It has taken quite a while, but the FDA has finally released a document that may help pave the way for whole slide imaging pathology system approval. On February 25th they released the “Technical Performance Assessment of Digital Pathology Whole Slide Imaging Devices Draft Guidance for Industry and Food and Drug Administration Staff”. It is available at http://www.fda.gov/ucm/groups/fdagov-public/@fdagov-meddev-gen/documents/document/ucm435355.pdf for a period of 90 days from release for public comment. The goal of the document is to provide “recommendations regarding the technical performance assessment data that should be provided for regulatory evaluation of a digital whole slide imaging (WSI) system.” It does “not cover the clinical submission data that may be necessary to support approval or clearance.”
What it does do is provide suggestions on how to characterize technical aspects of WSI performance as well as possible limitations potentially affecting safety and effectiveness. It covers just about every technical aspect one might consider: slide feeder, light source, imaging optics, mechanical scanner movement, digital imaging sensor, image processing software, image file format, image review manipulation software, computer environment, display, color reproducibility, spatial resolution, focusing, whole slide tissue coverage, stitching error, user interface, labeling, and quality control.
This may sound super technical to some people, but this is what digital and telepathology users and vendors have been waiting for. Hopefully this guidance, once finalized, will provide recommendations that should be included in the assessment of technical characteristics of a WSI device that will lead to approval of these devices for primary interpretation. The implications are huge. Telepathology – not just consultation but primary review – may finally hit center stage, become reimbursable, and a part of routine clinical practice.
Time is ticking! You have less than 90 days to review the document and comment. There are lots of aspects here and not everyone will be interested in every aspect, but if you are involved at all in the technical aspects of WSI I strongly encourage you to read this document. I for one will be reading the display section very closely as to me that is the interface between the pathologist and the information required to render a diagnostic decision. Every step in the imaging chain however is critical. Not only does this document lay the foundation for getting WSI into clinical practice, it opens up a number of doors for those of us doing basic research! Kudos to the FDA, Nicholas Anderson and Aldo Badano in particular, for moving this critical issue ahead!