COVID-19: Safe Guidelines for Breast Imaging During the Pandemic.

During the COVID-19 pandemic, breast imaging must be performed using safe practices. Balancing the need to avoid delays in the diagnosis of breast cancer while avoiding infection requires careful attention to personal protective equipment and physical distancing and vigilance to maintain these practices. The Canadian Society of Breast Imaging/Canadian Association of Radiologists guideline for breast imaging during COVID-19 is provided based on priority according to risk of breast cancer and impact of delaying treatment. A review of the best practices is presented that allow breast imaging during COVID-19 to maximize protection of patients, technologists, residents, fellows, and radiologists and minimize spread of the infection. The collateral damage of delaying diagnosis of breast cancer due to COVID-19 should be avoided when possible.

Clinical Image Quality and Sensitivity in an Organized Mammography Screening Program.

PURPOSE: The study sought to examine the association between clinical image quality of mammograms and screening sensitivity. METHODS: Four radiologists evaluated the clinical image quality of 374 invasive screen-detected cancers and 356 invasive interval breast cancers for which quality evaluation of screening mammograms could be assessed from cancers diagnosed among participants in the Quebec Breast Cancer Screening Program in 2007. Quality evaluation was based on the Canadian Association of Radiologists accreditation criteria, which are similar to those of the American College of Radiology. The association between clinical quality and screening sensitivity was assessed by logistic regression. Adjusted sensitivity and adjusted sensitivity ratios were obtained through marginal standardization. No institutional review board approval was required. RESULTS: A proportion of 28% (206 of 730) of screening mammograms had lower overall quality for the majority of assessments. Positioning was the quality attribute that was the most frequently deficient. The 2-year screening sensitivity reached 68%. Sensitivity of screening was not statistically associated with the overall quality (ratio of 2-year sensitivity = 1.03; 95% confidence interval: 0.93-1.15) or with any quality attributes (positioning, exposure, compression, sharpness, artifacts, contrast). Results were similar for the 1-year sensitivity. CONCLUSIONS: Although not all mammograms in the Quebec screening program met the optimum quality required by the Canadian Association of Radiologists or American College of Radiology accreditation, the screening mammograms produced in this population-based organized screening program reached a high enough level of quality so that the remaining variation in quality is too little to impair screening sensitivity.

Clinical image quality in daily practice of breast cancer mammography screening.

OBJECTIVE: To assess the quality of screening mammograms performed in daily practice in the Quebec Breast Cancer Screening Program. SUBJECTS AND METHODS: Clinical image quality of a random subsample of 197 screening mammograms performed in 2004-2005 was independently evaluated by 2 radiologists based on the criteria by Canadian Association of Radiologists (CAR). When disagreement occurred for overall judgement or positioning score, the mammograms were reviewed by a third radiologist. Cohen's kappas for interrater agreement were computed. Multivariable robust Poisson regression models were used to study associations of overall quality and positioning with body mass index (BMI) and breast density. RESULTS: The CAR criteria were not satisfied for 49.7% of the mammograms. Positioning was the quality attribute most often deficient, with 37.2% of mammograms failing positioning. Interrater agreement ranged from slight (kappa = 0.02 for compression and sharpness) to fair (kappa = 0.30 for exposure). For overall quality, women with a BMI ≥ 30 kg/m(2) had a failure proportion of 67.5% compared with 34.9% for women with a BMI<25 kg/m(2) (risk ratio 2.1 [95% confidence interval, 1.5-3.0]). For positioning, women with a BMI ≥ 30 kg/m(2) had a failure proportion of 53.8% compared with 27.9% for women with a BMI < 25 kg/m(2) (risk ratio 1.9 [95% confidence interval, 1.2-3.1]). Effects of breast density on image quality differed among radiologists. CONCLUSION: Despite measures to ensure high-quality imaging, including CAR accreditation, approximately half of this random sample of screening mammograms failed the CAR quality standards. It would be important to define quality targets for screening mammograms carried out in daily practice to interpret such observations.

Organized breast screening programs in Canada: effect of radiologist reading volumes on outcomes.

PURPOSE: To examine retrospectively the relationship between radiologist screening program reading volumes and interpretation results. MATERIALS AND METHODS: This research project was reviewed by the University of British Columbia Research Ethics Board. Informed patient consent was not required. Data were requested from Canadian provincial screening programs for the period 1988-2000. Cancer detection rates, abnormal interpretation rates, and positive predictive values (PPVs) were calculated for individual radiologists in those programs. Multivariate Poisson mixed regression models were used to examine the effect of patient age, screening examination sequence (first or subsequent screening examination), province, radiologist reading volume, and interradiologist differences on cancer detection rate, abnormal interpretation rate, and PPV. RESULTS: The results of the interpretation of 1406678 screening mammograms by 304 radiologists from seven provincial programs were analyzed. Cancer detection rate, abnormal interpretation rate, and PPV all varied according to age of woman screened and screening sequence and across the sample of radiologists. None of the rates varied by province. Neither the cancer detection rate nor the abnormal interpretation rate varied by reading volume, but the average PPV was increased by 34% for volumes over 2000 mammograms versus volumes of 480-699 mammograms per year. There was no evidence that the magnitude of variability around the average, for radiologists reading the same volume of mammograms, varied across different volume groups for any of the outcome measures. CONCLUSION: Cancer detection did not vary with reading volume. The average PPV for individual radiologists increased as reading volume rose up to 2000 mammograms per year; it stabilized at higher volumes.

Breast cancer screening in Canada: a review.

Organized screening for breast cancer in Canada began in 1988 and has been implemented in all provinces and 2 of the 3 territories. Quality initiatives are promoted through national guidelines which detail best practices in various areas, including achieving quality through a client-service approach, recruitment and capacity, retention, quality of mammography, reporting, communication of results, follow-up and diagnostic workup, and program evaluation; it also offers detailed guidelines for the pathological examination and reporting of breast specimens. The Canadian Breast Cancer Data Base is a national breast cancer screening surveillance system whose objective is to collect information from provincial-screening programs. These data are used to monitor and evaluate the performance of programs and allow comparison with national and international results. A series of standardized performance indicators and targets for the evaluation of performance and quality of organized breast cancer screening programs have been developed from the data base. Although health care is a provincial responsibility in Canada, the collective reporting and comparison of results both nationally and internationally is beneficial in evaluating and refining both screening programs and individual radiologist performance. The results of Canadian performance indicators compare favourably with those of other well-established international screening programs. There are variations in performance indicators across the provinces and territories, but these differences are not extreme.