940 research outputs found

    Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.

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    BackgroundAn alternative approach to the traditional model of radiologists interpreting screening mammography is necessary due to the shortage of radiologists to interpret screening mammograms in many countries.MethodsWe evaluated the performance of 15 Mexican radiographers, also known as radiologic technologists, in the interpretation of screening mammography after a 6 months training period in a screening setting. Fifteen radiographers received 6 months standardized training with radiologists in the interpretation of screening mammography using the Breast Imaging Reporting and Data System (BI-RADS) system. A challenging test set of 110 cases developed by the Breast Cancer Surveillance Consortium was used to evaluate their performance. We estimated sensitivity, specificity, false positive rates, likelihood ratio of a positive test (LR+) and the area under the subject-specific Receiver Operating Characteristic (ROC) curve (AUC) for diagnostic accuracy. A mathematical model simulating the consequences in costs and performance of two hypothetical scenarios compared to the status quo in which a radiologist reads all screening mammograms was also performed.ResultsRadiographer's sensitivity was comparable to the sensitivity scores achieved by U.S. radiologists who took the test but their false-positive rate was higher. Median sensitivity was 73.3 % (Interquartile range, IQR: 46.7-86.7 %) and the median false positive rate was 49.5 % (IQR: 34.7-57.9 %). The median LR+ was 1.4 (IQR: 1.3-1.7 %) and the median AUC was 0.6 (IQR: 0.6-0.7). A scenario in which a radiographer reads all mammograms first, and a radiologist reads only those that were difficult for the radiographer, was more cost-effective than a scenario in which either the radiographer or radiologist reads all mammograms.ConclusionsGiven the comparable sensitivity achieved by Mexican radiographers and U.S. radiologists on a test set, screening mammography interpretation by radiographers appears to be a possible adjunct to radiologists in countries with shortages of radiologists. Further studies are required to assess the effectiveness of different training programs in order to obtain acceptable screening accuracy, as well as the best approaches for the use of non-physician readers to interpret screening mammography

    Breast cancer risk is increased in the years following false-positive breast cancer screening

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    A small number of studies have investigated breast cancer (BC) risk among women with a history of false-positive recall (FPR) in BC screening, but none of them has used time-to-event analysis while at the same time quantifying the effect of false-negative diagnostic assessment (FNDA). FNDA occurs when screening detects BC, but this BC is missed on diagnostic assessment (DA). As a result of FNDA, screenings that detected cancer are incorrectly classified as FPR. Our study linked data recorded in the Flemish BC screening program (women aged 50-69 years) to data from the national cancer registry. We used Cox proportional hazards models on a retrospective cohort of 298 738 women to assess the association between FPR and subsequent BC, while adjusting for potential confounders. The mean follow-up was 6.9 years. Compared with women without recall, women with a history of FPR were at an increased risk of developing BC [hazard ratio = 2.10 (95% confidence interval: 1.92-2.31)]. However, 22% of BC after FPR was due to FNDA. The hazard ratio dropped to 1.69 (95% confidence interval: 1.52-1.87) when FNDA was excluded. Women with FPR have a subsequently increased BC risk compared with women without recall. The risk is higher for women who have a FPR BI-RADS 4 or 5 compared with FPR BI- RADS 3. There is room for improvement of diagnostic assessment: 41% of the excess risk is explained by FNDA after baseline screening

    Impact of Digital Mammography on Cancer Detection and Recall Rates: 11.3 Million Screening Episodes in the English National Health Service Breast Cancer Screening Program.

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    Purpose To report the impact of changing from screen-film mammography to digital mammography (DM) in a large organized national screening program. Materials and Methods A retrospective analysis of prospectively collected annual screening data from 2009-2010 to 2015-2016 for the 80 facilities of the English National Health Service Breast Cancer Screening Program, together with estimates of DM usage for three time periods, enabled the effect of DM to be measured in a study of 11.3 million screening episodes in women aged 45-70 years (mean age, 59 years). Regression models were used to estimate percentage and absolute change in detection rates due to DM. Results The overall cancer detection rate was 14% greater with DM (P < .001). There were higher rates of detection of grade 1 and 2 invasive cancers (both ductal and lobular), but no change in the detection of grade 3 invasive cancers. The recall rate was almost unchanged by the introduction of DM. At prevalent (first) screening episodes for women aged 45-52 years, DM increased the overall detection rate by 19% (P < .001) and for incident screening episodes in women aged 53-70 years by 13% (P < .001). Conclusion The overall cancer detection rate was 14% greater with digital mammography with no change in recall rates and without confounding by changes in other factors. There was a substantially higher detection of grade 1 and grade 2 invasive cancers, including both ductal and lobular cancers, but no change in the detection of grade 3 invasive cancers. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by C.I. Lee and J.M. Lee in this issue

    Effect of protocol-related variables and women's characteristics on the cumulative false-positive risk in breast cancer screening

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    Background: Reducing the false-positive risk in breast cancer screening is important. We examined how the screening-protocol and women's characteristics affect the cumulative false-positive risk. Methods: This is a retrospective cohort study of 1 565 364 women aged 45-69 years who underwent 4 739 498 screening mammograms from 1990 to 2006. Multilevel discrete hazard models were used to estimate the cumulative false-positive risk over 10 sequential mammograms under different risk scenarios. Results: The factors affecting the false-positive risk for any procedure and for invasive procedures were double mammogram reading [odds ratio (OR) = 2.06 and 4.44, respectively], two mammographic views (OR = 0.77 and 1.56, respectively), digital mammography (OR = 0.83 for invasive procedures), premenopausal status (OR = 1.31 and 1.22, respectively), use of hormone replacement therapy (OR = 1.03 and 0.84, respectively), previous invasive procedures (OR = 1.52 and 2.00, respectively), and a familial history of breast cancer (OR = 1.18 and 1.21, respectively). The cumulative false-positive risk for women who started screening at age 50-51 was 20.39% [95% confidence interval (CI) 20.02-20.76], ranging from 51.43% to 7.47% in the highest and lowest risk profiles, respectively. The cumulative risk for invasive procedures was 1.76% (95% CI 1.66-1.87), ranging from 12.02% to 1.58%. Conclusions: The cumulative false-positive risk varied widely depending on the factors studied. These findings are relevant to provide women with accurate information and to improve the effectiveness of screening programs

    Quality and safety considerations in breast cancer screening

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    Breast cancer is a leading cause of premature mortality among United States women. Early detection has been shown to reduce breast cancer morbidity, mortality and cost of treatment. The relative safety of breast cancer screening has been viewed in terms of benefits and harms. The quality and safety of breast cancer screening depends on both technical and human factors. Focusing on quality and safety considerations, we review two imaging modalities recommended for primary breast cancer screening: mammography and magnetic resonance imaging, and the use of ultrasound (US) for supplemental breast cancer screening

    Overdiagnosis in the Dutch and Norwegian breast cancer screening program

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    Breast cancer screening in the Czech Republic: time trends in performance indicators during the first seven years of the organised programme

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    <p>Abstract</p> <p>Background</p> <p>The Czech Breast Cancer Screening Programme (CBCSP) was initiated in September 2002 by establishing a network of accredited centres. The aim of this article is to describe progress in the programme quality over time after the inception of the organised programme.</p> <p>Methods</p> <p>The CBCSP is monitored using an information system consisting of three principal components: 1) the national cancer registry, 2) a screening registry collecting data on all screening examinations, further assessments and final diagnoses at accredited programme centres, and 3) administrative databases of healthcare payers. Key performance indicators from the European Guidelines have been adopted for continuous monitoring.</p> <p>Results</p> <p>Breast cancer incidence in the Czech Republic has steadily been increasing, however with a growing proportion of less advanced stages. The mortality rate has recently stabilised. The screening registry includes 2,083,285 records on screening episodes between 2002 and 2008. In 2007-2008, 51% of eligible women aged 45-69 were screened. In 2008, the detection rates were 6.1 and 3.7 per 1,000 women in initial and subsequent screening respectively. Corresponding recall rates are 3.9% and 2.2%, however, it is necessary to pay attention to further assessment performed during the screening visits. Benign to malignant open biopsy ratio was 0.1. Of invasive cases detected in screening, 35.6% was less than 10 mm in diameter. Values of early performance indicators, as measured by both crude and standardized estimates, are generally improving and fulfil desirable targets set by European Guidelines.</p> <p>Conclusions</p> <p>Mammography screening in the Czech Republic underwent successful transformation from opportunistic prevention to an organised programme. Values of early indicators confirm continuous improvement in different aspects of process quality. Further stimulation of participation through invitation system is necessary to exploit the full potential of screening mammography at the population level.</p

    Overdiagnosis in the Dutch and Norwegian breast cancer screening program

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    Digital Breast Tomosynthesis : - the future screening tool for breast cancer?

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    Bakgrunn: Brystkreft er den vanligste kreftformen blant kvinner og en av de hyppigste årsakene til kreftdødsfall i Norge og globalt. Målsettingen med mammografiscreening er å oppdage brystkreft i et tidlig stadium og redusere dødeligheten av sykdommen. Studier har vist høyere deteksjon av screeningoppdagede krefttilfeller med digital brysttomosyntese som inkluderer ~200-250 bilder sammenlignet med standard digital mammografi (DM) med fire bilder. Vi utførte en randomisert kontrollert studie (RCT), Tomosyntese-studien i Bergen (To-Be1). Målsettingen med studien var å sammenligne tidligindikatorer i screening ved bruk av digital brysttomosyntese i kombinasjon med syntetiske 2D-bilder (DBT) versus standard DM. Avhandlingen inkluderer tre studier med følgende mål: Studie 1: Å sammenligne lesetid, stråledose, konsensus og tilbakekalling ved bruk av DBT og DM etter det første året av To-Be1. Studie 2: Å sammenligne tilbakekalling, falske positive screeningsresultater og screeningoppdaget kreft for kvinner med ulik mammografisk tetthet målt automatisk (Volpara tetthetsgrad, VDG 1-4) og med ulike screeningteknikker (DBT versus DM). Studie 3: Å undersøke fordeling av mammografiske funn hos kvinner tilbakekalt etter screening med DBT versus DM og analysere sammenhenger mellom mammografiske funn og det endelige resultatet av screeningundersøkelsen. Metode: Alle kvinner som deltok i screening utført i Bergen i løpet av 2016-2017 som en del av Mammografiprogrammet (n=32 976) ble invitert til å delta i To-Be1. Totalt aksepterte 89,3 % av kvinnene invitasjonen og ble randomisert til DBT eller DM. Etter uavhengig dobbelttyding med konsensus ble resultater etter DBT sammenlignet med DM. Mammografisk tetthet ble oppgitt som VDG 1-4, som er analog til kategoriene i BI-RADS´ 5. utgave. Radiologene klassifiserte mammografiske funn hos etterinnkalte kvinner etter en modifisert BI-RADS skala. Vi brukte deskriptive analyser og t-test for å sammenligne gjennomsnittsverdier, samt kji-kvadrat-test med tilhørende 95% konfidensintervall (KI) for å sammenligne kategorier. Log-binominale regresjonsmodeller ble brukt for å estimere relativ risiko. En p-verdi lavere enn 0,05 ble definert som statistisk signifikant. Vi brukte statistikkprogrammet STATA. Resultater: Studie 1: Gjennomsnittlig lesetid var 1:11 min:sek for DBT og 0:41 min:sek for DM i det første året av To-Be1. Det var ingen statistiske forskjeller i gjennomsnittlig stråledose for noen av tetthetskategoriene for DBT (2,96 mGy) versus DM (2,95 mGy). Tilbakekallingen var 3,0 % for DBT og 3,6 % for DM etter det første året med To-Be1. Studie 2: Etterundersøkelsesraten for kvinner med VDG 1 var 2,1% for DBT og 3,3% for DM, mens den var 3,2% for DBT og 4,3% for DM for de med VDG 2. Raten av falske positive screening resultater var 1,6% for DBT og 2,8% for DM for kvinner med VDG 1. For kvinner med VDG 2 var den 2,4% for DBT og 3,6 for DM. Ingen statistiske forskjeller i screeningoppdaget kreft ble funnet mellom DBT og DM for noen av tetthetskategoriene. Justert relativ risiko for tilbakekalling, falskt positivt screeningsresultat og screeningoppdaget kreft økte med VDG i DBT, mens det ikke ble funnet forskjeller i DM. Studie 3: Studien inkluderte 182 screeningdetekterte krefttilfeller (n=95 for DBT og n=87 for DM). Blant disse var 36,8% spikulerte masser for DBT mens det var 18,4% for DM. Kalk var det hyppigste mammografiske funnet for brystkrefttilfeller for de som var screenet med DM (23%). For DBT var andelen på 13,7%. Asymmetri, uskarp og skjult masse var mindre hyppig hos kvinner med et falsk positiv screening resultat etter screening med DBT versus DM. Konklusjon: Resultater fra To-Be1 indikerte at DBT var minst like god som DM når det gjelder etterundersøkelser og deteksjon av brystkreft, som betyr at DBT er trygt å bruke i screening. DBT var bedre egnet enn DM for kvinner med VDG 1 og 2 med hensyn til etterundersøkelsesrate og falske positive, mens deteksjon av brystkreft ikke var forskjellig. Det tok lengre tid å lese DBT enn DM bilder, og konsensus tok lengre tid med DBT. Mer kunnskap om forskjeller i mammografiske funn og sammenheng med screeningsresultater for DBT versus DM kan bidra til å ytterligere forbedre fordelene med DBT som et screeningverktøy.Background: Breast cancer is the most common cancer and one of the leading causes of cancer deaths in Norway and globally. Mammographic screening aims for early detection of breast cancer and reduced mortality from the disease. Studies have shown higher rates of screen-detected cancers for digital breast tomosynthesis including ~200-250 images compared to standard digital mammography (DM) including four images. We performed a randomized controlled trial (RCT), the Tomosynthesis trial in Bergen (To-Be1), were the aim was to compare early performance measures for digital breast tomosynthesis including synthesised 2D images (DBT) versus DM in screening. This thesis includes three studies with the following aims: Study 1: To compare preliminary results of reading time, radiation dose, consensus and recall for DBT and DM after the first year of To-Be1. Study 2: To compare recall, false positive screening results and screen-detected cancers by automated mammographic density (Volpara density grade, VDG 1-4) and screening technique (DBT versus DM). Study 3: To investigate distribution of mammographic features in women recalled after screening with DBT versus DM and assess associations between mammographic features and final outcome of the screening examination. Method: All women who attended the screening unit in Bergen during 2016-2017 as part of BreastScreen Norway (n=32 976) were invited to participate in To-Be1. In total, 89.3% of the women accepted the invitation and were randomized to undergo either DBT or DM. After independent double reading with consensus, results for DBT were compared with DM. Mammographic density were described by VDG 1-4 which are analogue to the categories in the BI-RADS 5th edition. The radiologists classified the mammographic features of recalled women according to a modified BI-RADS scale. We presented descriptive results and used t-tests to test for means, and chi-squared tests for categories with corresponding 95% confidence intervals (CI). Log-binominal regression models were used to estimate relative risks. A p-value lower than 0.05 was defined as statistically significant. We used STATA software. Results: Study 1: Mean reading time was 1:11 min:sec for DBT versus 0:41 min:sec for DM in the first year of To-Be1. Mean glandular dose did not differ statistically for women screened with DBT (2.96 mGy) versus DM (2.95 mGy). Recall was 3.0% for DBT and 3.6% for DM in the first year of To-Be1. Study 2: Recall rate for women with VDG 1 was 2.1% for DBT and 3.3% for DM, while it was 3.2% for DBT and 4.3% for DM for women with VDG 2. The rate of false positive screening results was 1.6% for DBT and 2.8% for DM for women with VDG 1. For women with VDG 2 it was 2.4% for DBT and 3.6% for DM. No statistical difference in screen-detected cancers was observed between DBT and DM in any density categories. Adjusted relative risk of recall, false positives and screen-detected cancers increased with VDG for DBT. No difference was found for DM. Study 3: The study included 182 screen detected cancers (n=95 DBT and n= 87 DM). 36.8% of those detected with DBT was spiculated mass, while it was 18.4 % for DM. Calcifications was the most frequent feature for breast cancer among those screened with DM (23.0%), which did not differ statistically from the 13.7% for DBT. Asymmetry, indistinct and obscured mass was less frequent in women with a false positive screening result after screening with DBT versus DM. Conclusion: Results from To-Be1 indicated DBT to be as least as good as DM in terms of recall and cancer detection, which means that DBT is safe for the women. DBT was superior to DM in women with VDG 1 and 2 (lower recall, fewer false positives, no difference in cancer detection). However, time spent on initial screen reading and on consensus was longer for DBT compared with DM. More knowledge of the differences in distribution of mammographic features and their association with screening outcome, might contribute to further improve the benefits of DBT as a screening tool for breast cancer.Doktorgradsavhandlin
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