JP4288351B2 - System for simultaneous measurement of target organ and dose distribution during irradiation - Google Patents

Description

  The present invention relates to a method for measuring a target organ and a dose distribution at the time of radiotherapy capable of displaying in real time an organ position and radiation dose distribution in the body for cancer treatment and the like, and an apparatus for measuring the same.

  As a method of treating cancer, there is radiation therapy, and charged particle beams such as proton beams are used in addition to X-rays and gamma rays. In radiotherapy, it is important that the position and shape of the cancer and the position and shape of the high-dose region of radiation coincide with each other with high accuracy.

  In radiotherapy, the position and shape of the cancer are grasped in advance by an X-ray computed tomography (CT), and then the irradiation condition is optimized and the radiation dose distribution is calculated by the treatment planning device. A means for confirming whether the dose distribution of radiation formed in the body is as planned has not been established.

As described in Patent Document 1, the body dose distribution grasping means is generated from an accelerating means for accelerating a charged particle beam, a means for transporting and ejecting the charged particle beam, and a portion irradiated with the charged particle beam. An invention of a medical charged particle beam apparatus comprising a means for detecting an acoustic signal, a calculating means for obtaining an irradiation location, and a means for recording the irradiation location is also disclosed.
JP-A-10-52509

  However, in the invention described in Patent Document 1, an organ is imaged in advance with an X-ray computed tomography apparatus (CT), and a dose distribution is obtained by irradiating radiation such as a proton beam later. There is a time lag and the accuracy is poor.

  In the case of X-rays and gamma rays, the relative dose near the surface is strong and weakens as it enters the body, affecting cells other than cancer. Proton beams that can be matched are more suitable.

  Therefore, the present invention provides a target at the time of radiotherapy capable of displaying in real time information on the position and shape of organs in the body and dose distribution information by proton beams in order to improve the accuracy of radiotherapy for cancer. It is an object of the present invention to provide a method for measuring organs and dose distribution simultaneously and a measuring apparatus therefor.

  In order to solve the above-mentioned problems, the present invention is an organ information detecting means for transmitting and receiving ultrasonic waves by an ultrasonic detector, and transmission of the ultrasonic detector is stopped and generated by irradiation with radiation such as a proton beam. Dose distribution information detection means for receiving acoustic waves by the ultrasonic detector, recording means for storing information detected by the organ information detection means and dose distribution information detection means in a computer, and recorded organ information and dose distribution information A method for simultaneous measurement of a target organ and a dose distribution during radiation therapy, and beam transport from an accelerator, characterized in that it comprises a computing means for editing and imaging an image with a computer and a visualization means for displaying the imaged information on a screen Radiation apparatus for irradiating proton beam or other radiation through the system, reflected wave of ultrasonic wave transmitted from the ultrasonic detector, and irradiation of proton beam or the like from the radiation apparatus An ultrasonic device that receives the generated acoustic wave, a storage device that stores organ information and dose distribution information detected by the ultrasonic device, a central processing unit that images the stored information, and imaged information are displayed. The apparatus comprises a computer having an output device, and is configured to simultaneously measure a target organ and a dose distribution during radiotherapy.

  Since this invention is the above structure, the following effects are acquired. First, it is possible to confirm the dose distribution by proton beam irradiation while grasping the organ position with ultrasound. Since superimposition can be performed in real time, highly accurate treatment can be performed.

  If you irradiate a proton beam while transmitting and receiving ultrasound, it will be received in a state where the reflected waves of the ultrasound are mixed, so when irradiating radiation, stop transmitting the ultrasound and reflect the reflected wave of the proton beam. Only to receive.

  Hereinafter, based on the attached drawings, a method for simultaneously measuring a target organ and a dose distribution at the time of radiotherapy according to the present invention and a measurement apparatus therefor will be described in detail. FIG. 1 is a flowchart showing a work procedure of a method for simultaneously measuring a target organ and a dose distribution during radiotherapy according to the present invention.

  The simultaneous measurement method 1 of the target organ and the dose distribution at the time of radiotherapy includes the organ information detection 2 means for transmitting and receiving ultrasonic waves by the ultrasonic detector 4a, the transmission of the ultrasonic detector 4a is stopped, and a proton beam or the like The dose distribution information detection 2a means for receiving the acoustic wave generated by the irradiation of the radiation by the ultrasonic detector 4a, and the information stored in the organ information detection 2 means and the dose distribution information detection 2a means are stored in the computer 5 2b means, a computing means 2c for editing and recording the recorded organ information 7b and dose distribution information 7c by the computer 5, and a visualization means 2d for displaying the imaged information on a screen.

  In the simultaneous measurement method 1 of the target organ and the dose distribution at the time of radiotherapy, as the radiation, a proton beam capable of adjusting a high dose region to a specific position in the body by the intensity of energy is used. Measured in combination with

  In the organ information detection 2 means, an ultrasonic wave is irradiated into the body from the ultrasonic detector 4a of the ultrasonic device 4, and a reflected wave bounced off the internal organ 6a is detected by a sensor of the ultrasonic detector 4a. The ultrasonic detector 4a transmits reflected ultrasonic waves simultaneously with transmitting ultrasonic waves.

  The ultrasonic wave is a sound wave that is not felt by human ears, and a frequency in the megahertz band is used in ultrasonic diagnosis. When an ultrasonic wave is propagated in the body, a reflected wave is obtained at an interface having different acoustic characteristics of the tissue.

  By irradiating with ultrasonic waves and measuring the time when the reflected wave returns, the position reflected in the body can be determined. The acoustic lens mounted in the ultrasonic detector 4a gives directivity to the ultrasonic wave, and beam scanning by the arrayed acoustic element array in the ultrasonic detector 4a makes it possible to base the reflected wave in each direction. A two-dimensional image including the position and shape information of the organ 6a is acquired.

  In the dose distribution information detection 2a means, a proton beam is irradiated into the body from the accelerator 3a of the radiation apparatus 3, and an acoustic wave generated in the body is detected by a sensor of the ultrasonic detector 4a. The ultrasonic detector 4a stops transmitting ultrasonic waves and only receives acoustic waves.

  The radiation includes radio wave radiation that is X-rays or gamma rays, charged particle beams such as alpha rays, beta rays, electron beams 8d, or proton beams, and uncharged particle beams that are neutron beams. Then, a charged particle beam such as a proton beam is used.

  Regarding the distribution of the dose 6b indicating the degree of irradiation, X-rays, gamma rays or neutron rays are strongest near the surface of the body and become weaker as they enter the body. A charged particle beam such as a proton beam suddenly becomes strong at a position at a depth corresponding to energy, and is weak before and after that position.

  When a charged particle beam such as a proton beam is irradiated into the body, expansion in proportion to the dose distribution occurs at each point, and an acoustic wave is generated. Since the acoustic wave is generated as a sound wave having the same frequency as the frequency characteristic of the radiation, the ultrasonic device 4 can measure the sound wave having a frequency in the same range as the ultrasonic wave.

  The proton beam is ionizing radiation having a large transmission power obtained by accelerating protons, which are positively charged particles obtained by taking electrons from hydrogen atoms, to high energy by an accelerator 3a such as a synchrotron, and has a beam intensity oscillation of several megahertz.

  If a proton beam having a beam intensity vibration of several megahertz is used, it is possible to confirm the position of the organ 6a in the body with the ultrasonic device 4 and also to confirm the dose 6b distribution by the proton beam. The relationship of the dose 6b distribution can be grasped accurately and easily.

  The recording 2b means captures the organ information 7b detected by the organ information detection 2 means and the dose distribution information 7c detected by the dose distribution information detection 2a means into the computer 5 and stores them in the storage device 5b of the computer 5.

  The calculation 2c means obtains information necessary for imaging by the central processing unit 5a of the computer 5 based on the organ information 7b and the dose distribution information 7c stored in the storage device 5b of the computer 5 by calculation. The calculation result is also stored in the storage device 5b.

  The visualization 2d means superimposes the dose distribution information 7c on the imaged organ information 7b after performing image processing such as color coding, and displays the superimposed information on the output device 5c of the computer 5.

  FIG. 2 is an overall view of a simultaneous measurement apparatus for target organ and dose distribution during radiotherapy according to the present invention, and FIG. 3 is an outline of the simultaneous measurement apparatus for target organ and dose distribution during radiotherapy according to the present invention. FIG. 4 is a block diagram showing a configuration of a simultaneous measurement apparatus for a target organ and a dose distribution during radiotherapy according to the present invention.

  The target organ and dose distribution simultaneous measurement apparatus 1a at the time of radiation therapy includes a radiation apparatus 3 that performs radiation irradiation such as a proton beam from an accelerator 3a via a beam transport system 3c, and an ultrasonic wave transmitted from the ultrasonic detector 4a. An ultrasonic device 4 that receives reflected waves and acoustic waves generated by irradiation of radiation such as proton beams from the radiation device 3, and a storage device that stores organ information 7b and dose distribution information 7c detected by the ultrasonic device 4. 5b, comprising a central processing unit 5a for imaging the stored information and a computer 5 having an output unit 5c for displaying the imaged information.

  As shown in FIG. 2, the radiation apparatus 3 accelerates particles such as protons with an accelerator 3a, and irradiates a patient 6 with a particle beam from an irradiation unit 3b via a beam transport system 3c. It should be noted that the position where the radiation such as a proton beam is applied and the intensity of the energy are grasped by the ultrasonic device 4.

  The accelerator 3a is a device for applying a kinetic energy to charged particles to accelerate and obtain a high energy particle beam. Examples of the circular accelerator that accelerates while making a circular motion include a cyclotron, a synchrotron, and a betatron.

  The ultrasonic device 4 transmits and receives ultrasonic waves using the ultrasonic detector 4a. The ultrasonic detector 4 a is connected to the computer 5, and the received data is sent to the computer 5. Moreover, the frequency of the ultrasonic wave emitted from the ultrasonic detector 4a can be changed by the computer 5.

  The position of the organ 6a in the body can be grasped by emitting ultrasonic waves from the ultrasonic detector 4a and measuring the reflected waves. By imaging the position of the organ 6a on the screen 7 of the computer 5, the irradiation position of a proton beam or the like can be determined.

  As shown in FIG. 3, the information obtained by applying the ultrasonic detector 4a of the ultrasonic device 4 to the patient 6 and transmitting / receiving ultrasonic waves is processed by the computer 5, and the position of the organ 6a can be visually confirmed. As shown in FIG.

  Based on the grasped organ information 7b, the position where the radiation such as a proton beam is applied and the intensity of the irradiated energy are determined. An acoustic wave generated by the irradiated proton beam or the like is detected by the ultrasonic detector 4a, and the dose distribution information 7c is processed by the computer 5.

  By displaying the dose distribution information 7c superimposed on the imaged organ information 7b, the organ information 7b and the dose distribution information 7c can be confirmed simultaneously. Further, since the organ information 7b and the dose distribution information 7c are detected by the same ultrasonic detector 4a, they can be displayed in real time.

  As shown in FIG. 4, the ultrasonic detector 4a includes a transmission unit 4c that irradiates ultrasonic waves and a reception unit 4b that detects ultrasonic waves. The ultrasonic waves emitted from the transmission unit 4c and the ultrasonic waves that can be detected by the reception unit 4b are ultrasonic waves in the megahertz band.

  The transmission unit 4c irradiates the body with ultrasonic waves, and the reception unit 4b detects a reflected wave bounced off when the ultrasonic waves irradiated by the transmission unit 4c hit the internal organ 6a. In addition, acoustic waves generated in the body by irradiation with proton beams or the like are also detected.

  Basically, the transmitter 4c emits ultrasonic waves and the reflected ultrasonic waves are measured by the receiver 4b. When measuring ultrasonic waves generated by another sound source, such as ultrasonic waves generated in the body, Irradiation of ultrasonic waves from the transmission unit 4c is stopped to prevent mixing of ultrasonic waves.

  The computer 5 includes a central processing unit 5a, a storage device 5b, an input device, an output device 5c, and the like, like a general computer. Note that the ultrasonic device 4 corresponds to the input device, and organ information 7 b and dose distribution information 7 c are input to the computer 5.

  The central processing unit 5a controls the storage device 5b, the input device or the output device 5c, and calculates or edits data stored in the storage device 5b. The organ information 7b and the dose distribution information 7c input from the ultrasonic device 4 are processed by the central processing unit 5a and visualized 2d.

  The storage device 5b is used as a data storage area or a work area during data processing. The central processing unit 5a stores the organ information 7b and the dose distribution information 7c taken from the ultrasonic device 4, and the processed data is also stored in the same manner.

  The output device 5c displays on the screen 7 organ information 7b and dose distribution information 7c that have been processed visually and easily. The organ information 7b is visualized 2d by the central processing unit 5a, and the dose distribution information 7c is added and displayed.

  FIG. 5 is a graph showing the radiation properties of the method for simultaneously measuring the target organ and the dose distribution during radiotherapy according to the present invention. Because the properties differ depending on the type of radiation, the dose distribution tends to be different. In addition, the graph 8 shows relatively the ratio of the dose 6b according to the depth in the body.

  In the case of the proton beam 8a, the relative dose is relatively weak near the surface and gradually increases, while the relative dose reaches a maximum at a certain depth, and then rapidly decreases. The carbon ion line 8b also shows almost the same tendency as the proton line 8a. The depth at which the relative dose is maximized varies depending on the intensity of energy.

  In the case of the high energy X-ray 8c, the relative dose is strong in the vicinity of the surface, and the relative dose gradually becomes weaker as it gets deeper from the surface. The fast neutron beam 8e shows a tendency similar to that in the case of the high energy X-ray 8c.

  In the case of the electron beam 8d, the relative dose near the surface is strong, and the relative dose becomes weaker as it gets deeper from the surface, similar to the high energy X-ray 8c, but suddenly weakens from the peak and does not reach a deep position. .

  By using the proton beam 8a, it becomes possible to irradiate a specific depth in the body. This is a very effective means especially when it is not desired to have an influence of radiation near the surface or deeper than the irradiation target.

  FIG. 6 is a diagram showing the imaged contents of the method for simultaneously measuring a target organ and a dose distribution during radiotherapy according to the present invention. The content of the screen 7 is the content displayed on the output device 5c of the computer 5 in the simultaneous measurement apparatus 1a for the target organ and dose distribution at the time of radiotherapy.

  In the display area 7a in the screen 7, information on the organ 6a and the dose 6b distribution is displayed. The dose 6b distribution is displayed in a color-coded manner so that it can be easily understood visually. The display area 7a has a fan shape because the ultrasonic detector 4a of the ultrasonic device 4 has directivity.

  The organ information 7b and the dose distribution information 7c are not acquired and superimposed separately, but are real-time information acquired almost simultaneously. The organ 6a always moves, and the patient 6 itself may move, but can respond immediately.

  The organ information 7b can grasp the latest state of the organ 6a position, and it can be confirmed by the dose distribution information 7c which position in the body has been irradiated with radiation such as a proton beam. Useful.

  As described above, the target organ and dose distribution simultaneous measurement method 1 and the measurement apparatus 1a thereof during radiotherapy according to the present invention grasp the position of the organ 6a by ultrasonic waves and at the same time, the dose 6b distribution by proton beam irradiation. Can be confirmed. Since superimposition can be performed in real time, highly accurate treatment can be performed.

It is a flowchart which shows the operation | movement procedure of the simultaneous measurement method of the target organ and dose distribution at the time of the radiotherapy which is this invention. 1 is an overall view of an apparatus for simultaneously measuring a target organ and a dose distribution during radiotherapy according to the present invention. It is the schematic of the simultaneous measurement apparatus of the target organ and dose distribution at the time of the radiotherapy which is this invention. It is a block diagram which shows the structure of the simultaneous measurement apparatus of the target organ and dose distribution at the time of the radiotherapy which is this invention. It is a graph which shows the property of the radiation of the simultaneous measurement method of the target organ and dose distribution at the time of the radiotherapy which is this invention. It is a figure which shows the image content of the simultaneous measurement method of the target organ and dose distribution at the time of the radiotherapy which is this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Simultaneous measurement method of target organ and dose distribution at the time of radiation therapy 1a Simultaneous measurement apparatus of target organ and dose distribution at the time of radiation treatment 2 Organ information detection 2a Dose distribution information detection 2b Recording 2c Operation 2d Visualization 3 Radiation apparatus 3a Accelerator 3b Irradiation 3c Beam transport system 4 Ultrasonic device 4a Ultrasonic detector 4b Receiver 4c Transmitter 5 Computer 5a Central processing unit 5b Storage device 5c Output device 6 Patient 6a Organ 6b Dose 7 Screen 7a Display area 7b Organ information 7c Dose distribution information 8 graph 8a proton beam 8b carbon ion beam 8c high energy X-ray 8d electron beam 8e fast neutron beam

Claims (2)

  An organ information detecting means for receiving the reflected wave of the ultrasonic wave transmitted from the ultrasonic detector by the ultrasonic detector, and stopping the transmission of the ultrasonic detector and irradiating radiation from the accelerator via the beam transport system A dose distribution information detecting means for receiving an acoustic wave generated by the ultrasonic detector, organ information detected by the organ information detecting means, and dose distribution information detected by the dose distribution information detecting means in a computer Radiation comprising recording means, computing means for editing the organ information and dose distribution information with a computer, and imaging means for displaying the imaged organ information and dose distribution information on a screen Simultaneous measurement system of target organ and dose distribution during irradiation.   The simultaneous measurement system of a target organ and a dose distribution at the time of radiation irradiation according to claim 1, wherein the radiation is a proton beam whose depth at which the relative dose becomes maximum varies depending on the intensity of energy.

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