Estimation of SAR Distribution of a Tip-Split Array Applicator for Microwave Coagulation Therapy Using the Finite Element Method

Kazuyuki SAITO  Takeshi TANIGUCHI  Hiroyuki YOSHIMURA  Koichi ITO  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E84-C   No.7   pp.948-954
Publication Date: 2001/07/01
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Techniques for Constructing Microwave Simulators--Design and Analysis Tools for Electromagnetic Fields, Circuits, and Antennas--)
Category: Applications of Electromagnetics Simulators
Keyword: 
microwave coagulation therapy,  coaxial-slot antenna,  array applicator,  FDTD,  FEM,  

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Summary: 
The microwave coagulation therapy has been used mainly for the treatment of hepatocellular carcinoma (small size tumor in the liver). In the treatment, a thin microwave antenna is inserted into the tumor, and the microwave energy heats up the tumor to produce the coagulated region including the cancer cells. At present, a problem occurs: the size of the coagulated region is insufficient, especially in the perpendicular direction of the antenna axis. In order to overcome this problem without increasing the physical load of the patient, the authors introduced a new type of array applicator composed of two coaxial-slot antennas. However, we cannot estimate heating characteristics of this array applicator precisely by using the FDTD calculation, because the use of staircasing approximation, which employs rectangular parallelepiped cells, is unsuitable for the analysis. Therefore, in this paper, we introduce the finite element method (FEM), which employs tetrahedral cells, to estimate the heating characteristics of the array applicator.