From Dream to Deployment

How many slides go through your lab per day? If your institution is anything like Leeds Teaching Hospitals NHS Trust in the UK, you may go through over a thousand per day – about five kilograms of glass in a meter-high stack. Imagine the resources involved in transporting, examining, labeling, storing, retrieving, and quality-controlling that volume – and imagine the personnel needed to keep such an extensive system working smoothly and accurately to ensure patients’ health and safety.

The glass slide, despite its pedigree over the last century or more of pathology practice, has its flaws. They take up space (and must often be stored for years or even decades), require time to be physically transported from one location to another (especially if consultations from faraway experts are needed), and run the risk of loss, breakage, or degradation. They can even affect pathologists’ health – because microscopes, though precision tools, are not the most ergonomic method for repetitive slide review. All of these reasons led the pathology department at Leeds to make a critical choice: to transition to a fully digitized service.

Uncontained excitement

“We have a lot of excitement around the lab and in the diagnostic department,” says Bethany Williams, Digital Pathology Fellow at Leeds. Williams, who completed the world’s first leadership and management fellowship in digital pathology and has spearheaded the project with a focus on patient safety and pathologist engagement. She explains, “In a conventional histopathology reporting workflow, a trained subspecialist views a piece of tissue taken from a patient using a standard light microscope to provide a definitive diagnosis. In digital pathology, we add an important step to this process.” Williams continues, “We still have that precious specimen of human tissue, but once we’ve made the glass slides, we scan them using a specialized scanner in our laboratory.” The scanner, a benchtop device, captures a high-resolution digital image of the slide, which can then be viewed by the pathologist on a suitable display screen for diagnosis and further assessment.”

Azzam Ismail, Consultant Neuropathologist at Leeds, is an enthusiastic adopter of digital technology. “I have been practicing pathology for 25 years,” he says. “I used to have to select a case, find the slides, match the slides with the case number and patient name, position them under the microscope, and then manipulate it to make sure I see everything important for diagnosis. If there is more than one slide, I have to switch between them.” He explains that, after a three-hour session on the microscope, he suffered serious back and shoulder pain. “Now, I just scan the barcode and click to open the case on my computer. I can move and zoom easily without having to adjust focus. I dictate my findings at the same time – and, in two minutes, I’ve diagnosed the case.” And it’s not just the ease of diagnosis that has Ismail excited. “I can take a second look at cases when I’m not in the department. I can do this with trainees. I never have to worry about missing slides – and look how neat my office is now!”

In the laboratory

“Digital slides are fantastic for capturing whole-slide views,” says Williams. “A lot of pathological diagnosis is based on architecture, so you can reach a diagnosis much more quickly – especially when the case involves a lot of slides.”

The laboratory at Leeds Teaching Hospitals is a busy one. “We produce about 290,000 slides in our histopathology lab per annum in total,” says Sian Gibson, Pathology Services Manager in the Department of Cellular Pathology. All tissue samples that enter the lab are sectioned, stained, quality-controlled, and then placed in racks according to priority. At this point, every single slide is scanned. The lab operates six high-throughput Aperio scanners from Leica Biosystems, each of which can tackle 400 slides per cycle. It takes 2–4 minutes per slide (depending on the amount of tissue) to produce a scan at 200,000 dpi – a resolution that, if printed, would result in an image the size of a tennis court.

The best part? As soon as the slides have been scanned, pathologists trained in digital diagnosis can begin their work. Gibson explains, “Otherwise, they’d have to wait for us to rack up the slides in here, send them to the pigeonholes, and then, of course, it’s up to them when and how often they check for new deliveries. This reaches their offices instantaneously – even those who work in a different wing.” For Gibson, the major benefit is the ability to share images. “If pathologists want second opinions from anywhere in the country, that can happen. There’s also a shortage of consultants at the moment; in the next five years, up to one-third may retire, and there aren’t enough new pathologists to replace them. This helps us disseminate the workload across the UK, and standardize the process as well.” She also highlights the fact that a digital archive saves on staff resources because there’s no need to search stacks of glass slides – or worse yet, prepare new ones – each time a pathologist needs a particular case.

Solving shortages

Williams agrees with the need for creative solutions to staffing shortages. “We are in the midst of a pathology recruitment and retention crisis,” she says. “Pathologists are also having to cope with increasing volume and complexity of workloads. We’ve got a year on year increase just in the crude number of specimens we’re asked to report; our cancer screening programs are so successful that we’re now being asked to look at smaller specimens taken from earlier stages; and, with the explosion of targeted therapies we’re performing more tests on each individual case.” On top of all of these demands, the pressure to reduce turnaround times is constant – especially in the NHS, where all patients have a maximum wait time from test to treatment. “So we’ve got more work to do, we’ve got to do it faster, and we’ve got to do it with fewer people.”

With a drive toward centralization and networking pathology resources, digital slides may help. “We’ve got more freedom as to who reports what, and from where,” says Williams. “Digital pathology improves the efficiency of diagnosis and laboratory workflows. It also opens up opportunities for collaboration, both between different NHS institutions in the region and between the clinic and academia. It’s really going to help recruit and retain new pathologists, too, by opening up more flexible ways of working that make the discipline more attractive.”

And not forgotten are the benefits to patient safety. A paperless NHS means both patients and physicians have easier access to medical records, with fewer opportunities for errors or mislaid information. The images, unlike slides, cannot break or degrade, and continuity of care can be maintained wherever the patient may go.

An evidence-based approach

Leeds Teaching Hospitals’ move to 100 percent digitization has gained international attention not only because of its ambition, but also because of the project’s systematic deployment. “I think digital pathology has suffered in the past because it has been seen as something that a few enthusiasts have grabbed hold of and pushed to the front of the agenda,” says Williams. “I think it’s right that pathologists should be a little skeptical when they’re being asked to use a completely new method of diagnosis in their everyday practice.” As a result, the laboratory took a research-based approach to implementation. “At every step, we’ve examined the evidence, and created it where necessary. We’ve decided what equipment and workflow to use; we’ve created new protocols for efficient slide scanning and for training and validating individual pathologists in digital diagnosis; and we’ve shared and published everything we’ve learned.”

Darren Treanor, Consultant Pathologist and leader of the Digital Pathology Group at Leeds, concludes, “This technology is exploding. Making a diagnosis on the computer instead of on the microscope may sound like a small step, but it’s an enormous change that we hope will allow us to use pathology for our patients’ benefit as best we can.”

The clinical use claims described in the information supplied have not been cleared or approved by the U.S. FDA or are not available in the United States.