167: Why Accuracy Matters in Digital Pathology Podcast with Keith Wharton, Jr.

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Why do some pathologists still hesitate to trust digital slides—even after the FDA says “yes”? Because accuracy in digital pathology isn’t just about pixels—it’s about precision, validation, and confidence.

In this episode, I talk with Dr. Keith Wharton, MD, PhD, Global Medical Director at Roche Diagnostics, about how the Roche Digital Pathology DX system earned its FDA clearance for primary diagnosis—and what that means for the field.

We explore the science and strategy behind whole slide imaging (WSI) validation, the challenges of feature recognition, the meaning of non-inferiority, and the future of interoperability and AI in diagnostic systems.

If you’ve ever wondered what it takes to make a digital system clinically equivalent to the microscope—this episode is your roadmap.

🔹 Highlights with Timestamps

• [00:00–02:30] What “primary diagnosis” really means—and how the human brain processes histopathology features.
• [02:30–06:00] How Roche achieved FDA clearance for its DP200 and DP600 scanners—and why it’s “clearance,” not “approval.”
• [06:00–11:00] Breaking down the Roche Digital Pathology DX System components: scanner, viewer (Navify DP), and monitor.
• [11:00–16:00] Understanding the pixel pathway—the heart of system validation.
• [16:00–19:00] How the FDA defines precision and accuracy in validation studies.
• [19:00–30:00] Inside the massive multi-year validation studies: design, washout periods, and thousands of slide reads.
• [30:00–33:00] The non-inferiority margin (−4%)—why it matters and how Roche exceeded the benchmark.
• [39:00–45:00] The surprising “nuclear groove” discovery and what it reveals about how pathologists adapt to digital.
• [1:10:00–1:13:00] Future-ready systems and FDA flexibility through predetermined change control plans (PCCP).
• [1:25:00–1:35:00] Keith’s reflection: bridging the gap between discovery and clinical impact, and why the future of digital pathology is brighter than ever.
  
  
  

Resources from This Episode

• Roche Digital Pathology DX (DP200 & DP600) – FDA-cleared systems for primary diagnosis
• FDA Guidance (2016) – Technical performance standards for WSI
• American Journal of Clinical Pathology – Paper in press on validation study design
• Book: Chasing the Invisible by Dr. Thomas Grogan
• Frontiers Journal (2021) – Tissue Multiplex Analyte Detection in Anatomic Pathology (co-authored by Aleks and Keith)
• AJCP Paper
• Aleks and Keith’s Paper - Frontiers | Tissue Multiplex Analyte Detection in Anatomic Pathology – Pathways to Clinical Implementation
  
  
  

Key Takeaways

✅ FDA clearance requires rigorous demonstration of precision, accuracy, and statistical confidence.
✅ Non-inferiority margins (typically −4%) define the threshold for clinical equivalence to microscopy.
✅ Feature recognition in digital environments (like nuclear grooves) challenges perception and training.
✅ Interoperability and predetermined change control plans (PCCP) may accelerate system evolution.
✅ Digital pathology’s foundation is the pixel pathway—where scanner, viewer, and monitor all align.
✅ The field’s future depends on bridging discovery and practice, guided by robust validation.

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