Further Rejection of Null Hypothesis: Digital Pathology Equal to Glass Slides

Now comes additional study from Dr. David Snead and colleagues at University Hospitals of Coventry and Warwickshire NHS Trust in the UK who examined 10,138 scanned slides and found 72 variances between GS and DP, including 21 clinically significant variances where the ground truth lay with GS in 12 cases and with DP in 9 cases. Seventeen pathologists reported 3,017 cases by DP. Of these 1,009 were reported by the same pathologist and 2,008 by a different pathologist (than the original GS interpretation). Their findings entitled, Validation of digital pathology imaging for primary histopathological diagnosis, using Omnyx, were reported in Histopathology in September.

Researchers in the UK have determined that whole slide imaging is just as effective for making a primary cancer diagnosis as examining glass slides under a microscope, with the future potential for digital systems to use algorithms to help separate normal from abnormal samples and grade cancers.

The study, one of the largest and most comprehensive validation studies of whole slide imaging for clinical use, was published earlier this month in the journal Histopathology.

The 17 pathologists at University Hospital Coventry used a computer system called The Omnyx Precision Solution, which digitizes slides that are traditionally placed under a microscope and allows pathologists to look at them on a computer. They evaluated biopsies and resections from more than 3,000 patients using both microscopes and the digital pathology system, determining if there were any statistical differences in the accuracy of the diagnoses.

Out of 3,017 cases, there were 72, or only 2 percent, where the glass slide and digital case diagnosis did not agree with each other. In just three cases, the digital platform was determined to be responsible for the variance, including a bronchial biopsy and penile biopsy, where dysplasia was reported on digital pathology but was not present on glass slide microscopy.

The results are within the 95 percent confidence interval for existing variability, proving that digital pathology is non-inferior to glass slide microscopy, the researchers concluded.

David Snead, a pathology consultant at University Hospital Coventry and an author of the study, explained that while the Omnyx system is not approved for primary diagnosis by the U.S. Food and Drug Administration, and can only be used for secondary diagnosis in the U.S., it’s up to individual institutions in the UK to determine whether the technology satisfies the requirements for putting it into practice.

“We’re confident that it works pretty well,” Snead told HCB News. “This study showed that you can use this technology for primary diagnosis.”

Snead said the FDA will likely look at his group’s study when making a decision about approving digital pathology for primary diagnosis in the U.S.

Read more about the research findings and remarks from Omnyx’s CEO.