A randomised controlled trial of digital breast tomosynthesis vs digital mammography as primary screening tests: Screening results over subsequent episodes of the Proteus Donna study.

Proteus Donna is a randomised controlled trial aimed at prospectively evaluating screening with digital breast tomosynthesis (DBT), including interval cancer detection (ICD) and cancer detection (CD) in the analysis as a cumulative measure over subsequent screening episodes. Consenting women aged 46 to 68 attending the regional Breast Screening Service were randomly assigned to conventional digital mammography (DM, control arm) or DBT in addition to DM (DBT, study arm). At the subsequent round all participants underwent DM. Thirty-six months follow-up allowed for the identification of cancers detected in the subsequent screening and interscreening interval. Relative risk (RR) and 95% confidence interval (95% CI) were computed. Cumulative CD and Nelson-Aalen incidence were analysed over the follow-up period. Between 31 December 2014 and 31 December 2017, 43 022 women were randomised to DM and 30 844 to DBT. At baseline, CD was significantly higher (RR: 1.44, 95% CI: 1.21-1.71) in the study arm. ICD did not differ significantly between the two arms (RR: 0.92, 95% CI: 0.62-1.35). At subsequent screening with DM, the CD was lower (nearly significant) in the study arm (RR: 0.83, 95% CI: 0.65-1.06). Over the follow-up period, the cumulative CD (comprehensive of ICD) was slightly higher in the study arm (RR: 1.15, 95% CI: 1.01-1.31). The Nelson-Aalen cumulative incidence over time remained significantly higher in the study arm for approximately 24 months. Benign lesions detection was higher in the study arm at baseline and lower at subsequent tests. Outcomes are consistent with a lead time gain of DBT compared to DM, with an increase in false positives and moderate overdiagnosis.

The professional quality criteria of Italian breast screening radiologists: results from a national survey comparing the programmes started in 2000-2012 versus the ones started in 1990-1999.

INTRODUCTION: In Italy, due to increasing healthcare budget and staff shortages, the recently created regional mammography screening programmes were established under worse radiology practice quality criteria than the previously created programmes. METHODS: Using available data from a national questionnaire survey conducted at the end of 2013 and involving 222 responder radiologists, we compared the main professional quality standards of radiologists working in the screening programmes established during the period 2000-2012 with those working in the screening programmes created from 1990 to 1999. RESULTS: The former reported more years of clinical experience in breast imaging and a greater clinical mammogram reading volume than the latter. Conversely, they dedicated less working time to breast imaging, were less likely to participate in the diagnostic assessment of screen-detected lesions, to work in large-staffed screening centres, and to have a screening and a total mammogram reading volume (SMRV and TMRV) ≥ 5000 per year. CONCLUSIONS: The level of most professional quality criteria of Italian mammography screening radiologists has decreased over time. As SMRV and TMRV are important predictors of diagnostic accuracy, we can expect a lower interpretation performance of radiologists working in the recently created screening programmes.

Factors associated with breast screening radiologists' annual mammogram reading volume in Italy.

PURPOSE: Screening mammogram reading volume (SMRV) and total (screening and clinical) mammogram reading volume (TMRV) per year are strongly associated with the radiologist's diagnostic performance in breast cancer screening. The current article reports the prevalence and correlates of a SMRV and a TMRV ≥5000 among Italian breast screening radiologists. MATERIALS AND METHODS: A questionnaire survey was carried out in 2013-2014 by the Italian Group for Mammography Screening (GISMa). The questionnaire included items of information for radiologist's experience-related characteristics and for facility-level factors supposedly associated with SMRV and TMRV. Multivariate analysis was performed using backward stepwise multiple logistic regression models. RESULTS: Data for 235 radiologists from 51 local screening programmes were received. Of the 222 radiologists who were eligible, 133 (59.9 %) reported a SMRV ≥5000 and 163 (73.4 %) a TMRV ≥5000. Multivariate factors positively associated with both characteristics included: the number of years of experience reading mammograms; the percentage of total working time dedicated to breast imaging and breast care; the participation in diagnostic assessment; and the availability of digital tomosynthesis at facility. Full-time dedication to breast imaging and breast care was associated with the highest odds ratio for a SMRV and a TMRV ≥5000, i.e. 11.80 and 46.74, respectively, versus a percentage of time ≤50 %. An early (<2000) year of implementation of the screening programme and the availability of vacuum-assisted biopsy at facility were associated with a SMRV and, respectively, a TMRV ≥5000. CONCLUSIONS: Increasing the proportion of radiologists with full-time dedication to breast imaging and breast care qualified as the most effective approach to improve SMRV and TMRV.