Han Song Mun MD, Abstract Co-Author: Nothing to Disclose

Hak Hee Kim MD, Abstract Co-Author: Nothing to Disclose

Patricia L Ruppel, Abstract Co-Author: Technical Consultant, Innovative Analytics, Inc

Hyunji Kim MD, Abstract Co-Author: Nothing to Disclose

Hee Jung Shin MD, Abstract Co-Author: Nothing to Disclose

Joo Hee Cha, Abstract Co-Author: Nothing to Disclose

Ha-Yeun Oh, Abstract Co-Author: Nothing to Disclose

Eun Young Chae, Presenter: Nothing to Disclose

To prospectively compare the accuracy of digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) in preoperative assessment of local extent of breast cancer.

Lesion sizes of known breast cancers were independently evaluated on DBT (MLO view) and FFDM (MLO & CC views) images by three experienced breast radiologists. Each lesion was flagged as either mis-sized or not, depending on whether the modality assessment of lesion size was within 1 cm of surgical lesion size. Additional analyses were also made by mammographic parenchymal density and by lesion size, using 2 cm as the boundary to separate the two sub-groups. Statistical comparisons between DBT and FFDM lesion size assessments were performed using a repeated measures linear model on the percent mis-sized. Confidence intervals within clinically relevant margins and p-values <0.05 were considered statistically significant.

The initial dataset included 173 breast cancers (mean lesion size 23.8 mm, 43.1% of lesions smaller than 2 cm in size, 82.2% IDC or micro IDC) in 169 patients, two-thirds of which had heterogeneously dense (46.5%) or extremely dense (22.1%) breasts. Overall, the percentage of lesions mis-sized with DBT was significantly lower than with FFDM (19% vs. 29%, p = 0.003). There was consistently less mis-sizing by DBT across all breast densities, but the difference was not significant for fatty or scattered fibroglandular breasts. There was significantly less mis-sizing by DBT in both heterogeneously dense breasts (11.1% difference between DBT and FFDM, p=0.016) and extremely dense breasts (15.8% difference, p=0.024). DBT also had significantly less mis-sizing than FFDM in the sub-group of lesions less than 2 cm in size (14.7% difference, p=0.005).

DBT was significantly superior to FFDM for the evaluation of lesion size overall, and specifically for small lesions and for lesions in dense breasts. Superiority of DBT versus FFDM increased with parenchymal density.

DBT provides added value in making accurate patient management decisions.

Mun, H, Kim, H, Ruppel, P, Kim, H, Shin, H, Cha, J, Oh, H, Chae, E, Assessment of Extent of Breast Cancer: Comparison between Digital Breast Tomosynthesis and Full-field Digital Mammography.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11004653.html