Pre-treatment planning for hepatic radiofrequency ablation

Abstract

We develop a pre-treatment planning method for optimum hepatic radiofrequency (RF) ablation. In conventional methods, pre-treatment planning is minimal and for a specific tumor size, it only includes reading pre-specified treatment length and input voltage values from a look-up table that lists experimentally obtained ablation parameters. Such planning, in order to assure certain level of cell death, usually results in more healthy cell damage than desired. Different than the conventional methods, here, we develop a model-based pre-treatment optimal planning framework. As an example, we use 1-D axisymmetric tissue geometry and over this geometry, we solve Pennes' bioheat and Laplace equations to model the RF heating. Using the solutions of these equations, we define constrained nonlinear optimization problems to achieve specific temperature profiles in certain areas of the tissue. Results demonstrate that compared to the conventional methods, our approach significantly improves the healthy tissue preservation.where h b is the convective heat transfer coefficient, T b is blood temperature. The convective heat transfer coefficient can be calculated as h b = ω b ρ b c b , where ρ b and c b are the mass density and specific heat of blood, respectively, and ω b is perfusion coefficient [25].

Particle swarm optimization solution for roll-off control in radiofrequency ablation of liver tumors: Optimal search for PID controller tuning

“…The output data represents the impedance of the liver tissue, calculated from the voltage and current measurements obtained via the SOFIA ® equipment. Only the real part of the impedance was considered as it is associated with Joule heating [ 60 ]. Reactances were neglected.…”

Untitled

“…The output data represents the impedance of the liver tissue, calculated from the voltage and current measurements obtained via the SOFIA 1 equipment. Only the real part of the impedance was considered as it is associated with Joule heating [60]. Reactances were neglected.…”