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

Abstract

Background:The aim of this study was to assess the performance of shear wave elastography combined with BI-RADS classification of greyscale ultrasound images for benign/malignant differentiation in a large group of patients.Methods:One hundred and seventy-five consecutive patients with solid breast masses on routine ultrasonography undergoing percutaneous biopsy had the greyscale findings classified according to the American College of Radiology BI-RADS. The mean elasticity values from four shear wave images were obtained.Results:For mean elasticity vs greyscale BI-RADS, the performance results against histology were sensitivity: 95% vs 95%, specificity: 77% vs 69%, Positive Predictive Value (PPV): 88% vs 84%, Negative Predictive Value (NPV): 90% vs 91%, and accuracy: 89% vs 86% (all P>0.05). The results for the combination (positive result from either modality counted as malignant) were sensitivity 100%, specificity 61%, PPV 82%, NPV 100%, and accuracy 86%. The combination of BI-RADS greyscale and shear wave elastography yielded superior sensitivity to BI-RADS alone (P=0.03) or shear wave alone (P=0.03). The NPV was superior in combination compared with either alone (BI-RADS P=0.01 and shear wave P=0.02).Conclusion:Together, BI-RADS assessment of greyscale ultrasound images and shear wave ultrasound elastography are extremely sensitive for detection of malignancy.

Anisotropy of Solid Breast Lesions in 2D Shear Wave Elastography is an Indicator of Malignancy

“…Berg et al recommended the use of a cut-off threshold for the maximum elasticity, E max of 80 kPa for the optimal benign/malignant differentiation [2]. Evans et al recommend a cut-off threshold for the mean elasticity, E mean of 50 kPa [4].…”

Shear-wave elastography and greyscale assessment of palpable probably benign masses: is biopsy always required?

“…A cut-off value for mean elasticity of the ROI of 50 kPa was used for benign/malignant differentiation, as this level has been validated in previous studies. 2,6,15 Static greyscale images underwent retrospective standard BI-RADS classification by a breast radiologist and a breast radiology trainee, both blinded to the elastography and pathology findings but aware of the patient's age (Category 3: probably benign, Category 4a: low suspicion, Category 4b: intermediate suspicion, Category 4c: moderate suspicion and Category 5: highly suggestive of malignancy). 16 BI-RADS Categories 1-3 were taken as negative, since the American College of Radiology guidelines state that such lesions can be managed without immediate biopsy.…”

“…[1][2][3][4][5] Several large studies have shown that the addition of SWE to greyscale ultrasound improves the performance of ultrasound in differentiating benign from malignant breast masses. 1,3,6 Notably, the combination of benign SWE and greyscale ultrasound findings has been shown to be highly specific, and malignancy is extremely unlikely, with a negative-predictive value for the combination of 100%. 6 The SWE parameter of mean stiffness is highly accurate in differentiating between benign and malignant solid breast masses and has performance parameters at least as good as the Breast Imaging Reporting and Data System (BI-RADS) evaluation of greyscale images.…”

“…1,3,6 Notably, the combination of benign SWE and greyscale ultrasound findings has been shown to be highly specific, and malignancy is extremely unlikely, with a negative-predictive value for the combination of 100%. 6 The SWE parameter of mean stiffness is highly accurate in differentiating between benign and malignant solid breast masses and has performance parameters at least as good as the Breast Imaging Reporting and Data System (BI-RADS) evaluation of greyscale images. 6 Cancers classified as benign by quantitative SWE are uncommon and are more often small (#10 mm), low grade or pure ductal carcinoma in situ (DCIS).…”

“…6 The SWE parameter of mean stiffness is highly accurate in differentiating between benign and malignant solid breast masses and has performance parameters at least as good as the Breast Imaging Reporting and Data System (BI-RADS) evaluation of greyscale images. 6 Cancers classified as benign by quantitative SWE are uncommon and are more often small (#10 mm), low grade or pure ductal carcinoma in situ (DCIS). 7 Since such tumours are more frequently detected at screening, SWE has been found to have superior performance in females who are symptomatic compared with females with screen-detected abnormalities (SWE sensitivity has been found to be 99% in symptomatic patient and 87% in screening patient).…”