign Biopsies in BI-RADS 4 Breast Lesions

OBJECTIVES

We evaluated whether lesion-to-fat ratio measured by shear wave elastography in patients with Breast Imaging Reporting and Data System (BI-RADS) 3 or 4 lesions has the potential to further refine the assessment of B-mode ultrasound alone in breast cancer diagnostics.

METHODS

This was a secondary analysis of an international diagnostic multicenter trial (NCT02638935). Data from 1288 women with breast lesions categorized as BI-RADS 3 and 4a-c by conventional B-mode ultrasound were analyzed, whereby the focus was placed on differentiating lesions categorized as BI-RADS 3 and BI-RADS 4a. All women underwent shear wave elastography and histopathologic evaluation functioning as reference standard. Reduction of benign biopsies as well as the number of missed malignancies after reclassification using lesion-to-fat ratio measured by shear wave elastography were evaluated.

RESULTS

Breast cancer was diagnosed in 368 (28.6%) of 1288 lesions. The assessment with conventional B-mode ultrasound resulted in 53.8% (495 of 1288) pathologically benign lesions categorized as BI-RADS 4 and therefore false positives as well as in 1.39% (6 of 431) undetected malignancies categorized as BI-RADS 3. Additional lesion-to-fat ratio in BI-RADS 4a lesions with a cutoff value of 1.85 resulted in 30.11% biopsies of benign lesions which correspond to a reduction of 44.04% of false positives.

CONCLUSIONS

Adding lesion-to-fat ratio measured by shear wave elastography to conventional B-mode ultrasound in BI-RADS 4a breast lesions could help reduce the number of benign biopsies by 44.04%. At the same time, however, 1.98% of malignancies were missed, which would still be in line with American College of Radiology BI-RADS 3 definition of <2% of undetected malignancies.

Fibroepithelial lesions of the breast: improving the accuracy of imaging diagnosis and reducing unnecessary biopsy

Fibroadenomas and phyllodes tumours are fibroepithelial lesions of the breast. Fibroadenomas are common benign breast masses encountered both symptomatically and incidentally. Phyllodes tumours are uncommon and usually present symptomatically. Management of fibroadenomas focuses on reducing biopsies without missing cancers while radiological management of phyllodes tumours should focus on predicting the need for surgical excision with or without margins.

Is there a potential biomarker in distinguishing invasive breast carcinomas with elevated Ki-67 levels among 2D-SWE, SMI, and 18F-FDG PET-CT/MRI-derived parameters?: A single-center data

PURPOSE

To investigate the strength of quantitative imaging and metabolic parameters in differentiating invasive breast carcinomas with elevated Ki-67 levels.

MATERIALS AND METHODS

A total of 123 patients with 129 breast lesions confirmed as invasive breast carcinoma underwent shear wave elastography (SWE), superb microvascular imaging (SMI) and positron emission tomography (PET)/CT or MRI. Adler's grade (classifying the microvascularity into four types) and Vascular Index (VI) was obtained by SMI as microvascular parameters. In addition, the stiffness value (E_mean ) was evaluated in kilopascal by SWE. The average of consecutive measurements was recorded as mean VI and mean E_mean . PET scan parameters were obtained as SUV_max and SUL_peak . Lesions were divided into two groups according to the Ki-67 expression, low as ≤ 14 and high as >14.

RESULTS

Adler's grading was the most correlated imaging parameter with high Ki-67 expression (p < 0.05), while VI and E_mean had poor correlation (p > 0.05). SUV_max and SUL_peak indicated a significant linear correlation with Ki-67 but a moderate correlation with the high levels of Ki-67 (p < 0,001). The sensitivity of VI, E_mean , SUV_max and SUL_peak was 64.6%, 66.7%, 65.7%, and 66.7% when the cut-off point was set to 5.25, 102.5, 6.59, and 2.63, respectively. SUV_max had the highest AUC value of 0.740, according to the ROC curve analysis.

CONCLUSIONS

Our results suggest that the quantitative parameters obtained by advanced imaging methods may be useful in predicting the high proliferation in invasive breast carcinomas. But none of them is eligible to be used as an independent biomarker in distinguishing aggressive behavior. Nevertheless, as a noninvasive method, visual assessment of microvascular morphology using SMI increases the prognostic efficiency in invasive breast carcinomas.

Shear wave elastography as a supplemental tool in the assessment of unsuspicious axillary lymph nodes in patients undergoing breast ultrasound examination

Objectives:

To define reference values for shear wave elastography (SWE) in unsuspicious axillary lymph nodes in patients undergoing breast ultrasound examination.

Methods:

In total, 177 clinically and sonographically unsuspicious axillary lymph nodes were prospectively evaluated with SWE using Virtual Touch Tissue Imaging Quantification (VTIQ) in 175 women. Mean values of tissue stiffness for axillary fatty tissue, lymph node cortex, and lymph node hilus were measured. Additionally, test-retest reliability of SWE in the assessment of axillary lymph node stiffness was evaluated by repeating each measurement three times.

Results:

In 177 axillary lymph nodes, the mean stiffness of lymph node cortex, hilus, and surrounding fatty tissue as quantified by SWE was 1.90 m/s (SD: 0.34 m/s), 2.02 m/s (SD: 0.37 m/s), and 1.75 m/s (SD: 0.38 m/s), respectively. The mean stiffness of cortex and hilus was significantly higher compared to fatty tissue (p < 0.0001). SWE demonstrated good test–retest reliability in the assessment of stiffness of the lymph node hilus, cortex, and the surrounding fatty tissue with an intraclass correlation of 0.79 (95% CI: 0.75; 0.83), 0.75 (95% CI: 0.70; 0.79), and 0.78 (95% CI: 0.74; 0.82), respectively, (p < 0.0001).

Conclusions:

Reference values for SWE in unsuspicious axillary lymph nodes are determined. These results may help to better identify axillary lymph node metastasis for breast cancer patients when combined with other lymph node features. SWE is a reliable method for the objective quantification of tissue stiffness of axillary lymph nodes.

Advances in knowledge:

This study presents physiological reference values for tissue stiffness by examining the axillary lymph nodes with SWE in 175 women with sonomorphologically unsuspicious lymph nodes.

Diagnostic value of strain elastography and shear wave elastography in differentiating benign and malignant breast lesions

BACKGROUND

Conventional B-mode breast ultrasonography, though the primary modality to determine benign or malignant nature of a solid breast lesion, sometimes encounters overlapping sonographic morphological features in a single lesion. Elastography leads to improvement by evaluating the structural aspects and characterization of the lesion as benign or malignant on the basis of multi-parametric assessment.

OBJECTIVE

Determine the role of strain elastography (SE) and shear wave elastography (SWE) in differentiating benign and malignant breast lesions.

DESIGN

Cross sectional SETTING: Radiology department of hospital PATIENTS AND METHODS: Patients meeting inclusion criteria referred to our hospital for ultrasonography followed by biopsy or surgical excisions were examined with B-mode ultrasonography and by both strain and shear wave elastography.

MAIN OUTCOME MEASURES

Mean values of SE and SWE in benign and malignant breast lesions, determination of cutoff using AUC curves and sensitivity and specificity of both techniques.

SAMPLE SIZE

One hundred breast lesions from 95 consecutive patients.

RESULTS

The mean (SD) strain elastography ratio in the overall patient population was 4.1 (2.0). Cutoff for benign vs. malignant lesions was 2.86 on the ROC curve. The AUC was 0.911 (95%CI; 0.835-0.988: SE, 0.039) with a sensitivity of 95.8% and a specificity of 89.3%. For the SWE kPa values, the ROC curve showed the AUC was 0.929 (95% CI, 0.870-0.988; SE: 0.030, P<.001). Assigning 45.3 as a cut off value provided a sensitivity of 95.8% with a specificity of 85.7%; the positive predictive value was 94.5% and the negative predictive value was 89.6%. The Breast Imaging Reporting and Data System (BI-RADS) category alone was able to differentiate between benign and malignant lesions with a sensitivity of 91.7% and a specificity 100% keeping the cut off value between 4a and 4b. The area under the ROC curve was 0.979. Combining the three (BI-RADS + SE + SWE) distinguished benign vs. malignant lesions with a sensitivity up to 100% and specificity up to 96.3%.

CONCLUSION

Combining SE and SWE as a complementary tool with conventional B-mode ultrasonography has a significant potential for better characterization of solid breast lesions and decreasing unnecessary biopsies of BI-RADS IVa lesions.

LIMITATIONS

Single institution study.

CONFLICT OF INTEREST

None.

Which combination of different ultrasonography modalities is more appropriate to diagnose breast cancer?: A network meta-analysis (a PRISMA-compliant article)

BACKGROUND

Abundant amount of literature that analyze the various detection of different ultrasound methods, no comprehensive literature that investigates the diagnostic values of breast cancer (BC) by different ultrasonography modalities through a network meta-analysis (NMA) has been made available. Each imaging diagnostic examination has its own advantages and disadvantages, and any imaging examination is not enough to make an accurate diagnosis of the disease. Thus, this study aimed to compare diagnostic values among different ultrasonography modalities, including the information of 2-dimension, stiffness and blood flow, by a network meta-analysis in the hopes of understanding which imaging methods are better and which combination of different ultrasonography modalities is more appropriate to diagnose BC.

METHODS

We made use of Cochrane Library, PubMed, and Embase in order to obtain literature and papers. The combination analysis of both direct and indirect evidence in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value(NPV) and accuracy was conducted so as to assess the odds ratios (ORs) and surface under the cumulative ranking curve (SUCRA) values of the 8 different ultrasound methods.

RESULTS

A total of 36 eligible diagnostic tests regarding 8 ultrasound methods were included in the study. According to this network meta-analysis, Breast Imaging Reporting and Data System (BI-RADS) 4b exhibited higher specificity, PPV, and accuracy and lower sensitivity and NPV than BI-RADS 4a. Contrast-enhanced ultrasound (CEUS) had the highest sensitivity, PPV, NPV and accuracy and superb microvascular imaging (SMI) had the highest specificity among color Doppler flow imaging (CDFI), power Doppler imaging(PDI), SMI and CEUS. There was no significant difference in diagnostic indexes between SMI and CEUS. Shear wave elastrography (SWE) had higher PPV and accuracy and lower sensitivity, specificity NPV than strain elastography (SE).

CONCLUSION

The results of this network meta-analysis suggested more appropriate combination of different ultrasound modalities is BI-RADS 4b, SMI, and SWE for the diagnosis of breast cancer.

Differential diagnosis of B-mode ultrasound Breast Imaging Reporting and Data System category 3-4a lesions in conjunction with shear-wave elastography using conservative and aggressive approaches

BACKGROUND

The high false-positive rates of US Breast Imaging Reporting and Data System (BI-RADS) category 3-4a breast lesions leads to excessive biopsies of many benign lesions, and our aim was to investigate the diagnostic performance achieved by adding a maximum elasticity (Emax) of shear-wave elastography (SWE) to ultrasound (US) to evaluate US BI-RADS category 3-4a breast lesions using conservative and aggressive approaches. We explored the capacity of using this method to avoid unnecessary biopsies without increasing the probability of missing breast cancers.

METHODS

A total of 123 breast lesions of 120 patients classified as BI-RADS category 3 or 4a were enrolled from January 2019 to December 2019. The US features were evaluated according to the US BI-RADS lexicon. The maximum diameter measured on the US was defined as the size of the lesion. The Emax was assessed by SWE, and the average Emax of breast lesions on two images were calculated and recorded as the final maximum Young's modulus. The diagnostic performance of the combined B-mode US and SWE approach for BI-RADS category 3-4a breast lesions was tested using a conservative approach and an aggressive approach. In the conservative approach, the lesions were downgraded with Emax of 30 kPa or less and upgraded with Emax of 160 kPa or more. In the aggressive approach, the lesions were downgraded with Emax of 80 kPa or less and upgraded with Emax of 160 kPa or more. Pathologic results were defined as the reference standard.

RESULTS

Among all 123 breast lesions, there were 60 lesions classified as BI-RADS category 3 and 63 lesions classified as BI-RADS category 4a. Compared to the B-mode US, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the receiver operating characteristic (ROC) curve (AUC) of the combined B-mode US and SWE with a conservative approach changed from 88.9% to 94.4%, 55.2% to 60.0%, 25.4% to 28.8%, 96.7% to 98.4%, 60.2% to 65.0%, and 0.721 to 0.772, respectively. The specificity, PPV, and accuracy of combined B-mode US and SWE with an aggressive approach increased from 55.2% to 72.4%, 25.4% to 29.3%, and 60.2% to 71.5%, respectively, but this was accompanied with decreases in the sensitivity from 88.9% to 66.7%, the NPV from 96.7% to 92.7%, and the AUC from 0.721 to 0.695.

CONCLUSIONS

The addition of SWE improves the diagnostic performance of breast US. Adding the diagnostic criteria of SWE to the BI-RADS assessment of B-mode US, downgrading the lesions with Emax 30 kPa or less, and upgrading the lesions with Emax 160 kPa or more helped discriminate low suspicion lesions from benign lesions in order to decrease false-positive findings and avoid missing cancer diagnosis.

Potential value of tumor stiffness and sE-cadherin in predicting the response to neoadjuvant therapy in HER2-positive breast cancers

Background: This prospective study compared the diagnostic value of tumor stiffness and serum soluble E-cadherin (sE-cadherin) expression for predicting response to neoadjuvant therapy in HER2-positive breast cancers. Methods: 112 patients with early or locally advanced HER2-positive breast cancer were enrolled. Maximum stiffness (Emax), mean stiffness (Emean) and their relative changes were assessed at t0 and t2. sE-cadherin levels were analyzed using ELISA. Pathological complete response was defined as no invasive disease in the breast and axilla (ypT0/is, ypN0) after surgery. The ability of tumor stiffness, sE-cadherin and the combination of ΔEmean (the relative change in Emean after the second cycle of neoadjuvant therapy) and sE-cadherin in predicting tumor responses was assessed using receiver operating characteristic curves and the Z-test. Results: Tumor stiffness and sE-cadherin decreased during neoadjuvant therapy. ΔEmean and sE-cadherin revealed the best predictive performance, with areas under the curve (AUCs) of 0.843 and 0.857, respectively. No significant differences in AUCs were reported between ΔEmean and sE-cadherin (p = 0.795). The combined use of ΔEmean and sE-cadherin showed the highest sensitivity and specificity (93.22 and 90.57%, respectively), with an AUC of 0.937. Conclusion: The combination of ΔEmean and sE-cadherin may improve the predictive power of each single factor. Although further verification is required, this study may promote noninvasive prediction of neoadjuvant therapy responses and help personalize the treatment regimen.

In situ monitoring of functional activity of extracellular matrix stiffness-dependent multidrug resistance protein 1 using scanning electrochemical microscopy

Extracellular matrix (ECM) stiffness affects the drug resistance behavior of cancer cells, while multidrug resistance protein 1 (MRP1) on the cell membrane confers treatment resistance via actively transporting drugs out of cancer cells. However, the relationship between ECM stiffness and MRP1 functional activity in cancer cells remains elusive, mainly due to the technical challenge of in situ monitoring. Herein, we engineered in vitro cancer cell models using breast cancer cells (MCF-7 and MDA-MB-231 cells) as the reprehensive cells on polyacrylamide (PA) gels with three stiffness, mimicking different developmental stages of cancer. We in situ characterized the functional activity of MRP1 and investigated the effect of ECM stiffness on MRP1 of cancer cells before and after vincristine treatment using scanning electrochemical microscopy (SECM) with ferrocenecarboxylic acid (FcCOOH) as the redox mediator and endogenous glutathione (GSH) as the indicator. The SECM results show that the functional activity of MRP1 is enhanced with increasing ECM stiffness, and the MRP1-mediated vincristine efflux activity of MCF-7 cells is more affected by ECM stiffness than that of MDA-MB-231 cells. This work, for the first time, applied SECM to in situ and quantitatively monitor the functional activity of MRP1 in cancer cells in different tumor mechanical microenvironments, which could help to elucidate the mechanism of matrix stiffness-dependent drug resistance behavior in cancer cells.

SECM using FcCOOH as the redox mediator and endogenous GSH as the indicator was employed to investigate the effect of extracellular matrix stiffness on the functional activity of MRP1 in cancer cells in situ.

Diagnostic Accuracy of Shear Wave Elastography as an Adjunct Tool in Detecting Axillary Lymph Nodes Metastasis

OBJECTIVES

This study evaluates the diagnostic performance of shear wave elastography (SWE) in differentiating between benign and axillary lymph node (ALN) metastasis in breast carcinoma.

MATERIALS AND METHODS

Breast lesions and axillae of 107 patients were assessed using B-mode ultrasound and SWE. Histopathology was the diagnostic gold standard.

RESULTS

In metastatic axillary lymph nodes, qualitative SWE using color patterns had the highest area under curve (AUC) value, followed by B-mode Ultrasound (cortical thickening >3 mm) and quantitative SWE using Emax of 15.2 kPa (AUC of 81.3%, 70.1%, and 61.2%, respectively). Qualitative SWE exhibited better diagnostic performance than the other two parameters, with sensitivity of 96.0% and specificity of 56.1%. Combination of B-mode Ultrasound (using cortical thickness of >3 mm as cut-off point) and qualitative SWE (Color patterns of 2 to 4) showed sensitivity of 71.6%, specificity of 95%, PPV of 96%, NPV of 66.7%, and accuracy of 80.4%.

CONCLUSION

Qualitative SWE assessment exhibited higher accuracy compared to quantitative values. Qualitative SWE as an adjunct to B-mode ultrasound can further improve the diagnostic accuracy of metastatic ALN in breast cancer.

Evaluation of Multiparametric Shear Wave Elastography Indices in Malignant and Benign Breast Lesions

RATIONALE AND OBJECTIVES

To evaluate the shear wave elastography indices (multiparametric SWE) of breast lesions based on patient and lesion dependent features and assess the contribution of different elastographic parameters to radiological diagnosis.

MATERIALS AND METHODS

Effect of patient-dependent (age and menopausal status) and lesion-dependent (distance from the areola, quadrant location, size, depth, margin and shape) factors on SWE parameters (Vmean, Vsd, Vmax, Vmin) in benign breast lesions were assessed. Only mass lesions were included in the study. Sensitivity, specificity, PPV, NPV and cut-off values for each elastography parameter was calculated.

RESULTS

A total of 496 mass lesions of breast were evaluated. 467 of the lesions were benign and 29 were malignant. There was no significant relationship among SWE indices and age, menopausal status, lesion shape and distance to the areola in benign lesions (p>0.05). SWE indices were found to be associated with lesion margin, depth from the skin, and lesion size in benign lesions (p<0.05). All BI-RADS 3 lesions that underwent biopsy were benign (n:35); 23.5% of 4a lesions were malignant (n:4/17) and all 4b-4c-5 lesions were malignant (n:25/25). The cut-off values for malignant lesions were: Vmean 3.38 m/s, Vsd 0.81, Vmax 6.87 m/s, Vmin 1.53 m/s. All SWE parameters were statistically significant in predicting malignancy on ROC analysis, Vmax was the most sensitive (96.3%) and specific (94.7%) parameter. Cut-off values for Vmax was 6.87 m/s with an accuracy rate of 94.7%, and 3.37 m/s for Vmean and 0.8 for Vsd with 92.5% accuracy.

CONCLUSION

The SWE parameters to predict malignancy in breast lesions can be affected by lesion dependent features, whereas no significant effect of patient's age or menopausal status on stiffness of the lesions was observed. Vmax had the highest sensitivity for predicting malignancy.

A pre-operative prognostic model predicting all cause and cause specific mortality for women presenting with invasive breast cancer

PURPOSE

The aim of this study is to develop a pre-operative prognostic model based on known pre-operative factors.

METHODS

A database of ultrasound (US) lesions undergoing biopsy documented US lesion size, stiffness, and patient source prospectively. Women with invasive cancer presenting between 2010 and 2015 were the study group. Breast and axillary core results and ER, PR and HER receptor status were collected prospectively. Assessment of US skin thickening, US distal enhancement and presence of chronic kidney disease (CKD) was performed retrospectively. Patient survival and cause of death were ascertained from computer records. Predictive models for (i) all-cause mortality (ACM) and (ii) breast cancer death (BCD) were built and then validated using bootstrap k-fold cross-validation. A comparison of predictive performance was made between a full cause-specific Cox model, a sub cause-specific Cox model, and a full Fine-Gray sub-distribution hazard model.

RESULTS

1136 patients were included in the study. The median follow-up time was 6.2 years. 125 (11%) women died from breast cancer and 155 (14%) died from other causes. For the prediction of BCD, the cause-specific Cox sub-model performed the best. The time dependent AUC begins above 0.91 in year one to 3 reducing to 0.83 in year 6. The factors included in the Cox sub model were tumour size, skin thickening, source of detection, tumour grade, ER status, pre-operative nodal metastasis and CKD.

CONCLUSION

We have shown that a model based on preoperative factors can predict BCD. Such prediction if externally validated and incorporating treatment data could be useful for treatment planning and patient counselling.

Single cell imaging-based chromatin biomarkers for tumor progression

Tumour progression within the tissue microenvironment is accompanied by complex biomechanical alterations of the extracellular environment. While histopathology images provide robust biochemical markers for tumor progression in clinical settings, a quantitative single cell score using nuclear morphology and chromatin organization integrated with the long range mechanical coupling within the tumor microenvironment is missing. We propose that the spatial chromatin organization in individual nuclei characterises the cell state and their alterations during tumor progression. In this paper, we first built an image analysis pipeline and implemented it to classify nuclei from patient derived breast tissue biopsies of various cancer stages based on their nuclear and chromatin features. Replacing H&E with DNA binding dyes such as Hoescht stained tissue biopsies, we improved the classification accuracy. Using the nuclear morphology and chromatin organization features, we constructed a pseudo-time model to identify the chromatin state changes that occur during tumour progression. This enabled us to build a single-cell mechano-genomic score that characterises the cell state during tumor progression from a normal to a metastatic state. To gain further insights into the alterations in the local tissue microenvironments, we also used the nuclear orientations to identify spatial neighbourhoods that have been posited to drive tumor progression. Collectively, we demonstrate that image-based single cell chromatin and nuclear features are important single cell biomarkers for phenotypic mapping of tumor progression.

The value of prognostic ultrasound features of breast cancer in different molecular subtypes with a focus on triple negative disease

The ultrasound (US) features of breast cancer have recently been shown to have prognostic significance. We aim to assess these features according to molecular subtype. 1140 consecutive US visible invasive breast cancers had US size and mean stiffness by shearwave elastography (SWE) recorded prospectively. Skin thickening (> 2.5 mm) overlying the cancer on US and the presence of posterior echo enhancement were assessed retrospectively while blinded to outcomes. Cancers were classified as luminal, triple negative (TN) or HER2 + ve based on immunohistochemistry and florescent in-situ hybridization. The relationship between US parameters and breast cancer specific survival (BCSS) was ascertained using Kaplan–Meier survival curves and ROC analysis. At median follow-up 6.3 year, there were 117 breast cancer (10%) and 132 non-breast deaths (12%). US size was significantly associated with BCSS all groups (area under the curve (AUC) 0.74 in luminal cancers, 0.64 for TN and 0.65 for HER2 + ve cancers). US skin thickening was associated most strongly with poor prognosis in TN cancers (53% vs. 80% 6 year survival, p = 0.0004). Posterior echo enhancement was associated with a poor BCSS in TN cancers (63% vs. 82% 6 year survival, p = 0.02). Mean stiffness at SWE was prognostic in the luminal and HER2 positive groups (AUC 0.69 and 0.63, respectively). In the subgroup of patients with TN cancers receiving neo-adjuvant chemotherapy posterior enhancement and skin thickening were not associated with response. US skin thickening is a poor prognostic indicator is all 3 subtypes studied, while posterior enhancement was associated with poor outcome in TN cancers

Quantitative analysis of shear wave elastic heterogeneity for prediction of lymphovascular invasion in breast cancer

OBJECTIVE

To evaluate the correlation between elastic heterogeneity (EH) and lymphovascular invasion (LVI) in breast cancers and assess the clinical value of using EH to predict LVI pre-operatively.

METHODS

This retrospective study consisted of 376 patients with breast cancers that had undergone shear wave elastography (SWE) with virtual touch tissue imaging quantification between June 2017 and June 2018. The EH was determined as the difference between the averaged three highest and three lowest shear wave value. Clinicalpathological parameters including histological type and grades, LVI, axillary lymph node status and molecular markers (estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 and Ki-67) were reviewed and recorded. Relationship EH and clinicalpathological parameters was investigated respectively. The diagnostic performance of EH in distinguishing LVI or not was analyzed.

RESULTS

At multivariate regression analysis, only EH (p = 0.017) was positively correlated with LVI in all tumors. EH (p = 0.003) and Ki-67 (p = 0.025) were positively correlated with LVI in tumors ≤ 2 cm. None of clinicalpathological parameters were correlated with LVI in tumors > 2 cm (p > 0.05 for all). Using EH to predict LVI in tumors ≤ 2 cm, the sensitivity and negative predictive value were 93 and 89% respectively.

CONCLUSION

EH has the potential to be served as an imaging biomarker to predict LVI in breast cancer especially for tumors ≤ 2 cm.

ADVANCES IN KNOWLEDGE

There was no association between LVI and other most commonly used elastic features such as SWV_mean and SWV_max. Elastic heterogeneity is an independent predictor of LVI, so it can provide additional prognostic information for routine preoperative breast cancer assessment.For tumors ≤ 2cm, using EH value higher than 1.36 m/s to predict LVI involvement, the sensitivity and negative predictive value can reach to 93% and 89%, respectively, suggesting that breast cancer with negative EH value was more likely to be absent of LVI.

Characterization of Suspicious Microcalcifications on Mammography Using 2D Shear-Wave Elastography

Our aim was to investigate the correlations between the findings of two-dimensional shear-wave elastography (2D-SWE) and the histopathologic results of microcalcifications (MCs) visualized using ultrasonography (USG). Fifty people with suspicious MCs without accompanying mass were evaluated. They underwent USG and 2D-SWE before USG-guided tru-cut biopsy. SWE values and histopathologic features were compared statistically. The variables between groups were analyzed using the Mann-Whitney U test. Receiver operating characteristic analysis was performed and cut-off values determined to discriminate malignancy, invasiveness and high grade. Pathology confirmed 27 malignant lesions (18 invasive ductal carcinomas, one invasive lobular and eight ductal carcinomas in situ) and 23 benign ones. There was a statistically significant difference between the SWE values of malignant and benign MCs (p < 0.001). The diagnostic performance of SWE for malignancy, invasiveness and high grade were as follows, repectively: sensitivity (93%, 83%, 88%), specificity (91%, 88%, 53%), positive predictive value (93%, 94%, 44%), negative predictive value (91%, 70%, 90%) and area under the curve (0.952, 0.885, 0.776). Cut-off values were determined as 57 kPa for malignancy, 124 kPa for invasiveness and 124.5 kPa for high grade. In conclusion, SWE is a useful method in clinical practice for characterizing MCs that can be visualized with USG.

A qualitative and quantitative assessment of simultaneous strain, shear wave, and point shear wave elastography to distinguish malignant and benign breast lesions

BACKGROUND

Ultrasound (US) elastography has become a routine instrument in ultrasonographic diagnosis that measures the consistency and stiffness of tissues.

PURPOSE

To distinguish benign and malignant breast masses using a single US system by comparing the diagnostic parameters of three kinds of breast elastography simultaneously added to B-mode ultrasonography.

MATERIAL AND METHODS

A total of 163 breast lesions in 159 consecutive women who underwent US-guided core needle biopsy were included in this prospective study. Before the biopsy, the lesions were examined with B-mode ultrasonography and strain (SE), shear wave (SWE), and point shear wave (STQ) elastography. The strain ratio was computed and the Tsukuba score determined. The mean elasticity values using SWE and STQ were computed and converted to Young's modulus E (kPa).

RESULTS

All SE, SWE, and STQ parameters showed similar diagnostic performance. The SE score, SE ratio, SWE_mean, SWE_max, STQ_mean, and STQ_max yielded higher specificity than B-mode US alone to differentiate benign and malignant masses. The sensitivity of B-mode US, SWE, and STQ was slightly higher than that of the SE score and SE ratio. The SE score, SE ratio, SWE_mean, SWE_max, STQ_mean, and STQ_max had significantly higher positive predictive value and diagnostic accuracy than B-mode US alone. The area under the curve for each of these elastography methods in differentiating benign and malignant breast lesions was 0.93, 0.93, 0.98, 0.97, 0.98, and 0.96, respectively; P<0.001 for all measurements.

CONCLUSION

SE (ratio and score), SWE, and STQ had higher diagnostic performance individually than B-mode US alone in distinguishing between malignant and benign breast masses.

Elastic Modulus and Elasticity Ratio of Malignant Breast Lesions with Shear Wave Ultrasound Elastography: Variations with Different Region of Interest and Lesion Size

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (E_min), mean (E_mean), maximal (E_max) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest E_min, E_mean and e-ratio values and lowest variability were observed when using the 2 mm ROI. E_max values did not differ between different ROI sizes. Larger lesions had significantly higher E_mean and E_max values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the E_min, E_mean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on E_max values while lesion size has no impact on e-ratio values.

Management of breast lesions seen on US images: dual-model radiomics including shear-wave elastography may match performance of expert radiologists

PURPOSE

To develop a nomogram incorporating B-mode ultrasound (BMUS) and shear-wave elastography (SWE) radiomics to predict malignant status of breast lesions seen on US non-invasively.

METHODS

Data on 278 consecutive patients from Hospital #1 (training cohort) and 123 cases from Hospital #2 (external validation cohort) referred for breast US with subsequent histopathologic analysis between May 2017 and October 2019 were retrospectively collected. Using their BMUS and SWE images, we built a radiomics nomogram to improve radiology workflow for management of breast lesions. The performance of the algorithm was compared with a consensus of three ACR BI-RADS committee experts and four individual radiologists, all of whom interpreted breast US images in clinical practice.

RESULTS

Twelve features from BMUS and three from SWE were selected finally to construct the respective radiomic signature. The nomogram based on the dual-modal US radiomics achieved good diagnostic performance in the training (AUC 0.96; 95% confidence intervals [CI], 0.94-0.98) and the validation set (AUC 0.92; 95% CI, 0.87-0.97). For the 123 test lesions, the algorithm achieved 105 of 123 (85%) accuracy, comparable to the expert consensus (104 of 123 [85%], P =  0.86) and four individual radiologists (93, 99, 95 and 97 of 123, with P value of 0.05, 0.31, 0.10 and 0.18 respectively). Furthermore, the model also performed well in the BI-RADS 4 and 5 categories.

CONCLUSIONS

Performance of a dual-model US radiomics nomogram based on SWE for breast lesion classification may comparable to that of expert radiologists who used ACR BI-RADS guideline.

Diagnostic Accuracy of Four Levels of Manual Compression Applied in Supersonic Shear Wave Elastography of the Breast

PURPOSE

To investigate the diagnostic accuracy of applying four levels of manual pressure in Shear Wave Elastography (SWE) of the breast and to assess inter-rater reliability.

MATERIALS AND METHODS

Single-center prospective preliminary study including patients receiving ultrasound examination of breast lesions as part of routine clinical practice. SWE was performed on 60 breast masses (26 benign and 34 malignant) in 54 patients by a breast fellowship trained radiologist. Stiffness values were compared between benign and malignant masses at four levels of manual compression: none, mild, moderate, and marked. Accuracy of SWE was assessed using receiving operating characteristics analysis at each level. In 18 patients, a second radiologist repeated the SWE acquisitions to evaluate reproducibility. Reproducibility was assessed using intraclass correlation coefficient.

RESULTS

Without compression, we observed no significant difference in stiffness (p > 0.99) between benign and malignant lesions, and SWE demonstrated low accuracy (area under the curve = 0.64). Stiffness was higher in malignant lesions at all levels of compression (p < 0.001). SWE demonstrated good accuracy at all three levels of compression (from area under the curve = 0.71 to 0.84 across Emax and Emean), with high interobserver agreement.

CONCLUSION

This preliminary study suggests that not using compression during SWE for breast lesion characterization offers suboptimal results. On the contrary, application of compression yields high diagnostic performance with good interobserver agreement and, as such, should be included in routine clinical practice.

The current value of quantitative shear wave sonoelastography in parotid gland tumors

Background

The preoperative differentiation between salivary gland tumor entities using computed tomography, magnetic resonance imaging (MRI) and ultrasound (US) is still limited. Biopsies are often regarded as indispensable for properly characterizing these various lesions. The aim of this study was to analyze the value of acoustic radiation force impulse (ARFI) sonoelastography as an US differentiation tool when examining parotid gland (PG) lesions.

Methods

We included 104 patients with PG masses in this study, employing two different US devices using quantitative ARFI-sonoelastography (Siemens Acuson-S3000, n=59; Siemens Acuson-Sequoia, n=45). The ability of sonoelastographic measurements to differentiate between different neoplasms was compared and analyzed for both US machines.

Results

Quantitative shear wave sonoelastography is limited in its ability to reliably differentiate between tumor entities of the PG as a stand-alone parameter. Measurement results were unsystematically distributed and not transferable between the two US devices. A significant differentiation of benign and malignant lesions was not possible with either US machine (S3000: P=0.770, Sequoia: P=0.382). A differentiation between pleomorphic adenomas (PA) and Warthin tumors was only possible with the Acuson S3000 system (P=0.001, Spearman-Rho =0.492, sensitivity 73.9%, specificity 65.0%).

Conclusions

A reliable identification and differentiation of PG tumors as well as clinical treatment decisions cannot be made with the sole use of ARFI-sonoelastography. The results emphasize the device-dependence and high error-proneness of this US technique when examining lesions of the PG.

Stiffness increases with myofibroblast content and collagen density in mesenchymal high grade serous ovarian cancer

Women diagnosed with high-grade serous ovarian cancers (HGSOC) are still likely to exhibit a bad prognosis, particularly when suffering from HGSOC of the Mesenchymal molecular subtype (50% cases). These tumors show a desmoplastic reaction with accumulation of extracellular matrix proteins and high content of cancer-associated fibroblasts. Using patient-derived xenograft mouse models of Mesenchymal and Non-Mesenchymal HGSOC, we show here that HGSOC exhibit distinct stiffness depending on their molecular subtype. Indeed, tumor stiffness strongly correlates with tumor growth in Mesenchymal HGSOC, while Non-Mesenchymal tumors remain soft. Moreover, we observe that tumor stiffening is associated with high stromal content, collagen network remodeling, and MAPK/MEK pathway activation. Furthermore, tumor stiffness accompanies a glycolytic metabolic switch in the epithelial compartment, as expected based on Warburg's effect, but also in stromal cells. This effect is restricted to the central part of stiff Mesenchymal tumors. Indeed, stiff Mesenchymal tumors remain softer at the periphery than at the core, with stromal cells secreting high levels of collagens and showing an OXPHOS metabolism. Thus, our study suggests that tumor stiffness could be at the crossroad of three major processes, i.e. matrix remodeling, MEK activation and stromal metabolic switch that might explain at least in part Mesenchymal HGSOC aggressiveness.

Repeatability of Linear and Nonlinear Elastic Modulus Maps From Repeat Scans in the Breast

Compression elastography allows the precise measurement of large deformations of soft tissue in vivo. From an image sequence showing tissue undergoing large deformation, an inverse problem for both the linear and nonlinear elastic moduli distributions can be solved. As part of a larger clinical study to evaluate nonlinear elastic modulus maps (NEMs) in breast cancer, we evaluate the repeatability of linear and nonlinear modulus maps from repeat measurements. Within the cohort of subjects scanned to date, 20 had repeat scans. These repeated scans were processed to evaluate NEM repeatability. In vivo data were acquired by a custom-built, digitally controlled, uniaxial compression device with force feedback from the pressure-plate. RF-data were acquired using plane-wave imaging, at a frame-rate of 200 Hz, with a ramp-and-hold compressive force of 8N, applied at 8N/sec. A 2D block-matching algorithm was used to obtain sample-level displacement fields which were then tracked at subsample resolution using 2D cross correlation. Linear and nonlinear elasticity parameters in a modified Veronda-Westmann model of tissue elasticity were estimated using an iterative optimization method. For the repeated scans, B-mode images, strain images, and linear and nonlinear elastic modulus maps are measured and compared. Results indicate that when images are acquired in the same region of tissue and sufficiently high strain is used to recover nonlinearity parameters, then the reconstructed modulus maps are consistent.

Novel approaches to needle tracking and visualisation

The accuracy and reliability of ultrasound are still insufficient to guarantee complete and safe nerve block for all patients. Injection of local anaesthetic close to, but not touching, the nerve is key to outcomes, but the exact relationship between the needle tip and nerve epineurium is difficult to evaluate, even with ultrasound. Ultrasound has insufficient resolution, tissues are difficult to discern due to acoustic impedance and needles are more difficult to see with increased angulation. The limitations of ultrasound have shifted the focus of innovation towards bio-markers that help detect needle tip position by utilising the physical properties of tissues, (e.g. pressure, electrical, optics, acoustic and elastic). Although most are at the laboratory stage and results are as yet only available from phantom or cadaver studies, clinical trials are imminent. For example, fine optical fibres placed within the lumen of block needles can measure needle tip pressure. Electrical impedance differentiates between intraneural and perineural needle tip placement. A new tip tracker needle has a piezo element embedded at its distal end that tracks the needle tip in-plane and out-of-plane as a blue/red or green circle depending on its relative location within the beam. Micro-ultrasound at the tip of the needle is in development. Early images using 40MHz in anaesthetised pigs reveal muscle striation, distinct epineurium and 30-40 fascicles > 75 micron in diameter. The next few years will see a technological revolution in tip-tracking technology that has the potential to improve patient safety and, in doing so, change practice.

Effect of Quantitative and Semi-quantitative Elastography Methods for the Management of Borderline Lesions on Ultrasonography

BACKGROUND

Elastography (strain or shear-wave) is a method that estimates tissue stiffness.

INTRODUCTION

The aim of this study is to evaluate the quantitative and semi-quantitative ultrasound elastography methods for the diagnosis of BI-RADS 4a and BI-RADS 3 lesions, which are borderline for biopsy and follow-up.

MATERIALS AND METHODS

175 consecutive women with 193 ultrasound-visible breast lesions were classified on Conventional B-mode Ultrasonography (CUS) according to the BI-RADS scoring system. Quantitative and semiquantitative values from ultrasound elastography in the form of strain Elastography Ratio (SER), shear Wave Elastography (SWE) and Shear Wave Elastography Ratio (SWER) were obtained. The lesions categorized as BI-RADS 4a and BI-RADS 3 on ultrasound were subsequently re-categorized according to the elastography values.

RESULTS

Except for the 13 BI-RADS 2 lesions, the remaining 180 lesions were biopsied. Pathology showed 83 lesions to be benign and 97 to be malignant. The sensitivity and specificity of the CUS were 96.9% and 75.0%, respectively with an accuracy of 86.0%. Cut-off points calculated based on ROC curves were 56.8 kPa for SWE, 3.53 for SWER and 3.81 for SER. When we downgraded BIRADS 4a lesions based on elastography results, the specificity (CUS+SER 96.9%, CUS+SWE 91.7%, and CUS+SWER 90.6%) and the accuracy (CUS+SER 95.3%, CUS+SWE 92.7%, and CUS+SWER 92.2%) were shown to be better than CUS. When we upgraded BI-RADS 3 lesions based on elastography results, the sensitivity of combined sets of SWE (99,0%) and SWER (100,0%) was better than CUS.

CONCLUSION

The rate of false-negative biopsies can be decreased with the combined use of elastography and ultrasonography.

Combination of shear-wave elastography with ultrasonography for detection of breast cancer and reduction of unnecessary biopsies: a systematic review and meta-analysis

Purpose

This study was undertaken to compare the diagnostic performance and biopsy reduction rate of combined shear-wave elastography (SWE) and B-mode ultrasonography (US) versus B-mode US alone for breast lesions and to determine the most discriminatory parameter in SWE.

Methods

A systematic review and meta-analysis were conducted. The resources for the study were obtained from MEDLINE, Embase, Cochrane Library, and KoreaMed on August 17, 2018. The quality of the articles was evaluated using the Scottish Intercollegiate Guidelines Network (SIGN) tool.

Results

Twenty-five articles with 5,147 breast lesions were selected. The meta-analysis showed pooled sensitivities of 0.94 and 0.97 (P=0.087), pooled specificities of 0.85 and 0.61 (P=0.009), and area under the receiver operating characteristic curve (AUC) of 0.96 and 0.96 (P=0.095) for combined SWE and B-mode US versus B-mode US alone. When SWE was combined with B-mode US, the Breast Imaging Reporting and Data System category changed from 4 to 3 in 71.3% of the tests, decreasing the frequency of unnecessary biopsies by 41.1%. All four parameters of SWE (the color grade of lesion stiffness, maximum elasticity, mean elasticity, and color grade of lesion stiffness/homogeneity of the lesion) improved the specificity when they were added to B-mode US. The AUC for each SWE parameter was 0.99, 0.96, 0.96, and 0.93, respectively.

Conclusion

Adding SWE to B-mode US not only provides additional diagnostic information for differentiating between benign and malignant breast lesions, but also decreases the likelihood of unnecessary biopsies.

Physical traits of cancer

The role of the physical microenvironment in tumor development, progression, metastasis, and treatment is gaining appreciation. The emerging multidisciplinary field of the physical sciences of cancer is now embraced by engineers, physicists, cell biologists, developmental biologists, tumor biologists, and oncologists attempting to understand how physical parameters and processes affect cancer progression and treatment. Discoveries in this field are starting to be translated into new therapeutic strategies for cancer. In this Review, we propose four physical traits of tumors that contribute to tumor progression and treatment resistance: (i) elevated solid stresses (compression and tension), (ii) elevated interstitial fluid pressure, (iii) altered material properties (for example, increased tissue stiffness, which historically has been used to detect cancer by palpation), and (iv) altered physical microarchitecture. After defining these physical traits, we discuss their causes, consequences, and how they complement the biological hallmarks of cancer.

Virtual touch imaging quantification shear-wave elastography for breast lesions: the diagnostic value of qualitative and quantitative features

AIM

To investigate the value of the qualitative and quantitative features of Virtual Touch imaging quantification (VTIQ) shear-wave elastography in the characterisation of breast lesions.

MATERIALS AND METHODS

Conventional ultrasound (US) and VTIQ were performed in 148 solid breast lesions in 148 women. During qualitative analysis, patterns of VTIQ were categorised into two patterns, 1 and 2. During quantitative analysis, the mean SWV (SWVmean) and the maximum SWV (SWVmax) of each lesion were used. The sensitivity, specificity, and the areas under the receiver operating characteristic (ROC) curve (Az value) were calculated for conventional US, VTIQ, and combined conventional US and VTIQ.

RESULTS

Malignant lesions were more likely to show VTIQ pattern 2 than the benign lesions (p<0.001). There was no significant difference in the Az values between SWVmean (0.907) and SWVmax (0.902; p=0.572). There was no significant difference in the Az values between the VTIQ pattern (0.884) and SWVmax (p=0.572). The combined conventional US and VTIQ pattern carried a similar Az value (0.949) as compared with the combined conventional US and SWVmax, which yielded an Az value of 0.952 (p=0.683).

CONCLUSION

The combination of either VTIQ pattern or SWVmax and conventional US may be helpful in the characterisation of benign and malignant breast lesions.

Combination of Quantitative Parameters of Shear Wave Elastography and Superb Microvascular Imaging to Evaluate Breast Masses

Objective

This study aimed to evaluate the diagnostic value of combining the quantitative parameters of shear wave elastography (SWE) and superb microvascular imaging (SMI) to breast ultrasound (US) to differentiate between benign and malignant breast masses.

Materials and Methods

A total of 200 pathologically confirmed breast lesions in 192 patients were retrospectively reviewed using breast US with B-mode imaging, SWE, and SMI. Breast masses were assessed based on the breast imaging reporting and data system (BI-RADS) and quantitative parameters using the maximum elasticity (Emax) and ratio (Eratio) in SWE and the vascular index in SMI (SMI_VI). The area under the receiver operating characteristic curve (AUC) value, sensitivity, specificity, accuracy, negative predictive value, and positive predictive value of B-mode alone versus the combination of B-mode US with SWE or SMI of both parameters in differentiating between benign and malignant breast masses was compared, respectively. Hypothetical performances of selective downgrading of BI-RADS category 4a (set 1) and both upgrading of category 3 and downgrading of category 4a (set 2) were calculated.

Results

Emax with a cutoff value of 86.45 kPa had the highest AUC value compared to Eratio of 3.57 or SMI_VI of 3.35%. In set 1, the combination of B-mode with Emax or SMI_VI had a significantly higher AUC value (0.829 and 0.778, respectively) than B-mode alone (0.719) (p < 0.001 and p = 0.047, respectively). B-mode US with the addition of Emax, Eratio, and SMI_VI had the best diagnostic performance of AUC value (0.849). The accuracy and specificity increased significantly from 68.0% to 84.0% (p < 0.001) and from 46.1% to 79.1% (p < 0.001), respectively, and the sensitivity decreased from 97.6% to 90.6% without statistical loss (p = 0.199).

Conclusion

Combining all quantitative values of SWE and SMI with B-mode US improved the diagnostic performance in differentiating between benign and malignant breast lesions.

Diagnostic utility of strain and shear wave ultrasound elastography in differentiation of benign and malignant solid breast lesions

Background

The purpose of our study was to assess diagnostic performance and comparison of strain and shear wave ultrasound elastography for differentiation of benign and malignant breast lesions compared to histopathological diagnosis as a reference standard. Our single center study involved 100 female patients with 132 solid breast masses. All patients underwent supervision of medical history, clinical examination, conventional B-mode ultrasound which was evaluated according to the BIRADS (Breast Imaging Reporting and Data System), and strain and shear wave ultrasound elastography. Strain ratio for strain elastography, mean elasticity value, and stiff ratio for shear wave elastography were calculated. All breast lesions were biopsied. Comparison of the elastography results with the histopathological diagnoses was done.

Results

There was no statistically significant difference as regard the AUCs for calculated values of strain and shear wave ultrasound elastography (strain ratio, 0.916; mean elasticity, 0.884; and stiff ratio, 0.872; P > 0.05). The AUCs for the combined use of B-mode US and elastography techniques were improved as the following: B-mode + strain, 0.920; B-mode + shear wave 0.952 with a significant P value < 0.001. Higher diagnostic accuracy was noted with the combination of strain and shear wave elastography than each single elastographic modality (P = 0.02).

Conclusions

Ultrasound elastography of breast masses is a non-invasive procedure with high sensitivity. Strain and shear wave elastography had almost similar diagnostic performance and displayed higher diagnostic performance if combined with B-mode ultrasound which helps in decreasing the number of unneeded breast biopsies.

Individualized-thresholding Shear Wave Elastography combined with clinical factors improves specificity in discriminating breast masses

PURPOSE

To investigate the diagnostic role of new metrics, defined as individualized-thresholding of Shear Wave Elastography (SWE) parameters, in association with clinical factors (such as age, mammographic density, lesion size and depth) and the BI-RADS features in differentiating benign from malignant breast lesions.

METHODS

Of 644 consecutive patients (median age, 55 years), prospectively referred for evaluation, 659 ultrasound detected breast lesions underwent SWE measurements. Multivariable logistic regression analysis was used to estimate the probability of malignancy. The area under the curve (AUC), optimal cutoff value, and the corresponding sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were determined.

RESULTS

265 of 659 (40.2%) masses were malignant. Using two E_mean cutoffs, 69.6 kPa for large superficial lesions (size >10 mm, depth ≤5 mm) and 39.2 kPa for the rest, the overall specificity, sensitivity, PPV and NPV were 92.6%, 86.8%, 88.8% and 91.3%, respectively. Combining multiple factors, including E_mean with two cutoffs, age and BI-RADS, the new ROC curve based on the malignancy probability calculation showed the highest AUC (0.954, 95% CI: 0.938-0.969). Using the optimal probability threshold of 0.514, the corresponding specificity, sensitivity, PPV and NPV were 92.9%, 89.1%, 89.4% and 92.7%, respectively.

CONCLUSIONS

The false-positive rate can be significantly reduced when applying two E_mean cutoffs based on lesion size and depth. Moreover, the combination of age, E_mean with two cutoffs and BI-RADS can further reduce the false negatives and false positives. Overall, this multifactorial analysis improves the specificity of ultrasound while maintaining a high sensitivity.

Accuracy of tumor size measurement on shear wave elastography (SWE): Correlation with histopathologic factors of invasive breast cancer

The aim of this study is to investigate the accuracy of tumor size assessment by shear wave elastography (SWE) in invasive breast cancer and also evaluated histopathologic factors influencing the accuracy.A total of 102 lesions of 102 women with breast cancers of which the size was 3 cm or smaller were included and retrospectively analyzed. Tumor size on B-mode ultrasound (US) and SWE were recorded and compared with the pathologic tumor size. If tumor size measurements compared to pathological size were within ±3 mm, they were considered as accurate. The relationship between the accuracy and histopathologic characteristics were evaluated.The mean pathologic tumor size was 16.60 ± 6.12 mm. Tumor sizes on SWE were significantly different from pathologic sizes (18.00 ± 6.71 mm, P < 0.001). The accuracy of SWE (69.6%) was lower than that by B-mode US (74.5%). There was more size overestimation than underestimation (23.5% vs 6.9%) using SWE. Conversely, there was more size underestimation than overestimation (18.6% vs 6.9%) using B-mode US. The accuracy of SWE was associated with ER positivity (P = .004), PR positivity (P = .02), molecular subtype (P = .02), and histologic grade (P = .03). In the multivariate analysis, ER positivity (P = .002) and molecular subtype (P = .027) significantly influenced the accuracy of tumor size measurement by SWE.In conclusion, the accuracy of the tumor size measured with SWE was lower than that measured with B-mode US and SWE tends to overestimate the size. ER positivity and molecular subtype are significantly associated with the accuracy of SWE in tumor size assessment.

Differentiating solid breast masses: comparison of the diagnostic efficacy of shear wave elastography and magnetic resonance imaging

OBJECTIVES

Shear wave elastography (SWE) quantitatively determines the nature of the breast lesions. Few previous studies have compared the diagnostic value of this modality with other imaging techniques. The present study aimed to compare the diagnostic value of SWE with that of magnetic resonance imaging (MRI) in detecting the nature of the breast masses.

METHODS

In this cross-sectional study, 80 patients with breast lumps who had Breast Imaging Reporting and Data System (BI-RADS) score of three or higher based on mammography and/or screening ultrasonography, underwent 3D SWE and MRI. The lesions were classified according to MRI BI-RADS scoring; Mean elasticity (Emean) and elasticity ratio (Eratio) for each lesion were also determined by SWE. The results of these two modalities were compared with histopathologic diagnosis as the gold standard method; diagnostic value and diagnostic agreement were then calculated.

RESULTS

Of the masses, 46.2% were histopathologically proven to be malignant. The Emean for benign and malignant masses was 34.04 ± 19.51 kPa and 161.92 ± 58.14 kPa, respectively. Both modalities had diagnostic agreement with histopathologic results (p<0.001). Kappa coefficient was 0.87 for SWE and 0.42 for MRI. The sensitivity of both methods was 94.59% (95% CI: 81.81-99.34), while the specificity and accuracy were 48.84% [95% CI: 33.31-64.54] and 70.0% [95% CI: 58.72-79.74] for MRI, and 93.02% [95% CI: 80.94-98.54] and 93.75% [95% CI: 86.01-97.94] for SWE.

CONCLUSIONS

SWE has better diagnostic value in terms of determining the nature of the breast masses. SWE can increase the diagnostic function of differentiating benign masses from malignant ones.