JP2003310590A - Dose distribution measuring device - Google Patents

Abstract

(57) [Problem] To provide a high-performance and inexpensive dose distribution measuring device. SOLUTION: In a dose distribution measuring device for detecting and measuring a dose distribution of radiation emitted from a predetermined radiation source,
A plurality of line sensors are arranged adjacent to each other along the same direction to constitute a radiation irradiation surface facing the radiation source, and a means for detecting a one-dimensional dose distribution; Means for rotationally driving at a predetermined rotational angle about an axis perpendicular to the plane, a means for detecting the rotational angle of the radiation detecting means for each rotational driving step by the rotational driving means, and the radiation detecting means Storage means for storing the one-dimensional dose distribution data detected by the method and the rotation angle data detected by the rotation angle detection means; and radiation irradiation of the radiation detection means based on the stored one-dimensional dose distribution data and the rotation angle data. A dose distribution deriving unit for deriving a two-dimensional dose distribution on the surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation dose distribution measuring apparatus for measuring a radiation dose distribution before a diagnostic examination or treatment using radiation irradiation, for example.

[0002]

2. Description of the Related Art Conventionally, for example, in a radiological diagnostic test or treatment apparatus for irradiating a predetermined site of a patient including cancer cells with radiation, normal tissue other than cancer cells is prevented from being irradiated with the radiation, and the irradiation site is also irradiated. A treatment plan is prepared in advance so as to calculate a desired dose distribution by using a predetermined device so that the radiation dose becomes uniform in. Usually, prior to irradiation, the dose distribution of the radiation emitted from the radiation source is measured to confirm whether or not the dose distribution calculated in the treatment plan is realized.

As a dose distribution measuring device used for dose distribution measurement, there is known a device using a dose sensor array arranged in a grid like a two-dimensional matrix. As an example of such a device, Japanese Patent Laid-Open No. 2001-3468
The dose distribution measuring device disclosed in Japanese Patent Publication No. 94 will be described with reference to FIG. In this dose distribution measuring apparatus, the radiation 102 generated from the radiation source 101 is applied to the inside of the water tank 103, and the dose distribution formed by the radiation 102 is measured in the water tank 10.
3 is detected by the scintillation detector 104 housed in 3.

The scintillation detector 104 is composed of a radiation sensor (not shown) composed of a plurality of scintillators arranged in a lattice in a plane perpendicular to the irradiation direction of the radiation 102, and outputs a signal from each sensor. By taking it out, the two-dimensional dose distribution of the radiation irradiated on the surface is measured.

The amount of light emission in each scintillator generated by the radiation incident on each scintillator arranged in a lattice of the scintillation detector 104 corresponds to the dose of the incident radiation, which is the dose at a predetermined site. Is transmitted to the CCD camera 107 via the optical fiber 106. The CCD camera 107 recognizes the transferred dose signal as image information. After that, the image processing device 108 and the computer 109
Processes the image information acquired by the CCD camera 107 and calculates a two-dimensional dose distribution from the image information. The acquired two-dimensional dose distribution is displayed on a monitor (not shown).

The scintillation detector 104 is
The water tank 1 is supported by a vertically movable mechanism unit 105.
It is possible to measure the dose distribution at a predetermined depth within 03. As a result, not only the two-dimensional dose distribution of radiation,
It is also possible to measure the three-dimensional dose distribution.

[0007]

However, as in the conventional dose distribution measuring apparatus, the scintillation detector 1 is used.
As 04, in the configuration using a plurality of sensors arranged in a grid to form a two-dimensional plane, each sensor forming the two-dimensional plane is miniaturized when a spatial resolution of, for example, several mm or less is realized. Becomes necessary, and the number of channels of the two-dimensional sensor array and its associated signal processing circuit also increases. Further, the wiring for taking out the signal such as the optical fiber 106 becomes more complicated, and the manufacturing cost increases.

Further, in the dose distribution measuring apparatus shown in FIG. 12, the signal extracting wiring such as the optical fiber 106 is arranged in the radiation irradiation range, and therefore, damage and noise due to the radiation are prevented. Can occur.

Further, as another example, when a so-called flat panel detector using a semiconductor detector is used instead of the scintillation detector, a large number of fine two-dimensional sensors are required, resulting in a very high cost. was there.

The present invention has been made in view of the above technical problems, and an object thereof is to provide a high-performance and inexpensive dose distribution measuring apparatus.

[0011]

According to a first aspect of the present invention, in a dose distribution measuring apparatus for detecting and measuring a dose distribution of radiation emitted from a predetermined radiation source, a plurality of line sensors are adjacent to each other and are the same. The radiation detecting means, which is arranged along the direction and constitutes a radiation irradiation surface facing the radiation source, and which detects a one-dimensional dose distribution, and the radiation detection means intersect perpendicularly to the radiation irradiation surface. A rotation driving means for rotating and driving a predetermined rotation angle about the axis;
Rotation angle detection means for detecting the rotation angle of the radiation detection means, and one-dimensional dose distribution data detected by the radiation detection means and rotation detected by the rotation angle detection means for each rotation driving step by the rotation driving means. And a dose distribution deriving unit for deriving a two-dimensional dose distribution on a radiation irradiation surface of the radiation detection unit based on the one-dimensional dose distribution data and the rotation angle data stored in the storage unit. It is characterized by doing.

A second invention of the present application is the same as the first invention, wherein an amount proportional to the integrated value of the one-dimensional dose distribution is stored for each rotation angle and reflected in the dose distribution deriving means. It is characterized by that.

Further, a third invention of the present application is the same as the first or second invention, wherein the storage means includes the one-dimensional dose distribution data detected by the radiation detection means and the rotation detected by the rotation angle detection means. Along with the angle data, the time information at the time when the one-dimensional dose distribution data and the rotation angle data are detected is stored.

Further, a fourth invention of the present application is characterized in that, in any one of the first to third inventions, the radiation detecting means is a solid-state detector.

Further, a fifth invention of the present application is characterized in that, in any one of the first to third inventions, the radiation detecting means is a gas detector.

Furthermore, a sixth invention of the present application is a dose distribution measuring device for detecting and measuring a dose distribution of radiation emitted from a predetermined radiation source, the dose distribution measuring devices being adjacent to each other and arranged in the same direction, Radiation measurement is performed on a plurality of ducts that constitute a radiation irradiation surface facing the radiation source and through which a predetermined fluid medium passes, and the fluid medium that has been activated by radiation through the ducts. Radiation detecting means including a radiation measuring device for obtaining a three-dimensional dose distribution, and rotation driving means for rotating the duct by a predetermined rotation angle about an axis perpendicular to the radiation irradiation surface,
The rotation angle detecting means for detecting the rotation angle of the duct, the one-dimensional dose distribution data detected by the radiation detecting means, and the rotation angle data detected by the rotation angle detecting means for each rotation driving step by the rotation driving means. And a dose distribution deriving unit for deriving a two-dimensional dose distribution on the radiation irradiation surface based on the one-dimensional dose distribution data and the rotation angle data stored in the storage unit. It is what

[0017]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. Embodiment 1. FIG. 1 is a diagram showing a radiation diagnostic apparatus having a configuration for performing dose distribution measurement according to the first embodiment of the present invention. The radiation diagnostic apparatus irradiates the inspection object 20 (inspection person or inspection object) with radiation 2 such as X-rays, detects the radiation 2 transmitted from the back surface of the inspection object 20, and detects the detected radiation. 2 is a device for determining the state of the object to be inspected 20 based on the distribution of 2, so that the normal tissue other than the cancer cells is not irradiated with the radiation prior to the irradiation of the object to be inspected 20, and the irradiation site. In order to make the radiation dose uniform, a function to perform a dose distribution measurement to calculate a desired dose distribution in advance using a predetermined device and to confirm whether or not this dose distribution is realized is provided.

The radiation diagnostic apparatus has, as its basic configuration, a radiation source 1 for generating a radiation 2, an intensity monitor 3 for detecting a temporal change in the intensity of the radiation 2, and an intensity monitor 3, which are connected to each other to control irradiation. A radiation detector comprising a control / dose distribution calculating means 4 for performing measurement control and dose distribution calculation, and a solid or gas detector arranged to face the radiation source 1 via the intensity monitor 3 and detecting incident radiation 2. 5 and
It has a signal processing / storing means 6 for processing / storing an electric signal based on the detected radiation 2, and a rotation angle detecting means 9 connected to the control / dose distribution calculating means 4.

The radiation detector 5 may be a solid-state detector such as a photodiode or a gas detector such as a parallel plate ionization chamber. The signal processing / storing means 6 is
Although not shown in particular, for example, it is composed of a signal amplifier, a power source for the radiation detector 5, a CPU and the like. Further, the control / dose distribution calculating means 4 is composed of, for example, a computer in which a software program for executing dose distribution control and calculation is installed. Between the control / dose distribution calculating means 4 and the signal processing / storing means 6, although not shown in particular, it is possible to transfer the dose measurement data and the like by using a communication method such as wireless LAN or infrared communication.

In this embodiment, the radiation diagnostic apparatus is
In addition to the above-described configuration, the radiation detector 5 has a rotation driving means 13 including a rotation shaft 11, a support 12 and a motor as a configuration capable of driving the radiation detector 5 to rotate. With reference to FIG. 2, the radiation detector 5 and a configuration capable of driving the radiation detector 5 will be described. The radiation detector 5 is configured by arranging a plurality of line sensors 5a each having a dose measurement width W and a dose measurement length L arranged in substantially the same plane in the same direction. A signal line 16 is connected to each line sensor 5a, and one end of each signal line 16 is connected to the signal processing / storing means 6.

The radiation detector 5 composed of the line sensor 5a is a support plate 1 attached to the upper end of a rotary shaft 11 which is rotationally driven by a rotary drive means 13.
4 are arranged on the above. According to such a configuration, the radiation detector 5 and the support plate 14 can be integrally driven to rotate about the extension line of the rotating shaft 11. In this embodiment, although not particularly shown, the signal processing / storing means 6 is supported by the support plate 14, and the signal processing / storing means 6 can be rotationally driven together with the radiation detector 5. The radiation detector 5 and the signal processing / storing means 6 are rotated intermittently or continuously.

The operation of radiation dose distribution measurement will be described. As can be seen from FIG. 1, the beam-shaped radiation 2 generated by the radiation source 1 is applied to the inspection object 20. that time,
The intensity monitor 3 monitors the time change of the radiation intensity during the measurement. Radiation 2 transmitted through the inspection object 20
Is incident on the radiation detector 5, and a signal such as an electric signal or a light emission signal corresponding to the amount of radiation incident on the detector is induced in the line sensor 5a of the radiation detector 5, and the signal line 1
It is collected in the signal processing / storage means 6 via 6.

As described above, the line sensor 5a, the support plate 14, and the signal processing / storing means 6 are integrated into one unit.
It can be rotationally driven around an extension of the rotary shaft 11, and every time these are driven by a predetermined rotational angle, the radiation detector 5 measures the radiation. That is, at each stop position after driving, the output signal obtained from each stop position and each line sensor 5a of the radiation detector 5 and accurate time information at the time of measurement are collected in the signal processing / storing means 6. To be done. At the same time, when the intensity of the radiation 2 from the radiation source 1 changes with time, the intensity signal monitored by the intensity monitor 3 is also stored in the control / dose distribution calculating means 4 together with the time information.

The number of rotation driving steps required to be measured and each line sensor 5a in the radiation detector 4
Is determined based on the required spatial resolution in the measurement plane. For example, when the number of line sensors 5a in the measurement range is 300 and the number of angles at which the measurement is performed is 360 points, the measurement is performed at every rotation angle of 1 degree.

The information collected by the measurement is transferred to the control / dose distribution calculation means 4 through a predetermined communication means, processed by the same method as the principle of computer tomography (CT), and processed by the line sensor. The two-dimensional dose distribution in the measurement plane where 5a is arranged is obtained by reconstruction.

A method of measuring the dose distribution by the radiation detector 5 which can be rotationally driven will be described with reference to FIGS. FIG. 3 is a plan view of the radiation detector 5. As shown in FIG. 3, the radiation detector 5 has a dose measurement width W.
And a plurality of line sensors 5a having a dose measurement length L. 2 and 3, the line sensor 5a forming the radiation detector 5 is simplified and shown by five and nine lines, respectively.

In this embodiment, the radiation detector 5 is rotationally driven by a predetermined angle, measurement is performed at each position for each rotational driving, and the CT method is used to allow the radiation to be transmitted through the object 20 to be inspected. The intensity distribution of the emitted radiation on the two-dimensional plane is measured and evaluated. Note that in normal CT, the radiation absorptance at each point in a predetermined cross section of the inspected object 20 is obtained, and these are reconstructed to perform cross-section imaging, but in this embodiment, the inspected object 20 is The transmitted radiation intensity distribution is detected. FIG. 4 shows an example of the intensity distribution of the radiation transmitted through the inspection object 20 in contour lines. The outer perfect circle represents the boundary of the measurement area. As shown in this figure, the radiation detector 5 is placed at a predetermined position.
When the intensity of radiation is measured using the line sensor 5a
A signal obtained by integrating the transmitted radiation intensity by an amount corresponding to the length of is obtained.

Next, when the radiation detector 5 is rotationally driven within the same plane by a predetermined rotational angle, the corresponding integration region is rotated as shown in FIG.
Here, for the line sensor 5a at the center, for example, the integrated value of the dose of the portion indicated by the thick line is the sensor output. The sensor output at this time is similar to the sensor output obtained when a normal CT as shown in FIG. 6 is performed. This makes it possible to reconstruct the radiation dose distribution from the output of the line sensor 5a using CT. In FIG. 6, as the sensor rotates, for example, the central line sensor 5
Regarding a, it corresponds to a value obtained by removing the integrated value of the radiation absorption amount in each part of the portion indicated by the thick line of the inspection object 20 in the length direction of the line sensor 5a from the radiation incident amount, that is, the radiation transmission amount. While the amount is the sensor output, in FIG. 5, the amount corresponding to the integrated value in the length direction of each line sensor 5a of the radiation dose irradiated to each line sensor 5a indicated by the thick line is the sensor output. Become. Since the difference in the sensor output corresponds to the difference in the distribution amount to be obtained for each, the CT method can be applied. The sectional structure of the inspection object shown in FIG. 6 is similar to the radiation intensity distribution shown in FIGS. 4 and 5 for convenience. The dose distribution may be read as the radiation intensity distribution.

As described above, the radiation intensity distribution is measured at a plurality of rotation angle positions using the radiation detector 5 in which the line sensors 5a are arranged in the one-dimensional direction, and the obtained data is used as the rotation angle. And the time information, the two-dimensional dose distribution within a predetermined plane is acquired by collecting the information in the signal processing / storing means 6 and processing the collected information according to the same principle as CT. In this embodiment, it is not necessary to use the conventional sensors arranged in a matrix, wiring can be simplified, and the number of signal processing circuits can be reduced. Thereby, the manufacturing cost can be reduced.

The radiation detector 5 composed of the line sensor 5a is rotationally driven to measure the dose distribution.
Especially when applied to an X-ray photograph where high spatial resolution is required, a great effect is brought about.

In the above embodiment, the signal processing /
Although the storage means 6 is supported by the support plate 14 and is driven to rotate together with the radiation detector 5, the signal processing / storage means 6 is not limited to this.
However, it may be configured such that it does not rotate together with the radiation detector 5. In this case, the radiation detector 5 may be rotated stepwise rather than continuously, and the measurement may be performed for each angle.

Further, in order to drive the radiation detector 5 to rotate, as shown in FIG. 7, a bearing structure for rotating the support plate 14, the radiation detector 5 and the signal processing / storing means 6 may be adopted. The support plate 14 and the radiation detector 5 are fixed to the inner ring 23 of the bearing 22, and are rotationally driven by the rotational driving means (not shown). The outer ring of the bearing 22 is omitted and not shown. When such a bearing structure is adopted, it becomes possible to measure the two-dimensional cross-sectional distribution of the radiation passing therethrough. By adopting this in various devices and systems that use radiation, the dose distribution of radiation can be monitored. In this case, the radiation detector 5
For this, it is desirable to use a thin radiation detecting element such as a parallel plate ionization chamber. Then, the radiation detector 5 is continuously rotated, and the measured data is transferred to the control / dose distribution calculating means 4 by using the communication function mounted in the signal processing / storing means 6, and the two-dimensional cross section of the radiation or the like is transmitted. The distribution is calculated and acquired based on the CT principle. It can also function as a monitor for the beam cross-sectional intensity distribution incorporated in equipment such as accelerators and lasers.

In the above embodiment, when the radiation detector 5 is continuously rotated, wireless or infrared rays are used to transfer the measurement data from the signal processing / storing means 6 to the control / dose distribution calculating means 4. However, the present invention is not limited to this, and the measurement signal may be taken out by using, for example, a rotary brush used in a conventionally known DC motor.

Furthermore, in the above embodiment, a gas detector such as a parallel plate ionization chamber or a solid detector such as a photodiode is used as the radiation detector 5, but the radiation detector 5 is not limited to this, and for example, scintillation detection is performed. The same effect can be obtained by using another detector such as a container. In this case, an optical fiber may be used as the signal line 16 between the radiation detector 5 and the signal processing / storage device 6.

Another embodiment of the present invention will be described in detail below. The same components as those in the above embodiment are designated by the same reference numerals, and further description will be omitted. Embodiment 2. FIG. 8 is a diagram schematically showing a radiation irradiation apparatus having a configuration for performing dose distribution measurement according to the second embodiment of the present invention. In the second embodiment, a disk-shaped support plate 34 that can be rotationally driven by the rotational driving means 13 is provided, and the radiation detector 5 including a plurality of line sensors 5a is provided at an upper side of a predetermined thickness. It is disposed on the support plate 34 in a state of being sandwiched between the lower acrylic plates 35 and 36.

In the second embodiment, when the radiation 1 passes through the intensity monitor 3 and is applied to the configuration including the upper acrylic plate 35, the radiation detector 5, and the lower acrylic plate 36, the substances of each component are emitted. A radiation dose distribution is formed therein. Then, while rotating the upper acrylic plate 35, the radiation detector 5, and the lower acrylic plate 36 by the rotation driving means 13, by measuring the dose distribution at each position,
The two-dimensional dose distribution is measured as in the first embodiment. In the second embodiment, the upper acrylic plate 3
A three-dimensional radiation dose distribution can be measured by changing the thickness T of No. 5 and similarly performing the dose distribution measurement.

Further, in the second embodiment, the signal line 16
Can be connected to the line sensor 5a constituting the radiation detector 5 outside the range where the radiation is irradiated, so that the deterioration of the signal line 16 and the generation of noise due to the radiation can be suppressed. As a result, the reliability of the device can be improved.

The upper acrylic plate arranged on the radiation incident side of the radiation detector 5 is not limited to a single plate, and a variable thickness energy compensator (not shown) composed of a plurality of acrylic plates can be used. (3) can be used to measure a three-dimensional radiation dose distribution.

Embodiment 3. FIG. 9 is a diagram schematically showing a radiation irradiation apparatus having a configuration for performing dose distribution measurement according to the third embodiment of the present invention. In the third embodiment, the radiation irradiation apparatus includes a water tank 41 arranged on the support plate 34, and the water in the water tank 41 is used instead of the upper acrylic plate 35 in the second embodiment. It The radiation detector 5 is housed in the water tank 41,
Water 1 is stored so that the incident surface of the radiation detector 5 is located below the water surface.

Further, the radiation detector 5 and the lower acrylic plate 36 are supported on the support plate 34 through the height adjusting means 43 which is vertically expandable and contractible. By expanding and contracting the height adjusting means 43, the depth D from the water surface to the incident surface of the radiation detector 5 can be changed in the water tank 41, and as a result, the dose distribution at each depth is measured. It becomes possible to measure the three-dimensional dose distribution.

Fourth Embodiment FIG. 10 is a diagram schematically showing a radiation irradiation apparatus having a configuration for performing dose distribution measurement according to the fourth embodiment of the present invention. In the fourth embodiment, the upper and lower acrylic plates 3 are provided on the support plate 34.
5, 36, a plurality of ducts 51 arranged in the same direction between both acrylic plates, and a side wall member 52 attached so as to cover both outer ducts 51 along the sides of the acrylic plates 35, 36. These are provided and can be rotationally driven as the support plate 34 is rotationally driven by the rotational driving means 13.

Further, in the fourth embodiment, each duct 5
1, the pipe member 57 is attached so as to communicate in a liquid-tight or air-tight manner. In addition, in order to clarify the drawing, FIG. 10 shows only one pipe member 57. A circulation pump 55 (or a water source) and a radiation measuring device 60 are provided in the middle of each pipe member 57. Then, at the time of measurement, water is flown into the duct 51 and the pipe member 57. Radiation 2 emitted from carbon or the radiation source 1 is incident on water in the duct 51 and reacts with oxygen nuclei in the water to generate a radionuclide that causes positron decay. The generated radionuclide (for example, 13N) is carried to the radiation measuring instrument 60 by the water flowing in the duct 51 and the pipe member 57. Here, the circulation pump 55 and the radiation measuring device 60 are also supported on a support member 59 which is rotationally driven by the rotational drive means 13, and each component on the support plate 34 (upper and lower acrylic plates 35, 36). , Duct 5
1, together with the side wall member 52, can be rotationally driven.

FIG. 11 shows the internal structure of the radiation measuring instrument 60. In the radiation measuring device 60, the detection element 61 is provided for each pipe member 57, and in order to ensure a predetermined detection accuracy, the detection element 61 and the pipe member 57 are separated from each other by a shield plate 62 such as a lead plate. Has been done. Duct 51
The radionuclide generated as described above under positron decay in the space of the radiation measuring instrument 60, and the positron generated at this time is annihilated with the nearby electron to generate γ.
Line pairs (ie annihilation gamma ray pairs) are counted. In this way, a one-dimensional dose distribution of the production amount of radionuclide such as 13N in the plane between the upper and lower acrylic plates 35 and 36 is obtained.

The rotation drive means 13 rotates the upper and lower acrylic plates 35, 36, the duct 51, the pipe member 57, the radiation measuring device 60, and the circulation pump 55 (or the water source) by a predetermined angle, and similarly. The one-dimensional dose distribution of the radionuclide generated as described above is measured. Using the measured one-dimensional dose distribution, the recorded rotation angle information, etc., the two-dimensional distribution of radionuclides in the measurement plane can be reconstructed in the same manner as the CT principle.

The water flowing through the duct 51 and the pipe member 57 may be disposable or may be reused in a circulating manner in consideration of the half life of 13N.

As described in the second embodiment, if the thickness T of the upper acrylic plate 35 is changed and the measurement of the two-dimensional dose distribution is repeated, the three-dimensional dose distribution of the radionuclide production amount can be obtained. It is possible. In order to improve the spatial resolution, the diameter of the pipe member 57 may be reduced.
Alternatively, the number of rotation angle steps by the rotation driving means 13 may be increased.

From the obtained three-dimensional distribution of the radionuclide, it is possible to estimate the three-dimensional dose distribution of the actually irradiated radiation 2 or the dose distribution. However, in this case, it is necessary to fully understand the details of possible nuclear reactions.

According to the fourth embodiment, the two-dimensional or three-dimensional distribution of the short-lived radionuclide produced in the substance is measured even when a particle beam such as a proton beam is applied to the acrylic plate or the water tank. There is an effect that can be done. Conventional PET (positron
Since the distribution of positron emission nuclei in a substance such as water can be measured without using an emission tomography device, the cost of the measurement system can be reduced.

In the fourth embodiment, water is used as the medium flowing in the duct 51 and the pipe member 57.
Without being limited to this, the two-dimensional dose distribution of the activated nuclei can be measured by using another medium such as oxygen gas. Further, in the above description, in order to measure the dose distribution, it was explained that the radioactive decay of the generated nuclei was measured, but the chemical or physical property of the product is used, and other measuring instruments such as a gas separation filter are used. May be used for detection.

Needless to say, the present invention is not limited to the illustrated embodiments, and various improvements and design changes can be made without departing from the gist of the present invention. Any of the dose distribution measuring devices described in the above-described embodiments can be incorporated into various devices such as a radiation diagnostic inspection device and a radiation treatment device.

[0051]

According to the first invention of the present application, the radiation intensity distribution is measured at a plurality of rotation angle positions by using the radiation detecting means in which the line sensors are arranged in the one-dimensional direction,
The obtained data is collected together with the rotation angle in the signal processing / storing means, and the collected information is processed according to the same principle as CT to obtain a two-dimensional dose distribution within a predetermined plane. Since it is not necessary to use the sensors arranged in a matrix, the wiring can be simplified and the number of signal processing circuits can be reduced. Thereby, the manufacturing cost can be reduced.

According to the second invention of the present application, the above-mentioned 1
An amount proportional to the integral value of the dimensional dose distribution can be stored for each rotation angle and reflected in the dose distribution deriving means to obtain the two-dimensional dose distribution.

Further, according to a third invention of the present application, in the first or second invention, the storage means is detected by the one-dimensional dose distribution data detected by the radiation detection means and the rotation angle detection means. Since the time information at the time when the one-dimensional dose distribution data and the rotation angle data are detected is stored together with the rotation angle data, a highly accurate two-dimensional dose distribution can be realized.

Further, according to the fourth invention of the present application,
A solid-state detector such as a photodiode can be used as the radiation detecting means.

Further, according to the fifth invention of the present application,
A gas detector such as a parallel plate ionization chamber can be used as the radiation detecting means.

Further, according to the sixth invention of the present application,
A plurality of ducts which are adjacent to each other and arranged in the same direction to form a radiation irradiation surface facing the radiation source and through which a predetermined fluid medium passes, and a plurality of ducts which have been activated through the ducts Radiation measurement is performed on a fluid medium,
The radiation intensity distribution is measured at a plurality of rotation angle positions by using the radiation detection means provided with a radiation measuring device for obtaining a one-dimensional dose distribution, and the obtained data is stored in the signal processing / storing means together with the rotation angle. By collecting and processing the collected information according to the same principle as CT, a two-dimensional dose distribution within a predetermined plane is acquired, so there is no need to use conventional sensors arranged in a matrix, and wiring is possible. Can be simplified and the number of signal processing circuits can be reduced. Thereby, the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a radiation diagnostic apparatus having a configuration for performing dose distribution measurement according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration for performing the dose distribution measurement.

FIG. 3 is a plan view showing a radiation detector including a plurality of line sensors.

FIG. 4 is a diagram showing an intensity distribution of radiation transmitted through an inspection object.

FIG. 5 is an explanatory diagram of a measurement procedure of intensity distribution.

FIG. 6 is an explanatory diagram of a measurement procedure of radiation that has passed through an object to be inspected by CT.

FIG. 7 is a diagram schematically showing a modification of the rotary drive mechanism in the configuration for performing dose distribution measurement.

FIG. 8 is a diagram schematically showing a radiation irradiation apparatus having a configuration for performing dose distribution measurement according to the second embodiment of the present invention.

FIG. 9 is a diagram schematically showing a radiation irradiation apparatus having a configuration for performing dose distribution measurement according to a third embodiment of the present invention.

FIG. 10 is a diagram schematically showing a radiation irradiation apparatus having a configuration for performing dose distribution measurement according to a fourth embodiment of the present invention.

FIG. 11 is a diagram showing an internal structure of a radiation measuring instrument incorporated in a configuration for performing dose distribution measurement according to the fourth embodiment.

FIG. 12 is a diagram schematically showing a conventional dose distribution measuring device.

[Explanation of symbols]

1 radiation source, 2 radiation, 4 control / dose distribution calculation means, 5 radiation detector, 5a line sensor, 6 signal processing / storage means, 9 rotation angle detection means, 13 rotation drive means, 35, 36 acrylic plate, 51 duct , 55
Circulation pump, 57 pipe members, 60 Radiation measuring instrument

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G088 EE01 FF02 GG01 GG19 GG21                       JJ04 JJ09                 4C082 AC02 AE01 AP03                 4C093 AA25 CA01 CA32 EB12 EB13                       EB14 EB17 EB18 EB20 EB28                       FA32 FA55 FE01 FH06

Claims (6)

[Claims] 1. A dose distribution measuring device for detecting and measuring a dose distribution of radiation emitted from a predetermined radiation source, wherein a plurality of line sensors are arranged adjacent to each other in the same direction, Radiation detecting means for forming opposing radiation radiating surfaces and rotation for rotating the radiation detecting means for detecting a one-dimensional dose distribution by a predetermined rotation angle about an axis perpendicular to the radiation radiating surface. The driving means, the rotation angle detecting means for detecting the rotation angle of the radiation detecting means at each rotation driving step by the rotation driving means, the one-dimensional dose distribution data and the rotation angle detecting means detected by the radiation detecting means. A storage unit that stores the detected rotation angle data, and an upper portion based on the one-dimensional dose distribution data and the rotation angle data stored in the storage unit. Dose distribution measuring apparatus characterized by having a dose distribution deriving means for deriving a two-dimensional dose distribution in radiation surface of the radiation detecting means. 2. The dose distribution measuring device according to claim 1, wherein an amount proportional to an integral value of the one-dimensional dose distribution is stored for each rotation angle and reflected in the dose distribution deriving means. 3. The storage means detects the one-dimensional dose distribution data and the rotation angle data together with the one-dimensional dose distribution data detected by the radiation detection means and the rotation angle data detected by the rotation angle detection means. The dose distribution measuring device according to claim 1, characterized in that time information at the time point of storage is stored. 4. The dose distribution measuring device according to claim 1, wherein the radiation detecting means is a solid-state detector. 5. The dose distribution measuring device according to claim 1, wherein the radiation detecting means is a gas detector. 6. A dose distribution measuring device for detecting and measuring a dose distribution of radiation emitted from a predetermined radiation source, the radiation irradiation surface being arranged adjacent to each other along the same direction and facing the radiation source. Constituting a plurality of ducts through which a predetermined fluid medium is passed, and performing radiation measurement on the fluid medium that has been activated by passing through the duct,
A radiation detecting means including a radiation measuring device for obtaining a one-dimensional dose distribution; a rotation driving means for rotating the duct by a predetermined rotation angle about an axis perpendicular to the radiation irradiation surface; Rotation angle detection means for detecting the rotation angle of the duct for each rotation drive step by the rotation drive means, one-dimensional dose distribution data detected by the radiation detection means, and rotation angle data detected by the rotation angle detection means. And a dose distribution deriving unit for deriving a two-dimensional dose distribution on the radiation irradiation surface based on the one-dimensional dose distribution data and the rotation angle data stored in the storage unit. Dose distribution measuring device.