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

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.

Accuracy of transvaginal sonoelastography for differential diagnosis between malignant and benign cervical lesions: A systematic review and meta-analysis

BACKGROUND

To evaluate the performance of transvaginal sonoelastography (TVSE) for differential diagnosis between malignant and benign cervical lesions using a meta-analysis.

METHODS

An independent literature search was conducted on the English medical database, including PubMed, Embase and Medline, Cochrane Library, Web of Science, and OVID. The diagnostic accuracy of TVSE was compared with that of histopathology, which is the gold reference standard for diagnosis. The accuracy of TVSE was assessed by calculating the pooled sensitivity, specificity, diagnostic odds ratio, and area under the curve (AUC). The imaging mechanisms, assessment methods, and QUADAS scores were assessed with a meta-regression analysis. A Deeks funnel plot was performed for evaluating publication bias.

RESULTS

Six eligible studies reported a total sample of 615 cervical lesions (415 cancers, 200 benign lesions). TVSE showed a pooled diagnostic odds ratio of 21.42 (95% CI 13.65-33.61), sensitivity of 0.87 (95% CI 0.84-0.90), specificity of 0.79 (95% CI 0.72-0.84), and an AUC of 0.892 (Q* = 0.822). The results of the meta-regression analysis showed that the imaging mechanism (P = .253), the assessment method (P = .279), or QUADAS score (P = .205) did not affect the study heterogeneity.

CONCLUSION

TVSE has a relatively high and satisfactory value for differential diagnosis between malignant and benign cervical lesions. The diagnostic performance of strain elastography and shear wave elastography were similar and good. However, to accommodate heterogeneity and publication bias, high-quality studies are required to further comparative effectiveness analyses to verify the efficacy of ultrasound detection.

Audit of eliminating biopsy for presumed fibroadenomas with benign ultrasound greyscale and shear-wave elastography findings in women aged 25-39 years

AIM

To assess the safety of a policy of not biopsying presumed fibroadenomas with benign ultrasound and shear-wave elastography findings in women aged 25-39 years.

MATERIALS AND METHODS

Patients aged 25-39 years were included after attending a one-stop clinic before 01/05/2019 where clinical and ultrasound greyscale findings suggested a benign mass and shear-wave elastography showed a mean stiffness of <50 kPa. Such patients were reassured and discharged without biopsy or follow-up. The archived ultrasound images were reviewed subsequently by a second radiologist who could recall patients for biopsy if he deemed the imaging findings to be not definitively benign. Local and national electronic records were reviewed to identify whether these patients later re-presented with breast problems.

RESULTS

Seventy-six women with a mean age of 33 years were included. The minimum follow-up was 12 months and the mean follow-up was 2 years. Three (4%) of patients were recalled after review of the ultrasound images by a second radiologist. Five (7%) patients re-presented with the same lump. Three (4%) patients re-presented with a different benign problem. Two patients presented with breast cancer in the ipsilateral breast but at a different location from the assessed benign lesion.

CONCLUSION

Early audit results of a policy of not biopsying or following up clinically benign masses with benign ultrasound greyscale appearances and shear wave stiffness <50 kPa in women aged 25-39 years suggest that this approach may be safe and acceptable.

Grayscale Ultrasound Radiomic Features and Shear-Wave Elastography Radiomic Features in Benign and Malignant Breast Masses

PURPOSE

 To identify and compare diagnostic performance of radiomic features between grayscale ultrasound (US) and shear-wave elastography (SWE) in breast masses.

MATERIALS AND METHODS

 We retrospectively collected 328 pathologically confirmed breast masses in 296 women who underwent grayscale US and SWE before biopsy or surgery. A representative SWE image of the mass displayed with a grayscale image in split-screen mode was selected. An ROI was delineated around the mass boundary on the grayscale image and copied and pasted to the SWE image by a dedicated breast radiologist for lesion segmentation. A total of 730 candidate radiomic features including first-order statistics and textural and wavelet features were extracted from each image. LASSO regression was used for data dimension reduction and feature selection. Univariate and multivariate logistic regression was performed to identify independent radiomic features, differentiating between benign and malignant masses with calculation of the AUC.

RESULTS

 Of 328 breast masses, 205 (62.5 %) were benign and 123 (37.5 %) were malignant. Following radiomic feature selection, 22 features from grayscale and 6 features from SWE remained. On univariate analysis, all 6 SWE radiomic features (P < 0.0001) and 21 of 22 grayscale radiomic features (P < 0.03) were significantly different between benign and malignant masses. After multivariate analysis, three grayscale radiomic features and two SWE radiomic features were independently associated with malignant breast masses. The AUC was 0.929 for grayscale US and 0.992 for SWE (P < 0.001).

CONCLUSION

 US radiomic features may have the potential to improve diagnostic performance for breast masses, but further investigation of independent and larger datasets is needed.

Diagnostic performance of shear wave elastography in discriminating malignant and benign breast lesions : Our experience with QelaXtoTM software

STUDY AIMS

We sought to evaluate the diagnostic performance of quantitative elastography (shear wave elastography) and to establish the optimal cutoff value to differentiate malignant and benign breast lesions using QelaXtoTM software.

METHODS

We conducted a retrospective observational study of adult women with suspicious breast lesions (BIRADS 3, 4 or 5) who underwent programmed ultrasound-guided core biopsies. Breast lesions were assessed using quantitative elastography combined with B-mode ultrasound. Histopathology was used as reference standard. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were estimated, and a ROC curve analysis was conducted. Three elastography cutoff values were considered: 36, 50 and 80 kPa.

RESULTS

We included 143 women (mean age of 56 years) with a total of 145 breast lesions: 68 benign tumors (47.26%) and 77 malignancies (52.74%). Mean elasticity measurements of benign and malignant lesions were significantly different (24.6 kPa, SD 28.47, vs. 101.49 kPa, SD 47.38, [Formula: see text]). Using the 50 kPa cutoff, elastography showed a global sensitivity of 87% to discriminate malignant lesions (AUC = 0.897). Moreover, sensitivity was 90.7% when lesions were located 5-40 mm below the skin surface (optimal elastographic field of view). Our false positive rate was 17.65%, comprised mainly of fibroepithelial neoplasms, fibroadenomas and fibrosis.

CONCLUSIONS

Quantitative elastography can differentiate malignant and benign breast lesions with acceptable to excellent performance. In our sample, the QelaXtoTM software showed a lower optimal cutoff than other ultrasound systems.

Shear-wave elastography of the testicle: potential role of the stiffness value in various common testicular diseases

AIM

To assess the value and efficacy of real-time shear-wave elastography (SWE) of normal testicular parenchyma and various common testicular diseases in clinical practice.

MATERIALS AND METHODS

SWE was undertaken in 338 patients (mean age: 43.2±17.2 years, range 17-78 years) comprising normal testicles (n = 358), testicular microlithiasis (n = 40), and various testicular diseases (n = 208) and the stiffness was recorded. The final diagnosis was correlated with the clinical context, long-term follow-up, or histopathology. Statistical evaluation was performed to provide a stiffness threshold for pathological diagnosis.

RESULTS

The mean size of testicular lesions was 2.6±1.5 cm (range: 10-42 mm). The mean Young's modulus value for normal testis was recorded at 4.55±2.54 kPa. Whatever the stage of microlithiasis, a higher statistically significant stiffness value was recorded. For acute orchitis, the mean stiffness value was slightly higher, but not statistically significantly. The testicular tumoural processes presented a median stiffness value of 21.02 kPa with a cut-off of 16.1 kPa. Fibrosis presented the highest median stiffness value of 30.03 kPa with a cut-off of 26.3 kPa. By analysing the distribution of the different pathological groups, the difference was statistically significant between fibrosis and tumoural processes (p = 0.001).

CONCLUSION

SWE is a feasible technique in the exploration of the testicular parenchyma. SWE values can be used to differentiate testicular fibrosis from a tumoural process with confidence.

Added Value of Quantitative Ultrasound and Machine Learning in BI-RADS 4-5 Assessment of Solid Breast Lesions

The purpose of this study was to evaluate various combinations of 13 features based on shear wave elasticity (SWE), statistical and spectral backscatter properties of tissues, along with the Breast Imaging Reporting and Data System (BI-RADS), for classification of solid breast lesions at ultrasonography by means of random forests. One hundred and three women with 103 suspicious solid breast lesions (BI-RADS categories 4-5) were enrolled. Before biopsy, additional SWE images and a cine sequence of ultrasound images were obtained. The contours of lesions were delineated, and parametric maps of the homodyned-K distribution were computed on three regions: intra-tumoral, supra-tumoral and infra-tumoral zones. Maximum elasticity and total attenuation coefficient were also extracted. Random forests yielded receiver operating characteristic (ROC) curves for various combinations of features. Adding BI-RADS category improved the classification performance of other features. The best result was an area under the ROC curve of 0.97, with 75.9% specificity at 98% sensitivity.

2-D Shear Wave Elastography for Focal Lesions in Liver Phantoms: Effects of Background Stiffness, Depth and Size of Focal Lesions on Stiffness Measurement

The aim of this study was to determine the factors influencing stiffness and conspicuity of focal lesions in deep organs by focusing on target properties using 2-D shear wave elastography (SWE). Two normal (4 ± 1 kPa) and cirrhotic (16 ± 2 kPa) liver-mimicking phantoms with spherical inclusions (23 ± 3 kPa) were used. Inclusions of three sizes (20, 15 and 10 mm in diameter) were arranged in a row at depths of 3, 5 and 7 cm. Two observers acquired quantitative stiffness values and a qualitative five-grade morphologic score at each inclusion using SWE. The coefficients of variation (CVs) of stiffness were calculated to assess measurement reliability. The generalized estimating equation was used to identify whether stiffness, CV and morphologic score were independent of background stiffness, depth and size of inclusions and observer. In the quantitative assessment, stiffness of the inclusion and CV were dependent on the type of phantom and depth of inclusion (p < 0.001). There were no significant differences in stiffness and CV according to the observer. Morphologic score differed significantly only in the size of the inclusion (p < 0.001). When the depth of the inclusion was 7 cm, the stiffness was the highest, and the 10 mm-sized inclusions had lower morphologic scores than the other inclusions (all p values < 0.001). In conclusion, 2-D SWE assessment of focal lesions could be affected by background stiffness and depth of focal lesions, and may be limited in evaluating focal hepatic lesions.

Targeting Tumor Microenvironment by Small-Molecule Inhibitors

The tumor microenvironment (TME) is a hypoxic, acidic, and immune/inflammatory cell–enriched milieu that plays crucial roles in tumor development, growth, progression, and therapy resistance. Targeting TME is an attractive strategy for the treatment of solid tumors. Conventional cancer chemotherapies are mostly designed to directly kill cancer cells, and the effectiveness is always compromised by their penetration and accessibility to cancer cells. Small-molecule inhibitors, which exhibit good penetration and accessibility, are widely studied, and many of them have been successfully applied in clinics for cancer treatment. As TME is more penetrable and accessible than tumor cells, a lot of efforts have recently been made to generate small-molecule inhibitors that specifically target TME or the components of TME or develop special drug-delivery systems that release the cytotoxic drugs specifically in TME. In this review, we briefly summarize the recent advances of small-molecule inhibitors that target TME for the tumor treatment.

•

Tumor microenvironment (TME) is an indispensable part of tumor and is an important therapeutic target.

•

TME is more penetrable and accessible than tumor cell area.

•

Small-molecule inhibitors that target TME are very promising.

•

The target efficiency can be improved by specific deliver and release systems.

Conventional US and 2-D Shear Wave Elastography of Virtual Touch Tissue Imaging Quantification: Correlation with Immunohistochemical Subtypes of Breast Cancer

Our study aimed to investigate the correlation of the imaging features obtained using conventional ultrasound (US) and elastography (conventional strain elastography of elasticity imaging [EI], virtual touch tissue imaging [VTI] and 2-D shear wave elastography [2-D-SWE] of virtual touch tissue imaging quantification [VTIQ]) with the clinicopathologic features and immunohistochemical (IHC) subtypes of breast cancer. The sample consisted of images from 202 patients with 206 breast lesions that were confirmed as breast cancers. Lesions with HER2 overexpression (luminal B HER2+ or HER2+) had higher mean shear wave velocity (SWV) values than the others. Older patients, lower histologic grade, no lymphovascular invasion and no lymph node metastasis were associated with luminal A (p < 0.001). There were significant differences in SWV values, histologic grade and lymph node status among the different pathologic types. This association may allow the use of 2-D-SWE in the pre-operative prediction of tumor characteristics and biologic activity, which may determine the prognosis in a non-invasive manner.

Utility of 2D-ultrasound in pelvic floor muscle contraction and bladder neck mobility assessment in women with urinary incontinence

INTRODUCTION AND HYPOTHESIS

Assessment of pelvic floor muscle (PFM) contraction and bladder neck (BN) mobility in women with stress urinary incontinence (SUI) is essentially clinical. Ultrasound is increasingly used as a method for evaluating BN mobility and PFM contraction, but has not been standardized. The aim of this study was to review ultrasound technics and parameters that might be relevant for PFM contraction and BN mobility assessment in women with urinary incontinence (UI).

METHODS

We reviewed articles indexed in the MEDLINE database between 1988 and 2018 and selected articles which had a cohort of women with UI who had undergone functional 2D-ultrasound evaluation of PFM or BN mobility.

RESULTS

Transperineal ultrasound provides a panoramic view of the pelvic organs without modifying the anatomical relationship between the urethra and surrounding structural landmarks. One of the measurements used to assess urethral mobility is bladder neck descent (BND), which has been shown to be extremely reliable. Measuring the anteroposterior diameter (APD) of the urogenital levator hiatus can also reliably quantify PFM contraction in women. The more recently developed technique of elastography could be an additional useful non-invasive method for measuring periurethral striated muscle stiffness.

CONCLUSIONS

Several ultrasound parameters such as BND, anorectal angle displacement and periurethral stiffness as measured by elastography are relevant for investigating UI in women undertaking pelvic floor muscle training. Our hypothesis is that these ultrasound parameters can be correlated with urinary symptoms and clinical contraction assessment. They need to be validated for clinical use.

Simultaneous comparison between strain and shear wave elastography of breast masses for the differentiation of benign and malignant lesions by qualitative and quantitative assessments

PURPOSE

To compare the addition of diagnostic strain elastography (SE) and shear wave elastography (SWE) values to the conventional B-mode ultrasonography in differentiating between benign and malignant breast masses by qualitative and quantitative assessments.

MATERIALS AND METHODS

B-mode ultrasound, SE, and SWE were simultaneously performed using one ultrasound system in 148 breast masses; 88 of them were malignant. The breast imaging reporting and data system category in the B-mode, Tsukuba score (SE_Tsu), Fat-Lesion-Ratio (SE_FLR) in SE, and five-point color assessment (SWE_col) and elasticity values (SWE_ela) in SWE were assessed. The results were compared using the area under the receiver-operating characteristic curve (AUC).

RESULT

The AUC for B-mode and each elastography were similar (B-mode, 0.889; SE_Tsu, 0.885; SE_FLR, 0.875; SWE_col, 0.881; SWE_ela, 0.885; P > 0.05). The combined sets between B-mode and either of the elastography technique showed good diagnostic performance (B-mode + SE_Tsu, 0.903; B-mode + SE_FLR, 0.909; B-mode + SWE_col, 0.919; B-mode + SWE_ela, 0.914). B-mode + SWE_col and B-mode + SWE_ela showed a higher AUC than B-mode alone (P = 0.026 and 0.029), and B-mode + SE_Tsu and B-mode + SE_FLR showed comparable AUC to B-mode alone (P = 0.196 and 0.085). There was no significant difference between qualitative and quantitative assessments for the combined sets of B-mode and elastography (P > 0.05).

CONCLUSION

The addition of both SE and SWE to B-mode ultrasound improved the diagnostic performance with increased AUC, and especially SWE was more useful than SE, and no significant difference was found between qualitative and quantitative assessments.

Use of ultrasound combined with magnetic resonance imaging for diagnosis of breast masses and fibroids

Objective

To investigate the clinical value of ultrasound plus magnetic resonance imaging (MRI) for the diagnosis of breast masses and fibroids.

Methods

Clinical data for 357 patients with breast masses diagnosed at our hospital were analyzed retrospectively. The diagnostic performances were compared between 243 patients who underwent routine ultrasound examinations (control group) and 114 patients who underwent routine ultrasound plus MRI (test group).

Results

The overall accordance rates of routine ultrasound and routine ultrasound plus MRI for the diagnosis of breast masses, based on postoperative pathological diagnoses, were 70.78% (172/243) and 90.35% (103/114). The addition of MRI significantly improved the overall diagnostic performance of routine ultrasound for breast masses. The diagnostic accordance rate of routine ultrasound for the diagnosis of breast fibroids (fibroadenomas) was 74.12% (63/85 cases) compared with 93.94% (31/33 cases) for routine ultrasound plus MRI. The diagnostic performance of routine ultrasound plus MRI was therefore also significantly higher than routine ultrasound alone for diagnosing breast fibroids.

Conclusions

Routine ultrasound plus MRI can greatly improve the diagnostic accordance rates for breast masses and fibroadenomas.

Breast sonoelastography: Now and in the future

PURPOSE

The purpose of this study was to identify practice trends and opinions concerning breast sonoelastography in two different health care systems, one in Europe (France) and the other in North America (Province of Québec/Canada).

MATERIALS AND METHODS

We distributed an 11-item online survey among French and Canadian breast radiologists. The survey comprised of four sections: (i) personal practice characteristics, (ii) breast sonoelastography usage in daily practice and evaluation of its usefulness, (iii) limitations and roles of sonoelastogrpahy in their clinical practice, and (iv) types of elastographic technique and interpretation.

RESULTS

We found that sonoelastography of the breast appears unpopular among Canadian radiologists, and poorly credible among French radiologists, who perceive it as an unreliable technique. To date, its real impact in clinical practice remains uncertain.

CONCLUSION

Continued learning and awareness of the indications, advantages and limitations of breast sonoelastography may motivate breast radiologists to adopt its use.

Diagnostic performance of qualitative and quantitative shear wave elastography in differentiating malignant from benign breast masses, and association with the histological prognostic factors

Background

To determine the diagnostic performance of qualitative and quantitative shear wave elastography (SWE) and the optimal cutoff values of the quantitative SWE parameters in differentiating malignant from benign breast masses, and to evaluate the association between the quantitative SWE parameters and histological prognostic factors.

Methods

A gray scale ultrasound and SWE were prospectively performed on a total of 244 breast masses (148 benign, and 96 malignant) in 228 consecutive patients before an ultrasound-guided needle biopsy. The qualitative SWE and quantitative SWE parameters (the mean elasticity, maximum elasticity, and elasticity ratio) were measured in each mass. The diagnostic performance of SWE and the optimal cutoff values of the quantitative SWE parameters were obtained. An association analysis of the parameters and histological prognostic factors was performed.

Results

The malignant masses had a more heterogeneous pattern on the qualitative SWE than benign masses (P<0.001). The quantitative SWE parameters of the malignant masses were higher than those of the benign masses (P<0.001); the mean elasticity, maximum elasticity, and elasticity ratio of the benign masses were 19.73 kPa, 23.98 kPa, and 2.78, respectively; and the mean elasticity, maximum elasticity, and elasticity ratio of the malignant masses were 88.13 kPa, 98.48 kPa, and 10.64, respectively. The optimal cutoff value of the mean elasticity was 30 kPa, of the maximum elasticity was 36 kPa, and of the elasticity ratio was 4.5. The maximum elasticity had the highest AUC. Combining the three SWE parameters to differentiate between the malignant and benign masses increased the negative predictive value (NPV), which correctly downgraded 72.73% of BI-RADS category 4A masses to BI-RADS category 3. No statistically significant association was found between the quantitative SWE parameters and the tumor grading, tumor types, axillary lymph node statuses, or molecular subtypes of the breast cancers (P>0.05).

Conclusions

The qualitative and quantitative SWE provided good diagnostic performance in differentiating malignant and benign masses. The maximum elasticity of the quantitative SWE parameters had the best diagnostic performance. Adding the three combined quantitative SWE parameters to the BI-RADS category 4A masses potentially downgraded them to BI-RADS category 3 and avoided unnecessary biopsies. No statistically significant association was found between the quantitative SWE parameters and the histological prognostic factors.

Utilizing size-based thresholds of stiffness gradient to reclassify BI-RADS category 3-4b lesions increases diagnostic performance

AIM

To investigate the role of utilizing size-based thresholds of stiffness gradient in diagnosing solid breast lesions and optimizing original Breast Imaging-Reporting And Data System (BI-RADS) classifications.

MATERIALS AND METHODS

Two-hundred and twenty-seven consecutive women underwent shear-wave elastography (SWE) before ultrasound-guided biopsy, and 234 solid breast lesions categorized as BI-RADS 3-5 were analysed. Receiver operating characteristic curve analysis was performed based on histopathology. Diagnostic performance among SWE, BI-RADS, and their combination were compared.

RESULTS

The stiffness gradient correlated with the standard deviation of elasticity (SD, r=0.90), and with Tozaki's pattern classification (r=0.64). The area under the receiver operating characteristic curves (AUC) for stiffness gradient (0.939) outperformed SD (0.897) or colour pattern (0.852). Due to significant association with lesion size (r=0.394, p<0.001), stiffness gradient's size-based thresholds (lesions >15 mm: 82.5 kPa; lesions ≤15 mm: 51.1 kPa) were established to reclassify BI-RADS 3-4b lesions. Upgrading category 3 lesions (over the corresponding cut-off value, 3 to 4a) and downgrading categories 4a-4b lesions (less than or equal to the corresponding cut-off value, 4b to 4a, 4a to 3), yielded significant improvement in specificity (90.28% versus 77.78%, p<0.001) and AUC (0.948 versus 0.926, p=0.035) than BI-RADS alone. No significant loss emerged in the sensitivity (88.89% versus 91.11%, p=0.500).

CONCLUSION

Stiffness gradient exhibited better discriminatory ability than SD or four-colour pattern classification in determining solid breast lesions and applying its size-specific thresholds to categorize BI-RADS 3-4b lesions could improve diagnostic performance.

Benign lesion evaluation: Factors causing the "stiff rim" sign in breast tissues using shear-wave elastography

OBJECTIVE:

To investigate the factors causing the "stiff rim" sign in breast lesions using shear-wave elastography.

METHODS:

A total of 907 patients with 907 lesions were included retrospectively in this study. Traditional ultrasound and shear-wave elastography imaging were both performed. Patients age, maximum diameter, depth, distance, echogenicity, shape, boundary, margin, internal components, CDFI, calcification, echogenicity attenuation and longitudinal growth of lesions were observed and calculated by both univariate and multivariate analyses.

RESULTS:

Univariate analyses indicated that the age, depth, shape, margin, internal components, CDFI, calcification and pathology showed significant difference between the benign lesions with and without a "stiff rim", whereas there was no correlation of "stiff rim" with maximum diameter, distance, boundary, echogenicity, echo attenuation and longitudinal growth of the lesions. Multivariate analysis expressed that CDFI, margin, internal components, depth and age were significantly associated with the "stiff rim" sign in breast benign lesions, whereas there was no correlation with the pathology, shape or calcification of the lesions.

CONCLUSIONS:

The "stiff rim" sign can be helpful for differentiation between benign and malignant lesions. Older patients with a "stiff rim" sign whose benign masses are deep, poorly defined, heterogeneous and have a positive CDFI should be examined more closely to avoid unnecessary false-positives.

ADVANCES IN KNOWLEDGE:

The "stiff rim" sign can be helpful for differentiation between benign and malignant lesions. Positive CDFI, poorly defined margin, heterogeneous internal components, deep depth and older age were significantly associated with the "stiff rim" sign in benign breast lesions.

Cellular shear stiffness reflects progression of arsenic-induced transformation during G1

Cancer cells consistently exhibit decreased stiffness; however, the onset and progression of this change have not been characterized. To study the development of cell stiffness changes, we evaluated the shear stiffness of populations of cells during transformation to a carcinogenic state. Bronchial epithelial cells were exposed to sodium arsenite to initiate early stages of transformation. Exposed cells were cultured in soft agar to further transformation and select for clonal populations exhibiting anchorage-independent growth. Shear stiffness of various cell populations in G1 was assessed using a novel non-invasive assay that applies shear stress with fluid flow and evaluates nanoscale deformation using quantitative phase imaging (QPI). Arsenic-treated cells exhibited reduced stiffness relative to control cells, while arsenic clonal lines, selected by growth in soft agar, were found to have reduced stiffness relative to control clonal lines, which were cultured in soft agar but did not receive arsenic treatment. The relative standard deviation (RSD) of the stiffness of Arsenic clones was reduced compared with control clones, as well as to the arsenic-exposed cell population. Cell stiffness at the population level exhibits potential to be a novel and sensitive framework for identifying the development of cancerous cells.

Identification of pathological complete response after neoadjuvant chemotherapy for breast cancer: comparison of greyscale ultrasound, shear wave elastography, and MRI

AIM

To assess the value of post-treatment shear-wave elastography (SWE) parameters (maximum stiffness [Emax], mean stiffness [Emean], and standard deviation [SD]) compared to greyscale ultrasonography (US) and magnetic resonance imaging (MRI) in identifying pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) in breast cancer.

MATERIALS AND METHODS

In a prospective cohort study, 80 patients receiving NACT for breast cancer underwent baseline and post-treatment US, SWE, and MRI examinations. Four SWE images in two orthogonal planes were obtained. Maximum greyscale US diameter and maximum diameter of lesion enhancement on MRI were measured. Percentage reductions between baseline and post-treatment scans were calculated for MRI and greyscale US diameter, and Emean, Emax, and SD. The percentage reduction in Emean and US diameter were also analysed as a combination. Analysis was undertaken using receiver operating characteristic (ROC) curves and the chi-squared test.

RESULTS

pCR occurred in 21 of 80 (26%) women. The area under the ROC curve (AUC) for pCR of percentage reductions in Emean, Emax, SD, and greyscale US diameter were 0.89, 0.85, 0.75, and 0.86, respectively. The combination of percentage reductions in Emean and greyscale ultrasound diameter yielded an AUC of 0.92, which is similar to the AUC for MRI of 0.96 (p=0.28).

CONCLUSIONS

SWE combined with greyscale US shows promise for end-of-treatment identification of response to NACT in women with breast cancer, with accuracies similar to breast MRI. This technique could be used to inform surgical decision-making after NACT.

Pre-operative stromal stiffness measured by shear wave elastography is independently associated with breast cancer-specific survival

INTRODUCTION

With the increased use of neoadjuvant therapy for breast cancer, there is a need for pre-operative prediction of prognosis. We aimed to assess the prognostic value of tumour stiffness measured by ultrasound shear wave elastography (SWE).

METHODS

A consecutive cohort of patients with invasive breast cancer underwent breast ultrasound (US) including SWE. The following were recorded prospectively: US diameter, stiffness at SWE, presentation source, core biopsy grade, oestrogen receptor (ER) status and pre-operative nodal status. Breast cancer-specific survival (BCSS) was analysed with regard to US size and stiffness, tumour grade on core biopsy, ER status, presentation mode and pre-operative nodal status. Analysis used Cox proportional hazards regression.

RESULTS

Of the 520 patients, 42 breast cancer and 53 non-breast cancer deaths were recorded at mean follow-up of 5.4 years. Hazard ratios (HR) for tertiles of stiffness were 1, 4.8 and 8.1 (P = 0.0001). HR for 2 groups based on US size < or ≥ 20 mm were 1 and 5.1 (P < 0.0001). HR for each unit increase in tumour grade on core biopsy was 3.9 (P < 0.0001). The HR for ER positivity compared to ER negativity was 0.21 (P < 0.001). BCSS was also associated with presentation mode and pre-operative nodal status. In a multivariable model, stiffness, US size and ER status were independently associated with BCSS.

CONCLUSION

Multiple pre-operative factors including stromal stiffness at SWE have independent prognostic significance. A larger dataset with longer follow-up could be used in the future to construct a pre-operative prognostic model to guide treatment decisions.

Diagnostic value of PD-1 mRNA expression combined with breast ultrasound in breast cancer patients

Introduction

This study explored the value of measuring programmed death 1 (PD-1) in peripheral blood, combined with breast ultrasound using the Breast Imaging Reporting and Data System (BI-RADS) classification, for differentiation between benign and malignant breast tumors.

Materials and methods

We enrolled 113 patients with breast cancer and 66 patients with benign breast tumors who were admitted to Hangzhou First People’s Hospital from September 2014 to August 2017. The mRNA level of PD-1 was detected by quantitative real-time polymerase chain reaction.

Results

The mRNA levels of PD-1 were significantly higher in the peripheral blood of patients with breast cancer than those in patients with benign breast tumors. The diagnostic sensitivity of PD-1 mRNA expression was 0.805, the specificity was 0.788, and the area under the curve (AUC) was 0.848 (P < 0.001); the sensitivity of breast ultrasound-based BI-RADS classification was 0.752, the specificity was 0.909, and the AUC was 0.906 (P < 0.001); and the combined sensitivity, specificity, and AUC of the two assays were 0.920, 0.879, and 0.938, respectively (P < 0.001). Progesterone receptor-positive breast cancer patients exhibited high levels of PD-1 expression (P < 0.001).

Conclusion

This study suggests that the measurement of PD-1 combined with breast ultrasound-based BI-RADS classification represents a significant improvement for breast cancer diagnosis compared with diagnoses based on either method alone.

Breast mass characterization using shear wave elastography and ultrasound

PURPOSE

To evaluate the role of SWE in characterizing breast masses and ascertain whether additional use of SWE to ultrasound for evaluating BI-RADS 3 and 4a masses could help reduce long-term follow-up and unnecessary biopsies of these suspicious breast masses.

MATERIALS AND METHODS

This prospective, cross-sectional study was performed between June 2013 and November 2014. All enrolled patients underwent clinical breast examination, ultrasound, SWE and ultrasound-guided core biopsy of the breast mass. Breast Imaging Reporting and Data System (BI-RAD) categories were assigned to breast masses. For qualitative and quantitative variables of SWE, cut-off values for differentiation between benign and malignant breast masses were estimated. Modified BIRADS' (up/downgrading of BIRADS category) was done for BI-RADS 3/4a masses by combining individual SWE parameters and ultrasound findings. Sensitivity, specificity, positive and negative predictive value of modified BI-RADS' and ultrasound BI-RADS were compared.

RESULTS

A total of 119 women (mean age, 42.3±13.6 [SD] years; range: 13-87 years) with a single breast mass each were enrolled. Histopathologically, 57/119 (48%) breast masses were benign and 62 (52%) were malignant. On ultrasound, 42 breast masses were BI-RADS3 and 77 were BI-RADS 4 (4a, n=10; 4b, n=24; 4c, n=43) leading to 96.8% sensitivity and 70.2% specificity. On SWE, benign breast masses were oval/round, homogenous/reasonably homogenous, blue/green with lower elasticity values and malignant breast masses were irregular, inhomogeneous, red/orange with high elasticity values. On modified BI-RADS' using E-color and E-mean/E-max, specificity improved to 78.9% and 75.4% respectively.

CONCLUSION

Addition of SWE to ultrasound improves characterization of BI-RADS 3 and 4a masses. E-max, E-mean and E-color are the most useful SWE parameters to differentiate between malignant and benign breast masses.

Sonoelastography for differential diagnosis between malignant and benign parotid lesions: a meta-analysis

Objectives

To assess the performance of sonoelastography for differential diagnosis between malignant and benign parotid lesions using a meta-analysis.

Methods

An independent literature search of English medical databases, such as PubMed, Embase and Medline (Embase.com), Web of Science, Cochrane Library and Ovid was performed. The diagnostic accuracy of sonoelastography was compared with that of histopathology and/or cytology, which was used as reference standard. The pooled sensitivity, specificity, diagnostic odds ratio (DOR) and area under the curve (AUC) were calculated to evaluate the accuracy of sonoelastography. A meta-regression analysis evaluating imaging mechanisms, shear wave elastography techniques, assessment methods and QUADAS scores was performed.

Results

Ten eligible studies that included a total sample of 711 patients with 725 parotid lesions were included. Sonoelastography showed a pooled sensitivity of 0.67 (95% CI 0.59–0.74), specificity of 0.64 (95% CI 0.60–0.68), DOR of 8.00 (95% CI 2.96–21.63) and an AUC of 0.77. The results of the meta-regression analysis revealed that no heterogeneity was due to the imaging mechanism (p = 0.119), shear wave elastography technique (p = 0.473) or QUADAS score (p = 0.462). However, the assessment method was a significant factor that affected the study heterogeneity (p = 0.035). According to the subgroup analysis, quantitative and semiquantitative methods performed better than qualitative ones.

Conclusion

Overall, sonoelastography has a limited value for differential diagnosis between malignant and benign parotid lesions. Quantitative and semiquantitative methods perform better than qualitative ones.

Key Points

• Overall, sonoelastography has a limited value for differential diagnosis between malignant and benign parotid lesions.

• Quantitative and semiquantitative assessment methods perform better than qualitative ones.

• Semiquantitative and quantitative methods are automatically calculated by an ultrasound machine and are thus less operator-dependent.

Performance of shear-wave elastography for breast masses using different region-of-interest (ROI) settings

Background Various size and shape of region of interest (ROI) can be applied for shear-wave elastography (SWE). Purpose To investigate the diagnostic performance of SWE according to ROI settings for breast masses. Material and Methods To measure elasticity for 142 lesions, ROIs were set as follows: circular ROIs 1 mm (ROI-1), 2 mm (ROI-2), and 3 mm (ROI-3) in diameter placed over the stiffest part of the mass; freehand ROIs drawn by tracing the border of mass (ROI-M) and the area of peritumoral increased stiffness (ROI-MR); and circular ROIs placed within the mass (ROI-C) and to encompass the area of peritumoral increased stiffness (ROI-CR). Mean (E_mean), maximum (E_max), and standard deviation (E_SD) of elasticity values and their areas under the receiver operating characteristic (ROC) curve (AUCs) for diagnostic performance were compared. Results Means of E_mean and E_SD significantly differed between ROI-1, ROI-2, and ROI-3 ( P < 0.0001), whereas means of E_max did not ( P = 0.50). For E_SD, ROI-1 (0.874) showed a lower AUC than ROI-2 (0.964) and ROI-3 (0.975) ( P < 0.002). The mean E_SD was significantly different between ROI-M and ROI-MR and between ROI-C and ROI-CR ( P < 0.0001). The AUCs of E_SD in ROI-M and ROI-C were significantly lower than in ROI-MR ( P = 0.041 and 0.015) and ROI-CR ( P = 0.007 and 0.004). Conclusion Shear-wave elasticity values and their diagnostic performance vary based on ROI settings and elasticity indices. E_max is recommended for the ROIs over the stiffest part of mass and an ROI encompassing the peritumoral area of increased stiffness is recommended for elastic heterogeneity of mass.

Impact of region of interest (ROI) size on the diagnostic performance of shear wave elastography in differentiating solid breast lesions

Background Shear wave elastography (SWE) using a region of interest (ROI) can demonstrate the quantitative elasticity of breast lesions. Purpose To prospectively evaluate the impact of two different ROI sizes on the diagnostic performance of SWE for differentiating benign and malignant breast lesions. Material and Methods A total of 154 breast lesions were included. Two types of ROIs were investigated: one involving an approximately 2-mm diameter, small round ROIs placed over the stiffest area of the lesion, as determined by SWE (ROI-S); and another ROI drawn along the margin of the lesion using a touch pen or track ball to encompass the entire lesion (ROI-M). Maximum elasticity (E_max), mean elasticity (E_mean), minimum elasticity (E_min), and standard deviation (SD) were measured for the two ROIs. The area under the receiver operating characteristic curve (AUC) as well as the sensitivity and specificity of each elasticity value were determined. Results The AUCs for ROI-S were higher than those for ROI-M when differentiating benign and malignant breast solid lesions. The E_max, E_mean, E_min, and SD of the elasticity values for ROI-S were 0.865, 0.857, 0.816, and 0.849, respectively, and for ROI-M were 0.820, 0.780, 0.724, and 0.837, respectively. However, only E_max ( P = 0.0024) and E_mean ( P = 0.0015) showed statistically significant differences. For ROI-S, the sensitivity and specificity of E_max were 78.8% and 84.3%, respectively, and those for E_mean were 80.8% and 81.4%, respectively. Conclusion Using ROI-S with E_max and E_mean has better diagnostic performance than ROI-M for differentiating between benign and malignant breast lesions.

Tumor Elastography and Its Association with Collagen and the Tumor Microenvironment

Purpose: The tumor microenvironment presents with altered extracellular matrix (ECM) and stroma composition, which may affect treatment efficacy and contribute to tissue stiffness. Ultrasound (US) elastography can visualize and quantify tissue stiffness noninvasively. However, the contributions of ECM and stromal components to stiffness are poorly understood. We therefore set out to quantify ECM and stroma density and their relation to tumor stiffness.Experimental Design: A modified clinical ultrasound system was used to measure tumor stiffness and perfusion during tumor growth in preclinical tumor models. In vivo measurements were compared with collagen mass spectroscopy and automatic analysis of matrix and stromal markers derived from immunofluorescence images.Results: US elastography estimates of tumor stiffness were positively correlated with tumor volume in collagen and myofibroblast-rich tumors, while no correlations were found for tumors with low collagen and myofibroblast content. US elastography measurements were strongly correlated with ex vivo mechanical testing and mass spectroscopy-based measurements of total collagen and immature collagen crosslinks. Registration of ultrasound and confocal microscopy data showed strong correlations between blood vessel density and T-cell density in syngeneic tumors, while no correlations were found for genetic tumor models. In contrast to collagen density, which was positively correlated with stiffness, no significant correlations were observed for hyaluronic acid density. Finally, localized delivery of collagenase led to a significant reduction in tumor stiffness without changes in perfusion 24 hours after treatment.Conclusions: US elastography can be used as a potential biomarker to assess changes in the tumor microenvironment, particularly changes affecting the ECM. Clin Cancer Res; 24(18); 4455-67. ©2018 AACR.

Tumor stiffness measured by quantitative and qualitative shear wave elastography of breast cancer

OBJECTIVE

To correlate clinicoradiologic and pathological features of breast cancer with quantitative and qualitative shear wave elastographic parameters.

METHODS

82 breast cancers in 75 patients examined by B-mode ultrasound and shear wave elastography (SWE) were included. SWE parameters including quantitative factors [maximum elasticity (E_max), mean elasticity (E_mean), elasticity ratio (E_ratio) and standard deviation (SD)] and qualitative factor (color pattern) were correlated with clinicoradiologic and pathological features using univariate and multivariate linear regression analyses.

RESULTS

Presence of symptoms and larger tumor size on ultrasound were significantly associated with higher E_max, E_mean, E_ratio, and SD (all p < 0.05) on univariate analysis. Older age was significantly correlated with higher E_max and E_mean (p = 0.026, 0.018). Lymphovascular invasion and larger pathologic size were significantly associated with higher E_max (p = 0.036, 0.043) and SD (p < 0.001, 0.019). No immunohistochemical biomarkers were significantly correlated with SWE parameters. There was no significant correlation between color pattern and any variable. Multivariate logistic regression analysis showed that the symptom, tumor size on ultrasound and lymphovascular invasion were independent factors that influenced the SWE values.

CONCLUSION

Tumor stiffness as measured by SWE and B-mode ultrasound could help predict cancer prognosis. Advances in knowledge: Clinicoradiologic factors had correlation with quantitative and qualitative SWE parameters. Using SWE parameters and B-mode ultrasound, we can predict breast cancer prognosis.

Biomechanical and biomolecular characterization of extracellular matrix structures in human colon carcinomas

The extracellular matrix (ECM) is extensively remodeled in tumor tissues. Overproduction of collagens, pathological collagen crosslinking and alignment of fibers are major processes that ultimately result in an increased tissue stiffness. Although it is known that glycosaminoglycans (GAGs) play an important role in tumor signaling, their contribution to the biomechanical properties of tumor ECM is unknown. In this study, ECM structures of human colon carcinoma and normal (control) colon tissues were histologically identified. Using atomic force microscopy (AFM) nanoindentation, we show that the collagen-rich regions within the ECM of colon carcinoma tissues were significantly stiffer than the submucosal collagen-rich layer of control tissues. Screening of these regions with Raman microspectroscopy revealed significantly different molecular fingerprints for collagen fibers in colon carcinoma tissues compared to control tissues. We further showed an increased alignment of collagen fibers and elevated levels of GAG immuno-reactivity within the collagen network of colon carcinoma tissues. GAGs such as heparan sulfate and chondroitin sulfate were detected in significantly elevated levels in collagen fibers of carcinoma tissues. Moreover, immunodetection of the collagen-associated proteoglycan decorin was significantly decreased in carcinomas tissues of individual patients when compared with the corresponding control tissues. Overall a strong patient-to-patient variability was evident in the ECM composition, structure and biomechanics of individual colon carcinoma tissues. Although, biomechanical characteristics of tumor ECM were not directly impacted by GAG content, GAGs might play an important role during the mechanical and structural remodeling of pathological tumor ECM. To manipulate GAG expression and deposition in tumor microenvironments could represent a novel potential therapeutic strategy.

Comparison and Combination of Strain and Shear Wave Elastography of Breast Masses for Differentiation of Benign and Malignant Lesions by Quantitative Assessment: Preliminary Study

OBJECTIVES

To compare the diagnostic performance of strain and shear wave elastography of breast masses for quantitative assessment in differentiating benign and malignant lesions and to evaluate the diagnostic accuracy of combined strain and shear wave elastography.

METHODS

Between January and February 2016, 37 women with 45 breast masses underwent both strain and shear wave ultrasound (US) elastographic examinations. The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) final assessment on B-mode US imaging was assessed. We calculated strain ratios for strain elastography and the mean elasticity value and elasticity ratio of the lesion to fat for shear wave elastography. Diagnostic performances were compared by using the area under the receiver operating characteristic curve (AUC).

RESULTS

The 37 women had a mean age of 47.4 years (range, 20-79 years). Of the 45 lesions, 20 were malignant, and 25 were benign. The AUCs for elasticity values on strain and shear wave elastography showed no significant differences (strain ratio, 0.929; mean elasticity, 0.898; and elasticity ratio, 0.868; P > .05). After selectively downgrading BI-RADS category 4a lesions based on strain and shear wave elastographic cutoffs, the AUCs for the combined sets of B-mode US and elastography were improved (B-mode + strain, 0.940; B-mode + shear wave; 0.964; and B-mode, 0.724; P < .001). Combined strain and shear wave elastography showed significantly higher diagnostic accuracy than each individual elastographic modality (P = .031).

CONCLUSIONS

These preliminary results showed that strain and shear wave elastography had similar diagnostic performance. The addition of strain and shear wave elastography to B-mode US improved diagnostic performance. The combination of strain and shear wave elastography results in a higher diagnostic yield than each individual elastographic modality.

Computer-Aided tumor diagnosis in 3-D breast elastography

BACKGROUND AND OBJECTIVE

Breast cancer is the major cause of cancer-related mortality in women. However, the death rate can be effectively decreased if the breast cancer can be detected early and treated appropriately. In recent years, many studies have indicated that the elastography has the better diagnosis performance than conventional ultrasound (US).

METHOD

In this study, the 3-D tumor contour is obtained by using the proposed segmentation methods and then the features containing texture information, shape information, ellipsoid fitting information are extracted respectively by using the segmented 3-D tumor contour and B-mode images, and the features containing elasticity information are calculated using the same contour and elastographic images.

RESULTS

In this experiment, totally 40 biopsy-proved lesions containing 20 benign tumors and 20 malignant tumors are used to evaluate the proposed computer-aided diagnosis (CAD) system. From the experimental results, the combination of shape, ellipsoid fitting and elastographic features has the best performance with accuracy 90.50% (36/40), sensitivity 85.00% (17/20), specificity 95.00% (19/20), and the area under the ROC curve Az 0.987.

CONCLUSION

The result shows that tumors can be diagnosed more precisely by using the elastography images.

Breast lesion classification based on supersonic shear-wave elastography and automated lesion segmentation from B-mode ultrasound images

Supersonic shear-wave elastography (SWE) has emerged as a useful imaging modality for breast lesion assessment. Regions of interest (ROIs) were required to be specified for extracting features that characterize malignancy of lesions. Although analyses have been performed in small rectangular ROIs identified manually by expert observers, the results were subject to observer variability and the analysis of small ROIs would potentially miss out important features available in other parts of the lesion. Recent investigations extracted features from the entire lesion segmented by B-mode ultrasound images either manually or semi-automatically, but lesion delineation using existing techniques is time-consuming and prone to variability as intensive user interactions are required. In addition, rich diagnostic features were available along the rim surrounding the lesion. The width of the rim analyzed was subjectively and empirically determined by expert observers in previous studies after intensive visual study on the images, which is time-consuming and susceptible to observer variability. This paper describes an analysis pipeline to segment and classify lesions efficiently. The lesion boundary was first initialized and then deformed based on energy fields generated by the dyadic wavelet transform. Features of the SWE images were extracted from inside and outside of a lesion for different widths of the surrounding rim. Then, feature selection was performed followed by the Support Vector Machine (SVM) classification. This strategy obviates the empirical and time-consuming selection of the surrounding rim width before the analysis. The pipeline was evaluated on 137 lesions. Feature selection was performed 20 times using different sets of 14 lesions (7 malignant, 7 benign). Leave-one-out SVM classification was performed in each of the 20 experiments with a mean sensitivity, specificity and accuracy of 95.1%, 94.6% and 94.8% respectively. The pipeline took an average of 20 s to process a lesion. The fact that this efficient pipeline generated classification accuracy superior to that of existing algorithms suggests that improved efficiency did not compromise classification accuracy. The ability to streamline the quantitative assessment of SWE images will potentially accelerate the adoption of the combined use of ultrasound and elastography in clinical practice.

Two-dimensional shear wave elastography of breast lesions: Comparison of two different systems

OBJECTIVE

To evaluate the diagnostic performance of two different shear wave elastography (SWE) techniques in distinguishing malignant breast lesions from benign ones.

MATERIALS AND METHODS

From March 2016 to May 2016, a total of 153 breast lesions (mean diameter, 16.8 mm±10.5; range 4.1-90.0 mm) in 153 patients (mean age, 46.4 years±15.1; age range 20-86 years) were separately performed by two different SWE techniques (i.e. T-SWE, Aplio500, Toshiba Medical System, Tochigi, Japan; and S-SWE, the Aixplorer US system, SuperSonic Imagine, Provence, France). The maximum (Emax), mean (Emean) and standard deviation (ESD) of elasticity modulus values in T-SWE and S-SWE were analyzed. All the lesions were confirmed by ultrasound (US)-guided core needle biopsy (n = 26), surgery (n = 122), or both (n = 5), with pathological results as the gold standard. The areas under the receiver operating characteristic curves (AUROCs) were calculated. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV) were calculated to assess the diagnostic performance between T-SWE and S-SWE. Operator consistency was also evaluated.

RESULTS

Among the 153 lesions, 41 (26.8%) were malignant and 112 (73.2%) were benign. Emax (T-SWE: 40.10±37.14 kPa vs. 118.78±34.41 kPa; S-SWE: 41.22±22.54 kPa vs. 134.77±60.51 kPa), Emean (T-SWE: 19.75±16.31 kPa vs. 52.93±25.75 kPa; S-SWE: 20.95±10.98 kPa vs. 55.95±22.42 kPa) and ESD (T-SWE: 9.00±8.55 kPa vs. 38.44±12.30 kPa; S-SWE: 8.17±6.14 kPa vs. 29.34±13.88 kPa) showed statistical differences in distinguishing malignant lesions from benign ones both in T-SWE and S-SWE (all p < 0.05). In T-SWE, the diagnostic performance of ESD was the highest (AUROC = 0.958), followed by Emax (AUROC = 0.909; p = 0.001 in comparison with ESD) and Emean (AUROC = 0.892; p < 0.001 in comparison with ESD), while in S-SWE, the diagnostic performance of Emax was the highest (AUROC = 0.967), followed by ESD (AUROC = 0.962, p > 0.05 in comparison with Emax) and Emean (AUROC = 0.930, p = 0.034 in comparison with Emax). AUROC-max (T-SWE: 0.909 vs.

S-SWE

0.967), AUROC-mean (T-SWE: 0.892 vs.

S-SWE

0.930) and AUROC-SD (T-SWE: 0.958 vs.

S-SWE

0.962) showed no significant difference between T-SWE and S-SWE (all p > 0.05). The intra-class correlation coefficients (ICC) of the intra-operator consistency and inter-operator consistency respectively were 0.961 and 0.898 in T-SWE, while 0.954 and 0.897 in S-SWE.

CONCLUSION

T-SWE and S-SWE are equivalent for distinguishing the breast lesions. In T-SWE, ESD had the best diagnostic performance, while in S-SWE, Emax had the best diagnostic performance.

Emerging roles for LPP in metastatic cancer progression

LIM domain containing proteins are important regulators of diverse cellular processes, and play pivotal roles in regulating the actin cytoskeleton. Lipoma Preferred Partner (LPP) is a member of the zyxin family of LIM proteins that has long been characterized as a promoter of mesenchymal/fibroblast cell migration. More recently, LPP has emerged as a critical inducer of tumor cell migration, invasion and metastasis. LPP is thought to contribute to these malignant phenotypes by virtue of its ability to shuttle into the nucleus, localize to adhesions and, most recently, to promote invadopodia formation. In this review, we will examine the mechanisms through which LPP regulates the functions of adhesions and invadopodia, and discuss potential roles of LPP in mediating cellular responses to mechanical cues within these mechanosensory structures.

Shear Wave Elastography for Surgically Verified Breast Papillary Lesions: Is It Effective for Differentiation Between Benign and Malignant Lesions?

OBJECTIVES

To evaluate the effectiveness of shear wave elastography (SWE) for differentiating benign from malignant breast papillary lesions METHODS: B-mode ultrasound (US) and SWE were available in 56 surgically confirmed papillary lesions (48 [85.7%] benign and 8 [14.3%] malignant). The diagnostic performances of US, SWE parameters, and combined US with SWE parameters were calculated by receiver operating characteristic curve analysis and compared.

RESULTS

The highest area under the receiver operating characteristic curve (A_z ) value for US was 0.500 (95% confidence interval [CI], 0.363, 0.637). The sensitivity was 100% (8 of 8), and the specificity was 0% (0 of 48). False-positive biopsy results were obtained in 48 (85.7%) of 56 lesions. The A_z value for mean elasticity (0.721; 95% CI, 0.585, 0.833) was higher than that for B-mode US (P < .01) and the highest with the optimal cutoff value of 44.3 kPa (sensitivity, 75%; specificity, 75%). By adding the mean elasticity cutoff value of 44.3 kPa to B-mode US, the performance was increased (A_z , 0.781; 95% CI, 0.585, 0.833) with sensitivity of 87.5% and specificity of 68.8%, and false-positive biopsy results were reduced to 26.8%.

CONCLUSIONS

The additional use of SWE to B-mode US may be effective for differentiating benign and malignant breast papillary lesions, with a significant decrease in the false-positive biopsy rate.

Value of shear wave elastography in discriminating malignant and benign breast lesions: A meta-analysis

The analysis was aimed to evaluate the diagnostic accuracy of shear wave elastography (SWE) for malignant breast lesions through a meta-analysis.Related articles were searched from Pubmed, Embase, and Cochrane library. Overall sensitivity and specificity were analyzed with DerSimonian and Laird random effects model. Area under curve with corresponding 95% confidence interval (were calculated to evaluate the diagnostic accuracy of SWE. Sensitivity and publication bias were assessed as well.A total of 25 articles including 4128 patients and 4546 breast lesions were included in the pooled analysis. In the subgroup analysis, diagnostic sensitivity and specificity of SWE in Asian population were 0.84 (0.79-0.88) and 0.87 (0.84-0.90), respectively, whereas they were 0.92 (0.86-0.96) and 0.89 (0.84-0.92) in Caucasian population. The diagnostic accuracy of SWE was a little higher for Caucasians than for Asians (0.95 vs. 0.92). The diagnostic sensitivity and specificity of virtual touch tissue quantification were 0.85 (0.77-0.91) and 0.93 (0.88-0.96), respectively. It showed a little higher value in specificity and summary ROC curve than SWE (0.93 vs. 0.87; 0.95 vs. 0.93). In addition, maximum stiffness exhibited higher detection sensitivity than that of mean stiffness (0.91 vs. 0.85).SWE serves as an accurate diagnostic technology for discriminating between malignant and benign breast lesions.

Comparing Performance of Combinations of Shear Wave Elastography and B-Mode Ultrasound in Diagnosing Breast Masses: Is It Influenced by Mass Size?

We determined the diagnostic performance of combinations of shear wave elastography (SWE) and B-mode ultrasound (US) in differentiating malignant from benign breast masses, and we investigated whether performance is affected by mass size. In this prospective study of 315 consecutive patients with 326 breast masses, US and SWE were performed before biopsy. Masses were categorized into two subgroups on the basis of mass size (≤15 mm and >15 mm), and the optimal thresholds for the SWE parameters were determined for each subgroup using receiver operating characteristic curves. The combination proposed here achieved an area under the receiver operating characteristic curve of 0.943, 95.00% sensitivity and 81.18% specificity, which approximated the diagnostic performance of US alone. The performance of the combinations using the subgroups' thresholds did not differ significantly from those based on the entire study group's thresholds, but the optimal thresholds were higher in the subgroup of larger masses. Further research is needed to determine whether mass size affects the performance of combinations of SWE and US.

Benign and malignant breast lesions identification through the values derived from shear wave elastography: evidence for the meta-analysis

Objective

The analysis was aimed to evaluate the diagnostic accuracy of shear wave elastography (SWE) for malignant breast lesions through a meta-analysis.

Materials and Methods

Related articles were searched in databases of Pubmed, Embase and Cochrane library. Overall sensitivity and specificity were analyzed with DerSimonian and Laird random effects model. Area under curve (AUC) with corresponding 95% confidence interval were also analyzed to evaluate the diagnostic accuracy of SWE. P value < 0.05 predicted the significant heterogeneity between study. Sensitivity and publication bias were assessed as well.

Results

According to the inclusion criteria, 25 articles were selected. In the subgroup analysis, diagnostic sensitivity and specificity of SWE in Asian population were 0.84 (0.79-0.88) and 0.87 (0.84-0.90), respectively, while they were 0.92 (0.86-0.96) and 0.89 (0.84-0.92) in Caucasian population. The diagnostic accuracy of SWE was a little higher for Caucasians than for Asians (0.95 vs. 0.92). The diagnostic sensitivity and specificity of virtual touch tissue quantification (VTTQ) were 0.85 (0.77-0.91) and 0.93 (0.88-0.96), respectively. It showed a little higher value in specificity and summary receiver operating curve (sROC) than that of SWE (0.93 vs. 0.87; 0.95 vs. 0.93). In addition, maximum stiffness exhibited higher detection sensitivity than that of mean stiffness (0.91 vs. 0.85).

Conclusions

SWE serves as an accurate diagnostic technology for discriminating malignant and benign breast lesions.

Role of BI-RADS Ultrasound Subcategories 4A to 4C in Predicting Breast Cancer

BACKGROUND

The Breast Imaging Reporting and Data System (BI-RADS) ultrasound (US) categorization revised in 2013 by the American College of Radiology resulted in unquestionable standardization of reports and confirmed category 3 and 5 as benign and malignant lesions, respectively. In contrast, suspected images (category 4) have subcategorization criteria, although theses have been detailed difficult to apply. The aim of the present study was to determine the role of the US 4A to 4C BI-RADS subcategories in predicting malignancy.

PATIENTS AND METHODS

We performed a cross-sectional study of diagnostic tests to estimate the performance of the US BI-RADS categorization to clearly differentiate benign from malignant lesions. A total of 975 US examinations performed at the Hospital Femina, Grupo Hospitalar Conceição teaching hospitals from January 2012 through March 2015 were included in the present study. The US BI-RADS lexicon was used to classify the examination findings. Suspicious lesions underwent core needle biopsy, and the US and histology reports were compared to determine the performance using receiver operating characteristic curves.

RESULTS

Overall, the BI-RADS US categorization showed good discriminating accuracy with a receiver operating characteristic curve of 91% (95% confidence interval [CI], 88%-93%). However, BI-RADS subcategory 4b had a positive predictive value of 25% (95% CI, 20%-31%) and subcategory 4A had a positive predictive value of only 6% (95% CI, 3.5%-9.8%).

CONCLUSION

Our results have shown that US BI-RADS subcategories 4A and 4B are clearly unfit for use in screening tests, because they cannot rule out the need for biopsy. Therefore, management will not be improved by subcategorizing category 4, because all suspicious lesions will still require definite biopsy.