Dutch Reference Center for Screening

Nijmegen, Netherlands

Dutch Reference Center for Screening

Nijmegen, Netherlands
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Luiten J.D.,Erasmus University Rotterdam | Luiten J.D.,Amphia Hospital | Voogd A.C.,Maastricht University | Luiten E.J.T.,Amphia Hospital | And 2 more authors.
Breast Cancer Research and Treatment | Year: 2017

Purpose: In a biennial screening mammography programme, we analysed the trends in incidence of screen-detected DCIS and invasive breast cancers in the era of screen-film mammography (SFM) screening, the period of the transition to full-field digital mammography (FFDM) screening and the period of FFDM screening. We also investigated a possible association between the incidence and grading of screen-detected DCIS and invasive breast cancer. Methods: In the southern part of the Netherlands, FFDM screening gradually replaced SFM screening between May 2009 and April 2010. We included a consecutive series of 484, 422 screens obtained between July 2005 and July 2015 and divided these screens into three groups; SFM-only cohort, transition cohort and FFDM-only cohort. Results: A total of 3059 referred women were diagnosed with DCIS (n = 623) or invasive breast cancer (n = 2436). The majority of DCIS were high-grade (48.2%), whereas the majority of the invasive breast cancers were low-grade (45.4%) or intermediate-grade (41.6%). The cancer detection rate (CDR) per 1000 screened women showed the same distribution by grade in both groups. The transition to FFDM was characterised by an increased overall detection rate of invasive cancers. Conclusions: Screening mammography detects mostly high-grade DCIS and low- or intermediate-grade invasive cancers. The grade distribution as well as the CDR in the years after the introduction of FFDM remained stable compared to the era of SFM screening. By diagnosing and treating high-grade DCIS, which otherwise may develop into high-grade invasive carcinoma, our findings provide new evidence for the beneficial value of screening mammography programmes. © 2017 Springer Science+Business Media, LLC

Rodriguez-Ruiz A.,Radboud University Nijmegen | Agasthya G.A.,Emory University | Sechopoulos I.,Radboud University Nijmegen | Sechopoulos I.,Dutch Reference Center for Screening
Physics in Medicine and Biology | Year: 2017

To characterize and develop a patient-based 3D model of the compressed breast undergoing mammography and breast tomosynthesis. During this IRB-approved, HIPAA-compliant study, 50 women were recruited to undergo 3D breast surface imaging with structured light (SL) during breast compression, along with simultaneous acquisition of a tomosynthesis image. A pair of SL systems were used to acquire 3D surface images by projecting 24 different patterns onto the compressed breast and capturing their reflection off the breast surface in approximately 12-16 s. The 3D surface was characterized and modeled via principal component analysis. The resulting surface model was combined with a previously developed 2D model of projected compressed breast shapes to generate a full 3D model. Data from ten patients were discarded due to technical problems during image acquisition. The maximum breast thickness (found at the chest-wall) had an average value of 56 mm, and decreased 13% towards the nipple (breast tilt angle of 5.2°). The portion of the breast not in contact with the compression paddle or the support table extended on average 17 mm, 18% of the chest-wall to nipple distance. The outermost point along the breast surface lies below the midline of the total thickness. A complete 3D model of compressed breast shapes was created and implemented as a software application available for download, capable of generating new random realistic 3D shapes of breasts undergoing compression. Accurate characterization and modeling of the breast curvature and shape was achieved and will be used for various image processing and clinical tasks. © 2017 Institute of Physics and Engineering in Medicine.

Dance D.R.,National Co ordinating Center for the Physics of Mammography | Dance D.R.,University of Surrey | Sechopoulos I.,Radboud University Nijmegen | Sechopoulos I.,Dutch Reference Center for Screening
Physics in Medicine and Biology | Year: 2016

The estimation of the mean glandular dose to the breast (MGD) for x-ray based imaging modalities forms an essential part of quality control and is needed for risk estimation and for system design and optimisation. This review considers the development of methods for estimating the MGD for mammography, digital breast tomosynthesis (DBT) and dedicated breast CT (DBCT). Almost all of the methodology used employs Monte Carlo calculated conversion factors to relate the measurable quantity, generally the incident air kerma, to the MGD. After a review of the size and composition of the female breast, the various mathematical models used are discussed, with particular emphasis on models for mammography. These range from simple geometrical shapes, to the more recent complex models based on patient DBCT examinations. The possibility of patient-specific dose estimates is considered as well as special diagnostic views and the effect of breast implants. Calculations using the complex models show that the MGD for mammography is overestimated by about 30% when the simple models are used. The design and uses of breast-simulating test phantoms for measuring incident air kerma are outlined and comparisons made between patient and phantom-based dose estimates. The most widely used national and international dosimetry protocols for mammography are based on different simple geometrical models of the breast, and harmonisation of these protocols using more complex breast models is desirable. © 2016 Institute of Physics and Engineering in Medicine.

van Landsveld-Verhoeven C.,Dutch Reference Center for Screening | den Heeten G.J.,Dutch Reference Center for Screening | Timmers J.,Dutch Reference Center for Screening | Broeders M.J.M.,Dutch Reference Center for Screening | Broeders M.J.M.,Radboud University Nijmegen
European Radiology | Year: 2015

Purpose: Our purpose was to compare mammographic positioning quality of new (NR) versus experienced screening radiographers (ER) in the Netherlands. Methods and Materials: Before starting to work in breast screening, NR must complete an education programme including a theoretical course (four days), practical training (six weeks), and a portfolio-review of 50 mammographic screening examinations performed by the radiographer. Furthermore, Dutch screening has an extensive system of quality assurance, including an audit-review of positioning quality of mammograms by ER. We analysed 13,520 portfolio views (NR) and 14,896 audit views (ER) based on pre-specified criteria, e.g., depiction of inframammary angle. Results: Overall positioning was more adequate for NR than ER (CC views: 97 % versus 86 %, p = 0.00; MLO views: 92 % versus 84 %, p = 0.00). NR scored better for most of the CC-criteria and showed, for instance, less folds (inadequate: 10 % versus 16 %, p = 0.00). In contrast, NR encountered more difficulties for MLO views in, for example, depiction of infra-mammary angle (inadequate: 38 % versus 34 %, p = 0.00). Overall, mammograms from NR were more often considered adequate, because of less severe errors. Conclusion: NR perform better than ER in overall positioning technique. These results stress the need for continuous monitoring and training in breast screening programmes to keep positioning skills up to date. Key Points: • We evaluated positioning quality of new and experienced Dutch screening radiographers. • New radiographers outperform their experienced colleagues in mammographic positioning quality. • New radiographers make less severe errors compared to experienced colleagues. • There is a need for a continuous individual monitoring and feedback system. © 2015, European Society of Radiology.

Broeders M.J.M.,Dutch Reference Center for Screening | Broeders M.J.M.,Radboud University Nijmegen | ten Voorde M.,Organization for Cancer Screening in the Eastern Part of the Netherlands | Veldkamp W.J.H.,Dutch Reference Center for Screening | And 8 more authors.
European Radiology | Year: 2014

Purpose: To compare pain, projected breast area, radiation dose and image quality between flexible (FP) and rigid (RP) breast compression paddles. Methods: The study was conducted in a Dutch mammographic screening unit (288 women). To compare both paddles one additional image with RP was made, consisting of either a mediolateral-oblique (MLO) or craniocaudal-view (CC). Pain experience was scored using the Numeric Rating Scale (NRS). Projected breast area was estimated using computer software. Radiation dose was estimated using the model by Dance. Image quality was reviewed by three radiologists and three radiographers. Results: There was no difference in pain experience between both paddles (mean difference NRS: 0.08 ± 0.08, p = 0.32). Mean radiation dose was 4.5 % lower with FP (0.09 ± 0.01 p = 0.00). On MLO-images, the projected breast area was 0.79 % larger with FP. Paired evaluation of image quality indicated that FP removed fibroglandular tissue from the image area and reduced contrast in the clinically relevant retroglandular area at chest wall side. Conclusions: Although FP performed slightly better in the projected breast area, it moved breast tissue from the image area at chest wall side. RP showed better contrast, especially in the retroglandular area. We therefore recommend the use of RP for standard MLO and CC views. Key points: • Pain experience showed no difference between flexible and rigid breast compression paddles. • Flexible paddles do not depict clinically relevant retroglandular areas as well. • Flexible paddles move breast tissue from image area at the chest wall side. • Rigid paddles depict more breast tissue and shows better contrast. • Rigid breast compression paddles are recommended for standard mediolateral-oblique and craniocaudal views. © 2014, The Author(s).

PubMed | University of Pennsylvania, Radboud University Nijmegen and Dutch Reference Center for Screening
Type: Journal Article | Journal: International journal of cancer | Year: 2016

Several reviews have estimated the balance of benefits and harms of mammographic screening in the general population. The balance may, however, differ between individuals with and without family history. Therefore, our aim is to assess the cumulative risk of screening outcomes; screen-detected breast cancer, interval cancer, and false-positive results, in women screenees aged 50-75 and 40-75, with and without a first-degree relative with a history of breast cancer at the start of screening. Data on screening attendance, recall and breast cancer detection were collected for each woman living in Nijmegen (The Netherlands) since 1975. We used a discrete time survival model to calculate the cumulative probability of each major screening outcome over 19 screening rounds. Women with a family history of breast cancer had a higher risk of all screening outcomes. For women screened from age 50-75, the cumulative risk of screen-detected breast cancer, interval cancer and false-positive results were 9.0, 4.4 and 11.1% for women with a family history and 6.3, 2.7 and 7.3% for women without a family history, respectively. The results for women 40-75 followed the same pattern for women screened 50-75 for cancer outcomes, but were almost doubled for false-positive results. To conclude, women with a first-degree relative with a history of breast cancer are more likely to experience benefits and harms of screening than women without a family history. To complete the balance and provide risk-based screening recommendations, the breast cancer mortality reduction and overdiagnosis should be estimated for family history subgroups.

Broeders M.,Radboud University Nijmegen | Broeders M.,Dutch Reference Center for Screening | Paci E.,Institute for Cancer Research and Prevention
Women's Health | Year: 2015

Breast cancer screening programs are still object of harsh debate. In 2012, the Independent UK Panel reviewed the benefits and harms of mammography screening based on randomized trials and the EUROSCREEN Working Group reviewed European observational outcome studies. The conclusion was that screening programs should continue, while acknowledging that harms, such as the occurrence of false-positive results and overdiagnosis, can have a negative impact on a woman's life. Information on the balance sheet of the benefits and harms of breast cancer screening should help women and their physicians to make an informed choice. The future challenge for breast screening programs is to assess the feasibility, acceptability, effectiveness and impact of risk-based screening in order to maximize benefit-to-harm ratios. © 2015 Future Medicine Ltd.

Ripping T.M.,Radboud University Nijmegen | Verbeek A.L.M.,Radboud University Nijmegen | Broeders M.J.M.,Radboud University Nijmegen | Broeders M.J.M.,Dutch Reference Center for Screening
Journal of Medical Screening | Year: 2016

It is widely accepted that overdiagnosis is a major harm of screening, but its extent is still topic of controversy. This is partly the result of incomparable overdiagnosis estimates in scientific literature, as a variety of denominators are used to calculate the percentage of overdiagnosis in cancer screening. We propose to use the following denominator to calculate the percentage of overdiagnosis: ‘all cancers detected during the screening period, both interval and screen-detected, in participants of a screening programme’. This denominator is more appropriate than existing denominators because it presents overdiagnosis as a real percentage, is unaffected by attendance percentages, is applicable to all observational study designs, and can be easily recalculated to absolute numbers. This denominator can be widely applied and increases comparability between overdiagnosis estimates, which is needed to correctly present the balance between the benefits and harms of screening. © The Author(s) 2015.

Van Der Waal D.,Radboud University Nijmegen | Broeders M.J.M.,Radboud University Nijmegen | Broeders M.J.M.,Dutch Reference Center for Screening | Verbeek A.L.M.,Radboud University Nijmegen | And 2 more authors.
Epidemiology | Year: 2015

Background: Ongoing breast cancer screening programs can only be evaluated using observational study designs. Most studies have observed a reduction in breast cancer mortality, but design differences appear to have resulted in different estimates. Direct comparison of case-control and trial analyses gives more insight into this variation. Here, we performed case-control analyses within the randomized UK Age Trial. Methods: The Age Trial assessed the effect of screening on breast cancer mortality in women ages 40-49 years. In our approach, case subjects were defined as breast cancer deaths between trial entry (1991-1997) and 2004. Women were ages 39-41 years at entry. For every case subject, five control subjects were selected. All case subjects were included in analyses of screening invitation (356 case subjects, 1,780 controls), whereas analyses of attendance were restricted to women invited to screening (105 case subjects, 525 age-matched controls). Odds ratios (OR) were estimated with conditional logistic regression. We used and compared two methods to correct for self-selection bias. Results: Screening invitation resulted in a breast cancer mortality reduction of 17% (95% confidence interval [CI]:-36%, +6%), similar to trial results. Different exposure definitions and self-selection adjustments influenced the observed breast cancer mortality reduction. Depending on the method, "ever screened" appeared to be associated with a small reduction (OR: 0.86, 95% CI: 0.40, 1.89) or no reduction (OR: 1.02, 95% CI: 0.48, 2.14) using the two methods of correction. Recent attendance resulted in an adjusted mortality reduction of 36% (95% CI:-69%, +31%) or 45% (95% CI:-71%, +5%). Conclusions: Observational studies, and particularly case-control studies, are an important monitoring tool for breast cancer screening programs. The focus should be on diminishing bias in observational studies and gaining a better understanding of the influence of study design on estimates of mortality reduction. © 2015 Wolters Kluwer Health, Inc.

PubMed | University Utrecht, Radboud University Nijmegen and Dutch Reference Center for Screening
Type: | Journal: Breast (Edinburgh, Scotland) | Year: 2016

Reliable breast density measurement is needed to personalize screening by using density as a risk factor and offering supplemental screening to women with dense breasts. We investigated the categorization of pairs of subsequent screening mammograms into density classes by human readers and by an automated system. With software (VDG) and by four readers, including three specialized breast radiologists, 1000 mammograms belonging to 500 pairs of subsequent screening exams were categorized into either two or four density classes. We calculated percent agreement and the percentage of women that changed from dense to non-dense and vice versa. Inter-exam agreement (IEA) was calculated with kappa statistics. Results were computed for each reader individually and for the case that each mammogram was classified by one of the four readers by random assignment (group reading). Higher percent agreement was found with VDG (90.4%, CI 87.9-92.9%) than with readers (86.2-89.2%), while less plausible changes from non-dense to dense occur less often with VDG (2.8%, CI 1.4-4.2%) than with group reading (4.2%, CI 2.4-6.0%). We found an IEA of 0.68-0.77 for the readers using two classes and an IEA of 0.76-0.82 using four classes. IEA is significantly higher with VDG compared to group reading. The categorization of serial mammograms in density classes is more consistent with automated software than with a mixed group of human readers. When using breast density to personalize screening protocols, assessment with software may be preferred over assessment by radiologists.

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