Carol H. Lee

Breast Cancer Screening With Imaging: Recommendations From the Society of Breast Imaging and the ACR on the Use of Mammography, Breast MRI, Breast Ultrasound, and Other Technologies for the Detection of Clinically Occult Breast Cancer

Screening for breast cancer with mammography has been shown to decrease mortality from breast cancer, and mammography is the mainstay of screening for clinically occult disease. Mammography, however, has well-recognized limitations, and recently, other imaging including ultrasound and magnetic resonance imaging have been used as adjunctive screening tools, mainly for women who may be at increased risk for the development of breast cancer. The Society of Breast Imaging and the Breast Imaging Commission of the ACR are issuing these recommendations to provide guidance to patients and clinicians on the use of imaging to screen for breast cancer. Wherever possible, the recommendations are based on available evidence. Where evidence is lacking, the recommendations are based on consensus opinions of the fellows and executive committee of the Society of Breast Imaging and the members of the Breast Imaging Commission of the ACR.

The ACR BI-RADS® Experience: Learning From History

The Breast Imaging Reporting and Data System (BI-RADS) initiative, instituted by the ACR, was begun in the late 1980s to address a lack of standardization and uniformity in mammography practice reporting. An important component of the BI-RADS initiative is the lexicon, a dictionary of descriptors of specific imaging features. The BI-RADS lexicon has always been data driven, using descriptors that previously had been shown in the literature to be predictive of benign and malignant disease. Once established, the BI-RADS lexicon provided new opportunities for quality assurance, communication, research, and improved patient care. The history of this lexicon illustrates a series of challenges and instructive successes that provide a valuable guide for other groups that aspire to develop similar lexicons in the future.

Targeted ultrasound of the breast in women with abnormal MRI findings for whom biopsy has been recommended.

OBJECTIVE This study was performed to identify characteristics of suspicious lesions seen on breast MRI that are most likely to have an ultrasound correlate and to determine how often the presumed ultrasound correlate actually corresponds to the MRI finding. MATERIALS AND METHODS From September 2005 through December 2007, targeted ultrasound was performed for 519 suspicious MRI-detected lesions in 361 women. Retrospective review was performed to determine lesion type (mass vs nonmass), lesion descriptors, lesion size, BI-RADS category, indication for MR examination, patient age, and biopsy outcome. The results of 80 follow-up MRI examinations among 154 cases with concordant benign results on ultrasound-guided biopsy were noted. RESULTS A presumed ultrasound correlate was found in 290 (56%) of the 519 lesions with masses more likely than nonmass lesions to be seen with ultrasound (62% of masses and 31% of nonmass lesions). Increasing lesion size, assessment of BI-RADS category 5 versus BI-RADS category 4, rim enhancement in masses, and clumped enhancement in nonmass lesions were also significantly more likely to have an ultrasound correlate. On follow-up imaging in 80 benign, concordant ultrasound-guided biopsies, the sonographic lesion did not correspond to the MRI finding in 10. Nine of these 10 lesions underwent subsequent MRI-guided biopsy and five cancers were diagnosed. CONCLUSION The MR characteristics of lesions most likely to be seen with an ultrasound correlate were mass versus nonmass, increasing size, and increased level of suspicion of the lesion. Clip placement and follow-up imaging after ultrasound-guided biopsy that yields benign concordant results should be performed to detect cases in which the presumed ultrasound correlate is inaccurate to detect unsuspected false-negative biopsies.

Screening mammography: proven benefit, continued controversy

Screening mammography, despite its limitations, remains the best means for diagnosing breast cancer in asymptomatic women. Regarding the continuing controversies concerning the age at which screening should start, evidence supports beginning regular screening at age 40 in women at average risk . Similarly, evidence suggests that the screening interval should be yearly, especially in younger women. Rather than an arbitrary age at which screening should stop, the decision on screening elderly women should be made on an individual basis, taking into account level of health and life expectancy. More work needs to be done on determining the optimum screening strategies for high-risk women. As to the interpretation of screening mammography, a certain level of observer variability and of false-negative and false-positive readings are inherent in the process. These should be kept to a minimum through efforts by the interpreting radiologist to improve performance through auditing of individual results and continuing education. The impact of double reading and computer-aided detection in the interpretation of screening mammograms warrants further evaluation in terms of efficacy and cost-effectiveness. Despite these continuing controversies, mortality from breast cancer in the United States has been decreasing steadily for the past 25 years. The magnitude of the decrease has been reported to range from 8% to 25%. Although some of this decrease may be attributable to improvements in the treatment of breast cancer, early detection through screening mammography has undoubtedly played a role in this mortality reduction. The controversies that surround the issue of screening should not detract from the fact that screening mammography has proved to save lives.

MRI Follow-Up After Concordant, Histologically Benign Diagnosis of Breast Lesions Sampled by MRI-Guided Biopsy

OBJECTIVE Follow-up MRI can be useful to confirm a benign diagnosis after MRI-guided breast biopsy. This retrospective study was undertaken to evaluate appropriate timing and imaging interpretation for the initial follow-up MRI when a benign, concordant histology is obtained using MRI-guided breast biopsy. MATERIALS AND METHODS Retrospective review was performed of 177 lesions visualized only by MRI in 172 women who underwent 9-gauge, vacuum-assisted core biopsy and marker placement with imaging-concordant benign histology. All underwent follow-up MRI within 12 months. Timing of the follow-up study, change in size, results of second biopsy if performed, and distance of localizing marker to the lesion on the follow-up study were recorded. RESULTS At initial follow-up, 155 lesions were decreased or gone, 14 lesions were stable, and eight were enlarged. Seventeen (9.6%, 17/177) lesions underwent a second biopsy, including six enlarging, 10 stable, and one decreasing. Of these, four were malignant. Enlargement was seen in two carcinomas at 6 and 12 months. Two carcinomas, one stable at 2 months and another stable at 3 and 11 months, were rebiopsied because of suspicion of a missed lesion in the former and worrisome mammographic and sonographic changes in the latter. The distance of the marker from the lesion on follow-up did not correlate with biopsy accuracy. CONCLUSION Follow-up MRI did not detect missed cancers because of lesion enlargement before 6 months after biopsy; two of four missed cancers were stable. The localizing marker can deploy away from the target despite successful sampling.

Impact of Tamoxifen on Amount of Fibroglandular Tissue, Background Parenchymal Enhancement, and Cysts on Breast Magnetic Resonance Imaging

Abstract:  The objective of this study was to evaluate the impact of tamoxifen treatment on amount of fibroglandular tissue (FGT), background parenchymal enhancement (BPE), and cysts on breast MRI. Retrospective search identified 96 women with breast cancer who had a breast MRI both before and during adjuvant tamoxifen therapy between 2002 and 2008. After exclusion of all irradiated breasts, 88 women were eligible. Two readers blinded to tamoxifen treatment status independently rated level of BPE, amount of FGT, and cysts using a 4‐point categorical scale: BPE––Minimal, Mild, Moderate, Marked; FGT––Fatty, Scattered, Heterogeneously Dense (HD), Dense; Cysts––Minimal, Mild, Moderate, Marked. A consensus interpretation was reached in cases of disagreement. During tamoxifen, there was a significant shift from higher to lower degree BPE, cysts, and FGT compared with before tamoxifen. BPE, cysts and FGT decreased in 68% (60/88), 38% (33/88), and 40% (35/88) of women during tamoxifen (p < 0.001 for all measures). After the exclusion of all cases with minimal BPE, cysts, or FGT on the pre‐tamoxifen MRI, the percentage of women demonstrating a decrease in these factors increased to 81% (60/74), 77% (33/43), and 41% (35/86), respectively. Exclusion of patients treated with chemotherapy did not substantially change these results. The percentage of women with decreases in FGT and cysts increased with greater duration on tamoxifen, whereas decreases in BPE were detected early in treatment (<90 days) and did not change substantially with longer duration on tamoxifen. A significant association exists between treatment with tamoxifen and decreases in BPE, cysts, and FGT on breast MRI.

Patient Follow-Up After Concordant Histologically Benign Imaging-Guided Biopsy of MRI-Detected Lesions

OBJECTIVE The purpose of this study was to review the reported experience and suggest follow-up after biopsy for MRI-detected lesions. CONCLUSION Imaging-guided biopsy, using MRI or sonographic guidance, of MRI-detected lesions may result in false-negative results that are not appreciated at the time of the biopsy. A 6-month follow-up MRI is suggested as the most appropriate interval to identify lesions that were missed at biopsy without clinically significant delay in diagnosis of those lesions that are malignant.

Voice-activated retrieval of mammography reference images

We undertook this project to integrate context sensitive computer-based educational and decision making aids into the film interpretation and reporting process, and to determine the clinical utility of this method as a guide for further system development. An image database of 347 digital mammography images was assembled and image features were coded. An interface was developed to a computerized speech recognition radiology reporting system which was modified to translate reported findings into database search terms. These observations were used to formulate database search strategies which not only retrieved similar cases from the image database, but also other cases that were related to the index case in different ways. The search results were organized into image sets intended to address common questions that arise during image interpretation. An evaluation of the clinical utility of this method was performed as a guide for further system development. We found that voice dictation of prototypical mammographic cases resulted in automatic retrieval of reference images. The retrieved images were organized into sets matching findings, diagnostic hypotheses, diagnosis, spectrum of findings or diagnoses, closest match to dictated case, or user specified parameters. Two mammographers graded the clinical utility of each form of system output. We concluded that case specific and problem specific image sets may be automatically generated from spoken case dictation. A potentially large number of retrieved images may be divided into subsets which anticipate common clinical problems. This automatic method of context sensitive image retrieval may provide a “continuous’; form of education integrated into routine case interpretation.

Breast Cancers Detected at Screening MR Imaging and Mammography in Patients at High Risk: Method of Detection Reflects Tumor Histopathologic Results

Purpose To compare the clinical, imaging, and histopathologic features of breast cancers detected at screening magnetic resonance (MR) imaging, screening mammography, and those detected between screening examinations (interval cancers) in women at high risk. Materials and Methods This retrospective institutional review board-approved, HIPAA-compliant review of 7519 women at high risk for breast cancer who underwent screening with MR imaging and mammography between January 2005 and December 2010 was performed to determine the number of screening-detected and interval cancers diagnosed. The need for informed consent was waived. Medical records were reviewed for age, risk factors (family or personal history of breast cancer, BRCA mutation status, history of high-risk lesion or mantle radiation), tumor histopathologic results, and time between diagnosis of interval cancer and most recent screening examination. The χ(2) test and logistic regression methods were used to compare the features of screening MR imaging, screening mammography, and interval cancers. The Wilcoxon signed-rank test was used to calculate P values. Results A total of 18 064 screening MR imaging examinations and 26 866 screening mammographic examinations were performed. Two hundred twenty-two cancers were diagnosed in 219 women, 167 (75%) at MR imaging, 43 (19%) at mammography, and 12 (5%) interval cancers. Median age at diagnosis was 52 years. No risk factors were associated with screening MR imaging, screening mammography, or interval cancer (P > .06). Cancers found at screening MR imaging were more likely to be invasive cancer (118 of 167 [71%]; P < .0001). Of the 43 cancers found at screening mammography, 38 (88%) manifested as calcifications and 28 (65%) were ductal carcinoma in situ. Interval cancers were associated with nodal involvement (P = .005) and the triple-negative subtype (P = .03). Conclusion In women at high risk for breast cancer who underwent screening with mammography and MR imaging, invasive cancers were more likely to be detected at MR imaging, whereas most cancers detected at screening mammography were ductal carcinoma in situ. Interval cancers were found infrequently and were more likely to be node positive and of the triple-negative subtype. (©) RSNA, 2016.

Breast Imaging Fellowships in the United States: Who, What, and Where?

OBJECTIVE The purpose of this study was to determine the characteristics of fellowship programs offering breast imaging training and their success in filling positions. CONCLUSION A comprehensive list of fellowship training opportunities in breast imaging may help potential applicants identify relevant programs.