Radiofrequency Ablation: Modeling the Enhanced Temperature Response to Adjuvant NaCl Pretreatment

PURPOSE: To characterize the effects of volume and concentration of adjuvant NaCl pretreatment on radiofrequency (RF) ablation and to model these results to determine their applicability to in vivo systems. MATERIALS AND METHODS: Standardized 1-L 5% agar phantoms were constructed with central wells of varying volume that were filled with a protein-based polymer gel of varying NaCl concentration (0%–35%). RF ablation to the maximum system current output (2,000 mA) was applied to internally cooled 2-cm electrodes placed in the center of the gel wells. Remote thermometry was performed 20 mm from the electrode. Temperatures generated within the phantom were then used to model the response surface by using regression analysis. The generated model was then applied to previously published in vivo data to determine its applicability to a porcine liver tissue model. Statistical analyses included one-way analysis of variance to compare the temperatures reached with different NaCl concentrations and volumes with tho...