Decoding the Prevalent High-Risk Breast Cancers: Demographics, Pathological, Imaging Insights, and Long-Term Outcome.

Objective: To investigate the features and outcomes of breast cancer in high-risk subgroups. Materials and Methods: REB approved an observational study of women diagnosed with breast cancer from 2010 to 2019. Three radiologists, using the BI-RADS lexicon, blindly reviewed mammogram and MRI screenings without a washout period. Consensus was reached with 2 additional reviewers. Inter-rater agreement was measured by Fleiss Kappa. Statistical analysis included Mann-Whitney U, Chi-square tests for cohort analysis, and Kaplan-Meier for survival rates, with a Cox model for comparative analysis using gene mutation as a reference. Results: The study included 140 high-risk women, finding 155 malignant lesions. Significant age differences noted: chest radiation therapy (median age 44, IQR: 37.0-46.2), gene mutation (median age 49, IQR: 39.8-58.0), and familial risk (median age 51, IQR: 44.5-56.0) (P = .007). Gene mutation carriers had smaller (P = .01), higher-grade tumours (P = .002), and more triple-negative ER- (P = .02), PR- (P = .002), and HER2- (P = .02) cases. MRI outperformed mammography in all subgroups. Substantial to near-perfect inter-rater agreement observed. Over 10 years, no deaths occurred in chest radiation group, with no significant survival difference between gene mutation and familial risk groups, HR = 0.93 (95% CI: 0.27, 3.26), P = .92. Conclusion: The study highlights the importance of age and specific tumour characteristics in identifying high-risk breast cancer subgroups. MRI is confirmed as an effective screening tool. Despite the aggressive nature of cancers in gene mutation carriers, early detection is crucial for survival outcomes. These insights, while necessitating further validation with larger studies, advocate for a move toward personalized medical care, strengthening the existing healthcare guidelines.

Primary MALT lymphoma of the breast: pathological and radiological characteristics.

PURPOSE: Primary Mucosa-associated lymphoid tissue (MALT) lymphoma is a rare diagnosis in the breast, and clinical diagnosis based on radiological features is often challenging. This study aimed to evaluate the clinicopathological, and radiological characteristics of the patients diagnosed with primary breast MALT lymphoma. METHODS: This study examined 18 cases of primary MALT lymphoma of the breast diagnosed at a single tertiary center between January 2002 to December 2020. Medical charts, radiological imaging and original pathology slides were reviewed for each case. RESULTS: All cases were female (gender assigned at birth) and presented with a palpable mass or an incidental imaging finding. Imaging presentation ranged from mammographic asymmetries, circumscribed masses, and ultrasound masses lacking suspicious features. Seventeen cases were biopsied under ultrasound; one received a diagnostic excision biopsy. Microscopic examination of the breast specimens demonstrated atypical small lymphocyte infiltration with plasmacytoid differentiation and rare lymphoepithelial lesions. Immunohistochemistry was performed in all cases and established the diagnosis. Most patients were treated with radiotherapy, and only three were treated with chemotherapy. The median follow-up period was 4 years and 7.5 months, and all patients were alive at the last follow-up. CONCLUSION: Primary MALT breast lymphomas are usually indolent and non-systemic, and local radiotherapy may effectively alleviate local symptoms. Radiological findings show overlap with benign morphological features, which can delay the diagnosis of this unusual etiology. Although further studies involving a larger cohort could help establish the clinical and radiological characteristics of primary breast MALT lymphomas, pathology remains the primary method of diagnosis. TRIAL REGISTRATION NUMBER: University Health Network Ethics Committee (CAPCR/UHN REB number 19-5844), retrospectively registered.

Evaluating persistent T1-weighted lesions without concurrent abnormal enhancement on breast MRI in neoadjuvant chemotherapy patients: implications for complete pathological response.

OBJECTIVE: This study aims to determine whether persistent T1-weighted lesions signify a complete pathological response (pCR) in breast cancer patients treated with neoadjuvant chemotherapy and surgery, and to evaluate their correlation with imaging responses on MRI. MATERIALS AND METHODS: A retrospective review was conducted on data from breast cancer patients treated between January 2011 and December 2018. Patients who underwent breast MRI and pre- and post-neoadjuvant chemotherapy followed by surgery were included. Those with distant metastasis, no planned surgery, pre-surgery radiation, ineligibility for neoadjuvant chemotherapy, or unavailable surgical pathology were excluded. Groups with and without persistent T1-weighted lesions were compared using the chi-square test for categorical variables and the Student t test or Wilcox rank sum test for continuous variables. Univariate logistic regression was used to evaluate the association of the final pathological response with the presence of T1-persistent lesion and other characteristics. RESULTS: Out of 319 patients, 294 met the inclusion criteria (breast cancer patients treated with neoadjuvant chemotherapy and subsequent surgery); 157 had persistent T1 lesions on post-chemotherapy MRI and 137 did not. A persistent T1 lesion indicated reduced likelihood of complete pathological response (14% vs. 39%, p < 0.001) and imaging response (69% vs. 93%, p < 0.001). Multivariable analysis confirmed these findings: OR 0.37 (95% CI 0.18-0.76), p = 0.007. No other characteristics correlated with T1 residual lesions. CONCLUSION: Persistent T1-weighted lesions without associated abnormal enhancement on post-treatment breast MRI correlate with lower complete pathological and imaging response rates. CLINICAL RELEVANCE STATEMENT: The study underscores the importance of persistent T1-weighted lesions on breast MRI as vital clinical markers, being inversely related to a complete pathological response following neoadjuvant chemotherapy; they should be a key factor in guiding post-neoadjuvant chemotherapy treatment decisions. KEY POINTS: • Persistent T1 lesions on post-chemotherapy breast MRI indicate a reduced likelihood of achieving a complete pathological response (14% vs. 39%, p < 0.001) and imaging response (69% vs. 93%, p < 0.001). • Through multivariable analysis, it was confirmed that the presence of a persistent T1 lesion on breast MRI post-chemotherapy is linked to a decreased likelihood of complete pathological response, with an odds ratio (OR) of 0.37 (95% CI 0.18-0.76; p = 0.007). • In addition to the convention of equating the absence of residual enhancement to complete imaging response, our results suggest that the presence or absence of residual T1 lesions should also be considered.

MRI-visualized T2 hyperintense breast lesions: identifying clinical and imaging factors linked to malignant biopsy outcomes.

PURPOSE: To determine the malignancy rate for MRI-guided breast biopsies performed for T2 hyperintense breast lesions and to assess additional clinical and MRI characteristics that can predict benign and malignant outcomes. METHODS: A retrospective chart review of consecutive MRI-guided breast biopsies performed in two tertiary hospitals was conducted over two years. Biopsies performed for T2 hyperintense lesions were selected, and further lesion imaging characteristics and patient risk factors were collected. Univariate and multivariate modeling regression were used to determine additional imaging and patient factors associated with malignant outcomes for biopsies of T2 hyperintense lesions. RESULTS: Out of 369 MRI-guided breast biopsies, 100 (27%) were performed for T2 hyperintense lesions. Two biopsy-proven benign lesions were excluded as the patient was lost on follow-up. With a study cohort of 98 lesions, the final pathology results were benign for 80 (80%) of these lesions, while 18 (18%) were malignant. Using multivariate logistic modeling, patient age > 50 (OR 5.99 (1.49, 24.08 95% CI), p < 0.05) and lesion size > 3 cm (OR 5.54 (1.54-18.7), p < 0.01) were found to be important predictors of malignant outcomes for MRI biopsies performed for T2 hyperintense lesions. CONCLUSION: Our study observed a high malignancy rate, challenging the assumption that T2 hyperintensity can be considered a benign imaging characteristic for otherwise suspicious MRI-detected lesions. Decision-making regarding tissue sampling should be made based on a thorough evaluation of more reliable additional demographic and imaging factors, including patient age and lesion size.

Breast Cancer Detection Using a Low-Dose Positron Emission Digital Mammography System.

Purpose To investigate the feasibility of low-dose positron emission mammography (PEM) concurrently to MRI to identify breast cancer and determine its local extent. Materials and Methods In this research ethics board-approved prospective study, participants newly diagnosed with breast cancer with concurrent breast MRI acquisitions were assigned independently of breast density, tumor size, and histopathologic cancer subtype to undergo low-dose PEM with up to 185 MBq of fluorine 18-labeled fluorodeoxyglucose (18F-FDG). Two breast radiologists, unaware of the cancer location, reviewed PEM images taken 1 and 4 hours following 18F-FDG injection. Findings were correlated with histopathologic results. Detection accuracy and participant details were examined using logistic regression and summary statistics, and a comparative analysis assessed the efficacy of PEM and MRI additional lesions detection (ClinicalTrials.gov: NCT03520218). Results Twenty-five female participants (median age, 52 years; range, 32-85 years) comprised the cohort. Twenty-four of 25 (96%) cancers (19 invasive cancers and five in situ diseases) were identified with PEM from 100 sets of bilateral images, showcasing comparable performance even after 3 hours of radiotracer uptake. The median invasive cancer size was 31 mm (range, 10-120). Three additional in situ grade 2 lesions were missed at PEM. While not significant, PEM detected fewer false-positive additional lesions compared with MRI (one of six [16%] vs eight of 13 [62%]; P = .14). Conclusion This study suggests the feasibility of a low-dose PEM system in helping to detect invasive breast cancer. Though large-scale clinical trials are essential to confirm these preliminary results, this study underscores the potential of this low-dose PEM system as a promising imaging tool in breast cancer diagnosis. ClinicalTrials.gov registration no. NCT03520218 Keywords: Positron Emission Digital Mammography, Invasive Breast Cancer, Oncology, MRI Supplemental material is available for this article. © RSNA, 2024 See also commentary by Barreto and Rapelyea in this issue.

Breast Magnetic Resonance Imaging for Preoperative Evaluation of Breast Cancer: A Systematic Review and Meta-Analysis.

Purpose: Preoperative breast magnetic resonance imaging (MRI) is known to detect additional cancers that are occult on mammography and ultrasound. There is debate as to whether these additional lesions affect clinical outcomes. The objective of this systematic review was to summarize the evidence on whether additional information on disease extent obtained with preoperative breast MRI in patients with newly diagnosed breast cancer affects surgical management, rates of recurrence, survival, re-excision, and early detection of bilateral cancer. Methods: Embase, MEDLINE, and Cochrane Central Register of Controlled Trials were searched until January 2021 (partial update July 2022) for studies comparing outcomes with versus without pre-operative MRI. Included were both randomized controlled trials and other comparative studies provided MRI and control groups had equivalent disease and patient characteristics or methods such as multivariable analysis or propensity score matching were used to control potential confounders. Results: The search resulted in 26,399 citations, of which 8 randomized control trials, 1 prospective cohort study, and 42 retrospective studies met the inclusion criteria. Use of MRI resulted in decreased rates of reoperations (OR = 0.73, 95% CI = 0.63 to 0.85), re-excisions (OR = 0.63, 95% CI = 0.45 to 0.89), and recurrence (HR = 0.77, 95% CI = 0.65 to 0.90). Increased detection of synchronous contralateral breast cancers led to a reduction in metachronous contralateral breast cancer (HR = 0.71, 95% CI = 0.59 to 0.85). Hazard ratios for recurrence-free and overall survival were 0.77 (95% CI = 0.53 to 1.12) and 0.89 (95% CI = 0.74 to 1.07). Conclusion: This systematic review indicates substantial benefits of pre-operative breast MRI in decreasing reoperations and recurrence.

Canadian Association of Radiologists Breast Disease Imaging Referral Guideline.

The Canadian Association of Radiologists (CAR) Breast Disease Expert Panel consists of breast imaging radiologists, a high-risk breast clinician, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 20 clinical/diagnostic scenarios, a systematic rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 30 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) for guidelines framework were used to develop 69 recommendation statements across the 20 scenarios. This guideline presents the methods of development and the recommendations for referring asymptomatic individuals, symptomatic patients, and other scenarios requiring imaging of the breast.

Preoperative Breast Magnetic Resonance Imaging: An Ontario Health (Cancer Care Ontario) Clinical Practice Guideline.

BACKGROUND: The use of preoperative breast magnetic resonance imaging (MRI) after the diagnosis of breast cancer by mammography and/or ultrasound is inconsistent. METHODS: After conducting a systematic review and meta-analysis comparing preoperative breast MRI versus no MRI, we reconvened to prepare a clinical practice guideline on this topic. RESULTS: Based on the evidence that MRI improved recurrence, decreased the rates of reoperations (re-excisions or conversion mastectomy), and increased detection of synchronous contralateral breast cancer, we recommend that preoperative breast MRI should be considered on a case-by-case basis in patients diagnosed with breast cancer for whom additional information about disease extent could influence treatment. Based on stronger evidence, preoperative breast MRI is recommended in patients diagnosed with invasive lobular carcinoma for whom additional information about disease extent could influence treatment. For both recommendations, the decision to proceed with MRI would be conditional on shared decision-making between care providers and the patient, taking into account the benefits and risks of MRI as well as patient preferences. Based on the opinion of the Working Group, preoperative breast MRI is also recommended in the following more specific situations: (a) to aid in surgical planning of breast conserving surgery in patients with suspected or known multicentric or multifocal disease; (b) to identify additional lesions in patients with dense breasts; (c) to determine the presence of pectoralis major muscle/chest wall invasion in patients with posteriorly located tumours or when invasion of the pectoralis major muscle or chest wall is suspected; (d) to aid in surgical planning for skin/nipple-sparing mastectomies, autologous reconstruction, oncoplastic surgery, and breast conserving surgery with suspected nipple/areolar involvement; and (e) in patients with familial/hereditary breast cancer but who have not had recent breast MRI as part of screening or diagnosis.

Effects of delayed callback from screening mammography due to the COVID-19 pandemic.

OBJECTIVE: To determine the frequency and distinguishing imaging characteristics of breast cancers detected on screening mammography which was initially evaluated as a probably benign lesion and the workup was delayed due to the COVID-19 pandemic. MATERIALS AND METHODS: REB-approved multicenter retrospective screening mammography studies and patient's chart review carried out between February 2020 and March 2020. According to an institutional decision, the frequency and imaging findings deemed probably benign on screening mammography after review by a breast fellowship-trained radiologist with workup deferred until after the first pandemic wave plateau in late July 2020 were recorded. Results were correlated with histopathology if tissue sample performed or an uneventful 2 years follow-up. Descriptive statistical analysis was used to describe the retrieved data set. RESULTS: Out of 1816 mammography screening between February 2020 and March 2020, 99 women, median age 58 years (range 35-84), 99 mammography had possibly benign findings with workup delayed, and two patients, age 49 and 56, had cancers (2.02%), misinterpreted as benign findings. Both malignant cases were focal asymmetries, with pathology of invasive ductal carcinoma, 12 mm and 9 mm in size. No in-situ carcinoma was detected. CONCLUSION: The low rate of cancer detected suggests that a delay callback may be a reasonable option for some likely benign findings when immediate callback is not an option, such as during a pandemic. Larger studies would be helpful to support our findings and may allow us to translate the adoption of such a model during potential future pandemic. CLINICAL RELEVANCE: The results of this study may be helpful for a future situation when delaying a call back from screening mammography is again required.

False-positive incidental lesions detected on contrast-enhanced breast MRI: clinical and imaging features.

PURPOSE: To identify demographic and imaging features of MRI-detected enhancing lesions without clinical, ultrasound, and mammographic correlation associated with false-positive outcomes, impacting patient care. MATERIALS AND METHODS: A retrospective multi-institutional study of imaging studies and patient's chart review of consecutive women with MRI-detected enhancing lesions without clinical, mammogram, or ultrasound correlation between January and December 2018, who underwent MRI-guided biopsy. According to the BI-RADS lexicon, lesions' frequency and imaging features were recorded. The demographic and imaging characteristics variables were correlated with histopathology as the gold standard and an uneventful follow-up of at least one year. Univariate logistic regression analysis was used to explore the correlation between the baseline variables such as age, genetic mutation, family history of breast cancer, personal history of breast cancer, MRI indication, background parenchymal enhancement, and MRI characteristic of the lesion with the false-positive results in main data and subgroup analysis. RESULTS: Two hundred nineteen women (median age 49 years; range 26-85 years) with 219 MRI-detected enhancing lesions that underwent MRI-guided vacuum-assisted biopsy during the study period fulfilled the study criteria and formed the study cohort. Out of 219, 180 lesions (82.2%) yielded benign pathology results, including 137 benign outcomes (76%) and 43 high-risk lesions (24%). Most demographic and imaging characteristics variables did not help to differentiate malignant from benign lesions. The variables that showed statistically significant association with true-positive results in univariate analyses were age (OR 1.05; 95% CI 1.02-1.08; p = 0.0015), irregular mass-lesion shape when compared with oval/round mass lesion (OR 11.2; 95% CI 1.6-78.4; p = 0.015), and clumped and clustered ring of enhancement when compared with homogeneous (OR 3.22, 95% CI 1.40-7.40; p = 0.0058). For participants with mass breast lesion, the hyperintense signal on the T2-weighted sequence (compared to the normal fibroglandular signal) was significantly related to the false-positive result (OR 0.13; 95% CI 0.02-0.76; p = 0.024). CONCLUSION: Young patients, oval/round mass-lesion shape, and homogeneous pattern of non-mass enhancement showed the strongest association with false-positive results of enhancing lesions depicted by MRI. For participants with mass breast lesion, T2-bright mass lesion showed significant association with false-positive result. It may impact the patient's management with a suggestion of follow-up rather than interventional procedure when these demographic and imaging parameters are present, consequently decreasing the patient's anxiety and health care costs.

Supplemental Breast Cancer Screening in Women with Dense Breasts and Negative Mammography: A Systematic Review and Meta-Analysis.

Background The best supplemental breast cancer screening modality in women at average risk or intermediate risk for breast cancer with dense breast and negative mammogram remains to be determined. Purpose To conduct systematic review and meta-analysis comparing clinical outcomes of the most common available supplemental screening modalities in women at average risk or intermediate risk for breast cancer in patients with dense breasts and mammography with negative findings. Materials and Methods A comprehensive search was conducted until March 12, 2020, in Medline, Epub Ahead of Print and In-Process and Other Non-Indexed Citations; Embase Classic and Embase; Cochrane Central Register of Controlled Trials; and Cochrane Database of Systematic Reviews, for Randomized Controlled Trials and Prospective Observational Studies. Incremental cancer detection rate (CDR); positive predictive value of recall (PPV1); positive predictive value of biopsies performed (PPV3); and interval CDRs of supplemental imaging modalities, digital breast tomosynthesis, handheld US, automated breast US, and MRI in non-high-risk patients with dense breasts and mammography negative for cancer were reviewed. Data metrics and risk of bias were assessed. Random-effects meta-analysis and two-sided metaregression analyses comparing each imaging modality metrics were performed (PROSPERO; CRD42018080402). Results Twenty-two studies reporting 261 233 screened patients were included. Of 132 166 screened patients with dense breast and mammography negative for cancer who met inclusion criteria, a total of 541 cancers missed at mammography were detected with these supplemental modalities. Metaregression models showed that MRI was superior to other supplemental modalities in CDR (incremental CDR, 1.52 per 1000 screenings; 95% CI: 0.74, 2.33; P < .001), including invasive CDR (invasive CDR, 1.31 per 1000 screenings; 95% CI: 0.57, 2.06; P < .001), and in situ disease (rate of ductal carcinoma in situ, 1.91 per 1000 screenings; 95% CI: 0.10, 3.72; P < .04). No differences in PPV1 and PPV3 were identified. The limited number of studies prevented assessment of interval cancer metrics. Excluding MRI, no statistically significant difference in any metrics were identified among the remaining imaging modalities. Conclusion The pooled data showed that MRI was the best supplemental imaging modality in women at average risk or intermediate risk for breast cancer with dense breasts and mammography negative for cancer. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Hooley and Butler in this issue.

Contralateral Breast Screening with Preoperative MRI: Long-Term Outcomes for Newly Diagnosed Breast Cancer.

Background The diagnostic value of screening the contralateral breast with MRI in patients with newly diagnosed breast cancer is poorly understood. Purpose To assess the impact of MRI for screening the contralateral breast on long-term outcomes in patients with newly diagnosed breast cancer and to determine whether subgroups with unfavorable prognoses would benefit from MRI in terms of survival. Materials and Methods Data on consecutive patients with newly diagnosed breast cancer seen from January 2008 to December 2010 were reviewed retrospectively. Patients with neoadjuvant chemotherapy, previous breast cancer, distant metastasis, absence of contralateral mammography at diagnosis, and no planned surgical treatment were excluded. Groups that did and did not undergo preoperative MRI were compared. Survival analysis was performed using the Kaplan-Meier method for propensity score-matched groups to estimate cause-specific survival (CSS) and overall survival (OS). A marginal Cox proportional hazards model was used to evaluate association of MRI and clinicopathologic variables with OS. Results Of 1846 patients, 1199 fulfilled the inclusion criteria. Median follow-up time was 10 years (range, 0-14 years). The 2:1 matched sample comprised 705 patients (470 in the MRI group and 235 in the no-MRI group); median ages at surgery were 59 years (range, 31-87 years) and 64 years (range, 37-92 years), respectively. MRI depicted contralateral synchronous disease more frequently (27 of 470 patients [5.7%] vs five of 235 patients [2.1%]; P = .047) and was associated with a higher OS (hazard ratio [HR], 2.51; 95% CI: 1.25, 5.06; P = .01). No differences were observed between groups in metachronous disease rate (MRI group: 21 of 470 patients [4.5%]; no-MRI group: 10 of 235 patients [4.3%]; P > .99) or CSS (HR, 1.34; 95% CI: 0.56, 3.21; P = .51). MRI benefit was greater in patients with larger tumor sizes (>2 cm) (HR, 2.58; 95% CI: 1.11, 5.99; P = .03) and histologic grade III tumors (HR, 2.94; 95% CI: 1.18, 7.32; P = .02). Conclusion Routine MRI screening of the contralateral breast after first diagnosis of breast cancer improved overall survival; the most pronounced benefit was found in patients with larger primary tumor size and primary tumors of histologic grade III. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Taourel in this issue.

COVID-19 vaccine-related axillary edema in breast imaging setting.

Worldwide, many vaccines have been developed in response to the COVID-19 pandemic. Unilateral reactive axillary adenopathy related to the COVID-19 vaccine is a well-known occurrence. In addition, axillary edema has also been observed following COVID-19 vaccinations in patients undergoing breast MRI, and radiologists need to be aware of this possibility to avoid performing unnecessary work-up that can be costly to the health care system and be stressful for patients.

Digital Breast Tomosynthesis: Potential Benefits in Routine Clinical Practice.

Digital breast tomosynthesis (DBT) is gradually being implemented in routine clinical breast imaging practice. The technique of image acquisition reduces the confounding effect of overlapping breast tissue, which substantially affects cancer detection, abnormal recall, and interval cancer rates in a screening/ surveillance setting. In a diagnostic setting, tomosynthesis also allows for improved lesion localization and characterization over conventional imaging, which potentially improves the accuracy and improved workflow efficiency. To optimize the utility of tomosynthesis, imagers should be aware of the pertinent aspects of image acquisition as it relates to interpretation, the appearance of benign and malignant pathologies, and sources of possible misinterpretation. This article aims to provide a practical knowledge base of DBT and demonstrate its potential benefits when incorporated into routine clinical practice.

Factors Influencing Trainees' Interest in Breast Imaging.

Purpose: To gauge the level of interest in breast imaging (BI) and determine factors impacting trainees' decision to pursue this subspecialty. Methods: Canadian radiology residents and medical students were surveyed from November 2020 to February 2021. Training level, actual vs preferred timing of breast rotations, fellowship choices, perceptions of BI, and how artificial intelligence (AI) will impact BI were collected. Chi-square, Fisher's exact tests and univariate logistic regression were performed to determine the impact of trainees' perceptions on interest in pursuing BI/women's imaging (WI) fellowships. Results: 157 responses from 80 radiology residents and 77 medical students were collected. The top 3 fellowship subspecialties desired by residents were BI/WI (36%), abdominal imaging (35%), and interventional radiology (25%). Twenty-five percent of the medical students were unsure due to lack of exposure. The most common reason that trainees found BI unappealing was repetitiveness (20%), which was associated with lack of interest in BI/WI fellowships (OR = 3.9, 95% CI: 1.6-9.5, P = .002). The most common reason residents found BI appealing was procedures (59%), which was associated with interest in BI/WI fellowships (OR, 3.2, 95% CI, 1.2-8.6, P = .02). Forty percent of residents reported an earlier start of their first breast rotation (PGY1-2) would affect their fellowship choice. Conclusion: This study assessed the current level of Canadian trainees' interest in BI and identified factors that influenced their decisions to pursue BI. Solutions for increased interest include earlier exposure to breast radiology and addressing inadequacies in residency training.

The characteristics associated with upgrade on surgical pathology of conventional imaging occult DCIS diagnosed by MRI.

PURPOSE: To characterize the clinical, pathological, and imaging features of DCIS occult on conventional imaging diagnosed on MRI-guided biopsy associated with increased risk of invasive disease on surgical excision. MATERIALS AND METHODS: All consecutive patients with MRI-detected DCIS occult on conventional imaging between January 2009 and December 2018 were included. Women were divided into two groups based on final pathology: Pure DCIS or DCIS with invasive component. Clinical, imaging, and pathological risk factors for upgrade to invasion were evaluated. RESULTS: Of 50 patients who met the inclusion criteria, 12 (24%) were upgraded to invasive malignancy in the final pathology. The only parameters that showed statistically significant association with upgrade were related to kinetic characteristics: 53% of patients with the combination of fast early upstroke and either plateau or washout curve were upgraded, compared to 12% of women without this combination (p = 0.006). The sensitivity of combined kinetic features for predicting upgrade was 67% (95% CI 35-90%), specificity was 84% (CI 95% 68-94%), positive predictive value was 57% (CI 95% 37-75%), negative predictive value was 89% (CI 95% 77-95%), and OR was 78% (64-88%). CONCLUSION: Kinetic characteristics show the strongest association with upgrade to invasion in DCIS occult on mammogram and US. Larger studies should be encouraged to consolidate our findings, which may have implication for treatment planning.

Tailored breast imaging during the first wave and preparedness for the second wave of COVID-19 pandemic.

The pandemic caused by the new Coronavirus has changed the way patient care is provided worldwide. This review focuses on the description of the operational measures implemented in a breast imaging department in accordance with existing recommendations for the treatment of breast cancer during the COVID-19 pandemic to make optimal use of finite resources without interruption of essential imaging services for breast cancer patients. It will also apply during a second-wave of the pandemic, which, according to experts, is inevitable and requires us to be better prepared.

Lobular neoplasia occult on conventional imaging and diagnosed on MRI-guided biopsy: can we estimate upgrade on surgical pathology?

PURPOSE: The goal of this study is to evaluate the frequency and imaging features of lobular neoplasia (LN) diagnosed on MRI-guided biopsy, determine the upgrade rate to malignancy, and assess for any features that may be associated with an upgrade on surgical excision. MATERIALS AND METHODS: Research ethical board approved the review of consecutive patients with MRI-detected LN between January 2009 and December 2018 with differentiation between pure LN and LN with associated other high-risk lesions. The final outcome was determined by final pathology results from surgical excision or 24 months of follow-up. Appropriate statistical tests were used. RESULTS: Out of 1250 MRI-guided biopsies performed, 76 lesions (6%) fulfilled the inclusion criteria and formed the study cohort. Of the 76 lesions, 54 (71%) were pure LN while the rest had coexistent high-risk lesion. Non-mass enhancement (NME) was the most common lesion type (62, 82%). Fifty-nine lesions (78%) were surgically excised, the other 17 had benign follow-up. Overall, 8 lesions (11%) were upgraded to malignancy on final pathology. Malignant outcome was associated with larger lesion size (5.5 versus 1.9 cm, P < 0.001) and a clumped NME pattern (75% versus 24%, P = 0.006). Lesion size and clumped NME remained significantly associated with upgrade on sub-analysis of the pure LN group. CONCLUSION: Larger lesion size and clumped NME are imaging findings associated with upgrade of LN diagnosed by MRI-guided biopsy. This may influence patient management in this clinical setting. Additional larger studies are needed to consolidate our results and to potentially detect additional factors associated with upgrade.

COVID-19: Safe Guidelines for Breast Imaging During the Pandemic.

During the COVID-19 pandemic, breast imaging must be performed using safe practices. Balancing the need to avoid delays in the diagnosis of breast cancer while avoiding infection requires careful attention to personal protective equipment and physical distancing and vigilance to maintain these practices. The Canadian Society of Breast Imaging/Canadian Association of Radiologists guideline for breast imaging during COVID-19 is provided based on priority according to risk of breast cancer and impact of delaying treatment. A review of the best practices is presented that allow breast imaging during COVID-19 to maximize protection of patients, technologists, residents, fellows, and radiologists and minimize spread of the infection. The collateral damage of delaying diagnosis of breast cancer due to COVID-19 should be avoided when possible.

Cellular fibroepithelial lesions diagnosed on core needle biopsy: Is there any role of clinical-sonography features helping to differentiate fibroadenomas and phyllodes tumor?

OBJECTIVE: The purpose of this study is to determine the role of clinico-sonographic features of breast cellular fibroepithelial lesions (CFELs) diagnosed on core needle biopsy (CNB) in the differentiation between fibroadenoma (FA) and phyllodes. MATERIALS AND METHODS: Results of consecutive women with a CNB showing CFEL from 2005 to 2010 were retrospectively reviewed. Clinical and sonographic findings were compared with surgical outcomes. Chi-square and Fisher's exact tests were used followed by a regression model for statistical analysis. RESULTS: A total of 131 women with 134 CFEL were included in the study; 89 (66%) were FAs and 45 (34%) were phyllodes (32 benign; 13 malignant). Significant predictors of increased risk of phyllodes tumor were patient age equal to or greater than 50 years (P = .021) and lesion size less than 2 cm at sonography (P = .043). No other imaging or clinical features were able to differentiate FA from phyllodes tumors. CONCLUSION: CFEL with a larger size in older women is associated with the surgical pathological result of phyllodes tumor and management should be tailored accordingly. Younger patients with small size nodules might be approached less aggressively, depending on a personalized discussion with the surgeons, taking into account the results obtained in this study.