Published in:
01-01-2015 | Breast
Characterisation of microcalcification clusters on 2D digital mammography (FFDM) and digital breast tomosynthesis (DBT): does DBT underestimate microcalcification clusters? Results of a multicentre study
Published in: European Radiology | Issue 1/2015
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Objectives
To compare DBT and FFDM in the classification of microcalcification clusters (MCs) using BI-RADS.
Methods
This Institutional Review Board-approved study was undertaken in three centres.
A total of 107 MCs evaluated with both DBT and FFDM were randomised for prospective reading by six experienced breast radiologists and classified using BI-RADS.
Results
The benign/malignant ratio of MC was 66/41. Of 11/107 discordant results, DBT classified MCs as R2 whereas FFDM classified them as R3 in 9 and R4 in 2. Three of these (3/107 = 2.8 %) were malignant; 8 (7.5 %) were nonmalignant and were correctly classified as R2 on DBT but incorrectly classified as R3 on FFDM. Estimated sensitivity and specificity, respectively, were 100 % (95 % CI: 91 % to 100 %) and 94.6 % (95 % CI: 86.7 % to 98.5 %) for FFDM and 91.1 % (95 % CI: 78.8 % to 97.5 %) and 100 % (95 % CI: 94.8 % to 100 %) for DBT. Overall intra- and interobserver agreements were 0.75 (95 % CI: 0.61-0.84) and 0.73 (95 % CI: 0.62-0.78).
Conclusions
Most MCs are scored similarly on FFDM and DBT. Although a minority (11/107) of MCs are classified differently on FFDM (benign MC classified as R3) and DBT (malignant MC classified as R2), this may have clinical relevance.
Key Points
• The BI-RADS classification of MC differs for FFDM and DBT in 11/107 cases
• DBT assigned lower BI-RADS classes compared to FFDM in 11 clusters
• In 4/107 DBT may have missed some malignant and high-risk lesions
• In 7/107 the ‘underclassification’ on DBT was correct, potentially avoiding unnecessary biopsies
• DBT may miss a small proportion of malignant lesions