Slowly But Surely, Digital Pathology Taking off at URMC
In an increasingly digital world, will glass slides and microscopes grow obsolete? The short answer is probably—but we’re not there yet. With the emergence of digital pathology, whole slide imaging (WSI) and assistive technologies that help pathologists work more efficiently, we are inching closer to going fully digital in everyday practice. Vektra Casler, M.D., director of our new Informatics division, is leading the effort to gradually incorporate WSI into certain subspecialties at URMC.
Whole slide imaging is a method in which glass slides are placed under a camera microscope that captures images that can then be viewed on a computer screen. From there, the images can be easily saved and shared virtually for diagnosis, and virtual consultation, as well as teaching purposes. This not only alleviates the burden of transporting slides back and forth between institutions (or even across the hall) but has potential to change how pathologists do their jobs. The end goal of becoming all-digital is still years away, she explains.
“The goal of diagnostic medicine overall is to have all the puzzle pieces at your fingertips so you can render a diagnosis quickly and as best and efficiently as you can,” said Casler. “We want to digitize as many aspects as possible so the pathologist and the slides don’t have to be in the same room.”
The benefits of WSI are two-fold. In addition to providing greater portability, going digital allows the user to apply artificial intelligence (AI) to the scanned image. While computers aren’t going to make them obsolete, this kind of AI can help set the stage for the pathologist to make a final diagnosis.
“AI is never going to be completely in the driver seat,” said Casler, who compares the pathologist to a pilot flying a plane with help from a GPS and radar. “You have a very real responsibility and if you misdiagnose a case, somebody could die or have their life change forever.”
Because a computer is very fast at doing mundane things, AI can identify visual hotspots and immediately pinpoint potential areas of concern on the scanned image so the pathologist can zero in on those areas. The result is a nice pairing of detection software, which is highly sensitive, with an expert pathologist, who is highly specific. Both can help the latter work more efficiently by saving time and tedium that comes with traditional microscope-based practice.
We as an institution are just getting into the game when it comes to WSI, and becoming fully digital will take time. One challenge is available equipment. URMC currently has some microscope scanners that can scan a few dozen slides at a time. The next step will be purchasing a scanner that can scan 10 times the number of slides.
Perhaps the greatest challenge, however, is the sheer size of the data. For example, one scanned slide is 1.5 gigabytes – which is as large as a full movie, Casler explained. Like other outside institutions that have hundreds of terabytes of storage, we hope to follow suit by getting a central server to host the files so they are not only easily accessible from anywhere but stored securely for years to come. Digital pathology will not only strengthen and streamline patient care, but teaching opportunities as well.
“This foray into WSI and getting our feet wet into digitizing is going to open a door to teaching sets and research so we can do our job better in the future,” said Casler.
John Plavnicky, chief supervisor of Cytology, recently gave a quick tutorial on a new digital scanning instrument called the Hologic Genius. The instrument performs whole slide imaging on gynecologic specimens, and though it’s currently being used in Europe, it’s still awaiting FDA approval in the U.S. Plavnicky’s team is working in conjunction with the vendor to use it for research in the meantime, making URMC one of the first institutions in the country to experiment with the Genius.
To start, they are running about 500 previously-tested samples on the Genius and re-screening slides to compare results to microscope-based diagnoses – very much like a “double blind” study. In future studies, they will likely simplify the process and compare the instrument’s findings to the known diagnoses.
The Genius works after samples are loaded into the machine, which then captures a scanned image of each slide and saves it to a server. The image is then viewable on a separate computer monitor from virtually anywhere. The software program then applies rapid detection to certain fields of view on the image, highlighting areas that could contain cells of interest.
“If it works, it’ll increase the flexibility in when and where screening is done,” said Plavnicky. Right now, the process of slide examination is laborious. Each slide has to be physically moved from a prep area to a cytotech, then to a pathologist and finally placed in a storage area. Going digital removes some of these (literal) moving parts.
“Now we’re limited to where we can sign these out because the scope has to be connected to the imager,” he said. “That would go away with this system because it’s linked to a server accessible anywhere.”
As a longtime cytotech who spends many hours at the scope, he said the prospect of going digital is a big shift. But it’s not as big of a leap as you’d think.
“It feels strange in field that revolves around microscopy. Not that it’s going away,” he said, pointing directly at the microscope within the machine itself. “The technology is not necessarily removing it. It’s removing the way it’s utilized.”
Bethany Bushen | 12/14/2021
