Feasibility study of modeling liver thermal damage using minimally invasive optical method adequate for in situ measurement

Abstract

Liver thermal ablation techniques have been widely used for the treatment of liver cancer. Kinetic model of damage propagation play an important role for ablation prediction and real-time efficacy assessment. However, practical methods for modeling liver thermal damage are rare. A minimally invasive optical method especially adequate for in situ liver thermal damage modeling is introduced in this paper. Porcine liver tissue was heated by water bath under different temperatures. During thermal treatment, diffuse reflectance spectrum of liver was measured by optical fiber and used to deduce reduced scattering coefficient (μ ). Arrhenius parameters were obtained through non-isothermal heating approach with damage marker of μ . Activation energy (E ) and frequency factor (A) was deduced from these experiments. A pair of averaged value is 1.200 × 10 J mol and 4.016 × 10 s . The results were verified for their reasonableness and practicality. Therefore, it is feasible to modeling liver thermal damage based on minimally invasive measurement of optical property and in situ kinetic analysis of damage progress with Arrhenius model. These parameters and this method are beneficial for preoperative planning and real-time efficacy assessment of liver ablation therapy.

Novel tumor localization model and prediction of ablation zone using an intertwined helical antenna for the treatment of hepatocellular carcinoma

“… where, A is the frequency factor (1/s), and Δ E is the activation energy for the irreversible damage reaction (J/mol). The parameters A and Δ E are dependent on the type of tissue and have been characterized for liver tissues to be A = 7.39 × 10 39 s −1 and Δ E = 2.577 · 10 5 J/mol 15 …”

“…Since at room temperature, the maximum value of permittivity is 55 for tumor tissue, therefore, the maximum value of permittivity in the level is 55. Further, the output parameters are ablation diameter (T and A) obtained from simulated results in Comsol Multiphysics and only 27 combinations were required to analyze the result using the Taguchi method, as shown in Table 6 15 . Also, since the the ablation diameter in Table 6 is obtained by considering temperature independent tissue thermo‐electrical paramaters therefore, a reduction of 4 and 2 mm along axial and transversal diameter, respectively have been incorporated as discussed in Section 3.…”

Design of a novel externally‐tapped intertwining helical antenna for microwave ablation and its statistical analysis on tissue model

“…The temperature-dependent heat properties and Arrhenius kinetics accurately predict the timedependent ablation zone. 30 Taguchi's statistical method is used to accurately predict the weightage of each biological, thermal, and electromagnetic property in determining the ablation diameter. Taguchi method is adopted because it is robust, requires lesser time, and lesser number of experiments as compared to the conventional factorial method.…”

“…A 3‐D finite element model (FEM) consisting of thermophysical heat property along with Penne's bioheat model and Arrhenius kinetics is used to simulate the ablation environment. The temperature‐dependent heat properties and Arrhenius kinetics accurately predict the time‐dependent ablation zone 30 . Taguchi's statistical method is used to accurately predict the weightage of each biological, thermal, and electromagnetic property in determining the ablation diameter.…”

Microwave Ablation Efficacy Evaluation of Bone Tissue Based on Near Infrared Spectrum

“…Liver cancer is the rst cancer type to be used by MWA, and it has gradually become one of the reliable methods to treat and cure liver cancer since the 1990s 12 . Studies have shown that the thermal damage of liver tissue under MWA is a dynamic process related to temperature and time 13,14 . Some researchers have con rmed that thermal injury signi cantly affects the optical properties of liver tissue 15,16 .…”