Predictions Of Tissue Denaturation During Experimental Laser Interstitial Thermotherapy For Breast Tumors

摘要

Purpose: The purpose of these preliminary experiments was to calculate the activation energy and the frequency factor constants of the Arrhenius equation for prediction of the denaturation zone produced by laser interstitial thermotherapy in female breast tissue models. Material and Methods: In a first step, pairs of parameters consisting of the activation energy (AE) and frequency factor (A) were calculated for different half denaturation times at 50 癈 and 60 癈. Pairs of parameters were eliminated if the calculated time of denaturation at 70 癈 was excessively short (<0.1s). In a second step, denaturation was calculated over time for each remaining pair of parameters using temperature measurements performed during a laser heating experiment in ex-vivo porcine mammary chain tissue; The zone of denaturation in the tissue after laser heating was 2.0 cm x 3.5 cm. One pair of Arrhenius parameters was chosen whose denaturation plot showed no denaturation outside the experimentally-observed denaturation zone, 50% denaturation at the border of the experimental denaturation zone, and 100% denaturation within the experimental denaturation zone after 1200 seconds. Results and Conclusion: The activation energy and frequency factor which best fit our experimental data were Δ=3.02 x 10~5 J mol~(-1) and Δ=1.18 x 10~(44) s~(-1), respectively. These values fall within the general range given in the literature.