Ten Abstracts Accepted for Presentation at ECR Demonstrate Value of Automated Breast Density and Analytics Data to Help Maintain Accuracy and Consistent Quality in Breast Screening
VIENNA, Austria, March 4, 2015 – The ability of volumetric breast imaging data to reduce subjectivity in density assessment and help improve breast cancer risk prediction models is the focus of numerous abstracts accepted for presentation at the European Congress of Radiology (ECR) meeting, March 4-8, 2015. Ten abstracts – eight posters and two session presentations – highlight the use of Volpara Solutions’ automated breast density and quantitative breast imaging software tools to provide insight into the impact of quantitative breast density on mammographic sensitivity, utilize volumetric density to improve breast cancer risk prediction, and monitor the impact of compression and breast thickness on image quality and dose.
Volpara will showcase updates to its industry leading suite of breast density and quantitative breast imaging software tools at ECR, including new versions of VolparaDensity for use with digital breast tomosynthesis and VolparaAnalytics, featuring expanded breast imaging metrics and additional quality metrics including positioning and time between study acquisition. (ECR2015 – Expo E #554)
In the first study, “Effect of volumetric mammographic density on performance of a breast cancer screening program using full-field digital mammography” (B-1028), researchers from UMC Utrecht and Nijmegen in the Netherlands looked at mammographic screening performance stratified according to volumetric breast density software. Designed to examine to what extent mammographic density affects screening performance, nearly 70,000 mammographic studies were analyzed using VolparaDensity, and recall and breast cancer detection information was obtained from the screening program registration system. The distribution of women in each VDG (Volpara Density Grade) was 19.7% (VDG 1), 43.1% (VDG 2), 29.4% (VDG 3), and 7.7% (VDG 4). For the 421 screen-detected and 150 interval cancers, cancer detection rates were 3.7%, 6.4%, 6.6%, and 6.3% in categories 1 through 4, respectively. The interval cancer rate increased as breast density increased, which also resulted in a decrease in sensitivity as density increased, ranging from 85% (VDG 1) to 58.6% (VDG 4) of cancers being detected by mammography. Additionally, the number of false-positives was also higher with increasing breast density, ranging from 11.4% (VDG 1) to 28.6% (VDG 4).
“In addition to stressing the volumetric nature of breast density, the new BI-RADS fifth edition focused heavily on the correlation between breast density and mammography sensitivity. This study not only demonstrates that screening performance was significantly lower for women with denser breasts, it one of the first large-scale studies to evaluate an automated breast density tool to sensitivity, clearly demonstrating that VolparaDensity is highly correlated to mammography sensitivity,” said Ralph Highnam, Ph.D., CEO and Chief Scientist of Volpara Solutions.
In a second study, “Impact of quantitative breast density on experienced radiologists’ assessment of mammographic breast density,” (C-1281) Dr. Kathy Schilling of Boca Raton Regional Hospital, investigated whether the use of quantitative breast density software improved the consistency in breast density assessment between radiologists. Eight dedicated breast radiologists assessed 88 digital mammographic studies and assigned each study into a BI-RADS density category. After two weeks, the radiologists re-read the studies using VolparaDensity as an interpretive aid. The use of VolparaDensity reduced the variability in the number of women allocated into each density category and significantly improved the inter-observer agreement in radiologists’ assessment of BI-RADS (p=0.0374), with a mean kappa statistic of 0.5664 and 0.6266 without or with VolparaDensity, respectively. Most readers accepted and used the automated scores to improve their readings.
In a third study, “Should volumetric breast density be included in breast cancer prediction models? Proposal of an integrated quantitative and reproducible approach” (B-0238), researchers investigated the relationship between volumetric breast density (VBD) and breast cancer risk estimates using the Tyrer-Cuzick model. For 249 patients undergoing mammographic screening, Tyrer-Cuzick lifetime risk estimates and Volpara Density Grades (VDG) were obtained. Median lifetime risk estimates comparing VDG2 (11.0%) versus VDG3 (14.5%) and VDG4 (15.6%) were significantly different (p=0.0011 and p=0.0002, respectively). Lifetime risks were comparable between VDG3 and VDG4 categories (p=0.0931). Lifetime risk increased with increasing breast density, indicating that VolparaDensity breast density measures could be used with existing risk prediction models to more accurately identify high-risk women.
In a fourth study “Impact of objective volumetric breast density estimates on mean glandular dose calculations in digital mammography” (C-1576), researchers compared mean glandular dose (MGD) estimation using Volpara’s breast glandularity output with the MGD output for 5076 patients on X-ray systems from various manufacturers. Comparing individual systems, Volpara’s MGD was significantly higher compared to the MGD output by the GE DS, GE Essential, IMS Giotto, and one of the Hologic Selenia Dimension. Volpara’s MGD was significantly lower compared to the Philips Microdose and one of the Hologic Selenia Dimension systems. MGD values provided by manufacturers using different models and different assumptions of breast density are significantly different to MGD estimates obtained using the patient’s own breast density.
In the educational exhibit, “Volumetric breast density and BI-RADS 5th edition,” (C-1070) Dr. Grivegnée of Institute Jules Bordet, looked at the potential impact of the recent BI-RADS fifth edition updates on the use of automated volumetric breast density software (VolparaDensity) and found: 1) the software can already be configured to output letters (a/b/c/d) to denote the new BI-RADS density categories; 2) removal of the quantitative quartile ranges should not impact visual density assessment; and 3) breasts that are predominantly fatty but still contain regions in the breast that are sufficiently dense to obscure small masses (i.e. focal densities) tend to be scored as BI-RADS c, in accordance with the ACR recommendations. Furthermore, use of the denser breast to assign the final density category (rather than the average) aligns better with the ACR recommendations, and implementing this change into the software would result in <5% of women being re-classified from non-dense (BI-RADS 1 or 2) to dense (BI-RADS 3 or 4). As a result, Dr. Grivegnée concludes that volumetric approaches are entirely consistent with the changes in the BI-RADS fifth edition provided that the software is configured to use the denser breast.
Other studies accepted for presentation at ECR include:
- “Mammographic compression – a need for mechanical standardization” [AMC; Nijmegen; Volpara Solutions; Weinstein Imaging Associates] (C-2052)
- “Indicators of future breast cancer risk at prevalent round screen” [St Georges] (C-1401)
- “Breast density across a screening population” [St Georges] (C-1398)
- “Robustness of automated volumetric breast density estimation for assessing temporal changes in breast density” [Volpara Solutions] (C-0737)
- “Impact of compressed breast thickness on detectability of simulated lesions: a clinical trial” [Leuven] (C-1175)
“When you factor the pivotal breast imaging research that has been presented over the past few months at RSNA, San Antonio, and ECR, we are seeing tremendous advances in our understanding of breast cancer risk and the impact of density on mammographic sensitivity and screening. We are extremely proud that Volpara’s automated breast density and analytics tools are being utilized globally to enable this critical clinical research,” added Dr. Highnam.
Cleared by the FDA, HealthCanada, the TGA and CE-marked, VolparaDensity is in use at breast imaging centers worldwide to help radiologists objectively assess density from digital mammography images to help doctors evaluate who might benefit from additional screening. Highly correlated to breast MR assessments, VolparaDensity is a reliable tool that automatically generates an objective measurement of volumetric breast density correlated to the ACR (American College of Radiology) breast density categories.
About Volpara Solutions
Founded to enable radiologists to give women the most accurate information possible regarding their breast health, Volpara Solutions is the wholly owned sales and marketing arm of Matakina Technology Limited of New Zealand. Matakina’s founders and Board of Directors includes John Hood, PhD, former Vice Chancellor of the University of Oxford, UK; Ralph Highnam, PhD, former CEO of Mirada Solutions, one of the University of Oxford’s most successful spin-outs of recent times and co-author of the seminal book Mammographic Image Analysis; and Professor Sir Michael Brady, a serial entrepreneur who recently retired from the University of Oxford where he was Professor of Information Technology for 25 years.