Supplemental Breast Cancer Screening With Molecular Breast Imaging for Women With Dense Breast Tissue.

OBJECTIVE: Molecular breast imaging was implemented in routine clinical practice at a large community-based breast imaging center. The aim of this study was to retrospectively assess the clinical performance of molecular breast imaging as a supplementary screening tool for women with dense breast tissue. MATERIALS AND METHODS: Women with dense breasts and negative mammography results who subsequently underwent screening with 300 MBq (8 mCi) (99m)Tc-sestamibi molecular breast imaging were retrospectively analyzed. Outcome measures included cancer detection rate, recall rate, biopsy rate, and positive predictive values (PPVs). RESULTS: Molecular breast imaging screening of 1696 women in this study resulted in the detection of 13 mammographically occult malignancies, of which 11 were invasive, one was node positive, and one had unknown node positivity. The lesion size ranged from 0.6 to 2.4 cm, with a mean of 1.1 cm. The incremental cancer detection rate was 7.7‰ (95% CI, 4.5-13.1‰), the recall rate was 8.4% (95% CI, 7.2-9.8%), and the biopsy rate was 3.7% (95% CI, 2.9%-4.7%). The PPV for recall (PPV 1) was 9.1% (95% CI, 5.4-15.0%), and the PPV for biopsy (PPV 3) was 19.4% (95% CI, 11.4-30.9%). CONCLUSION: When incorporated into a community-based clinical practice environment, molecular breast imaging yielded a high incremental cancer detection rate of 7.7‰ at an acceptable radiation dose. These results show the utility of molecular breast imaging as a supplementary screening tool to mammography for women with dense breasts.

Impact of Breast Density Legislation on Breast Cancer Risk Assessment and Supplemental Screening: A Survey of 110 Radiology Facilities.

Breast density notification laws, passed in 19 states as of October 2014, mandate that patients be informed of their breast density. The purpose of this study is to assess the impact of this legislation on radiology practices, including performance of breast cancer risk assessment and supplemental screening studies. A 20-question anonymous web-based survey was emailed to radiologists in the Society of Breast Imaging between August 2013 and March 2014. Statistical analysis was performed using Fisher's exact test. Around 121 radiologists from 110 facilities in 34 USA states and 1 Canadian site responded. About 50% (55/110) of facilities had breast density legislation, 36% of facilities (39/109) performed breast cancer risk assessment (one facility did not respond). Risk assessment was performed as a new task in response to density legislation in 40% (6/15) of facilities in states with notification laws. However, there was no significant difference in performing risk assessment between facilities in states with a law and those without (p < 0.831). In anticipation of breast density legislation, 33% (16/48), 6% (3/48), and 6% (3/48) of facilities in states with laws implemented handheld whole breast ultrasound (WBUS), automated WBUS, and tomosynthesis, respectively. The ratio of facilities offering handheld WBUS was significantly higher in states with a law than in states without (p < 0.001). In response to breast density legislation, more than 33% of facilities are offering supplemental screening with WBUS and tomosynthesis, and many are performing formal risk assessment for determining patient management.

The California breast density information group: a collaborative response to the issues of breast density, breast cancer risk, and breast density notification legislation.

In anticipation of breast density notification legislation in the state of California, which would require notification of women with heterogeneously and extremely dense breast tissue, a working group of breast imagers and breast cancer risk specialists was formed to provide a common response framework. The California Breast Density Information Group identified key elements and implications of the law, researching scientific evidence needed to develop a robust response. In particular, issues of risk associated with dense breast tissue, masking of cancers by dense tissue on mammograms, and the efficacy, benefits, and harms of supplementary screening tests were studied and consensus reached. National guidelines and peer-reviewed published literature were used to recommend that women with dense breast tissue at screening mammography follow supplemental screening guidelines based on breast cancer risk assessment. The goal of developing educational materials for referring clinicians and patients was reached with the construction of an easily accessible Web site that contains information about breast density, breast cancer risk assessment, and supplementary imaging. This multi-institutional, multidisciplinary approach may be useful for organizations to frame responses as similar legislation is passed across the United States. Online supplemental material is available for this article.

Benefit of semiannual ipsilateral mammographic surveillance following breast conservation therapy.

PURPOSE: To compare cancer recurrence outcomes on the basis of compliant semiannual versus noncompliant annual ipsilateral mammographic surveillance following breast conservation therapy (BCT). MATERIALS AND METHODS: A HIPAA-compliant retrospective review was performed of post-BCT examinations from 1997 through 2008 by using a deidentified database. The Committee on Human Research did not require institutional review board approval for this study, which was considered quality assurance. Groups were classified according to compliance with institutional post-BCT protocol, which recommends semiannual mammographic examinations of the ipsilateral breast for 5 years. A compliant semiannual examination was defined as an examination with an interval of 0-9 months, although no examination had intervals less than 3 months. A noncompliant annual examination was defined as an examination with an interval of 9-18 months. Cancer recurrence outcomes were compared on the basis of the last examination interval leading to diagnosis. RESULTS: Initially, a total of 10 750 post-BCT examinations among 2329 asymptomatic patients were identified. Excluding initial mammographic follow-up, there were 8234 examinations. Of these, 7169 examinations were semiannual with 94 recurrences detected and 1065 examinations were annual with 15 recurrences detected. There were no differences in demographic risk factors or biopsy rates. Recurrences identified at semiannual intervals were significantly less advanced than those identified at annual intervals (stage I vs stage II, P = .04; stage 0 + stage I vs stage II, P = .03). Nonsignificant findings associated with semiannual versus annual intervals included smaller tumor size (mean, 11.7 vs 15.3 mm; P = .15) and node negativity (98% vs 91%, P = .28). CONCLUSION: Results suggest that a semiannual interval is preferable for ipsilateral mammographic surveillance, allowing detection of a significantly higher proportion of cancer recurrences at an earlier stage than noncompliant annual surveillance.

Timeliness of follow-up after abnormal screening mammogram: variability of facilities.

PURPOSE: To describe the timeliness of follow-up care in community-based settings among women who receive a recommendation for immediate follow-up during the screening mammography process and how follow-up timeliness varies according to facility and facility-level characteristics. MATERIALS AND METHODS: This was an institutional review board-approved and HIPAA-compliant study. Screening mammograms obtained from 1996 to 2007 in women 40-80 years old in the Breast Cancer Surveillance Consortium were examined. Inclusion criteria were a recommendation for immediate follow-up at screening, or subsequent imaging, and observed follow-up within 180 days of the recommendation. Recommendations for additional imaging (AI) and biopsy or surgical consultation (BSC) were analyzed separately. The distribution of time to follow-up care was estimated by using the Kaplan-Meier estimator. RESULTS: Data were available on 214,897 AI recommendations from 118 facilities and 35,622 BSC recommendations from 101 facilities. The median time to subsequent follow-up care after recommendation was 14 days for AI and 16 days for BSC. Approximately 90% of AI follow-up and 81% of BSC follow-up occurred within 30 days. Facilities with higher recall rates tended to have longer AI follow-up times (P < .001). Over the study period, BSC follow-up rates at 15 and 30 days improved (P < .001). Follow-up times varied substantially across facilities. Timely follow-up was associated with larger volumes of the recommended procedures but not notably associated with facility type nor observed facility-level characteristics. CONCLUSION: Most patients with follow-up returned within 3 weeks of the recommendation.

Malignant seeding following percutaneous breast biopsy: documentation with comprehensive imaging and clinical implications.

The aim of this study was to demonstrate convincing evidence that percutaneous breast biopsy may result in displacement of malignant cells that can initiate tumor growth at a separate anatomic site, other than the index lesion. Two patients with malignancy diagnosed by percutaneous breast biopsy were followed up with subsequent imaging. The observation of displaced cells initiating subsequent malignant growth was compared retrospectively with the previous year's outcomes following percutaneous breast biopsy. Two cases of displaced malignant cells resulting in malignant growth at a separate site along the biopsy needle track were demonstrated by imaging. During the preceding year, 1644 biopsies with 298 malignant results were compared with the outcomes of these two patients, resulting in a 0.7% incidence of malignant seeding. No identifiable factors could be identified to predict under what conditions this iatrogenic complication occurs. Although uncommon, percutaneous breast biopsy can result in malignant seeding, and raises issues regarding informed consent and proper subsequent treatment.

Time trends in radiologists' interpretive performance at screening mammography from the community-based Breast Cancer Surveillance Consortium, 1996-2004.

PURPOSE: To examine time trends in radiologists' interpretive performance at screening mammography between 1996 and 2004. MATERIALS AND METHODS: All study procedures were institutional review board approved and HIPAA compliant. Data were collected on subsequent screening mammograms obtained from 1996 to 2004 in women aged 40-79 years who were followed up for 1 year for breast cancer. Recall rate, sensitivity, and specificity were examined annually. Generalized estimating equation (GEE) and random-effects models were used to test for linear trend. The area under the receiver operating characteristic curve (AUC), tumor histologic findings, and size of the largest dimension or diameter of the tumor were also examined. RESULTS: Data on 2,542,049 subsequent screening mammograms and 12,498 cancers diagnosed in the follow-up period were included in this study. Recall rate increased from 6.7% to 8.6%, sensitivity increased from 71.4% to 83.8%, and specificity decreased from 93.6% to 91.7%. In GEE models, adjusted odds ratios per calendar year were 1.04 (95% confidence interval [CI]: 1.02, 1.05) for recall rate, 1.09 (95% CI: 1.07. 1.12) for sensitivity, and 0.96 (95% CI: 0.95, 0.98) for specificity (P < .001 for all). Random-effects model results were similar. The AUC increased over time: 0.869 (95% CI: 0.861, 0.877) for 1996-1998, 0.884 (95% CI: 0.879, 0.890) for 1999-2001, and 0.891 (95% CI: 0.885, 0.896) for 2002-2004 (P < .001). Tumor histologic findings and size remained constant. CONCLUSION: Recall rate and sensitivity for screening mammograms increased, whereas specificity decreased from 1996 to 2004 among women with a prior mammogram. This trend remained after accounting for risk factors. The net effect was an improvement in overall discrimination, a measure of the probability that a mammogram with cancer in the follow-up period has a higher Breast Imaging Reporting and Data System assessment category than does a mammogram without cancer in the follow-up period.

Identifying minimally acceptable interpretive performance criteria for screening mammography.

PURPOSE: To develop criteria to identify thresholds for minimally acceptable physician performance in interpreting screening mammography studies and to profile the impact that implementing these criteria may have on the practice of radiology in the United States. MATERIALS AND METHODS: In an institutional review board-approved, HIPAA-compliant study, an Angoff approach was used in two phases to set criteria for identifying minimally acceptable interpretive performance at screening mammography as measured by sensitivity, specificity, recall rate, positive predictive value (PPV) of recall (PPV(1)) and of biopsy recommendation (PPV(2)), and cancer detection rate. Performance measures were considered separately. In phase I, a group of 10 expert radiologists considered a hypothetical pool of 100 interpreting physicians and conveyed their cut points of minimally acceptable performance. The experts were informed that a physician's performance falling outside the cut points would result in a recommendation to consider additional training. During each round of scoring, all expert radiologists' cut points were summarized into a mean, median, mode, and range; these were presented back to the group. In phase II, normative data on performance were shown to illustrate the potential impact cut points would have on radiology practice. Rescoring was done until consensus among experts was achieved. Simulation methods were used to estimate the potential impact of performance that improved to acceptable levels if effective additional training was provided. RESULTS: Final cut points to identify low performance were as follows: sensitivity less than 75%, specificity less than 88% or greater than 95%, recall rate less than 5% or greater than 12%, PPV(1) less than 3% or greater than 8%, PPV(2) less than 20% or greater than 40%, and cancer detection rate less than 2.5 per 1000 interpretations. The selected cut points for performance measures would likely result in 18%-28% of interpreting physicians being considered for additional training on the basis of sensitivity and cancer detection rate, while the cut points for specificity, recall, and PPV(1) and PPV(2) would likely affect 34%-49% of practicing interpreters. If underperforming physicians moved into the acceptable range, detection of an additional 14 cancers per 100000 women screened and a reduction in the number of false-positive examinations by 880 per 100000 women screened would be expected. CONCLUSION: This study identified minimally acceptable performance levels for interpreters of screening mammography studies. Interpreting physicians whose performance falls outside the identified cut points should be reviewed in the context of their specific practice settings and be considered for additional training.

Solitary dilated duct identified at mammography: outcomes analysis.

OBJECTIVE: The purpose of this study is to review the clinical and pathologic outcomes for cases of solitary dilated duct identified at mammography. MATERIALS AND METHODS: For all screening mammography examinations during a 22-year period and all diagnostic mammography examinations during the last 10 of these years, the radiologists recorded the principal finding of each abnormal mammographic examination during image interpretation. Only examinations with the recorded finding of solitary dilated duct were studied. We examined radiology records to determine imaging follow-up and pathology records to determine histologic diagnosis, and we performed linkage with our regional tumor registry to identify cancers not biopsied at our institution. RESULTS: The finding of solitary dilated duct was recorded for nine (0.0038%) of 235,209 consecutive screenings and for 12 (0.041%) of 29,267 consecutive diagnostic mammography examinations. Five screening and five diagnostic cases were stable at follow-up (minimum interval, 2 years) and did not undergo biopsy; tumor registry linkage showed no subsequent cancer diagnosis. Biopsy was performed for four (44%) of nine screening and seven (58%) of 12 diagnostic cases. One cancer each (ductal carcinoma in situ) was identified from the screening and diagnostic populations, yielding positive predictive values of 11% (1/9) and 8% (1/12), respectively. CONCLUSION: Solitary dilated duct is a rare mammographic finding, this series being the largest reported to date. Although few cases are studied, solitary dilated duct appears to have a greater than 2% likelihood of malignancy, sufficiently high to suggest that a suspicious (BI-RADS 4a) assessment may be appropriate.

Disclosing harmful mammography errors to patients.

PURPOSE: To assess radiologists' attitudes about disclosing errors to patients by using a survey with a vignette involving an error interpreting a patient's mammogram, leading to a delayed cancer diagnosis. MATERIALS AND METHODS: We conducted an institutional review board-approved survey of 364 radiologists at seven geographically distinct Breast Cancer Surveillance Consortium sites that interpreted mammograms from 2005 to 2006. Radiologists received a vignette in which comparison screening mammograms were placed in the wrong order, leading a radiologist to conclude calcifications were decreasing in number when they were actually increasing, delaying a cancer diagnosis. Radiologists were asked (a) how likely they would be to disclose this error, (b) what information they would share, and (c) their malpractice attitudes and experiences. RESULTS: Two hundred forty-three (67%) of 364 radiologists responded to the disclosure vignette questions. Radiologists' responses to whether they would disclose the error included "definitely not" (9%), "only if asked by the patient" (51%), "probably" (26%), and "definitely" (14%). Regarding information they would disclose, 24% would "not say anything further to the patient," 31% would tell the patient that "the calcifications are larger and are now suspicious for cancer," 30% would state "the calcifications may have increased on your last mammogram, but their appearance was not as worrisome as it is now," and 15% would tell the patient "an error occurred during the interpretation of your last mammogram, and the calcifications had actually increased in number, not decreased." Radiologists' malpractice experiences were not consistently associated with their disclosure responses. CONCLUSION: Many radiologists report reluctance to disclose a hypothetical mammography error that delayed a cancer diagnosis. Strategies should be developed to increase radiologists' comfort communicating with patients.

Predictors of radiologists' perceived risk of malpractice lawsuits in breast imaging.

OBJECTIVE: The shortage of radiologists in breast imaging may be related to heightened malpractice lawsuit concerns. Our objective was to examine radiologists' reported experiences and perceptions of future lawsuit risk and explore personal and professional factors that may be associated with elevated perceptions of risk. MATERIALS AND METHODS: Radiologists who routinely interpret mammography examinations in diverse regions of the United States (Washington, Colorado, and New Hampshire) completed a mailed survey in 2002 and 2006, including questions on demographics, practice characteristics, and medicolegal experience and perceptions as well as a validated scale measuring reactions to uncertainty in clinical situations. A survey assessing the radiologists' work facilities was also completed in 2002. RESULTS: Participation by eligible radiologists was 77% (139 of 181) in 2002 and 71% (84 of 118) in 2006. The percentage of radiologists reporting malpractice claims related to mammography in the previous 5 years was 8% on the 2002 survey and 10% on the 2006 survey. Radiologists' mean estimate of the probability of being sued for malpractice in the next 5 years (41% in 2002 and 35% in 2006) was markedly higher than the actual reported risk. Radiologists' age, sex, clinical experience, and workload were not associated with a higher perceived risk of being sued. Radiologists who reported higher perceived risk of lawsuits were more likely to have experienced a prior malpractice claim, to report knowing colleagues with prior lawsuits, and to score higher on a scale measuring anxiety caused by uncertainty in clinical situations. Radiologists working at facilities that did not use double reading reported higher perceived risk, but the difference was not statistically significant. CONCLUSION: Radiologists working in breast imaging substantially overestimate their risk of a future malpractice lawsuit. Radiologists with higher risk perceptions show more negative reactions to uncertainty in a clinical setting. Understanding that their actual risk of malpractice lawsuits may be substantially lower than anticipated may help reduce radiologists' fears and alleviate the manpower shortage in mammography. Programs to address the shortage of breast imagers could be targeted toward radiologists with heightened malpractice lawsuit concerns.

Radiologists' performance and their enjoyment of interpreting screening mammograms.

OBJECTIVE: One might speculate that radiologists who enjoy mammography may exhibit better performance than radiologists who do not. MATERIALS AND METHODS: One hundred thirty-one radiologists at three Breast Cancer Surveillance Consortium (BCSC) registries completed a survey about their characteristics, clinical practices, and attitudes related to screening mammography. Survey results were linked with BCSC performance data for 662,084 screening and 33,977 diagnostic mammograms. Using logistic regression, we modeled the odds of an abnormal interpretation, cancer detection, sensitivity, and specificity among radiologists who reported they enjoy interpreting screening mammograms compared with those who do not. RESULTS: Overall, 44.3% of radiologists reported not enjoying interpreting screening mammograms. Radiologists who reported enjoying interpreting screening mammograms were more likely to be women, spend at least 20% of their time in breast imaging, have a primary academic affiliation, read more than 2,000 mammograms per year, and be salaried. Enjoyment was not associated with screening mammography performance. Among diagnostic mammograms, there was a significant increase in sensitivity among radiologists who reported enjoyment (85.2%) compared with those who did not (78.2%). In models adjusting for radiologist characteristics, similar trends were found; however, no statistically significant associations remained. CONCLUSION: Almost one half of radiologists actively interpreting mammograms do not enjoy that part of their job. Once we adjusted for radiologist and patient characteristics, we found that reported enjoyment was not related to performance in our study, although suggestive trends were noted.

Long-term safety and effectiveness of style 410 highly cohesive silicone breast implants.

BACKGROUND: In 2006, a single-center Swedish study demonstrated a low rupture rate and high patient satisfaction with the Style 410 shaped, form-stable gel implant. The current study aimed to validate the accuracy of the previously published results across multiple European sites. METHODS: A total of 163 subjects (approximately 70% had augmentation [n = 112], 15% had reconstruction [n = 25], and 15% had revision [n = 26]) underwent a physical examination followed by breast magnetic resonance imaging (MRI) for rupture detection. These subjects had been implanted for 5 to 11 years with at least one Style 410 shaped gel breast implant before examination. The secondary end points included lactation, reproductive and breast disease history before and after implantation, and quality-of-life measurements and complications after implantation. RESULTS: The implant rupture rate was 1.7% a median of 8 years after implantation. Capsular contracture was the most common complication noted at the physical examination, occurring for 5.3% of implants, and there were no cases of grade 4 capsular contracture. The postimplantation rates for lactation and reproductive problems and breast disease were lower than the preimplantation rates. Breast implantation surgery was considered advantageous by 91% of the subjects, demonstrating high patient satisfaction. CONCLUSIONS: The Style 410 anatomically shaped, form-stable gel breast implants demonstrated long-term safety and effectiveness.

Intraoperative loss of core biopsy clips: clinical implications.

OBJECTIVE: The purpose of this study was to report the occurrence of intraoperative loss of metallic marking clips placed during image-guided biopsy and to hypothesize the likely mechanism of this clinical problem. MATERIALS AND METHODS: From January 2003 through December 2004, patients presenting for preoperative mammographic localization and operative excision of biopsy site marking clips were identified. Age, method of image-guided biopsy, number of excised specimens, and tissue diagnosis were determined. Specimen radiographs were used to identify cases of suspected intraoperative clip loss. Clips absent on specimen radiographs and postoperative mammograms were defined as lost intraoperatively. Biopsy site marking clips, surgical clips, and suction device apertures were measured. RESULTS: In 78 surgical procedures performed during the study period, three (3.8%) of the patients experienced clip loss. Specimen radiographs confirmed the absence of clips in all submitted tissues. A median of four (range, three to five) separate biopsy specimens were excised among these three cases. A healing biopsy site from the stereotactic biopsy preceding the clip placement procedure was confirmed in all cases. Absence of the metallic clip was confirmed on postoperative mammograms. The apertures of two types of suction device were four and two times those of the biopsy clips. CONCLUSION: Intraoperative loss of metallic clips placed at the conclusion of image-guided breast biopsy is unusual but can occur during subsequent surgical excision. Repeated inability to locate the clip on specimen radiographs after accurate preoperative localization should raise the suspicion that the target clip has been lost, not missed, during surgery, likely because of inadvertent removal of the clip with the suction device.

National trends and practices in breast MRI.

OBJECTIVE: The objective of our study was to report on the current practices of radiologists involved in the performance and interpretation of breast MRI in the United States. MATERIALS AND METHODS: We invited the 1,696 active physician members of the Society of Breast Imaging to participate in a survey addressing whether and how they performed and interpreted breast MRI. Respondents were asked to select one member of their practice to complete the survey. A total of 754 surveys were completed. Every respondent did not reply to every question. RESULTS: Contrast-enhanced breast MRI was offered at 557 of 754 (73.8%) practices. Of these, 346 of 553 (62.6%) performed at least five breast MRI examinations per week, and only 56 of 553 (10.1%) performed > 20 per week. Radiologists qualified under the Mammography Quality Standards Act supervised the performance of and interpreted breast MRI in the majority of facilities. Of 552 respondents, breast MRI was interpreted as soft copy with computer-aided detection (CAD) in 280 practices (50.7%), as soft copy without CAD in 261 (47.3%), and as hard copy in 11 (2.0%). Of 551 respondents, 256 (46.5%) never and 207 (37.6%) rarely interpreted breast MRI without correlating mammography or sonography findings. The majority of respondents never (269/561, 48.0%) or rarely (165/561, 29.4%) interpreted breast MRI performed at an outside facility. Screening breast MRI was offered at 359 of 561 (64.0%) practices. Of the practices performing contrast-enhanced examinations, 173 of 557 (31.1%) did not perform MRI-guided interventional procedures. CONCLUSION: Contrast-enhanced breast MRI is now widely used in the United States. The information gained from this survey should provide reasonable approaches for the development of professional practice guidelines.

Alternative breast-imaging approaches.

Although conventional breast-imaging techniques routinely include mammography and ultrasound, growing interest in other approaches, perhaps most notably MR imaging, has drawn increasing attention to exploiting the anatomic and physiologic basis for understanding breast cancer. Nuclear medicine techniques have been applied in several circumstances with the intent of approaching or defining a role for molecular imaging, exemplified by the use of F-18 fluorodeoxyglucose and positron emission tomography. Other techniques, including exploitation of additional components of the electromagnetic spectrum, have provided novel concepts that may ripen into clinical use.