Standardization and implementation of fluorescence molecular endoscopy in the clinic

Abstract

. Significance: Near-infrared fluorescence molecular endoscopy (NIR-FME) is an innovative technique allowing for in vivo visualization of molecular processes in hollow organs. Despite its potential for clinical translation, NIR-FME still faces challenges, for example, the lack of consensus in performing quality control and standardization of procedures and systems. This may hamper the clinical approval of the technology by authorities and its acceptance by endoscopists. Until now, several clinical trials using NIR-FME have been performed. However, most of these trials had different study designs, making comparison difficult. Aim: We describe the need for standardization in NIR-FME, provide a pathway for setting up a standardized clinical study, and describe future perspectives for NIR-FME. Body: Standardization is challenging due to many parameters. Invariable parameters refer to the hardware specifications. Variable parameters refer to movement or tissue optical properties. Phantoms can be of aid when defining the influence of these variables or when standardizing a procedure. Conclusion: There is a need for standardization in NIR-FME and hurdles still need to be overcome before a widespread clinical implementation of NIR-FME can be realized. When these hurdles are overcome, clinical outcomes can be compared and systems can be benchmarked, enabling clinical implementation.

Accounting for blood attenuation in intravascular near-infrared fluorescence-ultrasound imaging using a fluorophore-coated guidewire

“…The fluorophore-coated guidewire was measured concurrently with the vessel wall to enable readouts that accurately depict the true distribution of ICG in the tissue. 23 , 24 Light attenuation by blood in intravascular fluorescence imaging was modeled as an exponential function of the distance between the outer wall of catheter sheath and the vessel wall or fluorophore-coated guidewire. 4 , 8 – 11 The NIRF signals of the guidewire were segmented from tissue signals using the coregistered IVUS data.…”

“…The same fluorophore (ICG) was used to coat the guidewire and injected into the tissue. The fluorophore-coated guidewire was measured concurrently with the vessel wall to enable readouts that accurately depict the true distribution of ICG in the tissue 23 , 24 . Light attenuation by blood in intravascular fluorescence imaging was modeled as an exponential function of the distance between the outer wall of catheter sheath and the vessel wall or fluorophore-coated guidewire 4 , 8 …”

Skin Cancer Pathobiology at a Glance: A Focus on Imaging Techniques and Their Potential for Improved Diagnosis and Surveillance in Clinical Cohorts

“…In particular, for skin cancers, NIR fluorescence imaging proved helpful for the identification of sentinel lymph nodes (SLNs) in CM [ 184 ] and for the visualization of fluorescence-labeled immune cells, especially to track and monitor them in living organisms during immunotherapy [ 185 ]. Despite its potential for clinical translation, NIR bioimaging still faces challenges and one of the most important is the lack of consensus in performing quality control and standardization of procedures and systems [ 186 ].…”

Performance Assessment and Quality Control of Fluorescence Molecular Endoscopy with a Multi-Parametric Rigid Standard

“…We have recently reported the application of this technology in animal models for the validation of tracers specific for esophageal [4,5] and colorectal cancer [6,7]. Despite the anticipated clinical benefits, a more systematic use of FME in clinical and preclinical applications is impeded without a way to assess performance and carry out quality control of FME systems [8]. Quality control, for example, is particularly critical for FME, as cycles of usage and cleaning gradually affect the optics of the employed endoscopes, frequently leading to image fidelity degradation [8].…”

“…Despite the anticipated clinical benefits, a more systematic use of FME in clinical and preclinical applications is impeded without a way to assess performance and carry out quality control of FME systems [8]. Quality control, for example, is particularly critical for FME, as cycles of usage and cleaning gradually affect the optics of the employed endoscopes, frequently leading to image fidelity degradation [8]. Although most clinical HD-WLE systems have counters to determine the endpoint of the endoscope's lifetime, this is not the case for FME systems.…”