Diagnostic value of a power Doppler ultrasound-based malignancy index for differentiating malignant and benign solid breast lesions

Background: Power Doppler ultrasound (PDUS) can provide useful information regarding the vascularity of breast lesions. The aim of this study was to investigate the diagnostic performance of a new PDUS-driven malignancy index in differentiating between malignant and benign causes of solid breast lesions. Materials and Methods: Patients with solid breast lesions were enrolled consecutively and evaluated first by PDUS and subsequently by histopathologic assessment after undergoing surgical biopsy. A custom-made software was used to extract data from images for calculating malignancy index formula. Results: A total of 87 patients with solid breast lesions were enrolled. Histopathologic evaluation identified 49 patients as benign and 38 patients as malignant. Malignancy index was significantly higher in the malignant group as compared to benign tumors (6.31 vs 0.30,P < 0.001). Area under the receiver operating characteristics (ROC) curve (AUC) was 0.98 (95% confidence interval (CI) 0.95-1.00). According to the ROC curve analysis, the cut-off point of 1.23 for malignancy index had a sensitivity and specificity of 94.7% (95% CI 82.2-99.3) and 94.0% (95% CI 83.1-98.7), respectively. Conclusion: Comparing with the histopathologic evaluation as the gold standard for diagnosing breast lesions, PDUS-driven malignancy index was shown to have a high discriminative performance in identifying malignant lesions with high sensitivity, specificity, and diagnostic accuracy. The noninvasive nature of PDUS is an important advantage that could prevent unnecessary biopsies.