On September 21, 2021, the U.S. Food and Drug Administration authorized marketing of Paige Prostate, software from Paige.AI that helps pathologists detect areas suspicious for cancer on digitized prostate-biopsy slides. The FDA called it “the first artificial intelligence (AI)-based software designed to identify an area of interest on the prostate biopsy image with the highest likelihood of harboring cancer” - the first such product authorized for use in digital pathology, the discipline of diagnosing disease from tissue under the microscope.
Like the IDx-DR diabetic-retinopathy device three years earlier, Paige Prostate was cleared through the De Novo pathway, which the FDA uses for novel low-to-moderate-risk devices with no existing equivalent. Authorization establishes special controls that later, similar devices can reference, opening a faster route for the products that follow. Importantly, Paige Prostate is an assistive tool, not an autonomous diagnostician: it flags a region for a pathologist to review further, and is meant to supplement, not replace, the human read.
The supporting clinical study had 16 pathologists examine 527 digitized slides - 171 cancerous and 356 benign. With the software’s help, detection of cancer on individual slide images improved by an average of 7.3 percent compared with unassisted reads, with no measured effect on the reading of benign slides. The FDA noted the study did not assess impact on a patient’s final diagnosis, which usually draws on multiple biopsies and clinical context.
The authorization mattered because pathology is the ground truth of cancer diagnosis, and slides had only recently begun to be scanned into the high-resolution digital images that machine learning needs. Paige Prostate showed regulators were prepared to clear AI inside that workflow, while keeping the pathologist in charge of the diagnosis.