INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING Vol. 17, No. 2, pp. 253-256 FEBRUARY 2016 / 253
© KSPE and Springer 2016
Simulation and Experimental Evaluation of Selective
Heating Characteristics of 13.56 MHz Radiofrequency
Hyperthermia in Phantom Models
M. Tamim Hossain
1
, Bibin Prasad
2
, Ki Sun Park
2
, Hee Joon Lee
2
, You Ho Ha
3
,
Seung Ku Lee
3
, and Jung Kyung Kim
1,2,#
1 Department of Integrative Biomedical Science and Engineering, Graduate School, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul, 02707, South Korea
2 Department Mechanical Engineering, Graduate School, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul, 02707, South Korea
3 Research and Development, Union Medical Co., 76 Sandan-ro, Uijeongbu-si, Gyeonggi-do, 11781, South Korea
# Corresponding Author / E-mail: jkkim@kookmin.ac.kr, TEL: +82-2-910-4747, FAX: +82-2-910-4839
KEYWORDS: Deep heating, Hyperthermia, Selectivity, Phantom, SEMCAD X, Temperature
Hyperthermia with a radiofrequency electric field can treat a cancer by delivering energy to heat and kill cancer cells. For a deeply
located tumor, focused energy to raise its local temperature selectively is crucial for effective cancer treatment with minimal injury
to normal tissues. We evaluated the selective heating characteristics of hyperthermia with 13.56 MHz radiofrequency energy in
phantom models by experimental and computational approaches. Phantom materials with different electrical properties such as
distilled water, normal saline, egg white and porcine meat were used. Temperature rise in depthwise during heating at 75 W output
power was compared. The temperature of the egg white increased selectively in the distilled water but not significantly in the saline.
Numerical simulation was performed using SEMCAD X software to calculate the distributions of specific absorption rate (SAR) and
temperature, which enabled us to elucidate the selective heating mechanism in those phantom models.
Manuscript received: July 19, 2015 / Revised: November 16, 2015 / Accepted: November 17, 2015
1. Introduction
Hyperthermia is a common technique for treating tumor cells with
the application of heat and it is most effective when used with other
cancer treatments such as radiation therapy, chemotherapy, or
immunotherapy. The selective elevation of tumor cell temperature,
while sparing the normal cells during hyperthermia treatment, is a long-
standing issue in oncology. Numerous experimental and numerical
studies have been done by researchers to overcome this challenging
issue.
1,2
Hyperthermia with radiofrequency (RF) energy relies on the
dielectric energy absorption by the cells, which enables it to treat
deeply seated tumor cells selectively. Its selectivity of heating depends
on the electrical conductivity, dielectric constant, thermophysical
properties of tissues, and other metabolic differences between
malignant and healthy cells. Malignant cells have higher conductivity
due to high ion concentration gradient across the extracellular
membrane, high glucose influx, lower membrane potential and a
disorganized, loosely connected cell structure in comparison with
healthy cells. Based on these characteristics, RF distinguishes between
NOMENCLATURE
ε = permittivity
φ = electric potential
E = electric field strength
SAR = specific absorption rate
σ = electrical conductivity
ρ = mass density
c = specific heat
T = temperature
t = time
k = thermal conductivity
Q
r
= regional heat delivered by the source (= ρSAR)
DOI: 10.1007/s12541-016-0033-9 ISSN 2234-7593 (Print) / ISSN 2005-4602 (Online)