On the path toward system characterization standardization for in vivo applications of fluorescence imaging

The field of florescence guided surgery (FGS) has been growing rapidly since the initial market clearance of the SPY SP2000 in 2015. Many of the currently approved exogenous fluorophores have existed for half a century, yet adoption utilizing their florescence properties have only come to fruition in the past two decades. Now, a number of new near-infrared (NIR) contrast agents are poised to reach the market, pushing the limits of FGS beyond perfusion imaging into the realm of molecularly targeted contrast. The shear number and combinations of imaging systems and fluorophores will become increasingly burdensome for regulatory reviewers if standardized approaches for system characterization are not implemented. In 2017 the American Association of Physicists in Medicine (AAPM) convened Task Group 311 (TG311) to consider standardization criteria, but the implementation may prove difficult. Standardization tools will need to be developed and utilized to implement the recommendations by TG311. The progress of implementing standardized phantoms, augmented by computational aides in the form of image analysis and simulation packages are presented as a means to address future standardization efforts.