2442. Combined Screening with DBT and Supplemental Whole Breast Ultrasound Does Not Increase Screening Recall Rates in Women with Dense Tissue
Authors * Denotes Presenting Author
  1. Liane Philpotts; Yale School of Medicine
  2. Cameron Thomson *; UMass Medical School
  3. Reni Butler ; Yale School of Medicine
Supplemental screening for women with dense breast is an important and timely issue with multiple state and federal density notification legislation recently instituted. Screening ultrasound is a relatively low cost, non-invasive option, however is widely criticized for having a high false positive rate and thereby increasing screening recall rates. Digital breast tomosynthesis (DBT) has been shown to decrease mammography screening recall rate. The purpose of this study was to determine the overall abnormal interpretation rate of women with dense breasts undergoing both DBT and WBUS and compare to those undergoing DBT screening only in an established DBT and WBUS program.

Materials and Methods:
An IRB-approved (with waived informed consent) search of the breast imaging electronic database (PenRad, MN) was performed to identify all women undergoing screening DBT mammography as well as those undergoing WBUS at a tertiary academic cancer center and 3 satellite offices for a one-year period (1/1/2019 – 12/31/2019). Screening WBUS was performed by trained technologists and interpreted online by radiologists onsite to check abnormal findings. Abnormal interpretations were considered for BR0,4,5 assessment on screening DBT and BR3,4, or 5 on WBUS. Abnormal interpretations rates for women opting for WBUS performed in conjunction with DBT were compared to those women undergoing DBT only.

During the one year period 12,649 DBT screenings were performed in women with heterogeneously (11,314) or extremely (1335) dense breasts. The DBT screening mammography BR0 rate for women with dense tissue was 6.8% (855/12649). 4115 (33%) women underwent DBT only and 8534 (67%) women underwent concurrent WBUS. For women undergoing DBT only the BR0 rate was 14% (575/4115). For women undergoing DBT and WBUS the DBT BR0 rate was 3.3% (280/8534). In those women undergoing supplemental WBUS the abnormal interpretation rate of WBUS was 3% (253/8534). This yielded a combined screening abnormal interpretation rate of 6.2% (533/8534). The overall abnormal interpretation rate for women undergoing combined DBT and WBUS is significantly lower than those undergoing DBT alone (p < 0.00001).

Women with dense tissue who opt for supplemental WBUS have a significantly lower combined abnormal interpretation rate than women who do not undergo supplemental WBUS. This is likely due to improved confidence of the radiologist in interpreting DBT in conjunction with WBUS and the ability to generate a more comprehensive assessment by combining findings on both exams. This is important as women with dense breast tissue can benefit from additional cancer detection without adverse false positives.