The Digital Pathology Program in the FDA’s Center for Devices and Radiological Health (CDRH) conducts regulatory science research to help ensure patient access to innovative digital pathology devices that are safe and effective. This is one of 20 research programs in CDRH’s Office of Science and Engineering Laboratories (OSEL).
Digital Pathology and Medical Devices
Digital pathology is the development of digital scans of pathology tissues from slides and the visualization, analysis, transfer, storage, and interpretation of the resulting data. The digital scans are acquired through an opto-electronic mechanism that maps the physical tissue information to a digital file.
Digital Pathology still is a novel device space in which very few studies have been done to link technical performance of a system to diagnostic performance. The first whole-slide imaging (WSI) device was authorized for marketing in the US in 2017 through the de novo pathway. A second system was cleared in 2019. Both systems consist of end-to-end imaging pipelines involving proprietary data formats and components.
Although evaluation of digital pathology devices includes a considerable amount of technical data, according to the Technical Performance Assessment of Digital Pathology Whole Slide Imaging Devices guidance issued in 2016, the final decisions allowing for the marketing of these systems still rely heavily on costly clinical studies.
Regulatory Science Gaps and Challenges
Major regulatory science gaps and challenges that drive the Digital Pathology Program are:
- Lack of standardized test methods that allow for the correlation between technical performance and clinical performance of WSI systems. Current WSI assessment methods limit the availability of interoperable applications as well as the implementation of artificial intelligence and machine learning (AI/ML) to support pathology image interpretation.
- Lack of statistical methods and relevant data for designing and analyzing studies of image quality in terms of pathologist or AI algorithm performance. Methods and tools are needed that facilitate reproducible, generalizable, statistically efficient, and practical evaluations of WSI systems.
The Digital Pathology Program is intended to fill these knowledge gaps by fostering the development of regulatory science tools that address significant challenges in the evaluation of novel WSI scanners and interoperability of WSI components.
Digital Pathology Program Activities
The Digital Pathology Program focuses on regulatory science research in these areas:
- Test methods that enable the assessment of WSI scanners key performance characteristics, for example color reproducibility, spatial resolution, and focusing accuracy.
- Test methods for assessing the interoperability of the digital components between WSI scanners, and for assessing the image quality degradation.
- Quantitative approaches for determining minimum performance requirements for the display component of WSI systems.
- Efficient study designs and tools for collecting pathologist annotations that lead to accurate and precise estimates of truth.
- Properties of metrics for image segmentation algorithms and methods for choosing appropriate performance metrics.
- Technical factors influencing AI reproducibility for digital pathology applications.
- Methods for assessing the generalizability of AI performance in digital pathology applications.
For more information, email OSEL_DigitalPathology@fda.hhs.gov