What does FDA Approval Mean for the Digital Pathology Market? Part 1

Much is being said, written and discussed about the recent FDA clearance for Philips digital pathology solution for primary surgical pathology diagnosis.

Of course, this means an advantage for Philips right now in the market as the only FDA approved whole slide imaging system for primary diagnosis.

For groups and hospitals that appreciate the two main value drivers for digital pathology: when you are some distance from the slide and need a review sooner rather than later and/or the desire to incorporate image analysis/analytics into their practice AND wanted affirmation from the FDA for at least primary diagnosis, we have seen the regulatory barrier cleared by a manufacturer.

There are signs that others will follow. Given the way in which the FDA approached this, in conjunction with manufacturers, pathologists and the Digital Pathology Association (DPA), we now have a predicate device by which others can be measured.

The whole slide imaging system is an automated digital slide creation, viewing, and management system intended as an aid to the pathologist to review and interpret digital images of surgical pathology slides. The system generates digital images that would otherwise be appropriate for manual visualization by conventional light microscopy.

Future submissions will require data from a clinical study to demonstrate that viewing, reviewing, and diagnosing digital images of surgical pathology slides prepared from tissue slides using the whole slide imaging system is non-inferior to using an optical microscope. Studies should evaluate the difference in major discordance rates between manual digital (MD) and manual optical (MO) modalities when compared to the reference (e.g., main sign-out diagnosis).

And this is the most significant issue for the market with the recent FDA approval of the Philips Intellisite Pathology Solution (PIPS).

For as long as anyone can remember, the null hypothesis has been that whole slide imaging is inferior to the light microscope. There has been a concerted effort by several manufacturers along with pathologists and the DPA to reject the null hypothesis and show that digital diagnoses are no worse, if not better, than optical diagnoses. Digital versus analog. And prove that digital is not inferior to analogue.

And what was shown is that the null hypothesis was rejected.

As details emerge about the study design pending peer-review for a full scientific manuscript, given what we know from a USCAP poster this past March and a recent webinar, this was an exhaustive study to show that digital pathology was no worse than the light microscope for clinical diagnoses.

16 pathologists, over 2000 cases, 4 institutions, including academic, community and reference type laboratories, referee or adjudicating pathologists, 20 organ types and careful controls for the “gold standard” diagnosis.

All of this taken in conjunction with local slide production and slide scanning along with similar monitors and workflows.

And the null hypothesis was rejected.  The number of correct and incorrect diagnosis was statistically similar between digital and optical diagnoses.

Now others have a roadmap to follow what will be required to show that their devices and systems allow for an equivalent experience for pathologists to make interpretations that are equal to what can be expected through a microscope.

Why did FDA approval take as long as it took for digital pathology? In part, I think it was because a study was not submitted to encompass and control for enough cases, types of cases, stains, images, pathologists and diagnoses to have the “new” technology shown to be as safe and effective as the “old” technology. To show that “digital diagnoses” is as safe and effective as “optical diagnoses” to reject the null hypothesis.

In part 2, now that the technical regulatory/null hypothesis issue has been addressed by a successful study by a single manufacturer, what does this do for the business case(s) for digital pathology?