Digital Mammography versus Contrast Enhanced Spectral Mammography in the Evaluation of Cases with Suspicious Breast Calcifications and its Impact on Surgeon’s Decision

Abstract Background Digital mammography (DM) is still considered the most reliable imaging technique and gold standard for detecting breast microcalcifications. However, differentiating between benign and malignant microcalcifications based on their shape and distribution can be further improved when combined with pathological contrast enhancement in a rapid Contrast Enhanced Spectral Mammography (CESM) modality. Purpose This study aims to assess the diagnostic accuracy of CESM in suspicious breast calcifications as well as lesion extent and its impact on surgeon’s decision-making. Methods and materials This study is a prospective study that was approved by the Research Ethical Committees of the Radiology Department at Ain Shams University as well as the Radiology Department at the National Cancer Institute. It included 50 patients (with 54 breast lesions) with suspicious breast calcifications on DM. They were all scheduled for CESM. The identified lesions were classified into enhancing and non enhancing lesions. These lesions were further classified into benign and malignant by biopsy and histopathology, or follow up. The sensitivity, specificity, positive and negative predictive values and total accuracy of DM and CESM were calculated and compared when using each of the studied modalities alone and when adding the two modalities together in diagnosis. Further more, Wilcox-signed rank test was used to compare largest diameter of lesions by both DM and CESM in comparison to histopathology in cases who underwent excisional biopsy. Non parametric correlation analysis using spearman rho test was used to test association of tumor size by different measures (DM, CESM and histopathology). Results Out of the 54 identified breast lesions, 19/54, 35% were benign and 35/54, 65% were malignant. The calculated sensitivity, specificity, positive and negative predictive values and total accuracy of DM were 91.4%, 70.8%, 62.7%, 93.9%, and 78% respectively as compared to 85.7%, 90.7%, 83.3%, 92.2%, and 89% for CESM. When adding CESM to DM the calculated diagnostic indices were raised to 100%, 70.8%, 64.8%, 100%, and 81% respectively. Regarding size estimation, Results showed that size of tumor by CESM was more correlated to that by pathology, correlation coefficient (r = 0.86), than DM and pathology, (r = 0.588). Mean difference in diameter (compared to pathology) for CESM was 1.28 mm, and 2.8 mm for DM, with no effects on surgical decision making. Cronbach's Alpha as a measure of reliability was 0.740 between size measurement by DM and pathology, indicating acceptable reliability. But it was 0.92 between CESM and pathology, indicating excellent reliability. Conclusion CESM is more specific than DM or when the results are combined. Also, the size of tumor by CESM was more correlated to that by pathology than that between DM and pathology. Yet these minute differences in measurements did not affect the surgical decision making. However, the surgical decision was significantly affected in cases that showed multicentricity detected by CESM but missed in initial mammography reports.