Performance Evaluation for FGS Systems: Background

A preprint providing guidelines for performance evaluations of fluorescence-guided surgery (FGS) systems was recently posted (Read the full paper here). While the final peer-review is not yet complete, the authors are leaders in the field, having worked on this document for close to a decade, if not longer. Many of the concepts presented in this publication are at the core of why we founded QUEL Imaging. I’d like to cover some of these concepts over my next few posts, starting with some initial background.

To start, I’d like the reader to take a moment to appreciate the collaboration needed to bring this paper to fruition. Brian Pogue was my primary advisor at Dartmouth College during the beginning of my PhD. His research group received a solid Quantum-dot phantom from Vasilis Ntziachristos’ group in Munich sometime in 2016. As one of the newer PhD students, my task was to image the phantom on all of our fluorescence imaging systems before mailing it to another institution. We analyzed the data from the images in hopes of comparing the performance of multiple systems. At this point in time, the framework for the guidance paper was already well underway, based on ongoing discussions with other academic leaders in the field, as well as members of numerous government agencies (FDA, NIH-NCI, NIH-NIBIB, NIST).

The primary drivers behind the intended publication were organized by the American Association of Physicists in Medicine (AAPM): Task Group No. 311 - Guidance for Technical Performance Evaluation for Fluorescence-Guided Surgery Systems (TG311). This group had three official charges:

1. Provide recommendations on how to select FGS systems for clinical use and how to use them clinically; identify specific requirements and performance goals necessary for their clinical implementation.
2. Provide recommendations on how to calibrate these systems and other appropriate aids, such as targets and phantoms that test technical functionality in planned use.
3. Provide recommendations on risk-based approaches to quality management for Fluorescence-guided surgery systems.

There are a number of international organizations performing similar work, for example, the European Society for Molecular Imaging (ESMI) Study Group on Imaging Standardization and Intra-operative Imaging, and World Molecular Imaging Society (WMIS) Optical Surgical Navigation (OSN) Interest Group, but the next few blog posts will focus on the Pogue et al. preprint. The next post will provide more background on phantoms and how they’re constructed, followed by posts on performance characterization metrics and how to use phantoms for evaluations.

If you’re eager to get started with optical phantoms, please reach out and let us know how we can help!