JPH0241175A - Cavity resonator type hyperthermia device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a device for performing hyperthermia (thermal therapy) for cancer and the like, and particularly relates to a cavity resonator type hyperthermia device.

[Conventional technology]

Hyperthermia is a treatment method that takes advantage of the fact that the tissue of malignant tumors such as cancer is sensitive to heat and treats the tissue by heating the area. Warming only the affected area and avoiding heating other normal tissues as much as possible prevents damage to normal tissues.
This is important in improving the therapeutic effect of the affected area. Dielectric heating methods and microwave heating methods using a radiation applicator are conventionally known methods for heating the human body to about 43°C, but these methods are used when the affected area is deep within the human body. In some cases, there are problems such as insufficient heating or inefficiency in that only the deep part of the body is heated. Therefore, recently, a cavity resonator type hyperthermia device has been proposed. This uses, for example, a cylindrical or rectangular parallelepiped-shaped highly conductive outer shell as a cavity resonator, and a patient is inserted through a patient insertion hole provided on the side of the shell. Then, high frequency power is supplied to cause the cavity to resonate as a cavity resonator. In this case, if a higher-order resonance mode is generated as the resonance mode, an electric field intensity distribution pattern specific to that mode can be obtained. Since heating is concentrated at the maximum position of the electric field strength in this electric field strength distribution pattern, by positioning the affected area to be treated at this maximum position, local heating treatment of only the affected area is possible.

[Problem to be solved by the invention]

However, conventionally, this positioning has been performed by moving the patient's body within the patient insertion hole, and due to the size restrictions of the patient insertion hole, depending on the location of the affected area within the patient's body, the affected area may be located at the maximum position of the electric field strength. It may be difficult to position the Although the present invention moves the electric field intensity distribution pattern itself relative to the patient's body, and thus the movement of the patient's body is limited to only within the patient insertion hole, this restriction is virtually eliminated. As a method, it is possible to position the untreated affected area of a patient at the maximum electric field strength position.
The present invention aims to provide a cavity resonator type hyperthermia device.

[Means to solve the problem]

In order to achieve the above object, the cavity resonator type hyperthermia device according to the present invention includes a well-conducting outer shell forming the cavity resonator, and an insulating partition for liquid disposed inside the well-conducting outer shell. A plate, a liquid dielectric filled in the good conductor outer shell, and a liquid transport device for moving the liquid dielectric in the good conductor outer shell between the rooms partitioned by partition plates. .

[For production]

When a specific high-order resonance mode is generated within the outer shell of a good conductor, a complex pattern of electric field strength distribution is generated within the outer shell of the good conductor. It is essentially determined not by the shape but by the position and shape of the dielectric material filled therein, which has a dielectric constant comparable to that of the human body. Therefore, if an insulating partition plate for the liquid is provided inside the well-conducting outer shell to divide the liquid into several chambers, and the liquid dielectric is moved between these chambers, the patient's body can be placed inside the patient insertion hole. Even if the dielectric body is fixed in position, the position of the dielectric body itself can be moved relative to the patient or body. In other words, since the electric field intensity distribution pattern can be moved relative to the patient's body whose position is fixed relative to the outer shell of the good conductor, the restriction that the patient's body can only move within the patient insertion hole is effectively eliminated. The area to be treated within the patient's body can be easily positioned at the maximum position of the electric field intensity distribution pattern.

【Example】

Next, an embodiment of a cavity resonator type hyperthermia device according to the present invention will be described with reference to the drawings. As shown in FIG. 1, in this embodiment, the good conductor outer shell 1 is formed in the shape of a rectangular parallelepiped consisting of six good conductor plates, top and bottom, left and right, and front and back. And in this figure, the depth direction (
An insulating cylindrical body 2 is provided in the cylindrical body (Z direction), and a patient insertion hole 3 is formed inside the cylindrical body 2 that penetrates the outer shell 1 of a good conductor. The well-conducting outer shell 1 also serves as a container for liquid, and has several chambers partitioned by insulating partition plates 4 for liquid. This is filled with a liquid, such as pure water, that has a dielectric constant comparable to that of the human body, and this liquid is prevented from leaking from each room to another, and is also prevented from leaking into the patient insertion hole 3. It is designed not to leak. Each pipe extending from the liquid transport pump 5 is inserted into each of these chambers, so that the pump 5 moves the liquid dielectric between the chambers. In this embodiment, the partition plate 4 is arranged to partition in the horizontal direction (X direction), and by appropriately determining the position of the partition plate 4, the liquid dielectric is moved between the rooms partitioned by the partition plate 4. Only its position is moved in the X direction while the dielectric maintains its integrity and its size in the X direction. When this well-conducting outer shell 1 is used as a cavity resonator and high-frequency power is supplied, a specific resonance mode is generated depending on the frequency. In this embodiment, it is assumed that the TE3□1 mode is generated. In this TE, 2□ mode, the electric field intensity distribution pattern is as shown in FIG. The dotted line in Figure 2 is the electric field intensity distribution pattern in the X-Y plane located at the center of the Z direction, when the horizontal direction is the X direction, the vertical direction is the Y direction, and the depth direction is the Z direction in Figure 1. shows. The pattern of this electric field intensity distribution is not determined by the position and shape of the good conductor outer shell 1, but the pattern is substantially determined by the position and shape of the dielectric within the outer shell 1. Therefore, it is necessary to maintain the integrity of the dielectric as described above and its
If you move only that position in the X direction while maintaining the size in the direction (of course, the same size in the Y direction), the electric field strength distribution pattern shown by the dotted line in Figure 2 will change from that pattern. The entire outer frame moves in the X direction while maintaining the same pattern (that is, the entire outer frame while maintaining the pattern within the outer frame indicated by the two-dot chain line). Since this movement of the electric field strength distribution pattern as a whole is relative to the well-conducting outer shell 1, that is, the patient insertion hole 3, it is ultimately relative to the patient 6 inserted therein. Therefore, in the case of the pattern shown in FIG. 2, the maximum position of the electric field strength is exactly at the central position P, and this maximum position P can be positioned at the affected area 7. Although the patient 6 can be moved within the insertion hole 3, its movement is limited due to the relationship between the size of the patient 6 and the size of the insertion hole 3, and even when the patient 6 is moved to the maximum, the maximum position P is located at the affected area 7. Even if it seems impossible,
By moving the electric field intensity distribution pattern itself as described above, the position of the affected area 7 and the maximum position P can be made to coincide. Therefore, no matter where the affected area 7 is located in the body of the patient 6, only the affected area 7 can be locally heated to improve the therapeutic effect. Note that in the above description, the partition plates 4 are arranged in the left-right direction to enable the dielectric to move in the left-right direction, but it is also possible to add a configuration that allows the dielectric to move in the up-down direction. Although not mentioned above, in reality, a patient 6 inserted into the patient insertion hole 3 and a porous body filled with a liquid dielectric such as pure water are inserted into the patient 6 so as to fill the void inside the hole 3. It is desirable to wrap it around 6.

【Effect of the invention】

According to the cavity resonator type hyperthermia device of the present invention, by moving the electric field intensity distribution pattern itself relative to the patient's body, it is possible to position the affected area of the patient to be treated at the maximum electric field intensity position. can. Thereby, it is possible to locally heat the affected area deep within the patient's body, and the therapeutic effect can be improved without causing any inconvenience to normal tissues other than the affected area.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a cavity resonator type hyperthermia device according to an embodiment of the present invention, and FIG. 2 is a diagram showing an electric field intensity distribution pattern. DESCRIPTION OF SYMBOLS 1... Good conductive outer shell, 2... Cylindrical body, 3... Patient insertion hole, 4... Partition plate, 5... Liquid transport pump, 6
...patient, 7...affected area.

Claims (1)

[Claims] (1) A well-conducting outer shell forming a cavity resonator, an insulating partition plate for liquid disposed within the well-conducting outer shell, and a liquid dielectric filled into the well-conducting outer shell. 1. A cavity resonator type hyperthermia device, comprising: a liquid dielectric in the well-conducting outer shell and a liquid transport device for moving the liquid dielectric in the outer shell of the good conductor between rooms partitioned by partition plates.