Ultrasonography as a Guiding Method in Breast Micro-Calcification Vacuum-Assisted Biopsies

Purpose: To assess the visibility of breast micro-calcifications using ultrasonography (US) and the accuracy and clinical usefulness of vacuum-assisted biopsy (VAB) using US guidance (USVAB) as compared to stereotactic guidance (SVAB). Materials and Methods: The study material comprised 158 retrospectively reviewed micro-calcification cases examined with US before VAB. The pre-biopsy US positivity frequency distributions were calculated, and the sensitivity, specificity and accuracy of VAB determined by comparing VAB histology with the surgical pathology or a 12-month follow-up. Results: 158 US examinations yielded 80 positive and 78 negative results. US positivity correlated to a large size and a suspicious BI-RADS category of the calcifications. USVAB was performed in 49 cases with 61 % malignant, 12 % high-risk and 27 % benign results. The percentages for the 109 SVAB cases were 40 %, 28 % and 32 %, respectively. Specimen radiography demonstrated calcifications in 48 of the 49 (98 %) USVAB cases and in 107 of the 109 (98 %) SVAB cases. The overall accuracy of VAB was 94 % (USVAB 98 %, SVAB 94 %), the sensitivity was 88 % (USVAB 97 %, SVAB 83 %), and the specificity was 100 %. The higher sensitivity of USVAB was due to an accumulation of atypical hyperplasia diagnoses in the SVAB group. The final diagnosis was invasive ductal carcinoma in 21 US-positive and in 4 US-negative cases. Conclusion: Approximately 50 % of mammographically detected micro-calcifications could be detected with ultrasonography. US was found to be a valuable alternative guidance method for vacuum-assisted biopsy of micro-calcifications with a technical success rate and diagnostic accuracy well comparable to the stereotactic method.