Impact of the second reader on screening outcome at blinded double reading of digital screening mammograms

BACKGROUND: To determine the impact of the second reader on screening outcome at blinded double reading of digital screening mammograms. METHODS: We included a consecutive series of 99,013 digital screening mammograms, obtained between July 2013 and January 2015 and double read in a blinded fashion. During 2-year follow-up, we collected radiology, surgery and pathology reports of recalled women. RESULTS: Single reading resulted in 2928 recalls and 616 screen-detected cancers (SDCs). The second reader recalled another 612 women, resulting in 82 additional SDCs. Addition of the second reader increased the recall rate (3.0% to 3.6%, p < 0.001), cancer detection rate (6.2-7.0 per 1000 screens, p < 0.001) and false positive recall rate (24.4-28.7 per 1000 screens, p < 0.001). Positive predictive value of recall (21.0% vs. 19.7%, p = 0.20) and of biopsy (52.1% vs. 50.9%, p = 0.56) were comparable for single reading and blinded double reading. Tumour characteristics were comparable for cancers detected by the first reader and cancers additionally detected by the second reader, except of a more favourable tumour grade in the latter group. CONCLUSIONS: At blinded double reading, the second reader significantly increases the cancer detection rate, at the expense of an increased recall rate and false positive recall rate

Introduction of additional double reading of mammograms by radiographers: Effects on a biennial screening programme outcome

Purpose: To determine the effect of introducing radiographer double reading, in addition to standard radiologist double reading, on screening mammography outcome. Methods: In period A, 66,225 mammograms were read by two screening radiologists. In period B, 78,325 mammograms were read by two radiographers in addition and radiologists were blinded to the referral opinion of the radiographers. Mammograms, for which only radiographers had suggested referral, (i.e. cases that would only be referred by technologists) were re-evaluated by the screening radiologists. Women were referred if at least one radiologist considered this necessary, and diagnostic costs of these additional referrals were estimated. Results: In period A, 322 cancers were diagnosed after referral of 678 women. During period B, radiologists initially referred 1122 patients and 411 cancers were detected. Radiologists' referral rate was higher in period B than in period A (1.43% versus 1.02%, p < 0.001), as well as the cancer detection rate per 1000 women screened (CDR) (5.25 versus 4.86, p = 0.3). The positive predictive value of referral (PPV) was 36.6% versus 47.5% (p < 0.001). In period B, radiologist review of 544 additional positive radiographer readings led to 102 extra referrals, with 29 additional cancers detected, resulting in an overall referral rate of 1.56% (compared to period A, p < 0.001), an overall CDR of 5.62 (p = 0.048) and an overall PPV of 35.9% (p < 0.001). Workup expenses of the 102 additional referrals were Sic60,274. Conclusion: Additional radiographer double reading detected cancers that would have been missed by radiologists. Mean expenses for diagnostic confirmation of these extra cancers was Sic2078 per cancer. (C) 2008 Elsevier Ltd. All rights reserved

Inter-observer variability in mammography screening and effect of type and number of readers on screening outcome

We prospectively determined the variability in radiologists' interpretation of screening mammograms and assessed the influence of type and number of readers on screening outcome. Twenty-one screening mammography radiographers and eight screening radiologists participated. A total of 106 093 screening mammograms were double-read by two radiographers and, in turn, by two radiologists. Initially, radiologists were blinded to the referral opinion of the radiographers. A woman was referred if she was considered positive at radiologist double-reading with consensus interpretation or referred after radiologist review of positive cases at radiographer double-reading. During 2-year follow-up, clinical data, breast imaging reports, biopsy results and breast surgery reports were collected of all women with a positive screening result from any reader. Single radiologist reading (I) resulted in a mean cancer detection rate of 4.64 per 1000 screens (95% confidence intervals (CI)=4.23–5.05) with individual variations from 3.44 (95% CI=2.30–4.58) to 5.04 (95% CI=3.81–6.27), and a sensitivity of 63.9% (95% CI=60.5–67.3), ranging from 51.5% (95% CI=39.6–63.3) to 75.0% (95% CI=65.3–84.7). Sensitivity at non-blinded, radiologist double-reading (II), radiologist double-reading followed by radiologist review of positive cases at radiographer double-reading (III), triple reading by one radiologist and two radiographers with referral of all positive readings (IV) and quadruple reading by two radiologists and two radiographers with referral of all positive readings (V) were as follows: 68.6% (95% CI=65.3–71.9) (II); 73.2% (95% CI=70.1–76.4) (III); 75.2% (95% CI=72.1–78.2) (IV), and 76.9% (95% CI=73.9–79.9) (V). We conclude that screener performance significantly varied at single-reading. Double-reading increased sensitivity by a relative 7.3%. When there is a shortage of screening radiologists, triple reading by one radiologist and two radiographers may replace radiologist double-reading

Screening caused rising incidence rates of ductal carcinoma in situ of the breast

The purpose of this study was to examine trends in incidence and detection of ductal carcinoma in situ (DCIS) of the breast in southern Netherlands in the period 1984-2006 and assess the effect of mass screening. All patients with primary DCIS registered between 1984 and 2006 in the population-based Eindhoven Cancer Registry were included (n = 1,767). These data were linked to data from the population-based screening programme. The incidence of DCIS of the breast increased from 3/100,000 to almost 34/100,000 person-years in women aged 50-69 years in southern Netherlands since 1984. Mass screening was responsible for this increase. A stable 60% of DCIS was screen-detected. Over 11% of breast cancer patients have DCIS. In conclusion, the incidence of DCIS increased markedly in southern Netherlands with a clear effect of mammography screening since 1992