Lessons learned from three approaches to digital pathology system validation at a large academic medical institution

The University of Washington Department of Pathology validated whole-slide imaging (WSI) for clinical diagnostic use in 2020 in response to the COVID-19 pandemic. Subsequently, the project was expanded to address shortcomings in the initial validation and to include the adoption of new technologies and organizational restructuring goals. We describe three validation approaches: rapid (3-week emergency deployment), selective (single-subspecialty focused), and big-bang (simultaneous multi-subspecialty inclusion) methods utilized to validate digital pathology at our institution. Each method was selected based on the availability of resources, timeline constraints, and institutional needs at the time. WSI for clinical use was successfully validated using in each approach and eventually across all specialties. The rapid neuropathology validation achieved 100% accuracy in 3 weeks in the setting of an urgent pandemic response, however, it did not meet all CAP validation recommendations. The selective genitourinary service validation project achieved 96.45% concordance following all updated 2021 CAP WSI validation guidelines, but was time- and labor intensive, stressing a single specialty. The simultaneous multisubspecialty validation achieved 95.16% concordance while distributing the work effort. When combined, the system-wide concordance reached 95.78%. This descriptive article highlights our institution's various experiences with WSI validation. Success was dependent on matching the validation approach to the available infrastructure, timeline requirements, and clinical/organizational needs.