Ethan LaRochelle, QUEL Imaging
Fluorescence-guided surgery has been approved for clinical use for the last 20 years. But the field suffers from a critical blind spot: the lack of standardized characterization methods for imaging systems and contrast agents.
Many of the 30 systems on the market are designed to work with indocyanine green (ICG), a fluorophore that is excited by near-infrared light (750 to 800 nm) and emits fluorescence at longer wavelengths (800 to 850 nm). ICG’s excitation and emission properties have made it the standard for vascularity and perfusion assessments.
Recently approved fluorophores can target molecular markers in cancerous tissues. But without standards, the adoption of these innovations may be limited.
Fluorophore developers must screen numerous compounds to optimize brightness and biocompatibility, often relying on available imaging systems with poorly matched optical filter design.
Imaging system developers face regulatory and design challenges when adapting existing platforms to accommodate new fluorophores. While the FDA-clearance process allows flexibility in demonstrating system equivalence, the lack of publicly disclosed optical specifications (i.e., excitation wavelengths and filtering parameters) hinders alignment with other stakeholders, such as surgeons.
Training for fluorescence-guided surgery must evolve to reflect the growing diversity of imaging systems and contrast agents.
Hospital administrators face the task of weighing economic factors against clinical performance, often with limited quantitative data related to system capabilities.
The industry must adopt standardized characterization methods and redefine surgeon training.
The American Association of Physicists in Medicine (AAPM) Task Group 311 has already laid out guidelines for standardized characterization metrics for fluorescence-guided surgery systems. Adopting these metrics will:
• Empower fluorophore developers to optimize candidates based on objective criteria.
• Enable imaging system developers to demonstrate compatibility with emerging fluorophores.
Training for fluorescence-guided surgery must evolve to reflect the growing diversity of imaging systems and contrast agents. Currently, most training focuses on clinically approved indications; this leaves surgeons underprepared for novel applications. A system-agnostic training approach would educate surgeons on the fundamental principles of fluorescence imaging, including light-tissue interactions, excitation/emission properties, and system parameters.
Without these changes, new fluorophores may fail to achieve widespread adoption due to compatibility issues. More importantly, reliance on subjective assessments could lead to suboptimal patient care.
By adopting the standardized metrics defined by AAPM Task Group 311 and providing system-agnostic training, the industry will accelerate innovation and enhance patient outcomes, ensuring that fluorescence-guided surgery continues to be a cornerstone of precision medicine.
Meet the author
Ethan LaRochelle is the cofounder and CEO of QUEL Imaging, which is focused on standardized methods for clinical translation of in vivo optical imaging technologies. LaRochelle received his Ph.D. in 2020 from the Thayer School of Engineering at Dartmouth College. He is a 2017 recipient of the National Science Foundation GRFP Fellowship; email: [email protected].
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