WO2024252737A1 - Système d'irradiation par rayonnement, système de traitement par rayonnement, et procédé d'irradiation par rayonnement - Google Patents

Système d'irradiation par rayonnement, système de traitement par rayonnement, et procédé d'irradiation par rayonnement Download PDF

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WO2024252737A1
WO2024252737A1 PCT/JP2024/006877 JP2024006877W WO2024252737A1 WO 2024252737 A1 WO2024252737 A1 WO 2024252737A1 JP 2024006877 W JP2024006877 W JP 2024006877W WO 2024252737 A1 WO2024252737 A1 WO 2024252737A1
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radiation
irradiation
monitor
parameter
dose
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Japanese (ja)
Inventor
拓人 三好
拓也 野村
高士 豊田
友紀 伊藤
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Hitachi High Tech Corp
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Hitachi High Tech Corp
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy

Definitions

  • the present invention relates to a radiation irradiation system, a radiation therapy system, and a radiation irradiation method.
  • Radiation therapy is a treatment that aims to eradicate tumors and relieve pain by irradiating tumors in the patient's body with radiation such as X-rays, electron beams, proton beams, and heavy particle beams and providing a dose of radiation.
  • radiation therapy involves transporting accelerated radiation (hereafter referred to as beam) from an accelerator system consisting of a linear accelerator or synchrotron to an irradiation nozzle and irradiating the tumor.
  • beam accelerated radiation
  • an accelerator system consisting of a linear accelerator or synchrotron
  • irradiation nozzle There are two main beam irradiation methods: passive and scanning. In the passive method, the beam is expanded using scatterers and collimators to match the shape of the tumor.
  • the scanning method is a method in which the direction of a thin beam called a pencil beam is adjusted by a scanning magnet to sequentially irradiate the entire tumor.
  • the irradiation dose is monitored by a dose monitor on the beam path.
  • the irradiation control device calculates the cumulative dose from the measured value of the dose monitor, and when it is confirmed that the target irradiation dose included in the irradiation instruction data (hereafter referred to as prescription) created in advance by the treatment planning device has been reached, it instructs the transition to the next irradiation or the completion of irradiation. Therefore, to improve the accuracy of dose distribution and thus the effectiveness of treatment, high measurement accuracy is required for the dose monitor.
  • Ionization chambers are widely used for dose monitors.
  • An ionization chamber is a container in which the gap between two or more electrodes is filled with a fluid such as gas or liquid.
  • a fluid such as gas or liquid.
  • an appropriate current-voltage conversion coefficient is set using an analog circuit, etc., taking into account the range of beam dose rates used in treatment and the input voltage that can be applied to the signal processing system.
  • FLASH therapy requires irradiation at a dose rate of approximately 40 Gy/s or more, compared to the conventional dose rate of approximately 1 Gy/min. Therefore, since there is a difference of about 1000 times between conventional dose rates and the dose rate suitable for FLASH, radiation therapy systems compatible with both conventional and FLASH therapy are required to irradiate with high precision over the wide range of dose rates specified.
  • Patent Document 1 discloses a method for monitoring and controlling the irradiation dose with high accuracy, regardless of the dose rate, by connecting multiple systems of current-voltage conversion amplifiers and downstream pulse counters in a dose monitor signal processing system and selecting the system to be used for dose monitoring and control based on dose rate information included in the treatment plan.
  • Patent Document 1 it is necessary to connect multiple signal processing systems for the dose monitor, which increases the equipment and operating costs.
  • This disclosure has been made in consideration of the above circumstances, and discloses a radiation therapy system that enables low-cost, highly accurate beam monitoring at both conventional dose rates and FLASH dose rates by safely switching to monitor system parameters appropriate for the irradiation dose rate based on the treatment plan.
  • the present invention was made in consideration of the above problems, and its purpose is to provide a radiation irradiation system, a radiation therapy system, and a radiation irradiation method that can irradiate radiation of different intensities at low cost and with high reliability.
  • the radiation irradiation system is a radiation irradiation system that irradiates radiation of different intensities to an irradiation target, and includes a radiation monitor unit that detects radiation and acquires radiation information, a monitor control unit that changes the parameter values when the radiation information is detected according to the intensity of the radiation, and a judgment unit that judges whether the change in the parameter value made by the monitor control unit is correct.
  • the present invention by changing the parameter values of the radiation monitor unit, radiation information for radiation of different intensities can be obtained, and further, it can be determined whether the parameter value changes are correct.
  • FIG. 1 is an overall configuration diagram of a radiation therapy system including a radiation irradiation system.
  • FIG. 2 is a diagram showing a configuration of an irradiation nozzle.
  • FIG. 2 is a diagram illustrating an example of a configuration of a dose monitor.
  • 1 is a flowchart of radiation therapy.
  • FIG. 13 is a diagram showing a method for determining whether to switch settings of a dose monitor. 13 is a diagram showing an example of a circuit configuration for determining whether the switching of the setting of the dose monitor is normal. 13 shows another example of a circuit configuration for determining whether the switching of the settings of the dose monitor is normal or not according to the second embodiment.
  • FIG. 11 is a diagram illustrating a configuration of an irradiation nozzle according to a third embodiment. 13 is a flowchart of radiation therapy according to the fourth embodiment.
  • the difference between parameters is around 1000 times, as is the case with FLASH treatment, there are concerns about incorrect irradiation due to malfunction of the switching and the impact on the signal processing system.
  • the value of the coefficient for converting current to voltage is set too small, the signal size will be smaller than the noise, and the value when the beam is irradiated and the value when the beam is stopped may become close to each other.
  • the value of the coefficient for converting current to voltage is set too large, the beam will stop at about 1/1000 of the prescribed dose.
  • the radiation irradiation system disclosed herein safely switches to monitor system parameter values appropriate for the irradiation dose rate based on the treatment plan, making it possible to monitor the beam at low cost and with high accuracy, regardless of whether the dose rate is conventional or for FLASH, thereby achieving highly reliable beam irradiation.
  • a radiation therapy system 101 will be described with reference to Figures 1 to 6.
  • radiation therapy is performed using a scanning method.
  • the radiation therapy system 101 is assumed to be a radiation therapy system that uses a proton beam or a heavy particle beam as a beam, but a scanning method using other radiation such as X-rays may also be used.
  • Figure 1 is a diagram showing the overall configuration of the radiation therapy system 101.
  • the radiation therapy system 101 is a system that irradiates a beam 103 to an irradiation target 102 to perform treatment.
  • the radiation therapy system 101 includes, for example, an accelerator system 104, a beam transport system 105, an irradiation nozzle 106, a treatment table 107, an overall control device 108, an accelerator/beam transport system control device 109, an irradiation control device 110, and a treatment planning device 111.
  • the accelerator system 104 is a device that generates and accelerates the beam 103.
  • an example of an accelerator including an injector 112, a synchrotron accelerator 113, and an ion source 114 is shown, but the accelerator system is not limited to this and may be, for example, a group of other devices that accelerate a particle beam, such as a cyclotron accelerator or a linear accelerator.
  • the beam transport system 105 is a group of devices that transport the beam to the irradiation nozzle 106.
  • the irradiation nozzle 106 which is an example of a "radiation irradiation system", irradiates the irradiation target 102 with the beam 103.
  • the beam transport system 105 transports the beam 103 accelerated by the accelerator 104 to the irradiation nozzle 106, and connects the accelerator 104 and the irradiation nozzle 106.
  • the beam transport system 105 in this embodiment has a rotating gantry. A fixed irradiation port may be used instead of the rotating gantry.
  • the beam transport system 105 may be omitted and the accelerator system 104 may be directly connected to the irradiation nozzle 106.
  • the irradiation nozzle 106 adjusts the beam 103 transported from the beam transport system 105 and irradiates the irradiation target 102.
  • the irradiation nozzle 106 further includes a group of devices that measure the characteristics of the irradiated beam 103. Details of the irradiation nozzle 106 will be described later with reference to FIG. 2.
  • the treatment planning device 111 is configured as a computer system having, for example, an arithmetic unit, a memory, a storage device, a communication interface device, and a user interface device (none of which are shown).
  • the treatment planning device 111 executes a treatment plan prepared by a doctor or the like to prepare a prescription, and transfers the prescription to the overall control device 108.
  • the prepared prescription includes information regarding the beam current for each irradiation unit.
  • the overall control device 108 is connected to the treatment planning device 111, the accelerator and beam transport system control device 109, the irradiation control device 110, and the treatment table 107, and controls the operation of each device based on the prescription transferred from the treatment planning device 111.
  • the accelerator and beam transport system control device 109 controls the operation of each device that makes up the accelerator system 104 and the beam transport system 105 based on instructions from the overall control device 108.
  • the irradiation control device 110 controls the operation of each device constituting the irradiation nozzle 106 based on instructions from the overall control device 108.
  • the irradiation control device 110 processes the measurement results sent from each monitor of the irradiation nozzle 106 and transfers them to the overall control device 108.
  • the detailed configuration of the irradiation control device 110 will be described later with reference to FIG. 6.
  • the overall control device 108, the accelerator/beam transport system control device 109, and the irradiation control device 110 each have a CPU and a memory connected to the CPU.
  • the control process for the operations to be executed may be integrated into one program, or may be divided into multiple programs, or may be a combination of both.
  • Some or all of the programs held by each device may be implemented using dedicated hardware or may be modularized. Furthermore, the various programs may be installed on each device via a program distribution server or external storage media.
  • Each device may be an independent device and connected via a wired or wireless network. Multiple devices may also be combined into one.
  • the treatment table 107 is a bed on which the irradiation target 102 is placed.
  • the treatment table 107 is movable in what are called six axial directions. Based on instructions from the overall control device 108, the treatment table 107 can move in the directions of three perpendicular axes and can also rotate around each axis. By these movements and rotations, the treatment table 107 can move the irradiation target 102 to the desired position.
  • the accelerator/beam transport system control device 109 is a device that controls the accelerator 104 and the beam transport system 105.
  • Figure 2 shows an example of an irradiation nozzle 106 that irradiates a beam using a scanning method.
  • a plurality of scanning electromagnets 201A, 201B, a dose monitor 202, and a position monitor 203 are arranged inside the irradiation nozzle 106. Furthermore, the irradiation nozzle 106 may be provided with a ridge filter 204 and a range shifter 205 as necessary.
  • the irradiation nozzle 106 further includes a dose monitor signal processing system 206, a position monitor signal processing system 207, a scanning magnet control device 208, and a monitor setting control device 209.
  • the irradiation control device 110 is connected to a dose monitor signal processing system 206, a position monitor signal processing system 207, a scanning magnet control device 208, and a monitor setting control device 209.
  • the scanning magnets 201A and 201B deflect the beam 103 by generating a magnetic field.
  • the scanning magnets 201A and 201B deflect the beam in directions perpendicular to each other.
  • the beam 103 is scanned in two dimensions and irradiated to the target volume 210 within the irradiation subject 102.
  • the irradiation subject 102 represents the patient
  • the target volume 210 represents the area of the tumor plus a margin (a margin area that takes into account errors in the irradiation position).
  • the ridge filter 204 is used to expand the dose distribution in the incident direction.
  • the range shifter 205 is used to adjust the penetration depth of the beam 103.
  • the dose monitor 202 is a monitor for measuring the dose rate and thus the dose of the irradiated beam 103.
  • the dose monitor 202 transmits a dose monitor output having a magnitude corresponding to the dose rate to the dose monitor signal processing system 206.
  • an ionization chamber is used as the dose monitor 202.
  • the dose monitor output corresponds to the collection current of the ionization chamber.
  • the dose monitor 202 may be another type of monitor, such as a phosphor or semiconductor detector, in which there is a correlation between the beam dose rate and the detection signal.
  • the dose monitor signal processing system 206 processes the dose monitor output input from the dose monitor 202 and outputs it to the irradiation control device 110 as a dose signal.
  • the irradiation control device 110 calculates the irradiated dose based on the dose signal input from the dose monitor signal processing system 206.
  • the dose monitor signal processing system 206 can also be called the dose monitor signal processing unit 206.
  • the position monitor 203 is a monitor for measuring the position and size of the irradiated beam 103.
  • the output of the position monitor 203 is input to the position monitor signal processing system 207.
  • a multi-wire ionization chamber is used as the position monitor 203.
  • the position monitor output corresponds to a set of collected current values output from each wire of the ionization chamber.
  • the position monitor 203 may be another type of monitor that outputs a group of detection signals that are correlated with the dose rate of the beam at each point in a two-dimensional plane, such as a multi-strip ionization chamber or a two-dimensional array phosphor detector.
  • the position monitor signal processing system 207 processes the position monitor output and outputs it to the irradiation control device 110 as a position and size signal.
  • the position and size signal is a signal that indicates the position and size of the beam.
  • the irradiation control device 110 calculates the position and size of the irradiated beam based on the position and size signals input from the position monitor signal processing system 207.
  • the position monitor signal processing system 207 can also be called the position monitor signal processing unit 207.
  • the monitor setting control device 209 is connected to either or both of the dose monitor signal processing system 207 and the position monitor signal processing system 208, and sends instructions to switch the parameters of the connected monitor signal processing system (hereafter referred to as monitor settings).
  • the dose monitor 202 and the dose monitor signal processing system 206 are examples of a "radiation monitor unit.”
  • the dose monitor 202 is an example of a "sensor unit.”
  • the dose monitor signal processing system 206 is an example of a “signal processing circuit.”
  • the dose or dose rate is an example of "radiation information.”
  • the monitor setting control device 209 is an example of a “monitor control unit.”
  • the "judgment unit” is, for example, steps S111 and S112 in FIG. 4 described below, or one of steps S111 and S112. Furthermore, the "judgment unit” can also include step S113.
  • the overall control unit 108 may be an example of a "judgment unit” and/or a "monitor control unit.”
  • the collected current output from the ionization chamber type dose monitor 202 is input to a downstream current-voltage conversion circuit 301 and converted into a voltage signal by this circuit 301.
  • the voltage signal is converted into a frequency signal by a voltage frequency converter 302 and transmitted as a dose monitor signal to the irradiation controller 110.
  • the voltage frequency converter 302 is a circuit that converts a voltage signal into a frequency signal, and is indicated as a "VF converter” in the figure.
  • the resistance value of the current-voltage conversion circuit 301 can be switched to one of a plurality of resistance values by a switch 303.
  • the switch 303 is controlled by the monitor setting control device 209.
  • there are two parallel circuits (referred to as a first parallel circuit and a second parallel circuit).
  • the first parallel circuit has a resistance value R1.
  • the second parallel circuit has a resistance value R2.
  • the output voltage when switching to the second parallel circuit will be 1/1000 of the output voltage of the first parallel circuit. Therefore, even if there is a 1000-fold difference in beam intensity between conventional treatment and ultra-high dose rate treatment, it is possible to obtain the same voltage output by switching between the two parallel circuits, and the signal will not saturate or the signal-to-noise ratio will not decrease.
  • the resistance value of the current-voltage conversion circuit 301 is assumed as the monitor setting.
  • two parallel circuits are illustrated, a first parallel circuit having a resistance value R1 and a second parallel circuit having a resistance value R2, but this is not limiting, and three or more parallel circuits may be used.
  • a fixed resistor with a fixed resistance value may be used, or a variable resistor whose resistance value can be changed continuously or in steps may be used.
  • the conversion coefficient of the voltage-to-frequency converter 302 may be changed via the monitor setting control device 209.
  • the circuit configuration of the signal processing system 206 is not limited to the above, and may include, for example, a capacitor or other amplifier circuit.
  • signals other than frequency signals may be transmitted to the irradiation control device 110.
  • FIG. 4 is a flowchart of radiation therapy.
  • radiation therapy involves fractionated irradiation, in which the target dose is administered in several doses. This is to prevent normal tissue from being damaged by administering a high dose all at once.
  • the treatment period is divided into 30 days, for example, and the target dose is irradiated, but the number of fractions and the amount of radiation are not particularly important.
  • the fractional unit does not have to be one day, and one day of treatment can be divided into multiple sessions.
  • the treatment planning device 111 When treatment begins each day (S101), the treatment planning device 111 first executes a treatment plan (S102). The detailed steps of the treatment plan are as follows:
  • the treatment planning device 111 reads in-vivo images of the patient's affected area taken by X-ray CT or the like. Next, based on the in-vivo images displayed on the user interface device, the doctor extracts the contours of the tumor and dangerous organs, and adds a predetermined margin to these contours to determine the target volume 210 and the contours of the dangerous organs.
  • the treatment planning device 111 creates a prescription. First, the treatment planning device 111 sets a target dose and a target beam intensity index for the target volume 210 and the organs at risk.
  • the beam intensity index represents an arbitrary index that depends on the beam intensity and is determined for each minute region in the patient's body, such as the average dose rate obtained by dividing the dose by the time required for irradiation.
  • the target dose and target beam intensity index are input by the doctor via the user interface device.
  • the treatment planning device 111 performs irradiation optimization calculations to assign the target dose and target beam intensity index and determines the prescription.
  • the prescription specifies the irradiation position, irradiation amount, irradiation intensity, irradiation direction, and irradiation sequence of each pencil beam.
  • the dose distribution and beam intensity index distribution formed by the prescription are presented to the doctor via the user interface device.
  • the prescription approved by the doctor is transmitted to the overall control device 108.
  • the overall controller 108 creates control instruction data for each irradiation group based on the prescription received from the treatment planning device 111, and transmits it to the accelerator and beam controller 109 and the irradiation controller 110.
  • the transmitted data is stored in a memory in the accelerator and beam controller 109 and a memory in the irradiation controller 110 (neither of which are shown).
  • the prescription is now created. If the doctor does not approve the prescription, the target dose or target beam intensity indicators are reset.
  • the patient is placed on the treatment table 107.
  • the overall control device 108 moves the treatment table 107 to match the position of the patient when the internal body image is taken.
  • the radiation therapy system 101 then starts preparing to irradiate the beam 103.
  • the irradiation for each day is divided into several irradiation groups.
  • the boundaries of the irradiation groups are set, for example, at points where the irradiation position changes significantly or where the irradiation direction or irradiation intensity changes.
  • the accelerator and beam transport system control device 109 starts accelerating the beam in accordance with the control instruction data.
  • the irradiation control device 110 changes the current values of the scanning magnets 201A and 201B using the scanning magnet control device 208 based on the irradiation position information shown in the prescription.
  • the overall control device 108 determines whether or not the monitor settings should be switched (S104).
  • the overall control device 108 stores the irradiation intensity ranges RA1 and RA2 corresponding to each monitor setting value (resistance values R1 and R2 of the current-voltage conversion circuit 301 in FIG. 3) as setting values in a memory (not shown).
  • the range in which the illuminance intensity exceeds the threshold value Th is the range RA1 in which high-intensity radiation is irradiated.
  • the range in which the irradiation intensity is equal to or less than the threshold value Th is the range RA2 in which low-intensity radiation is irradiated.
  • the monitor setting value is set to "2" (resistor R2 is used).
  • the monitor setting value is set to "1" (resistor R1 is used).
  • resistor R1 is used.
  • the monitor setting has been switched (S104: YES). If the setting value at the previous irradiation group and the setting value (resistance value) calculated this time match, it is determined that the monitor setting has not been switched (S104: NO). However, for the first irradiation group, it is considered that the monitor setting has been switched for the sake of convenience.
  • the judgment process for each irradiation group may be executed after the start of irradiation for each irradiation group, or the switching judgment process for all irradiation groups may be executed together based on the treatment plan before the start of irradiation for the first irradiation group, and the judgment results may be stored in the memory of the overall control device 108.
  • the monitor settings are switched (S110).
  • the overall control device 108 instructs the monitor settings control device 209 on the monitor settings to be switched to and their values. Based on the instruction, the monitor settings control device 209 switches the monitor settings of the dose monitor signal processing system 206 or the position monitor signal processing system 207.
  • FIG. 6 is a circuit diagram in which components for determining the monitor settings are added to the dose monitor signal processing system 206 shown in FIG. 3.
  • a current source 401 is connected to the input side of the current-voltage conversion circuit 301.
  • the current source 401 applies a specified current (test current).
  • the magnitude of the current may be changed according to the irradiation intensity of the beam group, or may be constant regardless of the irradiation intensity.
  • the current input from the current source 401 is converted to a voltage by the current-voltage conversion circuit 301. The value of this voltage is measured by a voltmeter 402 connected to the output side of the current-voltage conversion circuit 301.
  • the voltage measured by the voltmeter 402 is sent to the overall control device 108 via the irradiation control device 110.
  • the overall control device 108 compares the resistance value of the current-voltage conversion circuit 301 specified as the monitor setting value with the voltage value predicted from the applied current value and the measured voltage value, and if the difference is less than the threshold value, it determines that the monitor setting is normal, and if the difference is greater than the threshold value, it determines that the monitor setting is abnormal (S111).
  • the threshold value of the voltage difference is pre-stored in the memory in the overall control device 108.
  • the threshold value may be defined as the relative magnitude of the difference with respect to the voltage value, may be defined as the absolute magnitude of the voltage difference, or may be different for each monitor setting value.
  • FIG. 6 shows an example of a monitor setting determination method when the monitor setting is to switch the resistance value of the current-voltage conversion circuit 301, but other determination methods are also possible.
  • a mechanism that detects the position or operation of the switch 303 and outputs a signal may be used.
  • the current setting value may be output as a digital signal.
  • step S112 it is determined whether the monitor settings are normal or not. If it is determined that the monitor settings are abnormal (S112: NO), a warning is output to the user in step S113, and the process returns to step S110. In step S110, the monitor settings are switched again.
  • the accelerator/beam transport system control device 109 starts beam extraction.
  • the extracted beam 103 passes through the irradiation nozzle 106 and is irradiated to the target volume 210.
  • the characteristics of the irradiation beam 103 are measured by the dose monitor 202 and position monitor 203, and the irradiation dose is integrated in the irradiation control device 110.
  • the irradiation control device 110 transmits a completion signal to the overall control device 108 (S106).
  • the overall control device 108 determines whether radiation irradiation for the last irradiation group for today has been completed (S107), and if there is an irradiation group that has not been executed (S107: NO), issues an instruction to the accelerator and beam transport system control device 109 and the irradiation control device 110 (S108), instructing them to prepare for irradiation for the second irradiation group.
  • the radiation therapy system 101 may be a system in which the irradiation control device 110 and the accelerator/beam transport system control device 109 are connected, and signals indicating completion of acceleration and completion of irradiation are sent and received directly between the irradiation control device 110 and the accelerator/beam transport system control device 109.
  • the monitor settings may be changed and a normal judgment may be performed before starting preparations for irradiation of the first irradiation group, such as before the patient enters the room or while the patient is being fixed to the treatment table.
  • part of the monitor signal processing system 206 is made switchable, and the monitor settings are switched based on the irradiation intensity specified in the treatment plan.
  • the monitor signal processing system 206 is a single system, and only part of the circuit is changed to a switchable mechanism. Therefore, overall costs are reduced compared to when multiple signal processing systems are provided and measurements are taken simultaneously with different monitor setting values.
  • the test current is actually measured to determine whether the switch is normal or abnormal, and irradiation begins only after it is determined that the monitor switch setting is normal. Therefore, according to this embodiment, malfunctions of monitor setting switching can be avoided.
  • the monitor setting switching and normality determination are performed in parallel with other irradiation preparations such as beam acceleration and bending magnet current changes, so there is no impact on the treatment flow and the treatment time is not extended unless an abnormality is determined.
  • the radiation therapy system of this embodiment can monitor the beam at low cost and with high accuracy, whether the treatment is at a conventional dose rate or at a high dose rate for FLASH.
  • Example 2 will be described using Figure 7. In the following examples, including this example, the differences from Example 1 will be mainly described.
  • Example 2 The overall configuration of the radiation therapy system 101 in Example 2 is the same as that in Example 1, but there may be differences in the configuration of the dose monitor or position monitor and the corresponding monitor signal processing system, as well as in some parts of the treatment flow.
  • a test beam is irradiated to determine whether the monitor switching setting is normal or abnormal.
  • the applied voltage of an ionization chamber-type dose monitor is used as an example of the monitor setting that performs the switching.
  • Figure 7 shows a circuit diagram that performs a determination of the monitor switching setting by test irradiating a beam.
  • a high-voltage power supply 501 is connected to apply a voltage between the collecting electrode and the high-voltage electrode.
  • the magnitude of the applied voltage changes the degree of gas amplification, i.e., the magnitude of the collected current for the same beam intensity. Therefore, by having the monitor setting control device 209 switch the applied voltage of the high-voltage power supply 501 according to the beam irradiation intensity, it is possible to obtain a dose monitor output of the same level regardless of the irradiation intensity, even if the conversion coefficients of the current-voltage conversion circuit 502 and the voltage-frequency converter 503 are not variable.
  • the settings of the dose monitor 202 itself are switched. For this reason, even if a test current is applied to the dose monitor signal processing system 206 using the configuration of FIG. 6, it is not possible to actually measure the state of the monitor settings. Therefore, in this embodiment, after switching the monitor settings, a test beam irradiation is performed, and the measurement results of the dose monitor 202 are compared with the predicted values to determine whether the monitor settings have been switched correctly.
  • the monitor setting that can be switched is not limited to the applied voltage of the dose monitor 202, but may be, for example, the electrode spacing of the ionization chamber, the applied voltage of the position monitor, or the electrode spacing.
  • the radiation therapy flow of this embodiment will be described below.
  • the outline of the treatment flow is shown in FIG. 4, similar to the first embodiment.
  • the current changes to the beam acceleration and bending magnets must be completed before the monitor setting determination starts in step S111.
  • the overall control device 108 sends instructions to the accelerator/beam transport system control device 109 and the irradiation control device 110 to irradiate the beam for a short time as a test irradiation.
  • the micro-time varies depending on the irradiation intensity of the beam group, and is stored in advance in the overall control device 108. During the micro-time irradiation, it is measured by the dose monitor 202. The output of the dose monitor 202 is compared with the monitor setting specified at the time of switching and the value predicted from the micro-time and irradiation intensity irradiated, and if the difference is less than a threshold value, the monitor setting is determined to be normal. If the difference is greater than the threshold value, the monitor setting is determined to be abnormal.
  • the threshold value may be defined as a relative value of the difference with respect to the dose monitor output, or may be defined as an absolute value of the difference.
  • the dose monitor output to be compared may be the voltage value immediately after the current-voltage conversion circuit 502, or the number of pulse signals immediately after the voltage-frequency converter 503. Furthermore, it may be a value obtained by integrating the above voltage value over a certain period of time.
  • the monitor setting switching is performed only when the patient is not present on the treatment table 107, the patient will not be exposed to additional radiation due to the test irradiation.
  • the monitor setting switching occurs while the patient is present on the treatment table 107, such as when the monitor setting switching is performed during treatment, the patient will be exposed to radiation due to the test irradiation. If the amount of radiation exposure during the short time period in which the test irradiation is performed is sufficiently small, the irradiation may be performed according to the treatment plan after the test irradiation.
  • the dose due to the test irradiation may be subtracted from the target dose of the therapeutic irradiation immediately after the test irradiation.
  • the treatment flow after the monitor setting determination (S105) is the same as in Example 1, and will not be described here.
  • test irradiation is performed to determine the monitor settings, so if a patient is present on the treatment table, additional processing is required, such as correcting the target dose during treatment according to the amount of irradiation.
  • the treatment time is slightly longer than when this embodiment is not applied.
  • the beam is actually irradiated and the response of the monitor system is measured, so it is possible to verify the validity of the setting switch of the monitor body, which was not possible to determine as normal in embodiment 1.
  • Example 3 will be described with reference to FIG. 8. Examples 1 and 2 were described using a radiation therapy system that uses the scanning method. In this example, a radiation therapy system and an X-ray therapy system that use the passive method will be described as examples.
  • the overall configuration of the radiation therapy system 101A is largely the same as that shown in FIG. 1, but in the case of an X-ray therapy system, an electron beam linear accelerator is used as the accelerator system 104, and furthermore, a target for converting the electron beam into X-rays is installed at the most downstream of the beam transport system 105 (neither is shown).
  • Figure 8 shows an example of the configuration of the irradiation nozzle 106A in the passive method.
  • the scatterer 601 is installed to expand the beam size and flatten the beam distribution.
  • the dose monitor 602 and dose monitor signal processing system 603 have the same configuration as in Example 1 or Example 2, and function to measure the intensity of the passing beam.
  • the monitor setting control device 604 issues a command to switch the monitor setting of the dose monitor 602 or the dose monitor signal processing system 603.
  • the multi-leaf collimator 605 is a shield in which multiple thin metal plates are stacked in a direction perpendicular to the beam, and each thin plate can be driven independently to form any collimator shape.
  • the collimator control device 606 controls the shape of the multi-leaf collimator 605 according to instructions from the irradiation control device 110.
  • the ridge filter 607 and bolus 607 are installed in the case of the radiation therapy system 101A, and change the characteristics of the beam so that the dose distribution in the depth direction matches the target volume 210.
  • the above components form a dose distribution that dimensionally matches the target volume 210.
  • the prescription created by the treatment planning device 111 contains information specifying the geometry of the multi-leaf collimator 605 for each irradiation direction, as well as the beam irradiation amount and irradiation intensity.
  • the configuration of the radiation therapy system 101A and the detailed description of each device have been described above.
  • the operation procedure of the system in this embodiment is generally similar to the procedure shown in the first or second embodiment.
  • the shape of the multi-leaf collimator 605 is changed in the irradiation preparation in step S103. Since there is no position monitor, the monitor setting switching is applied only to the dose monitor.
  • the present embodiment thus configured also has the same operational effects as those of embodiment 1.
  • the present embodiment can also be applied to a radiation therapy system 101A that uses a passive method.
  • the fourth embodiment will be described with reference to FIG. 9.
  • the results of monitor setting switching are stored and the information is provided to the user.
  • FIG. 9 is a flowchart of the treatment process by the radiation therapy system 101.
  • the switching history is stored in the memory of the overall control unit 108 (S114).
  • the overall control unit 108 creates a report 700 based on the switching history and provides it to the user (S115).
  • the report 700 includes the monitor setting switching history corresponding to the treatment plan.
  • a user operating the radiation therapy system 101 such as a doctor, can refer to the report 700 and utilize it in creating other treatment plans.
  • Examples 1 and 2 can also be applied to setting switching and normality determination methods for the position monitor.
  • radiation therapy systems often have two monitors, a main dose monitor and a secondary dose monitor, and the above embodiment may be applied to only one of the monitors or to both monitors.
  • At least one of steps S104 and S111 in FIG. 4 can be realized by machine learning.
  • a radiation irradiation system that irradiates radiation of different intensities to an irradiation target, the radiation irradiation system comprising: a radiation monitor unit that detects radiation and acquires radiation information; a monitor control unit that changes the value of a parameter when the radiation information is detected according to the intensity of the radiation; and a judgment unit that judges whether the change in the value of the parameter by the monitor control unit is correct.
  • Configuration 2 The radiation irradiation system described in Configuration 1, in which the determination unit determines whether the change in the parameter value is correct before irradiating the radiation to the irradiation target.
  • Configuration 4 A radiation irradiation system according to any one of configurations 1 to 3, in which the monitor control unit changes the value of the parameter according to the intensity of the radiation based on treatment plan information for irradiating the irradiation target with radiation.
  • Configuration 5 A radiation irradiation system according to any one of configurations 1 to 4, in which the parameter is a parameter related to a signal processing circuit that detects the intensity of radiation by the radiation monitor unit.
  • Configuration 6 A radiation irradiation system according to any one of configurations 1 to 5, in which the parameter is the resistance value of a feedback resistor included in the signal processing circuit, which converts the monitor current value detected by the radiation monitor unit into a voltage value.
  • (Configuration 7) A radiation irradiation system according to any one of configurations 1 to 6, further comprising a current source that supplies a test current to the feedback resistor, and the determination unit determines whether the change in the value of the parameter made by the monitor control unit is correct based on the resistance value of the feedback resistor when the test current is supplied, before irradiating the irradiation target with radiation.
  • (Configuration 8) A radiation irradiation system according to any one of configurations 1 to 7, wherein the radiation monitor unit includes a sensor unit that detects radiation and outputs a current signal, and a signal processing circuit that processes the current signal from the sensor unit and outputs it as the radiation information, and the parameter is a parameter that changes the sensitivity of the sensor unit.
  • the sensor unit is an ionization chamber, and the sensitivity of the sensor unit is changed by changing the value of the voltage applied between the electrodes included in the ionization chamber as the parameter.
  • Configuration 10 A radiation irradiation system according to any one of configurations 1 to 8, in which the determination unit, after a parameter that changes the sensitivity of the sensor unit is changed, test-irradiates radiation into a space in which the irradiation target is not present, and determines whether the parameter change made by the monitor unit control unit is correct.
  • (Configuration 11) A radiation irradiation system according to any one of configurations 1 to 4, in which the determination unit, after a parameter that changes the sensitivity of the sensor unit is changed, performs a test irradiation of the irradiation target, and subtracts the dose of the test irradiation from the target dose described in the treatment plan.
  • a radiation therapy system comprising the radiation irradiation system according to any one of configurations 1 to 11, an accelerator and a beam transport system that supply radiation of different intensities to the radiation irradiation system, and an irradiation device that irradiates the radiation supplied from the accelerator and the beam transport system to the irradiation target.
  • a radiation irradiation method in which radiation of different intensities is irradiated to an irradiation target by a radiation irradiation system, the radiation therapy system including a radiation monitor unit that detects radiation and acquires radiation information, changes a parameter value when the radiation information is detected according to the intensity of the radiation, and determines whether the change in the parameter value is correct.
  • 101 Radiation therapy system
  • 102 Irradiation target
  • 103 Beam
  • 104 Accelerator system
  • 105 Beam transport system
  • 106 Irradiation nozzle
  • 107 Treatment table
  • 108 Overall control device
  • 109 Accelerator/beam transport system control device
  • 110 Irradiation control device
  • 111 Treatment planning device
  • 202 Dose monitor
  • 203 Position monitor
  • 204 Ridge filter
  • 205 Range shifter
  • 206 Dose monitor control device
  • 207 Position monitor control device
  • 208 Scanning magnet Control device
  • 209 Monitor setting control device
  • 301 Current-voltage conversion circuit
  • 302 Voltage frequency converter
  • 303 Switch
  • 401 Current source
  • 402 Voltmeter
  • 501 High-voltage power supply
  • 502 Current-voltage conversion circuit
  • 503 Voltage frequency converter
  • 601 Scatterer
  • 602 Current-voltage conversion circuit
  • 503 Voltage frequency converter
  • 601 Scatterer
  • 602 Current-

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  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Pathology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Radiology & Medical Imaging (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Radiation-Therapy Devices (AREA)

Abstract

L'invention concerne un système et un procédé qui permettent d'émettre un rayonnement de différentes intensités à faible coût et avec une fiabilité élevée. Un système d'irradiation par rayonnement 106 irradie un objet avec un rayonnement 103 de différentes intensités. Le système d'irradiation par rayonnement comprend : une unité de surveillance de rayonnement 202, 206 qui détecte un rayonnement et acquiert des informations sur le rayonnement ; une unité de commande de surveillance 209 qui change la valeur d'un paramètre lorsque les informations de rayonnement sont détectées, en fonction de l'intensité du rayonnement ; et une unité de détermination qui détermine si le changement de la valeur du paramètre par l'unité de commande de surveillance est correct.
PCT/JP2024/006877 2023-06-05 2024-02-26 Système d'irradiation par rayonnement, système de traitement par rayonnement, et procédé d'irradiation par rayonnement Ceased WO2024252737A1 (fr)

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JP2023-092676 2023-06-05
JP2023092676A JP2024174701A (ja) 2023-06-05 2023-06-05 放射線照射システム、放射線治療システムおよび放射線照射方法

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080099689A1 (en) * 2006-10-31 2008-05-01 Einar Nygard Photon counting imaging detector system
US20150041665A1 (en) * 2013-08-06 2015-02-12 The Trustees Of The University Of Pennsylvania Proton dose imaging method and apparatus
JP2016154630A (ja) * 2015-02-23 2016-09-01 株式会社日立製作所 粒子線照射装置および荷電粒子ビームの線量監視方法
CN114721027A (zh) * 2022-06-09 2022-07-08 中国科学院近代物理研究所 一种高精度超高辐照剂量快速测量装置
US20220401757A1 (en) * 2021-06-21 2022-12-22 Varian Medical Systems, Inc. Monitor for high dose rate electron therapy, system and method
JP2023013801A (ja) * 2021-07-16 2023-01-26 国立大学法人大阪大学 治療支援システム、治療支援方法及び治療支援プログラム

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080099689A1 (en) * 2006-10-31 2008-05-01 Einar Nygard Photon counting imaging detector system
US20150041665A1 (en) * 2013-08-06 2015-02-12 The Trustees Of The University Of Pennsylvania Proton dose imaging method and apparatus
JP2016154630A (ja) * 2015-02-23 2016-09-01 株式会社日立製作所 粒子線照射装置および荷電粒子ビームの線量監視方法
US20220401757A1 (en) * 2021-06-21 2022-12-22 Varian Medical Systems, Inc. Monitor for high dose rate electron therapy, system and method
JP2023013801A (ja) * 2021-07-16 2023-01-26 国立大学法人大阪大学 治療支援システム、治療支援方法及び治療支援プログラム
CN114721027A (zh) * 2022-06-09 2022-07-08 中国科学院近代物理研究所 一种高精度超高辐照剂量快速测量装置

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