JPH04102465A - Dial plate and radiotherapy device - Google Patents

Abstract

PURPOSE:To measure the size of a tumor in the body of a morbid person by linear graphy by spotting a heavy metal on a plastic board transmitting radiation, electron beams and visual lights at equal intervals and in cross form, with respect to the wide surface of the plastic board. CONSTITUTION:In a radiotherapy device having a radioactive ray and electron beam radiating facility, a plastic board 1 is selected in a thickness optimizing influences of transmissivity, attenuation factor of radioactive ray and flatness of exposure distribution. A heavy metal 2 prevents the transmission of radioactive ray, electron beams and visible lights. A dial plate 3 is placed on the lower end of the radiation part 4 of the radiotherapy device. A radioactive cone 6 emitted from a radiation source 5 transmits the dial plate 3 and the tumor part 8 of a morbid person 7, and is radiated to a cassette 9 receiving a X-ray film. Thus, the heavy metal 2 spotted on the plastic board 1 at equal intervals in cross form is photographed on the X-ray film of a linear graphy. The dimensional relation between the photographed heavy metal 2 and the tumor part 8 is measured, whereby the size of the tumor part 8 in the body of the morbid person 7 can be known.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radiation therapy device, and more particularly to a radiation therapy device having a scale plate that can measure the size of a tumor.

[Conventional technology]

Conventionally, the scale plate for the irradiation field provided in the radiation irradiation section of this type of radiotherapy device is a plastic plate through which radiation (X-rays), electron beams, and visible light can pass, and the scale is printed or engraved on it. It was attached.

[Problem to be solved by the invention]

The conventional scale plate described above projects the scale of the scale plate onto the body surface by using a visible light projection system in the radiation irradiation part when the patient's tumor is on the body surface.
We were able to measure the size of the tumor. However, if the tumor is inside the body, its size cannot be measured.

[Means to solve the problem]

The scale plate of the radiation therapy apparatus of the present invention has a plastic plate through which radiation, electron beams, and visible light can pass, and heavy metals are dotted on a wide surface of the plastic plate at equal intervals and in a cross shape. In the radiation therapy device, this scale plate is installed at the lower end of the radiation irradiation unit, and radiation is irradiated to the patient's tumor through the scale plate to take a radiograph and measure the size of the tumor within the patient's body. are doing.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view of one embodiment of the present invention, and FIG. 2 is a side sectional view thereof. In FIGS. 1 and 2, 1 is a plastic plate through which radiation, electron beams and visible light can pass. Heavy metals 2 are arranged on the wide surface of the plastic plate at equal intervals a and dotted in a cross pattern.

The plastic plate 1 is selected to have a thickness that optimizes the influence of radiation transmittance, attenuation rate, flatness of irradiated radiation distribution, etc. in a radiation therapy apparatus having radiation and electron beam irradiation equipment. Heavy metals 2 prevent radiation, electron beams and visible light from passing through. Lead and tungsten are suitable for this type. Ordinary metals can also be used, but they have the disadvantage that dark spots caused by metals become blurred and difficult to see on X-ray film. When acrylic resin was used as the plastic plate 1 and tungsten was used as the heavy metal 2, the optimum thickness of the plastic plate 1 and the heavy metal 2 was 2 mm.

FIG. 3 is a second embodiment of the present invention, and shows a side view of a radiation therapy apparatus during linear radiography.

The scale plate 3 is installed at the lower end of the radiation irradiation section 4 of the radiation therapy apparatus. The radiation cone 6 irradiated by the radiation source 5 is
The radiation passes through the scale plate 3 and the tumor part 8 of the patient 7, and is irradiated onto the cassette 9 containing the X-ray film. An X-ray film in which this X-ray irradiation is continuously performed twice, once for the size of the tumor portion 8 and once for the maximum irradiation field, is generally referred to as linear photography.

Therefore, the heavy metals 2 scattered on the plastic plate 1 at equal intervals and in a cross pattern are also photographed on the X-ray film of the linear photography according to this embodiment.

By measuring the dimensional relationship between the photographed heavy metal 2 and the tumor 8, the size of the tumor 8 inside the patient's 7 body can be determined.

The size of the tumor on the body surface is measured by the conventional method described above.

〔Effect of the invention〕

As explained above, the present invention provides a scale plate in which heavy metals are dotted at equal intervals and in a cross shape on a wide surface of a plastic plate that can transmit radiation, electron beams, and visible light. By installing it at the lower end, the size of the tumor within the patient's body can be measured using linear imaging.

DESCRIPTION OF SYMBOLS 1...Plastic plate, 2...Heavy metal, 3...Scale plate, 4...Radiation irradiation part, 5...Radiation source, 6...
... Radiation cone, 7... Patient, 8... Tumor area, 9...
・Cassette.

Claims (1)

[Scope of Claims] 1. A scale plate comprising a plastic plate through which radiation, electron beams and visible light can pass, and heavy metals are dotted on a wide surface of the plastic plate at equal intervals and in a cross shape. 2. The scale plate according to claim 1, wherein the plastic plate has a thickness of 1 to 3 mm. 3. A radiation therapy apparatus, wherein the scale plate according to claim 1 or 2 is installed at the lower end of the radiation irradiation section.