|
Radiofrequency (RF) ablation is a popular therapeutic technique for heating solid
tumors that are medically unsuitable for resection or other treatments. Thermal ablation
applicators create high-frequency electromagnetic fields (EMFs) within the tumor site,
which causes heating, coagulation, and ultimately death of the cancer cells. The aim of this
study is the numerical analysis of the temperature distributions, ablation zones, and specific
absorption rates (SAR) during RF ablation in relation to an ellipsoidal shaped tumor placed
in the model of liver tissue. The source of heat is a three-element system of RF needle
applicators operating at a frequency 100 kHz, with a given electrode potential, inserted into
the tumor. In order to obtain an appropriate temperature distribution in the target area, the
Laplace equation coupled with the Pennes equation were solved using the finite element
method (FEM). The arrangement effect of three needle-type applicators on the resultant
thermal profiles and the volumes of ablation zones were analyzed and compared. In addition,
the ablation zones for various angles of the RF applicator placed in the center of the tumor
were analyzed. The paper shows that in order to control temperature distribution and ablation
zones the proposed system of RF applicators and the arrangement of electrodes can be
successfully applied in hepatocellular carcinoma treatment.
|
