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.

Short-term outcomes of screening mammography using computer-aided detection: a population-based study of medicare enrollees.

BACKGROUND: Computer-aided detection (CAD) has rapidly diffused into screening mammography practice despite limited and conflicting data on its clinical effect. OBJECTIVE: To determine associations between CAD use during screening mammography and the incidence of ductal carcinoma in situ (DCIS) and invasive breast cancer, invasive cancer stage, and diagnostic testing. DESIGN: Retrospective cohort study. SETTING: Medicare program. PARTICIPANTS: Women aged 67 to 89 years having screening mammography between 2001 and 2006 in U.S. SEER (Surveillance, Epidemiology and End Results) regions (409 459 mammograms from 163 099 women). MEASUREMENTS: Incident DCIS and invasive breast cancer within 1 year after mammography, invasive cancer stage, and diagnostic testing within 90 days after screening among women without breast cancer. RESULTS: From 2001 to 2006, CAD prevalence increased from 3.6% to 60.5%. Use of CAD was associated with greater DCIS incidence (adjusted odds ratio [OR], 1.17 [95% CI, 1.11 to 1.23]) but no difference in invasive breast cancer incidence (adjusted OR, 1.00 [CI, 0.97 to 1.03]). Among women with invasive cancer, CAD was associated with greater likelihood of stage I to II versus III to IV cancer (adjusted OR, 1.27 [CI, 1.14 to 1.41]). In women without breast cancer, CAD was associated with increased odds of diagnostic mammography (adjusted OR, 1.28 [CI, 1.27 to 1.29]), breast ultrasonography (adjusted OR, 1.07 [CI, 1.06 to 1.09]), and breast biopsy (adjusted OR, 1.10 [CI, 1.08 to 1.12]). LIMITATION: Short follow-up for cancer stage, potential unmeasured confounding, and uncertain generalizability to younger women. CONCLUSION: Use of CAD during screening mammography among Medicare enrollees is associated with increased DCIS incidence, the diagnosis of invasive breast cancer at earlier stages, and increased diagnostic testing among women without breast cancer. PRIMARY FUNDING SOURCE: Center for Healthcare Policy and Research, University of California, Davis.

External validation of Medicare claims codes for digital mammography and computer-aided detection.

BACKGROUND: While Medicare claims are a potential resource for clinical mammography research or quality monitoring, the validity of key data elements remains uncertain. Claims codes for digital mammography and computer-aided detection (CAD), for example, have not been validated against a credible external reference standard. METHODS: We matched Medicare mammography claims for women who received bilateral mammograms from 2003 to 2006 to corresponding mammography data from the Breast Cancer Surveillance Consortium (BCSC) registries in four U.S. states (N = 253,727 mammograms received by 120,709 women). We assessed the accuracy of the claims-based classifications of bilateral mammograms as either digital versus film and CAD versus non-CAD relative to a reference standard derived from BCSC data. RESULTS: Claims data correctly classified the large majority of film and digital mammograms (97.2% and 97.3%, respectively), yielding excellent agreement beyond chance (κ = 0.90). Claims data correctly classified the large majority of CAD mammograms (96.6%) but a lower percentage of non-CAD mammograms (86.7%). Agreement beyond chance remained high for CAD classification (κ = 0.83). From 2003 to 2006, the predictive values of claims-based digital and CAD classifications increased as the sample prevalences of each technology increased. CONCLUSION: Medicare claims data can accurately distinguish film and digital bilateral mammograms and mammograms conducted with and without CAD. IMPACT: The validity of Medicare claims data regarding film versus digital mammography and CAD suggests that these data elements can be useful in research and quality improvement.

Computer-aided detection of breast cancer: a cost-effectiveness study.

PURPOSE: To analyze the cost-effectiveness of adding computer-aided detection (CAD) to a screening mammography program. MATERIALS AND METHODS: A Markov model was developed to compare three hypothetical groups of women aged 40-79 years. The first group was composed of women undergoing mammographic screening without CAD; the second, of women undergoing mammographic screening with CAD; and the third, of women undergoing observation without screening. Cost-effectiveness was expressed as the marginal cost per year of life saved (MCYLS). MCYLS was calculated for screening mammography with CAD compared with screening mammography alone and for screening mammography alone compared with observation. Sensitivity analyses were performed by varying the cost of CAD, the rates of cancer detection with CAD, and the stage distribution of breast cancers diagnosed with CAD. RESULTS: Adding CAD to a mammographic screening program resulted in a MCYLS of $19,058. The MCYLS of screening mammography alone compared with observation was $16,023. CAD increases the marginal effectiveness of screening by 29%; however, the marginal cost of screening is also increased by 34%. Varying the cost of CAD yields a linear increase in MCYLS from $8937 with CAD at $9 per case to $24,924 with CAD at $25 per case. The cost-effectiveness of CAD is dependent on the magnitude of the increase in cancer detection rates with CAD but is also affected by the stage distribution of cancers diagnosed with CAD. CONCLUSION: The MCYLS is 19% greater for CAD added to screening versus screening mammography alone but is still within the accepted range for cost-effectiveness.

Technique factors and their relationship to radiation dose in pendant geometry breast CT.

The use of breast computed tomography (CT) as an alternative to mammography in some patients is being studied at several institutions. However, the radiation dosimetry issues associated with breast CT are markedly different than in the case of mammography. In this study, the spectral properties of an operational breast CT scanner were characterized both by physical measurement and computer modeling of the kVp-dependent spectra, from 40 to 110 kVp (Be window W anode with 0.30 mm added Cu filtration). Previously reported conversion factors, normalized glandular dose for CT-DgN(ct), derived from Monte Carlo methods, were used in concert with the output spectra of the breast scanner to compute the mean glandular dose to the breast based upon different combinations of x-ray technique factors (kVp and mAs). The mean glandular dose (MGD) was measured as a function of the compressed breast thickness (2-8 cm) and three different breast compositions (0%, 50%, and 100% glandular fractions) in four clinical mammography systems in our institution. The average MGD from these four systems was used to compute the technique factors for breast CT systems that would match the two-view mammographic dose levels. For a 14 cm diameter breast (equivalent to a 5 cm thick compressed breast in mammography), air kerma levels at the breast CT scanner's isocenter (468 mm from the source) of 4.4, 6.4, and 9.0 mGy were found to deliver equivalent mammography doses for 0%, 50%, and 100% glandular breasts (respectively) at 80 kVp. At 80 kVp (where air kerma was 11.3 mGy/100 mAs at the isocenter), 57 mAs (integrated over the entire scan) was required to match the mammography dose for a 14 cm 50% glandular breast. At 50 kVp, 360 mAs is required to match mammographic dose levels. Tables are provided for both air kerma at the isocenter and mAs for 0%, 50%, and 100% glandular breasts. Other issues that impact breast CT technique factors are also discussed.