A novel two-dimensional quantitative shear wave elastography to make differential diagnosis of breast lesions: Comprehensive evaluation and influencing factors

The Potential of Shear Wave Elastography to Reduce Unnecessary Biopsies in Breast Cancer Diagnosis: An International, Diagnostic, Multicenter Trial

PURPOSE

 In this prospective, multicenter trial we evaluated whether additional shear wave elastography (SWE) for patients with BI-RADS 3 or 4 lesions on breast ultrasound could further refine the assessment with B-mode breast ultrasound for breast cancer diagnosis.

MATERIALS AND METHODS

 We analyzed prospective, multicenter, international data from 1288 women with breast lesions rated by conventional 2 D B-mode ultrasound as BI-RADS 3 to 4c and undergoing 2D-SWE. After reclassification with SWE the proportion of undetected malignancies should be < 2 %. All patients underwent histopathologic evaluation (reference standard).

RESULTS

 Histopathologic evaluation showed malignancy in 368 of 1288 lesions (28.6 %). The assessment with B-mode breast ultrasound resulted in 1.39 % (6 of 431) undetected malignancies (malignant lesions in BI-RADS 3) and 53.80 % (495 of 920) unnecessary biopsies (biopsies in benign lesions). Re-classifying BI-RADS 4a patients with a SWE cutoff of 2.55 m/s resulted in 1.98 % (11 of 556) undetected malignancies and a reduction of 24.24 % (375 vs. 495) of unnecessary biopsies.

CONCLUSION

 A SWE value below 2.55 m/s for BI-RADS 4a lesions could be used to downstage these lesions to follow-up, and therefore reduce the number of unnecessary biopsies by 24.24 %. However, this would come at the expense of some additionally missed cancers compared to B-mode breast ultrasound (rate of undetected malignancies 1.98 %, 11 of 556, versus 1.39 %, 6 of 431) which would, however, still be in line with the ACR BI-RADS 3 definition (< 2 % of undetected malignancies).

The diagnostic performance of shear wave velocity ratio for the differential diagnosis of benign and malignant breast lesions: Compared with VTQ, and mammography

PURPOSE

To evaluate the diagnostic value of shear wave velocity (SWV) ratio for the differential diagnosis of benign and malignant breast lesions.

MATERIAL AND METHODS

Our retrospective study included 151 breast lesions that were diagnosed by biopsy and surgical pathology. All of the breast lesions were detected by conventional ultrasound and Virtual Touch tissue quantification (VTQ) and mammography. The sonographic characteristics of the breast lesion, such as the internal echo, shape, margin, color flow, and calcification so on, were also observed. The SWV in lesions and surrounding parenchyma were measured and the SWV ratio between the lesion and surrounding parenchyma was calculated. Pathological results were used as a diagnosis standard to compare the value of SWV ratio, VTQ, and mammography in the diagnosis of benign and malignant breast lesions.

RESULTS

The 151 breast lesions included 96 benign lesions and 55 malignant lesions. The cutoff value of VTQ in the diagnosis of benign and malignant breast lesions was 5.01 m/s, of SWV ratio was 2.43, and mammography was BI-RADS 4B. The sensitivity, specificity, accuracy and the area under the ROC curve (AUC) of the SWV ratio were 78.2%, 86.5%, 83.4%, and 0.83 respectively. While of SWV ratio with mammography was 86.4%, 89.4%, 88.3% and 0.87, respectively. The sensitivity, specificity, accuracy, and AUC of SWV ratio and SWV ratio with mammography were statistically higher than those of mammography, no statistically higher than VTQ and VTQ with mammography.

CONCLUSION

The SWV ratio can improve the sensitivity without sacrificing diagnostic specificity in the process of breast cancer diagnostic, provide a better diagnostic performance, and avoid unnecessary biopsy or surgery.

Virtual touch tissue imaging and quantification (VTIQ) in the evaluation of breast lesions: The associated factors leading to misdiagnosis

PURPOSE

To investigate the factors that could cause a misdiagnosis in virtual touch tissue imaging and quantification (VTIQ) when differentiating benign and malignant breast lesions, and to analyze the imaging characteristics of those lesions with incorrect findings.

METHODS

The conventional ultrasound (CUS) features and the VTIQ parameters of 153 benign lesions and 99 malignant lesions were retrospectively analyzed and compared with histopathological and/or core-needle biopsy (CNB)-proven results. Independent variables that led to inaccurate VTIQ results were selected by binary logistic regression analysis.

RESULTS

The maximum shear wave speed (SWS-max), the mean SWS (SWS-mean), the minimum SWS (SWS-min), the lesion-to-fat SWS ratio (SWS-L/F), and the lesion-to-gland SWS ratio (SWS-L/G) in malignant lesions were significantly higher than those in benign lesions (all P < 0.001). The false-positive rate (FPR) of benign lesions and the false-negative rate (FNR) of malignant lesions were 9.8% and 19.2%, respectively, using an SWS-max cut-off value of 4.46 m/s. Diameter, depth, and posterior acoustic features were independent variables related to false-positive VTIQ findings (P: 0.049, 0.010 and 0.032, respectively). The invasive status and the histologic grade of infiltrating carcinoma were significantly associated with false-negative VTIQ findings (P: 0.026 and 0.015).

CONCLUSION

Diameter, depth, posterior acoustic features, invasive status, and histologic grade have a significant influence on the accuracy of VTIQ results, and these characteristics of breast lesions should be taken into account when interpreting the results of VTIQ examinations.

VTIQ evaluates antitumor effects of NET-1 siRNA by UTMD in HCC xenograft models

The present study used a virtual touch tissue imaging and quantification (VTIQ) method to investigate the change in elasticity in xenograft tumor tissue models following silencing of the neuroepithelial-transforming protein 1 (NET-1) gene by ultrasound-targeted microbubble destruction (UTMD). A total of 24 xenograft models were established by subcutaneous injection of human hepatocellular carcinoma SMMC-7721 cells in BALB/c female nude mice. Then, NET-1 small interfering RNA (siRNA)-conjugated nanobubbles and a glypican-3 antibody were synthesized. The mean and maximum shear wave speed (SWS_mean and SWS_max) in the tumor tissue were measured prior to, during, and following therapy using VTIQ. The growth of the tumor size and survival time were recorded. The levels of NET-1 protein were evaluated by immunohistochemical staining. In addition, tumor, liver and kidney tissues of the nude mice were collected to confirm whether gene transfection treatment was toxic in vivo. In the UTMD delivery gene group, SWS_mean was correlated with the maximum diameter of the tumor (r=0.9806, P=0.0194). The immunohistochemical staining data indicated that the level of NET-1 protein in the treated groups was significantly decreased compared with those in the control groups. Additionally, no structural damage was observed in the nude mice liver and kidney tissues following treatment. Therefore, VTIQ measurement identified potential changes in the elastic properties of the tumors, which in turn may be associated with the stages of tumor development. The delivery method, UTMD, improves the antitumor effects of NET-1 siRNA and supports gene transfection as a promising therapeutic strategy.

Value of shear wave arrival time contour display in shear wave elastography for breast masses diagnosis

To evaluate the diagnostic performance of shear wave arrival time contour (SWATC) display for the diagnosis of breast lesions and to identify factors associated with the quality of shear wave propagation (QSWP) in breast lesions. This study included 277 pathologically confirmed breast lesions. Conventional B-mode ultrasound characteristics and shear wave elastography parameters were computed. Using the SWATC display, the QSWP of each lesion was assigned to a two-point scale: score 1 (low quality) and score 2 (high quality). Binary logistic regression analysis was performed to identify factors associated with QSWP. The area under the receiver operating characteristic curve (AUROC) for QSWP to differentiate benign from malignant lesions was 0.913, with a sensitivity of 91.9%, a specificity of 90.7%, a positive predictive value (PPV) of 74.0%, and a negative predictive value (NPV) of 97.5%. Compared with using the standard deviation of shear wave speed (SWS_SD) alone, SWS_SD combined with QSWP increased the sensitivity from 75.8% to 93.5%, but decreased the specificity from 95.8% to 89.3% (P < 0.05). SWS_SD was identified to be the strongest factor associated with the QSWP, followed by tumor malignancy and the depth of the lesion. In conclusion, SWATC display may be useful for characterization of breast lesions.

New diagnostic tools for breast cancer

Imaging plays a major role in the diagnosis, treatment, and follow-up of breast cancer. Findings that require further assessment will be detected both at screening and curative mammography. Most findings that are further worked up tend to yield benign diagnoses. Consequently, there is an ongoing search for new tools to reduce recalls and unnecessary biopsies while maintaining or improving cancer detection rates. The clinically most promising methods in this respect are described and discussed in this review.

Combination of conventional ultrasonography and virtual touch tissue imaging quantification for differential diagnosis of breast lesions smaller than 10 mm

OBJECTIVE

To determine the value of combining conventional ultrasonography with virtual touch tissue imaging quantification (VTIQ) for differential diagnosis of breast lesions smaller than 10 mm.

METHODS

A total of 98 breast lesions smaller than 10 mm were examined by conventional ultrasound and VTIQ using a Siemens ACUSON S3000 ultrasound machine. Pathologic diagnosis was established after surgery or fine needle biopsy.

RESULTS

Malignant lesions were characterized by taller-than-wide shape, poorly circumscribed margin, and marked hypoechogenicity. The mean VTIQ shear wave velocity (SWV) value of malignant lesions was 4.88±1.87 m/s (range, 1.75-9.34 m/s), significantly higher than that of benign lesions (2.68±1.02 m/s; range, 1.18-4.67 m/s). The optimal cutoff SWV value was 3.27 m/s, with sensitivity, specificity, diagnostic accuracy, positive predictive value (PPV), and negative predictive value (NPV) of 86.20%, 95.65%, 92.86%, 89.29%, and 94.29%, respectively. The combination of SWV >3.27 m/s plus the US feature of poorly circumscribed margin had the highest sensitivity (93.33%) and specificity (100%) for diagnosis of malignant breast lesions.

CONCLUSION

Features such as taller-than-wide shape, poorly circumscribed margin, and marked hypoechogenicity on conventional US, and SWV >3.27 m/s on VTIQ, are indicators of malignancy in breast lesions with diameter <10 mm. The combination of poorly circumscribed margin and SWV >3.27 m/s provides the highest specificity and diagnostic accuracy.