Role of Digital Breast Tomosynthesis in Screening and Diagnostic Breast Imaging

Literature review on the bilateral occurrence of invasive lobular breast cancer

Historically, it has been believed that invasive lobular carcinomas (ILC) occur more frequently bilaterally compared to other invasive subtypes, with estimates ranging between 20% and 29%. This study aims to determine if this historical perspective still holds true. A comprehensive literature review was conducted to examine the bilateral occurrence of lobular carcinoma using various imaging methods. Additionally, the role of magnetic resonance imaging (MRI) in detecting contralateral carcinomas was also investigated. A comprehensive search was conducted in the MedLine database on the PubMed platform, resulting in 307 articles published between January 1, 2014, and January 1, 2023. Various selection criteria were applied to identify articles relevant to the research question. After careful assessment, eight articles remained that met the eligibility criteria, all of which provided level-three evidence and were therefore included in the literature review. A total of 599 patients were included in this review, comprising a total of 602 cases of ILC. Six out of the eight articles reviewed provided information on the bilateral occurrence of ILC based on histopathology. A weighted average calculation yielded a bilaterality percentage of 4.95% (24 out of 485 cases). Four articles reported the number of bilateral cases identified through MRI, resulting in a weighted average of 10.2% (26 out of 255 cases). It is worth noting that 20.4% (100 out of 491) of the performed MRIs were found to be either useless or even harmful. Furthermore, MRI led to a change in the treatment plan in 27.7% (136 out of 491) of cases. Overall, it can be concluded that there is limited available data regarding the bilateral occurrence of ILC. The numbers found in the literature are also inconsistent and tend to vary. The literature review revealed a decrease in the percentage of bilaterality compared to historical beliefs. Based on this study, it can be concluded that a high number of MRI scans were found to be either useless or harmful. As a result of this conclusion and a higher sensitivity of other screening modalities, MRI may no longer be indicated as part of the standard workup for ILC. However, further research is necessary to validate these findings.

Clinicopathological and imaging features of ductal carcinoma in situ in BRCA1/2 mutation carriers

BACKGROUND

BRCA1/2-associated invasive breast cancer has been extensively studied. However, there are few reports of ductal carcinoma in situ (DCIS).

OBJECTIVE

This study aimed to investigate the clinicopathological and imaging findings of DCIS in patients with BRCA1/2 mutations.

METHODS

This was a single-institution, retrospective study. We identified patients diagnosed with DCIS with BRCA mutations between September 2003 and December 2020. Clinicopathological data and mammography (MG), magnetic resonance imaging (MRI), and ultrasound (US) findings were reviewed.

RESULTS

We identified 30 cancers in 28 patients; 7 (25.0%) patients had BRCA1 mutations, and 21 (75.0%) had BRCA2 mutations. The median patient age was 42 years. Screening was the most common reason for the detection of DCIS (50.0%), followed by occult cancer diagnosed by pathological examination after risk-reducing mastectomy (26.7%). The nuclear grade was most often 1 (46.7%), and 93.3% were estrogen and/or progesterone receptor positive. The detection rates of MG, MRI, and US were 64.3%, 72.0%, and 64.0%, respectively. The most common imaging findings were calcification (100%) on MG, non-mass enhancement (88.9%) on MRI, and hypoechoic area (75.0%) on US.

CONCLUSION

BRCA-associated DCIS was more strongly associated with BRCA2, and imaging features were similar to those of sporadic DCIS. Our results are helpful in informing surveillance strategies based on genotypes in women with BRCA mutations.

Diagnostic Challenge of Invasive Lobular Carcinoma of the Breast: What Is the News? Breast Magnetic Resonance Imaging and Emerging Role of Contrast-Enhanced Spectral Mammography

Invasive lobular carcinoma is the second most common histologic form of breast cancer, representing 5% to 15% of all invasive breast cancers. Due to an insidious proliferative pattern, invasive lobular carcinoma remains clinically and radiologically elusive in many cases. Breast magnetic resonance imaging (MR) is considered the most accurate imaging modality in detecting and staging invasive lobular carcinoma and it is strongly recommended in pre-operative planning for all ILC. Contrast-enhanced spectral mammography (CESM) is a new diagnostic method that enables the accurate detection of malignant breast lesions similar to that of breast MR. CESM is also a promising breast imaging method for planning surgeries. In this study, we compare the ability of contrast-enhanced spectral mammography (CESM) with breast MR in the preoperative assessment of the extent of invasive lobular carcinoma. All patients with proven invasive lobular carcinoma treated in our breast cancer center underwent preoperative breast MRI and CESM. Images were reviewed by two dedicated breast radiologists and results were compared to the reference standard histopathology. CESM was similar and in some cases more accurate than breast MR in assessing the extent of disease in invasive lobular cancers. Further evaluation in larger prospective randomized trials is needed to validate our preliminary results.

Evaluation of Breast Galactography Using Digital Breast Tomosynthesis: A Clinical Exploratory Study

Objectives: To compare the application value of digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) in breast galactography. Materials and Methods: A total of 128 patients with pathological nipple discharge (PND) were selected to undergo galactography. DBT and FFDM were performed for each patient after injecting the contrast agent; the radiation dose of DBT and FFDM was calculated, and the image quality was evaluated in consensus by two senior breast radiologists. Histopathologic data were found in 49 of the 128 patients. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for both FFDM- and DBT-galactography were calculated using histopathologic results as a reference standard. Data were presented as percentages along with their 95% confidence intervals (CI). Results: The average age of the 128 patients was 46.53 years. The average glandular dose (AGD) of DBT-galactography was slightly higher than that of FFDM-galactography (p < 0.001). DBT-galactography was 30.7% higher than FFDM-galactography in CC view, while DBT-galactography increased by 21.7% compared with FFDM-galactography in ML view. Regarding catheter anatomic distortion, structure detail, and overall image quality groups, DBT scores were higher than FFDM scores, and the differences were significant for all measures (p < 0.05). In 49 patients with pathological nipple discharge, we found that the DBT-galactography had higher sensitivity, specificity, PPV, and NPV (93.3%, 75%, 97.7%, and 50%, respectively) than FFDM-galactography (91.1%, 50%, 95.3%, and 33.3%, respectively). Conclusions: Compared to FFDM-galactography, within the acceptable radiation dose range, DBT-galactography increases the sensitivity and specificity of lesion detection by improving the image quality, providing more confidence for the diagnosis of clinical ductal lesions.

Imaging of Breast Cancers With Predilection for Nonmass Pattern of Growth: Invasive Lobular Carcinoma and DCIS-Does Imaging Capture It All?

OBJECTIVE. Invasive lobular carcinoma (ILC) and ductal carcinoma in situ (DCIS) are distinct histopathologic entities with several commonalities: both have subtle clinical and imaging presentation, have been linked with controversy regarding optimal imaging techniques and management, and exemplify the codependence of adequate imaging evaluation and optimal treatment strategies in breast care. CONCLUSION. We review molecular mechanisms and histopathologic patterns that define the biologic behavior of both ILC and DCIS and discuss how these mechanisms translate into distinct clinical and imaging presentations that affect the staging workup and patient management algorithm.

[Image-based screening]

Screening is a special issue in medical questions concerning disease prevention. Preconditions for screening are clearly defined by the World Health Organization. High prevalence, effectiveness of therapy, availability of accepted test procedure and consensus concerning the economic concerns are necessary for successful implementation of a screening program. Preventive diagnostic studies can only be understood if one is familiar with the statistical terms sensitivity, specificity, prevalence, incidence and bias (especially overdiagnosis and lead time bias). Aspects of radiation protection are especially important in asymptomatic volunteers. The new radiation protection law in Germany also gives the opportunity to define new screening procedures even with use of radiation exposure in individual prevention programs. Potential diseases for radiological secondary prevention with high mortality are malignant tumors (especially breast cancer, lung cancer, colorectal cancer) and cardiovascular diseases (coronary heart disease, stroke or aortic aneurysm).

[Digital breast tomosynthesis in diagnosis of dense breast lesions]

OBJECTIVE

To evaluate the value of digital breast tomosynthesis (DBT) in diagnosis of dense breast lesions.

METHODS

Clinical and pathological data of 163 patients (58 benign lesions, 122 malignant lesions, and 180 lesions in total) with breast lesions undergoing surgical treatment in Shaoxing Central Hospital from January 2017 to December 2018 were retrospectively analyzed. The lesions were classified into non-homogeneous dense gland type and extremely dense gland type according to BI-RADS creterion. Breast MRI and DBT examinations were performed before the surgery. ROC curve was generated and the diagnostic efficacy of two examination methods for dense breast lesions was evaluated with pathological results as the gold standard. The detection rate, diagnostic accuracy of benign and malignant breast lesions were compared between two methods using chi-square test. The accuracy of lesion size preoperatively evaluated by MRI and DBT was analyzed by Pearson correlation.

RESULTS

The detection rate and diagnostic accuracy for benign breast lesions by MRI were higher than those by DBT (91.4% vs. 75.9%, χ²=5.098, P<0.05 and 89.7% vs. 67.2%, χ²=8.617, P<0.01). But there were no significant differences in detection rate and accuracy for malignant lesions by MRI and DBT (98.4% vs. 95.1%, χ²=2.068, P>0.05 and 94.3% vs. 91.8%, χ²=0.569, P>0.05). The areas under the ROC curves of MRI, DBT based on BI-RADS classification were 0.910 and 0.832, respectively (Z=1.860, P>0.05). The sensitivities of MRI, DBT to breast lesions were 93.3% and 86.7%, and the specificities were 68.3% and 79.1%. DBT and MRI measurements were positively correlated with pathological measurements (r=0.887 and 0.949, all P<0.01).

CONCLUSIONS

DBT can effectively diagnose benign and malignant breast lesions under dense gland background, and it has similar diagnostic efficacy with MRI for breast malignant lesions.

Architectural distortion in the era of digital breast tomosynthesis: outcomes and implications for management

PURPOSE

Digital breast tomosynthesis (DBT) has been shown to increase conspicuity of some mammographic findings, particularly architectural distortion (AD). The purpose of this retrospective study was to determine the positive predictive value of AD on diagnostic DBT, and evaluate associations between AD characteristics and histopathologic outcomes.

METHODS

This IRB-approved, HIPAA-compliant study included diagnostic DBT exams performed between 1/2014 and 12/2015 that demonstrated AD. Imaging characteristics of AD, corresponding ultrasound and MRI exams, and pathology results were reviewed. Fisher's exact tests and a two-tailed t-test were performed.

RESULTS

Seventy-seven cases of AD were visualized in 68 patients (ages 36-78 years, mean 54 years). Core biopsy of 74 cases of AD yielded malignant pathology in 26/74 (35%) tissue samples. Among 48/74 (65%) non-malignant cases of AD, 25 demonstrated a high-risk lesion, including radial scar in 20, with no upgrades to malignancy among 20 high-risk lesions that underwent surgical excision. Among 23 non high-risk causes of benign AD, stromal fibrosis was most common, present in 12 biopsy specimens. Associations between imaging characteristics of AD on DBT and histopathologic outcome were not statistically significant (one-view visualization 3/13 malignant, 10/13 benign, P = 0.52; DBT-only finding 1/11 malignant, 10/11 benign, P = 0.09). Of 48 cases with an ultrasound correlate, 22/48 (46%) were malignant versus 4/26 (15%) cases without an ultrasound correlate (P = 0.01).

CONCLUSIONS

AD on diagnostic DBT was malignant in over one-third of cases. The presence of an ultrasound correlate was associated with malignancy.