Abstract
Many advances in histopathology have been made since publication of Virchow’s collected lectures, Cellular Pathology (Die Cellularpathologie in ihrer Begründung auf physiologische und pathologische Gewebelehre) in 1858, including de facto standardization of formaldehyde as the gold-standard preservative, and H&E as the gold-standard stain for histopathology; the development of immunohistochemistry; and creation of the electron microscope. What has remained largely unchanged in that time is the compound light microscope, and the need for the pathologist to be physically bound to their microscopes to do their work. However, the advent of whole-slide imaging in the late-1990s and the commercialization and maturation of that slide digitization technology in the last 10 y has finally broken the physical chain between the diagnostic veterinary pathologist and their microscopes.
Concurrent advancements in computer and information technology (including internet speeds, cloud storage, and artificial intelligence) has created the opportunity to manage virtual pathologists and their digital slide reading work in innovative, novel ways. This has been critical in allowing private or commercial diagnostic labs to keep pace with the increasing biopsy volume and service level demands of the veterinary clinical consumer, who more and more expect delivery of accurate, meaningful pathology reports in a fast, reliable, efficient manner at an attractive price point. Client expectations of pathology reports mirror the evolution of other test modalities (in-clinic bloodwork testing, digital radiology, molecular-based tests) over the past 30 y. Specifically, increased automation and digitization allow for more rapid, reliable, and cost-effective delivery of diagnostic results. As a pathology diagnostic profession, it is incumbent on the veterinary pathology community to keep pace with innovation, lest they be left behind.
Although the core of digital pathology is digitization of the glass slide,
The primary advantage of digital pathology specifically for the veterinary diagnostician is allowing the pathologist to be virtual (i.e., work remotely from where the tissue is processed and digitized). There is no longer any logistical or technical requirement to tie pathologists to a physical lab location if 100% of slides are digitized. The key benefit of allowing pathologists to go virtual is widening choices for work-life harmony in terms of where they choose to live and when they choose to work, which in turn, increases the talent pool that can be evaluated for virtual pathologist positions. Key considerations in managing virtual pathologists are work practice standardization, including quality control; promotion of team identity and engagement; effective management and professional development of the individual pathologist; and securing fast, reliable internet services. Of course, there are equally valuable side benefits of slide digitization and the virtual pathologist, including physical and environmental resource savings (removing the need for office space, daily work travel, and courier-based glass slide delivery) and increasing client satisfaction (better way of distributing slides to ensure delivery of results in a more relevant and timely fashion by leveraging the entire pool of pathologist talent and expertise available within the laboratory network).
The prime focus of digital pathology is reliable, efficient delivery of complete digitized cases to the virtual pathologists per their work schedule. A complete digitized case requires confluence of all the digitized slides for that case to be delivered to the pathologist’s virtual workspace with all the necessary ancillary information (i.e., requisition form with signalment and history; accompanying clinical data where available) in a digitized form at the same time. This is a complex task that requires deployment of case tracking and LIMS or reporting software to manage automated delivery of all pieces of a digitized case. As well, this chain of events relies on a solid foundation of adequate human and capital input (histotechnology and other technical support in the lab) to physically manage the samples and ancillary case material information in preparation for digitization. Critically, lab equipment and information technology support are needed to ensure that the slides continue to be produced and scanned, and digital case delivery is fast and secure with high fidelity. A robust quality assurance program should be in place to ensure that there is a mechanism to identify and manage cases and ancillary case material that require troubleshooting. Automation software can be immensely impactful in simplifying the logistics of marrying all necessary and complex components of a complete digitized case, as well as coordinating effective distribution of cases across a network of both pathologists and histotechnology laboratories that are located across more than one time zone.
In addition, veterinary diagnostic pathologists need a solid understanding of the underlying technology that powers whole-slide imaging, not only to fully realize the benefits that slide digitization affords them, but equally important, the implications that drive virtual workflow standards and deficiencies that exist (and what opportunities lie ahead in development). On the front end, where slides are digitized, this includes items such as current objective limitations (magnification issues; z-plane issues), scanning speeds, server set-up (hardware vs. the cloud), and how cases are distributed or linked to image viewers. On the back end, where the user sits, familiarity with digital slide file formats (including resolution and size limitation) and image manipulation tools (measuring, counting, annotating, color balance) are a must, especially if production of images for clients and/or publication is required.
Another often under-appreciated consideration is about the relationship with the slide digitization technology provider, and what expectations come with differing relationship levels. White-glove partnership is ideal to ensure high availability and minimal system downtime, and a collaborative partnership to align with future development needs.
Digital pathology creates huge datasets, which in turn present unique challenges and opportunities that are best managed with a big data mindset or approach. This is known as
Consumption of digital content in general is part of the social normal in most of the world, and this expectation is growing in the pathology arena. Digital pathology can help meet this expectation, especially in building a framework of how to deal with challenging cases (second opinion consultations within and between organizations), how we train pathologists (including new employees to the business or organization, and pathology trainees), how we raise the level of education of all pathologists, and how we educate our clients. Digital training sessions (Fig. 1) can be utilized by private or commercial diagnostic laboratories to create live, interactive training sessions for residents across multiple disciplines, institutions, and time zones. Prime benefits of such sessions include exposing trainees to lesions and conditions that are encountered more commonly by private or commercial diagnostic laboratories; exposing trainees to lesions and conditions that are encountered in other localities; raising awareness of the work pathologists and radiologists perform in private or commercial diagnostic laboratories; and creating networking opportunities. Additionally, live, interactive training sessions can be recorded for future training prosperity (e.g., archived in a training repository that can be consumed by future trainees at their leisure).
An example of a live, interactive training session for pathology residents based on mixed digital disciplines (histopathology, cytology, and radiology).
With reference to the ongoing COVID-19 outbreak, what role can and should digital pathology in a private or commercial company play in contributing to real-time conversations and management of emerging diseases in a One Health world? This speaks of the need for the entire veterinary and human pathology profession to get together and talk about how to collectively shape this digital pathology evolution.
In summary, digital pathology (particularly for private or commercial diagnostic laboratories) has clearly been and is continuing to be a disruptive force in terms of changing the way veterinary diagnostic pathologists approach histopathology, and how they support and interact with their veterinary clinical clients. Furthermore, it is likely that as computational pathology matures, it will provide an additional layer of disruption that will further evolve the landscape for pathologists and their clients. This means that the time is now for the veterinary pathology community to actively learn about and become intimately familiar with digital and computational pathology. This action will necessitate deep introspection about how and why things were approached in the past, and how and why things should be approached today (including recent developments in the digitization of the cytopathology and hematopathology space). In this way, the veterinary diagnostic profession can help shape the future and avoid the fate of those that resisted innovation (Eastman Kodak, Blockbuster). Indeed, the first step is for the veterinary diagnostic profession to embrace that digital pathology is here, and it is here to stay.
For more about computational pathology, the commenter encourages readers to refer to the DPA white paper.