Diagnostic role of shear wave elastography for differentiating benign and malignant breast masses.

Nichanametla Sravani,Pampa Ch Toi,Gopal Balasubramanian,K.M Abdulbasith,Chellappa Vijayakumar,Ananthakrishnan Ramesh,Sathasivam Sureshkumar

doi:10.4102/sajr.v24i1.1999

Abstract

BackgroundUse of B-mode ultrasound (US) may not obviate the need for diagnosis by histopathology, which is an invasive technique and remains the gold standard. These limitations are being overcome with the advent of shear wave elastography (SWE).ObjectivesTo assess the diagnostic role of SWE parameters and combined SWE and B-mode US in diagnosing malignant breast lesions.MethodThis cross-sectional study included all patients with a breast mass on clinical examination. A B-mode US with a Breast Imaging Reporting and Data System (BI-RADS) assessment and SWE evaluation (distance ratio [DR], area ratio [AR] and shear wave velocity [SWV]) in the lesion and healthy breast tissue of all recruited patients was performed. Cut-offs for SWE parameters were derived by receiver operating characteristic (ROC) analysis. The diagnostic performance of the B-mode US, the SWE parameters and the combined imaging in diagnosing malignancy was assessed.ResultsThis study included a total of 175 breast masses. The median values of the SWE parameters were significantly higher (p < 0.001) in the malignant breast masses (DR, 1.29 vs. 1.03; AR, 1.69 vs. 1.06; and SWV, 9.1 metre per second [m/s] vs. 2.1 m/s). The ROC cut-off for malignancy was derived at 1.135 m/s, 1.18 m/s and 3.18 m/s, respectively, for DR, AR and SWV. The area under the ROC curve was highest for the DR (0.930), whilst this value was 0.914 and 0.901 for the SWV and AR, respectively. Amongst the respective sensitivities and specificities of the B-mode US (90.6% and 90%), SWE (97.6% and 61.1%), SWE (excluding AR) (96.5% and 77.8%) and combined imaging (100% and 72.2%), the highest sensitivity was noted for the combined method.ConclusionAll the SWE parameters were significantly higher in the malignant breast masses, compared to the benign lesions. On combining SWE and B-mode US, there was a significant increase in sensitivity but a decrease in specificity.

Highlights

The foremost investigations used in the assessment of a breast mass are mammography and B-mode ultrasonography (US), depending on the patient’s age
155 patients had single breast lesions; two breast lesions were noted in six patients, whilst the remaining two patients had four lesions
Whilst the current study demonstrated a poor diagnostic performance for the area ratio (AR), Bai et al.[11] achieved a high specificity for the AR by excluding the AR for masses that followed Pattern 2 on acoustic radiation force impulse (ARFI) imaging

Summary

Introduction

The foremost investigations used in the assessment of a breast mass are mammography and B-mode ultrasonography (US), depending on the patient’s age These diagnostic methods have exhibited high sensitivity in diagnosing malignancy, but both have some limitations. The limitation of US is its low specificity, owing to the solid nature of most benign lesions.[3] As a result of these pitfalls, the use of B-mode US or mammography may not obviate the need for diagnosis by histopathology, which is an invasive technique and remains the gold standard. Use of B-mode ultrasound (US) may not obviate the need for diagnosis by histopathology, which is an invasive technique and remains the gold standard These limitations are being overcome with the advent of shear wave elastography (SWE)

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Conclusion