Role of Duplex Ultrasound for the Assessment of Malignancy in Breast Tumors

Abstract

Background: Breast cancer is the commonest form of cancer in females which may be curable if detected early. Breast ultrasound (US) is a non invasive, primary screening tool which can evaluate breast tumors in women even with dense breast. By adding color Doppler signal with B-mode US namely Duplex ultrasound better characterization of breast tumors is possible especially for the indeterminate tumors (BIRADS category 3 and 4) on B-Mode US. Objective: The purpose of this study is to assess the efficacy of Duplex Sonography (DS) for assessment of malignancy in breast tumors compared to histopathology. Materials and methods: This cross-sectional study was carried out at National Institute of Nuclear Medicine & Allied Science (NINMAS) from July 2017 to June 2018. A total of 57 female patients having breast tumors (age mean 42.09 years with SD ± 15.85) were included in this study. After clinical assessment, all study patients underwent Duplex Ultrasound and was then subjected to the excisional biopsy and histopathology for confirmation of the diagnosis. Diagnostic performance test of DS was done for diagnosis of breast malignancy compared to histopathology. Receiver-operator characteristic (ROC) curve was also constructed to determine the optimal cut-off point for each spectral Doppler indices. Results: On Color Doppler Sonography (CDS), hypervascularity was more common in malignant tumors than benign lesions (86.7%Vs 18.5%; p=0.001). Spectral Doppler indices including resistive index (RI) and pulsatility index (PI) were significantly higher in malignant tumors (p=0.001). All of these indices had high diagnostic accuracy for differentiating malignant from benign tumors with area under the curve (AUC) which is equals to 0.90, 0.92 for RI and PI respectively. The optimal cut-off points to differentiate benign and malignant tumors from ROC curve for RI was 0.75 (sensitivity: 89.0%, specificity: 85.0%) and that of PI was 1.2 (sensitivity: 96.6%, specificity: 80.0%). All obtained results of sensitivity, specificity and over all accuracy of DS (considering the vessel number on CDS & BIRADS criteria on B-mode US) were 93.3%, 81.5% and 87.7% respectively. Conversely, conventional B-Mode US alone had a sensitivity, specificity and over all accuracy of 100%, 55.6%, and 78.9% respectively. Addition of CDS to B-mode US in the same session increased specificity from 55.6% to 81.5% and accuracy from 78.9% to 87.7%. Conclusion: Duplex ultrasound has a significant role in the evaluation of breast tumors and adds value to B-mode US for distinguishing malignant tumors from benign lesions.