Literature Review: Validation of Digital Pathology for Primary Diagnosis in the Covid-19 Era

Literature Review: Validation of Digital Pathology for Primary Diagnosis in the Covid-19 Era

The adoption of digital technology in pathology has often been directly compared to radiology. Yet, in 2019 and more than a decade after the first slide scanners were introduced, it was not uncommon to see a conference presentation about regulatory frameworks for clinical use and digital pathology adoption for primary diagnosis.  Clearly the barriers to clinical adoption were much higher than anyone had anticipated a decade before.

All change in the face of the COVID-19 pandemic.  With a health crisis underway and social distancing rules in place, government agencies were compelled to loosen the regulatory rules.  Institutional plans for digital pathology, that had been moving slowly before COVID-19, were suddenly on the fast path.  Pathologists who were reluctant to transition were thrust into remote signout.

So, what was the result of this great digital pathology experiment? Is digital pathology finally ready for prime time?  The verdict may still be out for some, but there are at least a handful of publications that have validated its clinical use. We have highlighted three of these in the section below.

Hanna, M.G., Reuter, V.E., Ardon, O. et al. Validation of a digital pathology system including remote review during the COVID-19 pandemic. Mod Pathol 33, 2115–2127 (2020).

Published early in the pandemic, this study validates remote sign-out of cases at Memorial Sloan Kettering Cancer Center using a Leica Aperio GT450 whole slide scanner, a custom whole slide viewer and integration with laboratory information system, Cerner CoPathPlus.

This study reports validation of primary diagnostic review and reporting of complete pathology cases from a remote site during a public health emergency. Our experience shows high (100%) intraobserver digital to glass slide major diagnostic concordance when reporting from a remote site. This randomized, prospective study successfully validated remote use of a digital pathology system including operational feasibility supporting remote review and reporting of pathology specimens, and evaluation of remote access performance and usability for remote signout.

Araújo, A.L.D., do Amaral-Silva, G.K., Pérez-de-Oliveira, M.E. et al. Fully digital pathology laboratory routine and remote reporting of oral and maxillofacial diagnosis during the COVID-19 pandemic: a validation study. Virchows Arch (2021).

This article from Brazil reports on successful use of digital pathology within a specialist area of pathology (Oral & Maxillofacial).  Slides were scanned using an Aperio scanner, but this particular study is unique in that the delivery method for remote whole slide image assessment was the freely available online meeting platform, Google Meet.  Intraobserver agreement was high, but the authors concede that some diagnoses were more difficult to make by remote digital review.

The intraobserver agreement between the digital method (DM) and conventional method (CM) was considered almost perfect (κ ranged from 0.85 to 0.98, with 95% CI, ranging from 0.81 to 1). The most significant and frequent disagreements within trainees encompassed epithelial dysplasia grading and differentiation among severe dysplasia (carcinoma in situ) and oral squamous cell carcinoma. The most frequent pitfall from DM was lag in screen mirroring.

We analyzed 567 cases for diagnostic accuracy and recorded no major discordance and 1.2% minor discrepancy rate with WSI. (…) Although the pathologists took a longer time for WSI evaluation and digital sign-out compared to glass slide evaluation, the digital workflow eliminated the intermediate steps dependent on secretarial staff for report preparation before sign-out and helped to achieve an overall gain in efficiency quantifiable in terms of reduced TAT.

Rao V, Kumar R, Rajaganesan S, et al. Remote reporting from home for primary diagnosis in surgical pathology: A tertiary oncology center experience during the COVID-19 pandemic. J Pathol Inform 2021;12:3. 

Study published by the Department of Pathology at the Tata Memorial Hospital, Mumbai, India, a high-volume tertiary oncology center.  The department utilized a Roche VENTANA DP200 slide scanner with associated uPath image management software for remote viewing.  As with previous studies, intraobserver concordance was high between digital and conventional pathology.  The authors also report an overall gain in efficiency using the digital workflow.

We would love to hear from you! If you would like to report on your own experience of using digital pathology prior to and/or during the pandemic, you can email us at or simply leave your comments below (note: you must be a registered user and logged in to leave post comments).

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