Temperature dependence of thermal conductivity of liver based on various experiments and a numerical simulation for RF ablation.

Radiofrequency ablation (RFA) for liver cancer has increasingly been used over the past few years because RFA is minimally invasive treatment for patients. However, precise control of the formation of coagulation zones is difficult for operators due to inadequate imaging modalities. With this in mind, we have proposed a model-based robotic ablation system using numerical simulation to analyze temperature distributions in the organ to overcome this deficiency. The objective of our work is to develop a temperature-dependent thermophysical organ model to construct a precise numerical simulator for RFA. However, no standard methods exist for obtaining the thermophysical properties of biological tissues, as detailed evaluations of the accuracy of properties obtained from various experiments have not been completed. The purpose of this study was thus to measure and model the temperature dependence of thermal conductivity in hog liver from three representative methods, and to compare these results using our developed numerical simulator to reveal differences in temperature distributions stemming from differences in thermal conductivities.