Introduction Of Full-field Digital Mammography Research Articles

Consensus Review of Discordant Imaging Findings after the Introduction of Digital Screening Mammography: Irish National Breast Cancer Screening Program Experience.

Background When there are discordant results between individual readers interpreting screening mammograms, consensus by independent readers may reduce unnecessary recalls for further work-up. Few studies have looked at consensus outcomes following the introduction of full-field digital mammography (FFDM). Purpose To determine outcomes of women discussed at consensus meetings during a 5-year period after introduction of FFDM, including recall rates, cancer detection, and interval cancers. Materials and Methods In this retrospective study from January 2010 to December 2014, the authors reviewed all screening mammograms from a single unit of a biennial Irish national breast screening program after the introduction of FFDM. Screening mammograms were double reported. Abnormalities detected at discordant screening mammography readings were discussed at biweekly consensus meetings. Outcomes of consensus meetings were reviewed in terms of referral for assessment, biopsy rates, cancer detection, and outcomes from later rounds of screening. Statistical analysis was performed by using a χ2 test to compare recall rate and cancer detection rates between FFDM and screen-film mammography based on a previously published study from the authors' institution. Results A total of 2565 women (age range, 50-64 years) with discordant mammographic findings were discussed at consensus meetings. Of these 2565 women, 1037 (40%) were referred for further assessment; 108 cancers were detected in these women. Of the 1285 women who returned to biennial screening, malignancy was detected at the site of original concern in 12 women at a further round of screening. Three true interval cancers were identified. Sensitivity (88.5% [108 of 122]; 95% confidence interval [CI]: 81.5%, 93.6%) and negative predictive value (99.1% [1528 of 1542]; 95% CI: 98.5%, 99.4%) of consensus review remained stable after the introduction of FFDM. Specificity of consensus review increased from 57.6% (729 of 1264; 95% CI: 54.9%, 60.4%) to 62.2% (1528 of 2457; 95% CI: 60.2%, 64.1%) (P = .008). Conclusion Consensus review of discordant mammographic screening-detected abnormalities remains a valuable tool after introduction of full-field digital mammography as it reduces recall for assessment and demonstrates persistently high sensitivity and negative predictive values. © RSNA, 2020 See also the editorial by Hofvind and Lee in this issue.

Recall and Outcome of Screen-detected Microcalcifications during 2 Decades of Mammography Screening in the Netherlands National Breast Screening Program.

Background Trends in the detection of suspicious microcalcifications at mammography screening and the yield of these lesions after recall are unknown. Purpose To determine trends in recall and outcome of screen-detected microcalcifications during 20 years of mammography screening. Materials and Methods The authors performed a retrospective analysis of a consecutive series of 817 656 screening examinations (January 1997 to January 2017) in a national breast screening program. In 2009-2010 (transition period), screen-film mammography (SFM) was gradually replaced by full-field digital mammography (FFDM). The recalls of suspicious microcalcifications from all radiology reports and pathologic outcome of recalled women with 2-year follow-up were analyzed. Screening outcome in the era of SFM (1997-2008), the transition period (2009-2010), and the era of FFDM (2011-2016) were compared. Trends over time and variations between the SFM and FFDM periods were expressed by using proportions with 95% confidence intervals (CIs). In cases where the analysis based on the CI confirmed clear periods (eg, before and after introduction of FFDM), pre- and postchange outcomes were compared by using χ2 tests. Results A total of 18 592 women (median age, 59 years; interquartile range, 14 years) were recalled at mammography screening, 3556 of whom had suspicious microcalcifications. The recall rate for microcalcifications increased from 0.1% in 1997-1998 to 0.5% in 2015-2016 (P < .001). This was temporally associated with the change from SFM to FFDM. The recalls yielding ductal carcinoma in situ (DCIS) increased from 0.3 per 1000 screening examinations with SFM to 1.1 per 1000 screening examinations with FFDM (P < .001), resulting in a decrease in the positive predictive value for recall for suspicious microcalcifications from 51% to 33% (P < .001). More than half of all DCIS lesions were high grade (52.6%; 393 of 747). The distribution of DCIS grades was stable during the 20-year screening period (P = .36). Conclusion The recall rate for suspicious microcalcifications at mammographic screening increased during the past 2 decades, whereas the ductal carcinoma in situ detection rate increased less rapidly, resulting in a lower positive predictive value for recall. © RSNA, 2020.

Qualitative Versus Quantitative Mammographic Breast Density Assessment: Applications for the US and Abroad.

Mammographic breast density (MBD) has been proven to be an important risk factor for breast cancer and an important determinant of mammographic screening performance. The measurement of density has changed dramatically since its inception. Initial qualitative measurement methods have been found to have limited consistency between readers, and in regards to breast cancer risk. Following the introduction of full-field digital mammography, more sophisticated measurement methodology is now possible. Automated computer-based density measurements can provide consistent, reproducible, and objective results. In this review paper, we describe various methods currently available to assess MBD, and provide a discussion on the clinical utility of such methods for breast cancer screening.

Abstract P6-02-05: Digital versus screen-film mammography in population-based breast cancer screening: Performance indicators and tumor characteristics of screen-detected and interval cancers

Abstract Purpose: To evaluate whether the introduction of full-field digital mammography (FFDM) in screening has resulted in any changes in performance indicators compared to screen-film mammography (SFM), including tumor characteristics and incidence rates of interval cancers. Materials and Methods Data of the Dutch National Cancer Screening Programme, region North (2004-2010) were linked to the Netherlands Cancer Registry (N=902,868). Screening performance indicators (recall rate, detection rate, positive predictive value, sensitivity and specificity) and tumor characteristics of screen-detected cancers were compared between FFDM and SFM, as were incidence rates and tumor characteristics of interval cancers. Analyses were stratified by initial and subsequent examinations. Differences were compared using chi-square. Results Initial examinations: After initial examinations recall rates were 2.1% for SFM and 3.0% for FFDM (p&amp;lt;0.001). The positive predictive value was 25.6% for SFM and 19.9% for FFDM (p=0.002) and detection rates were similar. The detection rate for DCIS was 0.86 per 1000 women for SFM compared to 1.18 per 1000 women for FFDM (p=0.137). Similar percentages of low grade DCIS were found for SFM and FFDM (18% vs. 14%;p=0.860). No difference were found in tumor size, morphology, grade and nodal status of invasive screen-detected cancers. Subsequent examinations: After subsequent examinations performance indicators were similar. Detection rates for DCIS were 0.74 per 1000 women for SFM versus 0.81 per 1000 women for FFDM (p=0.298). For invasive cancers, detection rates were 4.54 per 1000 women for SFM versus 4.33 per 1000 women for FFDM (p=0.210). The percentages of low grade DCIS were similar for SFM and FFDM (12% vs.9%; p=0.524). Invasive cancers diagnosed with FFDM were more often of high grade (p=0.024) and ductal type (p=0.030). No difference was found in the incidence rates of interval cancers for SFM and FFDM after initial examinations (2.69/1000 vs.2.51/1000; p=0.787). The sensitivity after initial examinations was 66.1% for SFM and 69.1% for FFDM (p=0.657), specificity was 98.5% and 96.9% for SFM and FFDM, respectively (p&amp;lt;0.001). After subsequent examinations the incidence rates of interval cancer were 2.30/1000 for SFM and 2.41/1000 for FFDM (p=0.652), sensitivity was 69.7% for SFM and 66.7% for FFDM (p=0.232). Specificity was 99.4% SFM and 99.2% for FFDM (p&amp;lt;0.001). No differences were found in tumor size, morphology, grade or nodal status of interval cancers diagnosed after FFDM compared to SFM after initial or after subsequent examinations. Conclusions Compared to SFM, FFDM resulted in similar rates of screen-detected and interval cancers, indicating that FFDM performs as well as SFM in a breast cancer screening program, with more invasive cancers of high grade and ductal type found after subsequent screens. FFDM resulted in a higher recall rate and lower PPV. No signs of an increase in low-grade DCIS (which might connote possible overdiagnosis) were seen. Tumor characteristics of interval cancers were similar. Citation Format: De Munck L, De Bock GH, Otter R, Reiding D, Broeders MJM, Willemse PHB, Siesling S. Digital versus screen-film mammography in population-based breast cancer screening: Performance indicators and tumor characteristics of screen-detected and interval cancers. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-02-05.

Characteristics of tumors detected by screen-film and digital mammography during breast cancer screening.

e12516 Background: Screening mammography is the single most effective method of breast cancer (BC) detection, and the introduction of full-field digital mammography (FFDM) was suggested to be super...

Re: Effectiveness of Computer-Aided Detection in Community Mammography Practice

Measuring the clinical benefits of computer-aided detection (CAD) in mammographic screening is challenging, in part because metrics used to quantify the effectiveness of mammographic screening do not always apply in a straightforward way to comparisons of screening with and without CAD. This was illustrated in a recent article in the Journal by Fenton et al. (1) on the effect of introducing CAD to mammographic screening in the community setting. One of the principal conclusions of Fenton et al. (1) was that CAD increases detection of ductal carcinoma in situ (DCIS). Fenton et al. imply that this is an undesired result because DCIS may lead to overdiagnosis. However, their data showed that the increased rate of detection of DCIS in women whose mammograms included CAD was accompanied by a decrease in the rate of detection of invasive breast cancers. This result is consistent with the goal of CAD, the use of which should lead to the detection of DCIS that might ultimately progress to invasive cancer. Thus, the increased detection of DCIS by CAD should not be considered overdiagnosis, but rather earlier detection, which is an important goal of screening mammography. More importantly, perhaps, the detection of DCIS by CAD (in a CAD vs no CAD comparison) is not the same as mammographic detection of DCIS (in a screening vs no screening comparison). All cancers detected by CAD are mammographically detectable; hence, if the radiologists does not detect the DCIS (with or without using CAD), it will eventually be detected at a future screening exam. Therefore, CAD will not lead to potentially more overdiagnoses, as the authors imply, but rather to earlier treatment of women with CAD-detected DCIS who would be treated even if CAD were not used. The downside is that women with indolent DCIS will be treated one or two years earlier. The upside is that some of the additional treated women will have DCIS that would have progressed to invasive cancer if it were not for CAD. Fenton et al. (1) used the accepted standard method to calculate sensitivity of screening mammography. When CAD was used, both the numerator and the denominator of the sensitivity calculation appropriately included cancers that were detected only with the aid of CAD. However, that method introduces bias when CAD is compared with no CAD because without CAD, the estimated number of cancers in the screened population (the denominator in any calculation of sensitivity) included only cancers detected by screening and interval cancers, those cancers that were detected in the interval between routine screening. Although some other cancers are likely to have been missed, they were not counted in the denominator of the sensitivity calculation without CAD because there was no way of determining their number. Whether CAD is an effective clinical tool is an important question that remains unanswered. Careful attention must be given to the methodology used in the evaluation and interpretation of results. The article by Fenton et al. (1) presents a snapshot of the effect of CAD at the introduction of the technology. Improvements in the performance of CAD systems, radiologists who have gained more experience in using CAD, and the introduction of full-field digital mammography have greatly changed the landscape.

Current status of digital mammography for screening and diagnosis of breast cancer

Digital mammography is becoming the preferred technique for investigation of the breast. It is important, therefore, to analyze not only the accuracy of this technique in the screening and the diagnostic environment but also to evaluate its strengths and limits. In addition, communication with other specialists inside and outside the hospital is essential. Recent publications of large clinical trials have shown that digital mammography is as accurate as film-screen mammography in a screening setting. Technical protocols for acceptance testing of these modalities are emerging but they are not yet complete. The literature shows that reading on soft copy may be preferred to hard copy. The high cost is still an important limiting factor in the easy introduction of full-field digital mammography in a hospital. Digital mammography is becoming the method of choice in the detection and characterization of breast cancer. Today, physical and technical protocols as well as large clinical trials are assessing the performance of this technology. A lot of work remains in the optimization of the different parts of the imaging chain: exposure setting, acceptability of detectors, dedicated post processing, viewing conditions and computer-aided detection. In parallel with these developments, newer digital technologies are being explored (tomosynthesis).

Full Field Digital Mammography: Initial Medical Legal Concerns

The introduction of full-field digital mammography into clinical practice invites changing concepts of potential medical legal liability in a field already suffering from high medical malpractice exposure. These include the lack of uniform quality control measures and the ability to perform extensive postprocessing manipulations, with unknown legal consequences.