By Gail Balfour
Canadian Healthcare Technology
According to Dr. Andrew Evans, the benefits we will see from telepathology projects taking place throughout the country will go far beyond the ability to quickly share biopsy images with remote pathologists for consultation and diagnosis. This emerging technology will also have a profound impact on clinical education and research, quality assurance, accuracy and speed of diagnosis, as well as storage of data and integration with electronic health records.
“This technology is steadily evolving, with respect to scanning speed, image quality and image analysis –we are on the cusp of what you would call computer-aided diagnostics,” said Evans, Director of Telepathology at University Health Network (UHN) in Toronto.
The term telepathology refers to the digital transmission of pathology data, allowing faster and easier sharing of medical images, regardless of where the sender and recipient are located. These images are either captured from a digital camera connected to light microscope, or the pathology specimen slides are scanned to create high-resolution digital slides (or virtual slides) for transmission, analysis and storage. But this is not where the advantages end.
“Pathologists will soon be able to run algorithms on digital images and search for rare events – which normally take a long time under a microscope. A computer doesn’t get tired – it can process a huge amount of data over a long period of time, whereas the human eye fatigues. Digital pathology will also allow us to do certain things that the human eye and the light microscope simply cannot do, such as multiplex biomarker analysis on tiny biopsy samples.”
Dr. Evans is a telepathology pioneer in Canada. In 2003, Evans and his team at UHN’s Laboratory Medicine Program started investigating a digital system to address a need created when the individual hospitals within the network amalgamated and moved all of their staff pathologists to one site.
“When you take all the pathologists out of one place, you are left with few options if a surgeon at the unstaffed site needs an intra-operative pathology consultation (or frozen section): you can send the tissue to the place where all of the pathologists are, or you can send single pathologists to where the tissue is. Either way it’s a time-inefficient process. You are also one pathologist by yourself – so you don’t have the ability to show a difficult frozen section to someone else.”
Frozen sections need to be assessed by a pathologist right away, while the patient is still on the operating table. The benchmark is to have an answer back to the surgeon within 20 minutes, said Evans, so there is no time to send a physical specimen to off-site pathologists.
Today, Evans is one of the key players spearheading the Multi-Jurisdictional Telepathology (MJT) project, involving health organizations from three provinces: Ontario, Manitoba and Newfoundland, with funding from Canada Health Infoway.
The key objective of the MJT project is to establish a digital consultation network and an overall connectivity process for at least three provinces, Evans said. The hope is that this linkage will pave the way for a pan-Canadian digital network in the future.
There is also a growing emphasis on sub-specialty pathology, which creates the added challenge of getting cases to the right expert, at the right time. Digitizing the specimens into shareable images makes this type of review possible and also allows several sub-specialists to review a challenging case, regardless of where the patient, slides and pathologists are located.
Currently, each of the three provinces has moved beyond the concept phase and is reviewing RFPs for their individual hardware and software procurement. “Each province is responsible for finding the digital pathology system that will best meet their needs now and in the future. The number and type of slides that need to be scanned, the user interface and whether the system needs to be integrated into a laboratory information system (LIS) are some of the key factors to consider,” Evans said. “This will cause different provinces to explore different vendors. However, we will need to end up with a scanner agnostic or interoperable network that allows pathologists to review digital slides regardless of the scanner that was used to generate them.”
One of UHN’s technology partners for the project is GE Healthcare, which is helping to implement workflow and technology solutions around capture and transmission of pathology images. UHN worked with the company on an 18-month long concordance study to determine if the digital images were of comparable diagnostic quality as the same slides when viewed under a microscope. The study looked at more than 3,000 cases and 20,000 slides from 11 different anatomic sites, in a detailed process known as a validation study.
When trying to do something in a new way, it’s healthy to start out being a skeptic, Evans said. “You prove the new technology to yourself by looking at the same cases with both modalities to make sure what you see on the digital image matches what you see with the microscope. Ultimately, you need to make sure the diagnosis you give to a clinical colleague for the care of a patient will be the same, regardless of how you review the slides. Once you have done this you are ready to think about going live.”
Many valuable insights have come out of the UHN project, he said. “We have had real dialogue with the pathologists throughout the study, gaining their feedback and suggestions with respect to image quality and system performance. Several product iterations and design improvements were made by the engineering teams based on this feedback. And that’s about as good as it can get.” Moreover the study showed concordance between glass and digital slides.
Insights: “Pathologists look for details at the cellular level, so the equipment must capture images in full colour and at a higher magnification allowing for a much greater degree of resolution,” said Luigi Gentile, executive director of GE Healthcare’s Pathology Innovation Centre of Excellence (PICOE).
“This requirement translates into extremely large images – posing a challenge for both storage and transmission of files. At GE, we have developed proprietary technology to compress these image files, while still maintaining very high image quality, allowing for reliable streaming of images in real-time across networks,” Gentile said.
The ability to collaborate more closely with colleagues, something that is made possible by shared images, is one of the key drivers of the MJT project, said Dr. Gabor Fischer, clinical pathology associate and medical director for the Telepathology Project at Diagnostic Services of Manitoba (DSM), based in Winnipeg.
“Right now, if I have a difficult case, I have a microscope and I have a glass slide. If I am not sure about the diagnosis, what I have to do today is take that slide to a colleague who may be a few corridors away, or may be in a different building, or in a different town. There are risks associated with shipment, and there is also the issue of lost time.”
By using telepathology, however, slide images can be sent within seconds to colleagues; and two or more pathologists can view the images at the same time, to discuss the diagnosis.
Fischer pointed out that digital pathology will offer “huge benefits” on the education and research side as well.
“Today, if I want to share a case with the residents, I only have one glass slide. One of them is looking at the slide, and then when he or she is done, passes it to the next resident. So they can’t look at the same image at the same time. And it’s difficult to build a bank of interesting cases for the purposes of pathology education,” he said.
“Digital pathology allows you to scan your best cases and develop a bank online. Residents can access these and have dozens and dozens of cases they can review. You can scan the most informative, the most interesting or the most diagnostic images for the bank.”
Evans agreed, adding that this will also address a common problem found in academic centres where people do tissue-based research.
“The original glass slides get signed out of the archive and can go to somebody’s office where they might be kept for an extended period of time. The glass slides may be needed again for patient care or a second opinion, or for medico-legal reasons and problems arise if they cannot be readily found,” he said. By digitizing the slides, the original glass slides can be kept in the archive so everybody knows where they are. Digital versions of these slides can be used for research in most cases.
Fischer said another advantage digital pathology offers is precise measurement, which matters – especially in cancer cases.
“What is crucially important in many tumour resections is the distance of the margin from the tumour. Sometimes this is very difficult to measure with a microscope. It depends on what lens you are using, and what microscope. But if you use an image, the digital pathology system will measure it for you and you can even make annotations on the screen for your colleagues.”
Independent of the MJT project, there are also initiatives going on in other parts of Canada. One of the largest is taking place in eastern Québec, where more than 20 sites are updating their telepathology equipment, workflow and processes.
The aim of this project is to provide services across a large, remote region in order to avoid unnecessary patient transfer or pathologist travel. Each site is equipped with a whole slide scanner, a macroscopy station, a videoconferencing device and a case management and collaboration solution.
According to Dr. Bernard Têtu, pathologist at the Centre hospitalier universitaire de Québec (CHUQ) and medical director of the Telepathology Project for the Integrated Health University Network (IHUN), they are currently doing validation testing and using the system primarily for consultations, but are in the process of digitizing certain specimens and integrating digital pathology practices into their diagnostic workflow so it can be eventually used as a primary diagnostic tool down the road.
“Timing alone is a huge advantage. What could once take days or even weeks, now by telepathology takes less than 24 hours,” he said. “It opens up a world of possibilities.”
Agfa HealthCare, in Toronto, is one of the CHUQ’s technology partners helping to scan and validate images, establish improved workflow and to develop image management practices. According to Andy Hind, vice president of Agfa HealthCare, the benefits to digital pathology are in some ways very similar to digital imaging in radiology, but in other ways they are quite different.
“In radiology, for example, one of the biggest business benefits is that you don’t need film anymore. Essentially, hospitals were able to get rid of their large film archives,” Hind said.
“Now in digital pathology, you don’t have that same advantage, because you still have to create a slide, and you have to keep it for a certain period of time. So you are not suddenly going to get rid of the slide. Not today. But, what happens is that once you digitize that image, you are able to do all sorts of things you couldn’t do before.”
In addition, he said, there could be advantages from a multidisciplinary medical team and electronic health record perspective, to be able to see associated images of a patient all at once. “For the first time, you will be able to bring those digital pathology images together with the rest of that patient’s record.”
But despite all the obvious benefits, there remains some resistance to the technology. Pathologists are familiar and comfortable with specific equipment, and it will take time to overcome the learning curve and develop new working practices.
Dr. Evans added the profession also needs to recognize: “This technology is certainly not meant to replace pathologists, but to help us do our jobs better.”
Copyright © 2013
Canadian Healthcare Technology Magazine
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