Comparing fluorescent contrast agents for fluorescence guided surgery using 3-D cryo-imaging.

Fluorescence cryo-imaging is a high-resolution optical imaging technique that produces 3-D whole-body biodistributions of fluorescent molecules within an animal specimen. To accomplish this, animal specimens are administered a fluorescent molecule or reporter and are frozen to be autonomously sectioned and imaged at a temperature of -20°C or below. Thus, to apply this technique effectively, administered fluorescent molecules should be relatively invariant to low temperature conditions for cryo-imaging and ideally the fluorescence intensity should be stable and consistent in both physiological and cryo-imaging conditions.

Comparing spatial distributions of ALA-PpIX and indocyanine green in a whole pig brain glioma model using 3D fluorescence cryotomography.

Significance: ALA-PpIX and second-window indocyanine green (ICG) have been studied widely for guiding the resection of high-grade gliomas. These agents have different mechanisms of action and uptake characteristics, which can affect their performance as surgical guidance agents. Elucidating these differences in animal models that approach the size and anatomy of the human brain would help guide the use of these agents.