Yuya Iseki

SAR analysis of the improved resonant cavity applicator with electrical shield and water bolus for deep tumors by a 3-D FEM

This paper discusses the improvements of the re-entrant resonant cavity applicator, such as an electromagnetic shield and a water bolus for concentrating heating energy on deep tumors in an abdominal region of the human body. From our previous study, it was found that the proposed heating system using the resonant cavity applicator, was effective for heating brain tumors and also for heating other small objects. However, when heating the abdomen with the developed applicator, undesirable areas such as the neck, arm, hip and breast were heated. Therefore, we have improved the resonant cavity applicator to overcome these problems. First, a cylindrical shield made of an aluminum alloy was installed inside the cavity. It was designed to protect non-tumorous areas from concentrated electromagnetic fields. Second, in order to concentrate heating energy on deep tumors inside the human body, a water bolus was installed around the body. Third, the length of the lower inner electrode was changed to control the heating area. In this study, to evaluate the effectiveness of the proposed methods, specific absorption rate (SAR) distributions were calculated by FEM with the 3-D anatomical human body model reconstructed from MRI images. From these results, it was confirmed that the improved heating system was effective to non-invasively heat abdominal deep tumors.

A new heating method with dielectric bolus using resonant cavity applicator for brain tumors

In this paper, we discuss a new method of controlling heating location in the proposed resonant cavity applicator. A dielectric bolus was used to non-invasively treat brain tumors. We have already confirmed that our heating system using resonant cavity is useful to non-invasively heat brain tumors. In order to heat tumors occurring at various locations, it is necessary to control the heating area with our heating system. First, we presented the proposed heating method and a phantom model to calculate temperature distributions. The results of temperature distributions were discussed. Second, a 3-D human head model constructed from 2-D MRI images was presented. The results of specific absorption rate distributions were discussed. From these results, it was found that the proposed heating method was useful to non-invasively treat brain tumors.

SAR analysis of resonant cavity applicator using dielectric bolus with anatomical human model by finite element method

In this study, we propose a new heating method using a resonant cavity applicator to control the heated area using a dielectric bolus. The dielectric bolus is filled with a dielectric material such as water and is attached to a human head inside the cavity. In this paper, first, the proposed heating method using the dielectric bolus was described. Second, a 3-D anatomical human head model, which was constructed from 2-D MRI and X-ray CT images, was presented. Finally, from the results of specific absorption rate (SAR) distributions using 3-D FEM, it was shown that the heated area inside a human brain could be controlled by changing the electromagnetic field distribution. From these results, it was found that the proposed method for controlling the heated area was useful for effective hyperthermia treatments.

SAR analysis of the improved resonant cavity applicator by a 3-D FEM

This paper discusses the improvement of the reentrant resonant cavity applicator, such as an electromagnetic shield and water bolus for concentrating heating energy on deep tumors in an abdominal region of a human body.

Heating Properties of Resonant Cavity Applicator using Dielectric Bolus with Anatomical Human Head Model

In this paper, we propose a new heating control method of resonant cavity applicator using a dielectric bolus. The dielectric bolus is filled with dielectric such as water and is attached to a human head inside the cavity.

Heating control method of resonant cavity applicator for non-invasive hyperthermia treatment

This paper describes a heating control method of the resonant cavity applicator for brain tumor hyperthermia treatment. In this study, we proposed several heating control method. In the first method, the diameters of the inner electrodes are changed. In addition, the position of the phantom between the inner electrodes was changed. In the second method, the dielectric bolus was used. The bolus is attached to the human head and is filled with dielectric materials, such as pure water, saline and so on. By changing the dielectric properties inside the bolus, heated region can be controlled. From these results, it was confirmed that proposed methods are useful for treating brain tumors.