The Role of Sonoelastography in Evaluating Breast Masses Detected on Mammography With Histopathological Correlation at Kenyatta National Hospital

Abstract

Study background Breast cancer is a high burden disease in Kenya and worldwide, therefore any efforts to reduce its morbidity and mortality are not misplaced. A relatively new and increasingly popular breast imaging modality, sonoelastography exploits differences in tissue stiffness to differentiate benign and malignant lesions, increasing the confidence of diagnosing breast lesions non-invasively. Broad Objective: To determine the role of breast sonoelastography in assessing mammographically detected breast masses before histopathological diagnosis at Kenyatta National Hospital (KNH). Study Design and Site: A descriptive cross sectional study was conducted at Kenyatta National Hospital Radiology Department and Department of Diagnostic Imaging and Radiation Medicine, over a period of six months (January to June 2021). Methodology: Sixty seven (67) solid breast masses from fifty two (52) patients identified on diagnostic and screening mammography were assessed using the ACR BIRADS classification. The identified masses were further analyzed by sonoelastography and correlated with histopathology. Patients’ bio-data was collected to determine the demographic characteristics associated with breast cancer in a Kenyan population. Data analysis was done using SPSS software version 20. The sensitivity, specificity and diagnostic accuracy of both imaging techniques and in combination were determined. Statistically significant data was defined as a p value <0.05. Results: A total of 67 breast lesions from 52 patients were analyzed. All the participants were females, age range 35-81years, with a mean age of 53.8years. 8 (15%) patients had a positive family history of breast cancer. 47 (70%) lesions were malignant on histology with 20 (30%) benign lesions. Invasive ductal carcinoma was the single most common lesion, while fibroadenoma was the most common benign lesion. 38(56.7%) lesions were classified as BIRADS 4 which was the most prevalent BIRADS classification on mammography, with all BIRADS 2 and 5 lesions showing no discordancy on histological correlation. UE score of 4 was the most prevalent with 29(43.3%) lesions. Scores of 1 and 5 showed no discordancy on histological correlation. UE sensitivity, specificity and accuracy were 89.3%, 90% and 89.5% respectively versus mammography 87.3%, 70%, 82% respectively and in combination 95.75, 90% and 92.5% xiii respectively. UE shows superior diagnostic accuracy compared to mammography though the best diagnostic accuracy is seen when the two modalities are used in combination. Conclusion: Sonoelastography is a noninvasive technique that can be used to complement mammography. It has a high diagnostic accuracy in the evaluation of breast lesions. Combined, the two modalities show the best diagnostic accuracy and cancer detection rate. The study findings therefore, favor the routine and complementary use of UE with mammography in the work-up of breast lesions, with the potential of reducing benign biopsies and/or unwarranted follow-ups while increasing the cancer detection rate.