Are digital whole slide imaging systems ready to replace conventional light microscopy for diagnostic surgical pathology?
Next week, an FDA committee will consider whether to allow pathologists to use digital pathology systems for primary diagnosis. Even if the committee does not make a positive recommendation, the timing demonstrates the swift progress in the quality of digital pathology images and the systems that present them to the pathologists.
Digital pathology imaging systems are slowly replacing microscopes in the nation’s clinical labs. There is now enough momentum in the market for digital pathology imaging that the FDA’s Hematology and Pathology Devices Panel of the Medical Devices Advisory Committee will meet October 22 and 23 in Gaithersburg, Maryland, to hear from experts in digital imaging. (See agenda) The FDA review committee may later make recommendations on the public health issues related to the use of digital whole slide imaging systems to replace conventional light microscopy for diagnostic surgical pathology.
One expert who will address the panel next week is Robert Monroe, M.D., Chief Medical Officer for BioImagene, a company in Sunnyvale, California, that produces digital pathology systems for clinical diagnostics. “We are proceeding with our vision, regardless of the FDA’s stance,” he said. “We feel the technology is ready, the images are of high quality, and the diagnostic information is the equivalent to that in glass slides. We feel very confident that—one way or another—the FDA will not derail the future of digital pathology.”
BioImagene and other companies such as Aperio Technologies Inc., in Vista, California, are continuing to introduce digital imaging systems for pathologists. Among the latest offerings are digital pathology systems with the capability to allow pathologists—in a variety of locations many miles apart—to view and comment on images. Such digital pathology systems are fostering collaboration among pathologists and other physicians in a way that is not possible with slides viewed under microscopes. For now, however, the FDA will discuss using digital whole slide imaging systems to replace conventional light microscopy for diagnostic surgical pathology. The committee will not discuss computer-assisted image analysis or remote real-time microscopy.
“It is our view that the FDA wants to inform itself and listen to the experts in the field of digital pathology imaging and digital pathology systems,” he added. “These experts likely will say that the images are equivalent for most applications, but there are some applications and aspects of the technology that bear further discussion. Therefore, the FDA review committee will be looking for advice from these experts on the potential pitfalls.
“Many of the people who will address the panel will talk about studies that have been performed in the United States, Canada, and Europe,” Monroe predicted. “These studies show that pathologists who review whole slide images come up with the same diagnoses as pathologists who view glass slides. Based on these studies, we are hopeful that the FDA will not impose burdensome restrictions on the use of the technology for diagnosis.
“We believe the FDA cannot realistically require companies in digital pathology to produce the tremendous number of studies that would be required to show that, for every diagnosis you can make with a microscope, you can also make the diagnosis with a computer monitor and whole slide imaging,” Monroe added. “Assume that the FDA did decide it would require studies to show equivalence [microscope versus computer screen], the most viable and conclusive approach would be for companies to provide studies that assessed a broad range of pathology cases. Requiring companies to go through equivalence studies for each single diagnosis would be impractical. The FDA would find itself overwhelmed reviewing such studies.
“Our view is that digital imaging offers tremendous promise for improving patient care,” Monroe stated. “In addition to supporting primary diagnosis, digital pathology imaging is, in many ways, an important key to personalized medicine. Digital pathology will be at the forefront of helping patients obtain individualized, specific therapies for their disease.
“To realize the full potential of personalized medicine, physicians need the results of complex and quantitative diagnostic assays, the interpretation of which can be made more accurate and reproducible through the use of digital pathology and image analysis,” concluded Monroe. “In the near future, a growing number of diagnostics will require digital pathology imaging to help pathologists and physicians stratify patients for treatment.
“Regardless of any decisions the FDA makes, we still feel very strongly that digital imaging in pathology has a very bright future,” concluded Monroe.