Sonoelastography in Distinguishing Benign from Malignant Complex Breast Mass and Making the Decision to Biopsy

ABSTRACT

OBJECTIVE: To evaluate the additional effect of sonoelastography on the radiologist's ability for distinguishing benign from malignant complex breast masses and to decide whether to perform biopsy by B-mode US. MATERIALS AND METHODS: One hundred eighteen complex breast masses (15 malignant lesions, 103 benign lesions) were included. Five blinded readers independently assessed the likelihood of the malignancy score from 1 to 5 for two data sets (B-mode ultrasound alone and B-mode ultrasound with sonoelastography). Elasticity scores were categorized as 0, 1, or 2 based on the degree and distribution of strain of the echogenic component within complex masses. The readers were asked to downgrade the likelihood of the malignancy score when an elasticity score of 0 was assigned and to upgrade the likelihood of the malignancy score when an elasticity score of 2 was assigned. The likelihood of the malignancy score was maintained as it was for the lesions with an elasticity score of 1. The Az values, sensitivities, and specificities were compared. RESULTS: The Az value of B-mode ultrasound with sonoelastography (mean, 0.863) was greater than that of B-mode ultrasound alone (mean, 0.731; p = 0.001-0.007) for all authors. The specificity of B-mode ultrasound with sonoelastography (mean, 37.1%) was greater than that of B-mode ultrasound alone (mean, 3.8%; p < 0.001) for all readers. The addition of sonoelastography led to changes in decisions. A mean of 33.6% of benign masses were recommended for follow-up instead of biopsy. CONCLUSION: For complex breast masses, sonoelastography allows increase in both the accuracy in distinguishing benign from malignant lesions and the specificity in deciding whether to perform biopsy.