My Path in Hyperthermia Research and Expectations for the Future

Abstract

The purpose of this paper is to review a history of hyperthermia research in Japan focusing on the fields in which I have been engaged. Hyperthermia research in Japan was started in 1975 when T.Sugahara,Professor of Kyoto University organized a hy perthermia research group supported by a Grant-in-Aid for Cancer Research from the Ministry of Education, Science and Culture. T. Sugahara and M. Abe developed an 8 MHz RF capacitive heating device in cooperation with Yamamoto Vinyter Co. in 1983. This machine named Thermotron-RF8 was first officially recognized as a heating device for cancer therapy by the Ministry of Health and Welfare in 1984. Thereafter a variety of machines have been developed for clinical use and the rapid expansion of activity in hy perthermia research in various fields including radiation biology and physics led to the foundation of the Japanese Society for Hyperthermic Oncology in 1984. From the latter of 1980 to the first half of 1990 hyperthermia has gained a significant degree of popularity .However since clinical hy perthermia today is a time-and man power-consuming procedure,done with still immature machines and is an inexact treatment method,enthusiasm has gradually been reduced. In order to revitalize clinical hy perthermia it is absolutely important to develop a heating device that can heat tumors in various locations selectively and homogeneously to desired temperatures and to obtain thermal mapping and monitor the temperature non-invasively during each treatment session. We must also define" thermal dose"in terms which are clinically relevant to the biological effect. It is my hope that hyperthermia will be established as one of the standard methods for cancer therapy by resolving the problems stated above in the future.

Temperature calculations inside body during treatment by capacitive heating device

“…This heating scheme can also be called regional heating. Recently, thermal treatments are studied not only for cancer treatment (hyperthermia) but also various treatments which expect low temperature effect such as mild hyperthermia [3]. In this kind of studies, the capacitive heating device also plays an important role.…”

Heating analysis of a realistic human model for non-invasive hyperthermia using multi-electrode applicator

“…1(a) illustrates a standard human model [1] with multi-electrode applicator for explaining the multi-electrode method where left is zx plane (side), center is xy plane (top), right is xy plane (bottom). The body is made of three-layer…”

“…In cancer hyperthermia, radio frequency (RF) wave capacitive-type heating (target temperature: 42.5°C) is an effective treatment method [1]. In Japan, one of the proven treatment devices is the heating method using a pair of electrodes (electrode method) [2].…”