Medical Physics 3.0 approach to optimizing image quality in a breast screening program.

Abstract

Background: Sensitivity and specificity of screening mammography is linked to image quality (IQ) and should be optimized and consistent for all women screened. Optimization, typically based on equipment performance metrics from quality control tests, do not correlate directly with clinical performance.

Purpose: The principles of Medical Physics 3.0 have been applied to combine medical physics Quality Control (QC) with screening clinical outcome to optimize the quality in a national breast screening program. Medical Physics 3.0 has been advocated as an initiative to enhance the practice of Medical Physics and leverage the value of medical physics to drive improved patient care.

Methods: A retrospective analysis of the cancer detection rate (CDR), of approximately 1.5 million screening examinations, was conducted within a screening program following the introduction of a new mammography system type. Significative differences in CDR (with nonoverlapping 95% confidence intervals [CI]) and performance metrics (lower [IQ] and mean glandular dose [MGD]) were observed between this new system type and the other system types in the screening program. The CDR for individual mammography system types was correlated with medical physics QC metrics of IQ and dosimetry. Preliminary investigations lead to an increase of the operational dose multiplier from 1.2 to 1.6 and the new setting was applied over all the new systems.

Results: Following optimization, the medical physics metrics revealed a 19% increase in MGD accompanied by a 12% improvement in IQ for the new system type. Meanwhile, a retrospective analysis of CDR showed overlapping 95% CI, indicating convergence between the two system types.

Conclusions: Applying Medical Physics 3.0 principles to aggregated screening and clinical outcome data in support of medical physics quality assurance processes has demonstrated potential to deliver optimization of quality for individual women and for the screened population.