Can the sensitivity/specificity of reporting indeterminate breast calcifications be improved?

Aim

To assess whether the sensitivity and specificity of the current grading system for screen-detected mammographic indeterminate microcalcification can be improved.

Materials and methods

One hundred and twenty-seven screen-detected indeterminate (R3) microcalcifications were retrospectively and independently assessed by six experienced screening radiologists. Information was gathered in relation to specific features of the calcification and their level of suspicion graded 1–4. An informed decision was requested as to outcome. These outcomes were then related to final histological diagnosis.

Results

Of the 127 cases, 32 were histologically malignant and 95 benign. In only 19 cases of R3 microcalcification did all radiologists agree. There was significant interobserver variation. Reader sensitivity was 53% (median, range 31–69%) and specificity was 72% (median, range 57–88%). Cut-off points for features graded 3 or greater gave a change in sensitivity to 64% (median, range 34–88%) and specificity 55% (median, range 34–82%).

Conclusion

Radiological interpretation of indeterminate microcalcification lesions is difficult. Significant variation was identified between individual radiologists. Attention to specific features allows some increase in sensitivity but not enough to obviate biopsy.