Can Shear Wave Elastography Increase Speci(cid:976)icity in Diagnosis of Benign and Malignant Breast Masses?
Amornthip Tasma MD1, Jenjeera Prueksadee MD1
Affiliation : 1 Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Chulalongkorn University,
King Chulalongkorn Memorial Hospital, Bangkok, Thailand
Objective : To determine whether shear wave elastography [SWE] can increase speci(cid:976)icity in diagnosis of benign and malignant
breast masses in BI-RADS category 3 and 4.
Materials and Methods : Data were collected retrospectively between January 2013 and December 2015 at King Chulalongkorn
Memorial Hospital. Breast sonography with supplementary SWE of BI-RADS category 3 and 4, according to the ACR BI-RADS
2013, which had histopathology-proved diagnosis or at least two years of stability, were randomly reviewed by the researchers.
Elasticity values were all generated by Supersonic Imagine ultrasound system. Minimal elasticity [Emin], mean elasticity [Emean],
and maximal elasticity [Emax] values were separately evaluated among benign and malignant groups.
Results : One hundred sixteen lesions in 107 female patients were eligible for the present study. Eighty lesions (68.9%) were
benign and 36 lesions (31.0%) were malignant. All Emin, Emean, and Emax showed statistically signi(cid:976)icant difference between
benign and malignant lesions (p-value 0.022, 0.001, and <0.001, respectively). The area under the receiver operating curve [AUC]
for elasticity value was slightly higher for maximum (0.733) than mean (0.710) values. The cut-off value of Emax was 110 kPa,
showing sensitivity 63.9%, speci(cid:976)icity 78.8%, PPV 57.5%, NPV 82.9%, and accuracy 74.1%. All BI-RADS category 3 lesions were
benign, as well as all BI-RADS category 4c lesions, were malignant. The cut-off value of Emax below 48 kPa in BI-RADS category 4a
lesions proved to be all benign except medullary carcinoma. Maximal Emax value was 300 kPa, which was proven to be diabetes
mellitus mastopathy and some malignant lesions.
Conclusion : Emin, Emean, and Emax values were signi(cid:976)icantly different between benign and malignant masses and the speci(cid:976)icity
was increased as compared with conventional ultrasound alone, especially in BI-RADS category 4a. The present study showed
Emax value at 110 kPa had good speci(cid:976)icity and high NPV. Elasticity values primarily re(cid:976)lect the degree of (cid:976)ibrosis of breast lesions,
which help the diagnosis.
Keywords : Shear wave elastography, Diagnostic accuracy, Benign, Malignant, Breast masses, BI-RADS 3 and 4
