Evaluation of diagnostic accuracy of ultrasound elastography in differentiating benign and malignant solid breast masses.

Abstract

Objective The purpose of this study was to determine the diagnostic accuracy of breast ultrasound elastography in differentiating benign from malignant breast masses using histology diagnosis as the gold standard. Material and Method The study was carried out at Kenyatta National Hospital. 112 patients with solid breast lumps were reviewed. They fulfilled our inclusion criteria gave consent to standard breast ultrasound supplemented by strain elastography. The imaging was carried out using a logic E- 9 GE Ultrasound machine with Elastography software packages. A specifically designed data collection form was used to record the demographic details of the patient, the clinical findings, gray scale and ultrasound elastography findings and the histological diagnosis. Histopathologic results and strain elastography results were correlated. Results Female patients accounted for 96.5% of the total number of patients reviewed. The age range was 15-79 years. The median age of presentation was 28 years (interquartile range 22 – 40). Using ultrasound elastography to differentiate benign and malignant breast lumps, with histology as the gold standard, the sensitivity for strain score and strain ratio was 92.9% and 96.4% respectively. Specificity was however the same for both (95.2%).Strain ratio yielded a higher sensitivity compared to elasticity score (96.4% versus 92.9%). However, strain ratio against elasticity score were positively correlated with a Spearman’s coefficient of 0.7842 (P value <0.001) indicating that by performing both techniques, a more confident diagnosis can be made. Conclusion Strain elastography is a non invasive, fast, simple tool that can compliment conventional gray scale ultrasound of the breast. It has a high accuracy level and could be used as a good tool for the classification of breast masses prior to the decision to biopsy a lesion.