The added benefit of digital breast tomosynthesis in second breast cancer detection among treated breast cancer patients

Frequency and Outcomes of BI-RADS Category 3 Assessments in Patients With a Personal History of Breast Cancer: Full-Field Digital Mammography Versus Digital Breast Tomosynthesis

BACKGROUND. Studies establishing the validity of BI-RADS category 3 excluded patients with personal history of breast cancer (PHBC). Use of category 3 in patients with PHBC may be impacted not only by this population's increased breast cancer risk, but also by adoption of digital breast tomosynthesis (DBT) over full-field digital mammography (FFDM). OBJECTIVE. The purpose of this article was to compare the frequency, outcomes, and additional characteristics of BI-RADS category 3 assessments between FFDM and DBT in patients with PHBC. METHODS. This retrospective study included 14,845 mammograms in 10,118 patients (mean age, 63 years) with PHBC who had undergone mastectomy and/or lumpectomy. Of these, 8422 examinations were performed by FFDM from October 2014 to September 2016, and 6423 examinations by FFDM with DBT from February 2017 to December 2018, after interval conversion of the center's mammography units. Information was extracted from the EHR and radiology reports. FFDM and DBT groups were compared in the entire sample and among index category 3 lesions (i.e., earliest category 3 assessment per lesion). RESULTS. The frequency of category 3 assessment was lower for DBT than FFDM (5.6% vs 6.4%; p = .05). DBT, compared with FFDM, showed a lower malignancy rate for category 3 lesions (1.8% vs 5.0%; p = .04), higher malignancy rate for category 4 lesions (32.0% vs 23.2%; p = .03), and no difference in malignancy rate for category 5 lesions (100.0% vs 75.0%; p = .24). Analysis of index category 3 lesions included 438 and 274 lesions for FFDM and DBT, respectively. For category 3 lesions, DBT, compared with FFDM, showed lower PPV3 (13.9% vs 36.1%; p = .02) and a more frequent mammographic finding of mass (33.2% vs 23.1%; p = .003). CONCLUSION. The malignancy rate for category 3 lesions in patients with PHBC was less than the accepted limit (2%) for DBT (1.8%), but not FFDM (5.0%). A lower malignancy rate for category 3 lesions but higher malignancy rate for category 4 lesions for DBT supports more appropriate application of category 3 assessment in patients with PHBC through use of DBT. CLINICAL IMPACT. These insights may help establish whether category 3 assessments in patients with PHBC are within benchmarks for early detection of second cancers and reduction of benign biopsies.

The diagnostic value of digital breast tomosynthesis with complementary ultrasound in comparison with magnetic resonance imaging in assessment of postoperative changes and locoregional recurrence of breast cancer

Background

Digital breast tomosynthesis with complementary ultrasound is a powerful imaging modality in detection of breast cancer. Magnetic resonance imaging has many limitations due to its low specificity multiple pitfalls especially signal-to-noise ratio, as well as the spatial resolution. Our purpose of the study is to evaluate the role of digital breast tomosynthesis with complementary ultrasound compared to magnetic resonance imaging in the assessment of postoperative changes and locoregional recurrence of breast cancer.

Results

Our prospective study included thirty women who underwent conservative breast surgery. Digital breast tomosynthesis with complementary ultrasound revealed greater specificity (95.2%) than Magnetic resonance imaging (90.5%) in the detection of locoregional recurrence of breast cancer. On the other hand, it revealed the same sensitivity (88.9%). Subsequently, digital breast tomosynthesis with complementary ultrasound showed higher accuracy (93.3%) and higher positive predictive value (88.9%) than magnetic resonance imaging (90%), (80%), respectively. However, both of them revealed a comparable negative predictive value (95%).

Conclusion

Digital breast tomosynthesis with complementary ultrasound is a powerful imaging modality that can be used to detect any recurrence in patients who are surgically treated for breast cancer with higher specificity, accuracy than magnetic resonance imaging. Additionally, the use of these modalities enhances the diagnosis of surgically treated breast cancer for early detection of recurrence.

Imaging Surveillance of Breast Cancer Survivors with Digital Mammography versus Digital Breast Tomosynthesis

Background Among breast cancer survivors, detecting a breast cancer when it is asymptomatic (rather than symptomatic) improves survival; thus, imaging surveillance in these patients is warranted. Digital breast tomosynthesis (DBT) is used for screening, but data on DBT for surveillance in this high-risk population are limited. Purpose To determine whether DBT leads to improved screening performance metrics when compared with two-dimensional digital mammography among breast cancer survivors. Materials and Methods In this study, screening mammograms obtained in breast cancer survivors before and after DBT implementation were retrospectively reviewed (March 2008-February 2011 for the digital mammography group; January 2013-December 2017 for the DBT group). Mammograms were interpreted by breast imaging radiologists with the assistance of computer-aided detection. Performance metrics and tumor characteristics between the groups were compared using multivariable logistic regression models. Results The digital mammography and DBT groups were composed of 9019 and 22 887 mammographic examinations, respectively, in 8170 women (mean age, 62 years ± 12 [standard deviation]). In the DBT group, the abnormal interpretation rate was lower (5.8% [1331 of 22 887 examinations] vs 6.2% [563 of 9019 examinations]; odds ratio [OR], 0.80; 95% CI: 0.71, 0.91; P = .001) and specificity was higher (95.0% [21 502 of 22 644 examinations] vs 94.7% [8424 of 8891 examinations]; OR, 1.23; 95% CI: 1.07, 1.41; P = .003) than in the digital mammography group. The cancer detection rates did not differ (8.3 per 1000 examinations with DBT vs 10.6 with digital mammography; OR, 0.76; 95% CI: 0.57, 1.02; P = .07). The proportions of screening-detected invasive cancers, versus in situ cancers, were similar (74% [140 of 189 cancers] in the DBT group vs 72% [69 of 96 cancers] in the digital mammography group; P = .69). Of 86 interval cancers, 58% (50 of 86 cancers) manifested with symptoms, and 33% (28 of 86 cancers) were detected at screening MRI. Conclusion Among breast cancer survivors, screening with digital breast tomosynthesis led to fewer false-positive results and higher specificity but did not affect cancer detection. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Hooley and Butler in this issue.