Image-guided biopsy of mammographic microcalcifications

Aims

To audit the accuracy of radiographers taking stereotactic core biopsies. To study whether cluster morphology influences calcium retrieval rates. To compare radiological opinion against histological findings.

Methods and materials

Retrospective analysis of all stereotactic 14G core biopsies performed in a Breast Screening Unit over an 18-month period (January 2004–June 2005). Usage of department database, mammograms and case notes.

Results

Of 300 biopsies, 264 were performed by radiographers. All cases had specimen radiography. The calcium retrieval rate was 80% in early 2004 and 95% by the end of July 2005.

The calcifications were classified into cluster, tiny cluster and scattered cluster, according to the mammographic appearances. In the negative biopsies they were 32%, 43% and 25%, respectively.

The comparison between the radiologist opinion against the final core biopsy results shows 90% concordance with pathology for opinions 2 and 5, and 75% for opinions 3 and 4.

Conclusion

Calcium retrieval rates for radiographers initially matched, then exceeded, those for radiologists. They also showed a steady improvement during the study period, rising to 95%. The cluster morphology did influence the calcium retrieval rate. There was a good concordance of radiology and pathology opinion.