A novel method for monitoring liver ethanol injections: activity tissue distribution in rat liver using digital...

Accurate ethanol microdistribution during percutaneous ethanol injections (PEI) have not previously been reported by in vivo monitoring methods (e.g. by using ultrasound or other flow methods). Any real-time imaging method is insufficient to show the gradual diffusion of ethanol and its ultimate spread. Therefore a novel method to study the microdistribution and radiopharmacokinetics of labeled ethanol in rat liver was developed. Rats were injected with C-14-labeled ethanol into the right liver lobe. Liver slices were investigated at 1, 5, 15, and 30 min using a novel digital quantitative autoradiographic (DQAR) method. Tissue slices at 1 and 5 min demonstrated increased activity of C-14-labeled ethanol around the injection site, resulting in a uniform distribution at 15 min. At 30 min, a weak elimination was observed. Our results indicate that in PEI treatment, toxic effects may be found outside the primary injection site. Our DQAR method shows the dynamic spread of ethanol with great anatomical detail. It may therefore be used in future studies on ethanol kinetics in the liver and tumor tissues to optimize the antitumor effect of PEI while minimizing the potential for adverse spread and complications.