Summary
International Symposium on Antennas and Propagation
2012
Session Number:POS1
Session:
Number:POS1-60
Evaluation of Heating Characteristics of Microwave Thermal Therapy Using Biliary Stent Fed by Coaxial Probe
Hiroshi Itakura, Kazuyuki Saito, Masaharu Takahashi, Koichi Ito,
pp.-
Publication Date:2012/10/29
Online ISSN:2188-5079
Summary:
Recently, various types of medical applications of microwaves have widely been investigated and reported. In particular, microwave thermal therapies using thin coaxial probes are of a great interest. Up to now, the authors have been studying the intracavitary microwave hyperthermia using a thin coaxial antenna combined with endoscope that is an effective and minimally invasive treatment for deep-seated carcinoma such as bile duct carcinoma. Hyperthermia is one of the modalities for cancer treatment, utilizing the difference of the thermal sensitivity between tumor and normal tissue. In this treatment, the tumor is heated up to the therapeutic temperature between 42 and 45 degrees centigrade without overheating the surrounding normal tissues. We can enhance the treatment effect of other cancer treatments such as radiotherapy and chemotherapy by using them together with the hyperthermia. Today, placement of self-expandable metallic stents is the standard of care for patients with malignant objective jaundice caused by bile duct carcinoma if their life expectancy is less than 3 months. In addition, in previous study, we have known that the metallic stent would shield microwave energy from the antenna inserted into the metallic stent. From the above, newer endoscopic thermal treatment modalities in situation that the stent has implanted in a patient are needed. Therefore, the authors present the endoscopic modality of microwave hyperthermia for bile duct carcinoma. It uses the proposed biliary stent fed by a thin coaxial probe in order to heat efficiently around the biliary stent. Figure 1 shows the proposed treatment scheme. It is possible to be the curative treatment for the patients with stent for life-short bile duct carcinoma. This paper describes the heating characteristics around the proposed biliary stent fed by a coaxial probe by conducting both numerical simulations using the FDTD method and heating experiments using a tissue-equivalent solid phantom.