Impact of errors in recorded compressed breast thickness measurements on volumetric density classification using volpara v1.5.0 software

Waade, G; Highnam, R; Hauge, I; McEntee, M; Hofvind, S; Denton, E; Kelly, J; Sarwar, J; Hogg, P

Abstract

Purpose: Mammographic density has been demonstrated to predict breast cancer risk. It has been proposed that it could be used for stratifying screening pathways and recommending additional imaging. Volumetric density tools use the recorded compressed breast thickness (CBT) of the breast measured at the x-ray unit in their calculation, however the accuracy of the recorded thickness can vary. The aim of this study was to investigate whether inaccuracies in recorded CBT impact upon volumetric density classification and to examine whether the current quality control (QC) standard is sufficient for assessing mammographic density.
Methods: Raw data from 52 digital screening mammograms were included in the study. For each image, the clinically recorded CBT was artificially increased and decreased to simulate measurement error. Increments of 1mm were used up to ±15% error of recorded CBT was achieved. New images were created for each 1mm step in thickness resulting in a total of 974 images which then had Volpara Density Grade (VDG) and volumetric density percentage assigned.
Results: A change in VDG was recorded in 38.5% (n= 20) of mammograms when applying ±15% error to the recorded CBT and 11.5 % (n= 6) were within the QC standard prescribed error of ±5mm.
Conclusion: The current QC standard of ±5mm error in recorded CBT creates the potential for error in mammographic density measurement. This may lead to inaccurate classification of mammographic density. The current QC standard for assessing mammographic density should be reconsidered.

Citation

Waade, G., Highnam, R., Hauge, I., McEntee, M., Hofvind, S., Denton, E., …Hogg, P. (2016). Impact of errors in recorded compressed breast thickness measurements on volumetric density classification using volpara v1.5.0 software. Medical Physics, 43(6 Pt.1), 2870-2876. https://doi.org/10.1118/1.4948503

• Journal Article Type: Article
• Acceptance Date: Apr 18, 2016
• Online Publication Date: May 16, 2016
• Publication Date: Jun 1, 2016
• Deposit Date: May 3, 2016
• Publicly Available Date: May 16, 2017
• Journal: Medical Physics
• Print ISSN: 0094-2405
• Electronic ISSN: 2473-4209
• Publisher: American Association of Physicists in Medicine
• Volume: 43
• Issue: 6 Pt.1
• Pages: 2870-2876
• DOI: https://doi.org/10.1118/1.4948503
• Publisher URL: http://dx.doi.org/10.1118/1.4948503
• Related Public URLs: http://www.medphys.org/subscrib.asp
• Additional Information: Additional Information : Title on accepted manuscript is "Error in recorded compressed breast thickness measurement impacts on volumetric density classification using Volpara v1.5.0 software2" - title changed on publication