Additional Breast Cancer Detection at Digital Screening Mammography through Quality Assurance Sessions between Technologists and Radiologists.

Background Screening technologists may function as readers in breast cancer screening programs. In the Netherlands, they attend quality assurance sessions. The frequency and characteristics of additional breast cancers detected through these sessions have not been reported. Purpose To determine the frequency and characteristics of cancers detected through quality assurance sessions. Materials and Methods This secondary analysis of a prospective cohort included 466 647 screening mammograms obtained between January 1, 2009, and January 1, 2017. Mammograms were single read by certified screening technologists before being double read by two certified screening radiologists who were not blinded to the technologists' reading. The technologists and a coordinating screening radiologist regularly discussed mammograms that the technologists considered suspicious but that did not prompt recall at radiologist double reading. The coordinating radiologist decided whether secondary recall was indicated. During a 2-year follow-up, radiologic and pathologic outcome data for all recalled women were obtained. Characteristics of cancers detected at radiologist double reading and those detected through quality assurance sessions were compared by using χ2 and Fisher exact tests. Results A total of 14 142 women (mean age, 59 years ± 7.8 [standard deviation]; range, 49-75 years) were recalled (recall rate, 3.0% [14 142 of 466 647]): 14 057 after radiologist double reading and 85 by the coordinating radiologists after quality assurance sessions. This resulted in 3156 screening-detected cancers (6.8 cancers detected per 1000 screenings), of which 26 (0.8% of screening-detected cancers [26 of 3156]) were detected after secondary recall through quality assurance sessions. The latter comprised eight ductal carcinomas in situ (88% intermediate or high grade [seven of eight]) and 18 invasive cancers (14 T1a-c and four T2+ cancers, 89% Nottingham grade I or II [16 of 18]). No significant differences in tumor characteristics were found (P values ranging from .22 to .95). Sensitivity of quality assurance sessions for additional cancer detection was 52% (26 of 50; 95% confidence interval: 38%, 66%). Conclusion The role of quality assurance sessions in additional cancer detection is limited. Tumor characteristics did not differ significantly from those of cancers detected at radiologist double reading. © RSNA, 2020.

Characteristics of screen-detected cancers following concordant or discordant recalls at blinded double reading in biennial digital screening mammography.

OBJECTIVES: To analyse which mammographic and tumour characteristics led to concordant versus discordant recalls at blinded double reading to further optimise our breast cancer screening programme. METHODS: We included a consecutive series of 99,013 screening mammograms obtained between July 2013 and January 2015. All mammograms were double read in a blinded fashion. Discordant readings were routinely recalled without consensus or arbitration. During the 2-year follow-up, relevant data of the recalled women were collected. We compared mammographic characteristics, screening outcome and tumour characteristics between concordant and discordant recalls. RESULTS: There were 2,543 concordant recalls (71.4%) and 997 discordant recalls (28.0%). The positive predictive value of a concordant recall was significantly higher (23.5% vs. 10.0%, p < 0.001). The proportion of BI-RADS 0 was significantly higher in the discordant recall group (75.7% vs. 56.3%, p < 0.001). Discordant recalls were more often an asymmetry or architectural distortion (21.8% vs. 13.2% and 9.3% vs. 6.5%, respectively, p < 0.001). There were no differences in the distribution of DCIS and invasive cancers and tumour characteristics were comparable for the two groups, except for a more favourable tumour grade in the discordant recall group (54.7% vs. 39.9% grade I tumours, p = 0.022). CONCLUSIONS: Screen-detected cancers detected by a discordant reading show a more favourable tumour grade than cancers diagnosed after a concordant recall. The higher proportion of asymmetries and architectural distortions in this group provide a possible target for improving screening programmes by additional training of screening radiologists and the implementation of digital breast tomosynthesis. KEY POINTS: • With blinded double reading of screening mammograms, screen-detected cancers detected by a discordant reading show a more favourable tumour grade than cancers diagnosed after a concordant recall. • The proportions of asymmetries and architectural distortions are higher in case of a discordant reading. • Possible improvement strategies could target additional training of screening radiologists and the implementation of digital breast tomosynthesis in breast cancer screening programmes.

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.

Incorporation of the technologist's opinion for arbitration of discrepant assessments among radiologists at screening mammography.

PURPOSE: We determined whether the addition of the technologist's opinion may be helpful in deciding if discordant readings at blinded double reading should be recalled. METHODS: A consecutive series of 99,013 digital screening mammograms, obtained between July 2013 and January 2015, were included. All mammograms were first interpreted by a technologist and then double read in a blinded fashion by a team of 13 screening radiologists. All concordant and discordant positive readings among radiologists were recalled. RESULTS: Out of 3562 recalls, 998 women were recalled after a discordant reading. Of these women, 337 (33.8%) had a positive technologist assessment, of which 40 (11.9%) were diagnosed with breast cancer. Sixty women with a negative technologist assessment (60/661, 9.1%) were diagnosed with breast cancer (p = 0.16). Recall rate would have decreased with technologist arbitration (3.6% vs. 2.9%, p < 0.001). Cancer detection rate decreased with 8.5%, from 7.1/1000 screens to 6.5/1000 screens (p = 0.10). Among women with a positive technologist assessment, the probability of breast cancer was highest in case of suspicious microcalcifications and lowest for suspicious masses (30.4% (17/56) versus 7.0% (16/212), p < 0.001). Breast cancers were diagnosed in all groups of mammographic abnormalities, except in women with a suspicious asymmetry and a negative technologist assessment. CONCLUSIONS: Assessment by a technologist does not provide a significant discriminating ability in case of a discordant radiologist reading and, taking into account the decrease in cancer detection rate, does not appear to be a suitable arbitration strategy for discordant recalls at blinded double reading.

Causes and consequences of delayed diagnosis in breast cancer screening with a focus on mammographic features and tumour characteristics.

PURPOSE: To study the prevalence, causes and consequences of delayed breast cancer diagnosis in the screening population. METHODS: This retrospective study was performed in women who underwent biennial screening mammography between January 1, 2009 and June 30, 2019. Patients were divided into 3 groups; screen-detectedbreast cancer (SDC) without a diagnostic delay, a primary diagnostic delay(i.e. missed cancer at previous screening round)and a delay in diagnostic work-up after recall. Women with a true interval cancer (IC; i.e. not visible on prior examinations) were excluded. Outcome parameters included mammographic and tumour characteristics, lymph node status and surgical treatment. RESULTS: In our sample of 4491 women with breast cancer (4292 SDC and 199 'missed' IC), respectively, a total of 1112 women experienced a diagnostic delay of ≥ 4 months. Compared to women without a diagnostic delay (n = 2720), the 176 women with a delay in diagnostic work-up showed overall similar mammographic abnormalities (P = 0.052). These groups show similar distributions in invasive tumours, tumour stage and lymph node status (P = 0.25, P = 0.95 and P = 0.93, respectively). Women with a primary diagnostic delay (n = 936) showed less calcifications (P < 0.001), and more masses with calcifications and architectural distortions on mammography (P = 0.01 and P = 0.04, respectively). Moreover, this group comprised larger tumours (P < 0.001) and lymph node metastases (P < 0.001), and more often underwent mastectomy (P < 0.001). CONCLUSIONS: A primary diagnostic delay in breast cancer diagnosis results in less favourable tumour characteristics and relatively more mastectomies compared to no delay in breast cancer diagnosis and a delay in diagnostic work-up after recall.