E1944. The Usefulness of Selective Addition of Breast-Specific Gamma Imaging to Mammography in Women with Dense Breasts
  1. Young Joong Kim; Konyang University Hospital
  2. Rae Rim Ryu; Konyang University Hospital
  3. Jae Young Seo; Konyang University Hospital
  4. KeumWon Kim; Konyang University Hospital
  5. Cheol Mog Hwang; Konyang University Hospital
Mammography (MG) has been adopted as a screening modality for breast cancer; however, the diagnostic yield was reported to decrease in women with dense breasts. Several modalities have been introduced to improve the drawbacks. Breast-specific gamma imaging (BSGI), a nuclear medicine imaging technique, has been introduced as a supplementary tool for diagnosing breast cancer. This study evaluated whether the selective addition of BSGI according to MG category could improve the diagnostic accuracy and reduce unnecessary examinations or biopsies.

Materials and Methods:
This retrospective study was conducted on 548 patients with 628 breast lesions from February 2013 to December 2018. We compared the performances of BSGI with those of MG among the overall group, dense and non-dense groups for malignant breast lesions. We also performed subgroup analyses through the selective addition of BSGI results according to the MG results. It was divided into three subgroups: BSGI +- MG, BSGI +- MG0, and BSGI +- MG4a. For each subgroup, diagnostic performance was calculated in overall and dense/non-dense divided by breast density. Factors associated with false-negative BSGI were evaluated.

The specificity and AUC of BSGI (specificity, 81.44%; AUC, 0.85) were significantly higher than those of MG (specificity, 66.83%; AUC, 0.77) (p <0.001). In terms of sensitivity, BSGI (88.39%) was comparable to MG (87.95%). The sensitivity and specificity of BSGI showed no significant difference according to breast density, whereas the specificity of MG was significantly higher in women with dense breasts. And BSGI showed a significantly higher NPV in dense breasts. In subgroups analysis, the specificity and AUC of BSGI +- MG did not show superior results to those of MG alone. The selective BSGI addition to MG result, the AUC and sensitivity of BSGI +- MG0 or BSGI +- MG4a were significantly higher than those of MG alone. In women with dense breasts, AUC and sensitivity were significantly higher in BSGI +- MG0 or BSGI +- MG4a, whereas no subgroups showed a significant difference with MG except for the specificity and AUC of BSGI +- MG4a in non-dense breasts. A nodule = 10 mm and a low Ki-67 were significantly associated with false-negativity of BSGI.

In this study, the addition of BSGI to MG showed higher sensitivity and AUC than MG alone. Particularly, the selective addition of BSGI to MG category 0 or 4a lesions in dense breasts improved the diagnostic accuracy. Breast-specific gamma imaging could be helpful as a supportive tool for MG for detecting breast cancer, even in dense breasts.