Particle beam irradiation system, control method thereof, and control device for particle beam irradiation system

Abstract

In a particle beam irradiation system, in order to maintain sufficient safety without causing an unexpected treatment interruption, there are provided a charged particle beam generation unit, an irradiation unit that has a dose monitor and sequentially point-irradiates a charged particle beam to an irradiation target, a scan controller, and an accelerator / transport system controller. In this particle beam irradiation system, the scan controller is configured to determine whether to skip the irradiation of the charged particle beam to the next point where the charged particle beam has been irradiated, based on the irradiation dose measured by the dose monitor at the point where the charged particle beam has been irradiated until immediately before, after the scan controller outputs a signal to stop the irradiation, when the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit has stopped according to the accelerator / transport system controller that has received a signal to stop the irradiation of the charged particle beam, and to control the accelerator / transport system controller.

Description

Technical Field

[0001] The present invention relates to a particle beam irradiation system, a control method thereof, and a control device for a particle beam irradiation system. Background Art

[0002] In a particle beam irradiation system, the beam (hereinafter simply referred to as the beam) of the particle beam is controlled in units called points for treatment. In recent years, in order to cope with irradiation of more complex shapes and dose distributions than in the past, there has been a trend to reduce the irradiation amount per point, and a control function is required to continue treatment even for points with such small-dose irradiation.

[0003] In Japanese Patent No. 3806723 (Patent Document 1), the following "particle beam irradiation system" is provided. Regarding the monitoring of the irradiation amount, it is monitored not in units of points but as an accumulated value of each point, and the dose distribution of the irradiation target can be made more uniform.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 3806723 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] In the embodiment of Patent Document 1, when the beam emission start signal of the point is output, if the dose measured during the period from when the target irradiation amount of the previous point was full to when the signal is output exceeds the target irradiation amount of the point, irradiation is interrupted due to an error and treatment cannot be continued.

[0009] In addition, the above dose is a dose based on the response delay of the accelerator used in this system, and its value varies according to the beam current value. Therefore, if the beam current value suddenly increases, the dose increases sharply, and unexpected treatment interruption may occur.

[0010] In addition, due to the above response delay, even if the target irradiation amount of the point is not exceeded, the irradiation amount may become infinitely small. At such a point, the actual irradiation amount value also becomes very small, and in the actual value determination after irradiation, the monitoring function detects a set value deviation error, which may lead to treatment interruption.

[0011] The above phenomena are particularly likely to occur at points where small-dose irradiation is performed.

[0012] In order to solve the above problems of the prior art, the present invention provides a particle beam irradiation system, a control method thereof, and a control device for the particle beam irradiation system, which have a skip point function that can maintain sufficient safety without causing unexpected treatment interruption.

[0013] Means for Solving the Problems

[0014] In order to solve the above problems, in the present invention, the particle beam irradiation system includes: a charged particle beam generation unit that generates a charged particle beam; an irradiation unit that includes a scanning electromagnet and a dose monitor, wherein the scanning electromagnet sequentially point-irradiates the charged particle beam generated by the charged particle beam generation unit to the irradiation target, and the dose monitor measures the irradiation dose of the charged particle beam; a scanning controller that generates a signal for starting or stopping the irradiation of the charged particle beam irradiated by the irradiation unit to the irradiation target; and an accelerator / transport system controller that receives the signal for starting or stopping the irradiation of the charged particle beam output from the scanning controller, and thereby starts or stops the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit. The scanning controller determines whether to skip the irradiation of the charged particle beam to the next point of the point where the charged particle beam has been irradiated based on the irradiation dose measured by the dose monitor at the point where the charged particle beam has been irradiated until immediately before the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit has stopped after receiving the signal for stopping the irradiation of the charged particle beam, and thus controls the accelerator / transport system controller.

[0015] In addition, in order to solve the above problems, in the present invention, the particle beam irradiation system includes: a charged particle beam generation unit that generates a charged particle beam; an irradiation unit that includes a scanning electromagnet and a dose monitor, the scanning electromagnet sequentially point-irradiates the charged particle beam generated by the charged particle beam generation unit to the irradiation target, and the dose monitor measures the irradiation dose of the charged particle beam; a scanning controller that generates a signal for starting or stopping the irradiation of the charged particle beam irradiated by the irradiation unit to the irradiation target; and an accelerator / transport system controller that receives the signal for starting or stopping the irradiation of the charged particle beam output from the scanning controller to start or stop the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit. The scanning controller controls the accelerator / transport system controller to continuously irradiate the charged particle beam to a plurality of points. When the total irradiation dose of the plurality of points of continuous irradiation measured by the dose monitor reaches a predetermined irradiation dose, a signal for stopping the irradiation of the charged particle beam is output to the accelerator / transport system controller. Based on the irradiation dose measured by the dose monitor after the stop signal is output, it is determined whether to skip the irradiation of the charged particle beam to the first point at the next point of continuous irradiation, so as to control the accelerator / transport system controller.

[0016] In addition, to solve the above problems, in the control method of the particle beam irradiation system of the present invention, when the particle beam irradiation system irradiates the charged particle beam generated by the charged particle beam generation unit to a plurality of points of the irradiation target in sequence while measuring the irradiation dose by the dose monitor, the irradiation of the charged particle beam is started or stopped according to the signal output from the scan controller. When the irradiation dose of the charged particle beam at one of the plurality of points measured by the dose monitor reaches a predetermined irradiation dose, a signal for stopping the irradiation of the charged particle beam is output from the scan controller to the accelerator / transport system controller, and based on the irradiation dose measured by the dose monitor after the stop signal is output, it is determined whether to skip the irradiation of the charged particle beam to the next point of the point where the charged particle beam has been irradiated, so as to control the accelerator / transport system controller.

[0017] In addition, to solve the above problems, in the control method of the particle beam irradiation system of the present invention, when the particle beam irradiation system continuously irradiates the charged particle beam generated by the charged particle beam generation unit to a plurality of points of the irradiation target while measuring the irradiation dose by the dose monitor, the irradiation of the charged particle beam is started or stopped according to the signal output from the scan controller. When the total irradiation dose of the charged particle beam at the continuously irradiated plurality of points measured by the dose monitor reaches a predetermined irradiation dose, a signal for stopping the irradiation of the charged particle beam is output from the scan controller to the accelerator / transport system controller, and based on the irradiation dose measured by the dose monitor after the stop signal is output, it is determined whether to skip the irradiation of the charged particle beam to the first point at the next continuously irradiated point, so as to control the accelerator / transport system controller.

[0018] In addition, to solve the above problems, in the control device of the particle beam irradiation system of the present invention, the particle beam irradiation system includes: a charged particle beam generation unit that generates a charged particle beam; and an irradiation unit that irradiates the charged particle beam generated by the charged particle beam generation unit to the irradiation target point by point in sequence. The control device includes: a scan controller that generates a signal for starting or stopping the irradiation of the charged particle beam irradiated by the irradiation unit to the irradiation target; and an accelerator / transport system controller that receives a signal for stopping the irradiation of the charged particle beam from the scan controller and starts or stops the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit. When the irradiation dose of the charged particle beam at one of the plurality of points measured by the dose monitor reaches a predetermined irradiation dose, the scan controller outputs a signal for stopping the irradiation of the charged particle beam to the accelerator / transport system controller, and based on the irradiation dose measured by the dose monitor after the stop signal is output, it is determined whether to skip the irradiation of the charged particle beam to the next point of the point where the charged particle beam has been irradiated, so as to control the accelerator / transport system controller.

[0019] In addition, to solve the above problems, in the control device of the particle beam irradiation system of the present invention, the particle beam irradiation system includes: a charged particle beam generation unit that generates a charged particle beam; an irradiation unit that continuously irradiates a plurality of points of an irradiation target with the charged particle beam generated by the charged particle beam generation unit; and a dose monitor that monitors the irradiation dose of the charged particle beam irradiated from the irradiation unit. The control device includes: a scan controller that generates a signal for starting or stopping the irradiation of the charged particle beam irradiated by the irradiation unit to the irradiation target; and an accelerator / transport system controller that receives a signal for stopping the irradiation of the charged particle beam from the scan controller and starts or stops the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit. When the total irradiation dose of the charged particle beam at a plurality of continuously irradiated points measured by the dose monitor reaches a predetermined irradiation dose, the scan controller outputs a signal for stopping the irradiation of the charged particle beam to the accelerator / transport system controller, and determines whether to skip the irradiation of the charged particle beam to the first point at the next continuously irradiated point after the point where the stop signal is output based on the irradiation dose measured by the dose monitor after the stop signal is output, and controls the accelerator / transport system controller.

[0020] Advantages of the Invention

[0021] According to the present invention, even when the target irradiation dose at a point has been exceeded before the beam emission start signal is output and the target irradiation dose is zero, or when small-dose irradiation is performed at a point to cope with accelerator response delay or complex shape and dose distribution, treatment can be continued through a skip function that maintains sufficient safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a block diagram showing the overall structure of the particle beam irradiation systems of Embodiments 1 and 2 of the present invention.

[0023] Figure 2 It is a flowchart showing the control sequence executed by the scan controller and the accelerator / transport system controller in Embodiment 1.

[0024] Figure 3 It is a flowchart showing the detailed content of the control sequence executed by the scan controller in Embodiment 1.

[0025] Figure 4 It is a graph showing the change in the irradiation dose at each point achieved by the control sequence executed by the scan controller in Embodiment 1.

[0026] Figure 5 It is a flowchart showing the control sequence executed by the scan controller and the accelerator / transport system controller in Embodiment 2.

[0027] Figure 6It is a flowchart showing the details of the control sequence executed by the scan controller in Example 2.

[0028] Figure 7 It is a graph showing the transition of the irradiation dose at each point achieved by the control sequence executed by the scan controller in Example 2. Detailed implementation mode

[0029] In the present invention, in a particle beam irradiation system, when the target irradiation dose at a point is exceeded before the output beam emission start signal is output, the beam emission is skipped and the system proceeds to the next point.

[0030] In addition, for a point where a dose below a preset lower limit has been irradiated before the irradiation beam, the determination of the irradiation actual value is skipped and the system proceeds to the next point. A monitoring function is installed for skipping the determination of the irradiation actual value to maintain treatment safety.

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings used to illustrate the present embodiment, the same reference numerals are assigned to parts having the same function, and repeated explanations thereof are omitted in principle.

[0032] However, the present invention is not to be construed as limited to the description of the embodiments shown below. Those skilled in the art can easily understand that the specific structure can be changed without departing from the idea or gist of the present invention.

[0033] Example 1

[0034] Figure 1 Shows the particle beam irradiation system 150 of this embodiment.

[0035] The particle beam irradiation system 150 of this embodiment includes a charged particle beam generation device 1 and a beam transport system 4 connected to the downstream side of the charged particle beam generation device 1.

[0036] The charged particle beam generation device 1 includes an ion source (not shown), a pre-stage charged particle beam generation device (linear accelerator) 11, and a synchrotron (accelerator) 12. The synchrotron 12 has a high-frequency application device 9 and an acceleration device 10.

[0037] The high-frequency application device 9 is configured by connecting a high-frequency application electrode 93 disposed on the circumferential orbit of the synchrotron 12 to a high-frequency power supply 91 using an on-off switch 92.

[0038] The acceleration device (second element, charged particle beam energy change device) 10 includes a high-frequency acceleration cavity (not shown) disposed on its circumferential orbit, and a high-frequency power supply (not shown) for applying high-frequency power to the high-frequency acceleration cavity.

[0039] Ions (e.g., proton ions (or carbon ions)) generated by an ion source (not shown) are accelerated by a pre-stage charged particle beam generating device (e.g., a linear charged particle beam generating device) 11.

[0040] The ion beam emitted from the pre-stage charged particle beam generating device 11 is incident on the synchrotron 12. This ion beam as a charged particle beam (particle beam) is accelerated in the synchrotron 12 by high-frequency power applied to the ion beam from the high-frequency power supply of the acceleration device 10 via the high-frequency acceleration cavity. After the ion beam is raised to the set energy, the ejection high-frequency power from the high-frequency power supply 91 of the high-frequency application device 9 reaches the high-frequency application electrode 93 via the closed opening / closing switch 92, and is applied to the ion beam from the high-frequency application electrode 93.

[0041] The ion beam orbiting within the stability limit is transferred outside the stability limit by applying high-frequency power by this high-frequency application electrode 93, and exits from the synchrotron 12 to the beam delivery system 4 through the ejection deflector 8.

[0042] On the other hand, by opening the opening / closing switch 92, the application of high-frequency power to the high-frequency application electrode 93 is stopped, and the ejection of the ion beam from the synchrotron 12 is stopped. In the case of the synchrotron 12 as an accelerator in this embodiment, according to its characteristics, even if a beam stop command is input from the accelerator / delivery system controller described later, strictly speaking, there may be a certain response delay before the opening / closing switch 92 of the high-frequency application device 9 is immediately opened and the output of the ion beam from the ejection deflector 8 to the beam delivery system 4 stops.

[0043] The ion beam exiting from the synchrotron 12 through the ejection deflector 8 is delivered downstream by the beam delivery system 4. The beam delivery system 4 includes quadrupole electromagnets 18 and deflection electromagnets 17, and quadrupole electromagnets 21, 22, deflection electromagnets 23, and deflection electromagnets 24 (each electromagnet is a first element) arranged on the beam path 62 connected to the irradiation device 15 disposed in the treatment room starting from the upstream side in the beam traveling direction.

[0044] The ion beam introduced into the beam delivery system 4 is delivered through the beam path 62 to the irradiation device 15 disposed in a treatment room (not shown).

[0045] The treatment room includes an irradiation device 15 mounted on a rotating gantry (not shown) provided inside. An inverted U-shaped beam delivery device and the irradiation device 15 including a part of the beam path 62 of the beam delivery system 4 are provided on a substantially cylindrical rotating body (not shown) of the rotating gantry (not shown). The rotating body is configured to be rotatable by a motor (not shown). A treatment instrument (not shown) is formed inside the rotating body.

[0046] The irradiation device 15 has a housing (not shown) that is mounted on a rotating body and is connected to the above-described inverted U-shaped beam delivery device. Scanning electromagnets 5A, 5B for scanning the beam, dose monitors 6A, position monitors 6B, etc. are provided inside the housing.

[0047] The ion beam introduced into the irradiation device 15 from the inverted U-shaped beam delivery device via the beam path 62 is two-dimensionally scanned in sequence by the scanning electromagnets (charged particle beam scanning devices) 5A, 5B at the irradiation position, and irradiates the affected part (e.g., the site where cancer or tumor occurs) of the patient 30 lying on the treatment table 29. This ion beam releases its energy at the affected part, forming a high-dose region.

[0048] The control system 90 included in the particle beam irradiation system 150 of this embodiment has a central control device 100, a storage device 110 that stores treatment plan information, a scan controller 41, and an accelerator / delivery system controller (hereinafter referred to as an accelerator controller) 40. Moreover, the particle beam irradiation system of this embodiment has a treatment planning device 140.

[0049] The central control device 100 includes a CPU 101 and a memory 103 for storing information required for treatment control, and cooperates with the accelerator controller 40 and the scan controller 41.

[0050] The above-mentioned treatment plan information (patient information) of each patient stored in the storage device 110 includes data such as patient ID number, irradiation dose (per time), irradiation energy, irradiation direction, irradiation position, etc.

[0051] The scan controller 41 that controls the scanning electromagnets 5A, 5B inside the irradiation device 15 has a memory 41A for storing various treatment information and a counter 41B related to the detection of the irradiation dose inside.

[0052] The counter 41B obtains the irradiation dose by counting the number of pulses output from the dose monitor 6A. This count value represents the irradiation dose from the start of counting. Hereafter, the count value and the irradiation dose are treated as having the same meaning.

[0053] In the particle beam irradiation system 150 of this embodiment, the central control device 100, the scan controller 41, and the accelerator controller 40 perform control in cooperation based on the treatment plan information generated by the treatment planning device 140.

[0054] The central control device 100 reads out the treatment plan information generated by the treatment planning device 140 and stored in the storage device 110, and stores it in the memory 103.

[0055] Based on the treatment plan information stored in the memory 103, the CPU 101 generates information related to the irradiation of the ion beam (information such as the number of layers (slices) obtained by dividing the ion beam irradiation target area including the affected part in the depth direction, the number of irradiation positions (number of points), the irradiation positions within each slice, the target irradiation dose at each irradiation position, and the current values of the scanning electromagnets 5A and 5B related to all points in each slice), and sends it to the scanning controller 41. Here, the target irradiation dose at each irradiation position can be the cumulative irradiation dose (cumulative dose) starting from the initial irradiation of the affected part, or the irradiation dose per point.

[0056] The CPU 101 transfers all the data of the acceleration parameters of the synchrotron 12 related to all the slices in the treatment plan information to the accelerator controller 40.

[0057] Next, the control sequence executed by the scanning controller 41 and the accelerator controller 40 will be described.

[0058] Figure 2 Flowcharts of the scanning controller 41 and the accelerator controller 40 during irradiation implementation and their cooperation are shown.

[0059] When the irradiation start indicating device (not shown) located in the treatment room is operated, the accelerator controller 40 correspondingly initializes the operator i representing the slice number to 1, the operator j representing the point number to 1, and the number of irradiation times n for one slice to 1 in step S201.

[0060] After completing the initialization in step S201, in step S202, the accelerator controller 40 reads and sets the accelerator parameters for the i-th (at this time i = 1) slice from the acceleration parameters of multiple modes stored in the memory 103 of the central control device 100, and outputs it to the synchrotron 12 in step S203.

[0061] In step S203, the accelerator controller 40 outputs the excitation current information for these electromagnets included in the i-th accelerator parameter to the power supplies of the synchrotron 12 and each electromagnet of the beam delivery system 4, and controls the corresponding power supplies according to this excitation current information so that each electromagnet is excited with a predetermined current.

[0062] Also, in step S203, the accelerator controller 40 controls the high-frequency power supply that applies high-frequency power to the high-frequency acceleration cavity of the acceleration device 10 to increase the high-frequency power and frequency to a predetermined value.

[0063] Accordingly, the energy of the ion beam circulating within the synchrotron 12 is increased to a value determined by the treatment plan. Then, it proceeds to step S204, where an emission preparation instruction is output to the scan controller 41.

[0064] The scan controller 41 receives the information of the initial setting in step S201 and the emission preparation instruction in step S204 from the accelerator controller 40. In step S205, the current value data and the target irradiation dose data of the j-th point (at this time point j = 1) are read out from the current value data and the target irradiation dose data already stored in the memory 41A and set.

[0065] After the irradiation preparation for this point is completed, the scan controller 41 outputs a beam emission start signal to the accelerator controller 40 in step S300. The accelerator controller 40 controls the high-frequency application device 9, and an ion beam is emitted from the synchrotron 12 to the beam delivery system 4 through the emission deflector 8 (step S207). That is, the accelerator controller 40 receives the beam emission start signal from the scan controller 41 (point irradiation: S300), operates the on-off switch 92 of the high-frequency application device 9 to close the on-off switch 92, and high-frequency applies the high-frequency power from the high-frequency power supply 91 to the high-frequency application electrode 93.

[0066] Within the synchrotron 12, the ion beam circulating within the stability limit has its energy transferred outside the stability limit by the high-frequency power applied by the high-frequency application electrode 93, and is emitted from the synchrotron 12 to the beam delivery system 4 through the emission deflector 8. The ion beam emitted from the synchrotron 12 to the beam delivery system 4 reaches the irradiation device 15 through the beam path 62.

[0067] The scanning electromagnets 5A and 5B of the irradiation device 15 are excited by receiving the control signal from the scan controller 41 in step S300, so that the ion beam reaches the position of the first point. Therefore, the ion beam is irradiated to the first point of the corresponding slice from the irradiation device 15.

[0068] When the irradiation dose to the first point reaches the corresponding target irradiation dose, if it is a point to stop beam emission, the scan controller 41 outputs a beam emission stop signal (step S207), and then proceeds to step S208.

[0069] When there are still points to be irradiated remaining in the first slice, the determination in step S208 is "no", so it proceeds to step S209, and the point number j is incremented by 1 (that is, the irradiation position is moved to the adjacent point). Then, the processes of steps S205, S300, and S208 are repeated. That is, before the irradiation of all points in the first slice is completed, the ion beam is sequentially moved to adjacent points by the scanning electromagnets 5A and 5B for ion beam irradiation (point scanning irradiation).

[0070] When the irradiation of all points with the irradiation count n = 1 in the first slice has ended, the determination in step S208 becomes "Yes". At this time, the scan controller 41 initializes the point number j (step S210). If the set irradiation count n has not been reached (the irradiation for the set number of times has not been completed for all points in the first slice), then step S211 is "No", and after incrementing n by 1 in step S212, it proceeds to S205 for the next irradiation.

[0071] On the other hand, if n = the set irradiation count (the irradiation for the set number of times has been completed for all points in the first slice), then step S211 is "Yes", and a slice change instruction is output to the CPU of the accelerator controller 40.

[0072] The CPU of the accelerator controller 40 that has received the slice change instruction increments the slice number i by 1 in step S213 (i.e., changes the irradiation target to the second slice), and outputs a remaining beam deceleration instruction to the synchrotron 12 in step S214.

[0073] By outputting the remaining beam deceleration instruction, the accelerator controller 40 controls the power supplies of the respective electromagnets of the synchrotron 12 to gradually reduce the excitation current of each electromagnet until it finally reaches a predetermined value, for example, an excitation current such that the ion beam is within the stable limit of the ion energy within the synchrotron 12. Thereby, the ion beam circulating within the synchrotron 12 is decelerated.

[0074] The period during which the ion beam exits from the synchrotron 12 varies depending on the number of points within the slice and the irradiation dose. At this time point, only the irradiation of the first slice has ended. When there is still irradiation remaining for the second slice and subsequent slices, the determination in step S215 is "No". In this case, it returns to step S202, and the accelerator parameters for the second slice are read from the memory of the accelerator controller 40 and set.

[0075] Thereafter, the processes of steps S203 to S215 are executed for the second slice. In addition, the processes of steps S202 to S215 are executed until the irradiation of all points in the final slice has ended.

[0076] When the determination in step S215 becomes "Yes" (the predetermined irradiation of all points within all slices in the target of the patient 30 has been completed), the CPU of the accelerator controller 40 outputs an irradiation end signal to the CPU 101 of the central control device 100.

[0077] Thereafter, use Figures 3 - 4 The detailed content of the control of the scan controller 41 and an example of the operation of the skip point function in this embodiment will be described.

[0078] Figure 3Shows the details in steps S205 and S300 executed by the scan controller 41. Figure 2 of

[0079] As a step corresponding to S205 of Figure 2 in Figure 3 the scan controller 41 outputs a setting instruction of a count value corresponding to the target irradiation number already stored in the memory 41A to the counter 41B in step S301.

[0080] The counter 41B sets the target count value of the j-th point of the slice i based on this setting instruction in step S302.

[0081] When the process of step S301 ends, as a step corresponding to S300 of Figure 2 it transfers to step S303, and outputs a current setting instruction of the scan electromagnets 5A and 5B for this point to the power supplies of the scan electromagnets 5A and 5B. The scan electromagnets 5A and 5B generate a deflection electromagnetic force with the corresponding current values, and output a current setting completion signal indicating that such a state has been completed to the scan controller 41 (step S304).

[0082] The scan controller 41 enters step S321 on the condition that a current setting instruction has been output (step S303) and a current setting completion signal from the scan electromagnets 5A and 5B has been input (step S304), and determines whether to start the beam emission at this point. However, it is also possible to enter step S321 without waiting for the condition of step S304 to be satisfied.

[0083] In step S321, before outputting the beam emission start signal (step S305), it is determined whether the count value of the counter 41B has not exceeded the target count value set in step S302.

[0084] In this determination, when the target count value is greater than the count value of the counter 41B (when it is "Yes" in S321), it enters step S305. On the other hand, when the target count value is less than or equal to the count value of the counter 41B (when it is "No" in S321), it means that the target irradiation amount at this point is full, so the beam emission at this point is skipped (step S322), and it enters step S316. As long as the determination in step S321 is "No", the beam emission skip in step S322 is executed, so the beam emission can be skipped even at two or more consecutive points.

[0085] When reaching step S322, immediately transfer to the completion process of irradiation at this point (step S316 and later). Therefore, when proceeding to step S321 without waiting for the condition of step S304 to hold, the establishment of step S304 can be added to the proceeding condition of step S322. Thus, duplication of the process of step S304 at this point and the process of step S304 at the next point can be avoided.

[0086] When step S321 is "Yes", the scan controller 41 outputs a beam emission start signal to the accelerator controller 40 in step S305. The accelerator controller 40 that receives the beam emission start signal controls the opening / closing switch 92 of the high-frequency application device 9 to close the opening / closing switch 92. Thereby, high-frequency power is applied from the high-frequency power supply 91 to the high-frequency application electrode 93.

[0087] Through the high-frequency power applied to the high-frequency application electrode 93, the energy of the ion beam orbiting inside the synchrotron 12 within the stability limit is transferred outside the stability limit, and exits from the synchrotron 12 to the beam transport system 4 through the outgoing deflector 8. The ion beam exiting to the beam transport system 4 exits from the irradiation device 15 through the beam path 62 to the corresponding point of the affected part of the patient 30 lying on the treatment table 29.

[0088] When the count value based on the input pulse to the scan controller 41 counted by the counter 41B becomes equal to or greater than the set value of the target count value (target irradiation dose) set in step S302 (step S309), in step S310, the counter 41B outputs a trigger signal.

[0089] The scan controller 41 that receives the trigger signal generates a beam emission stop signal based on the trigger signal and outputs the beam emission stop signal to the accelerator controller 40 (step S312). The accelerator controller 40 that receives the beam emission stop signal controls the opening / closing switch 92 to open the opening / closing switch 92. Thereby, the application of high-frequency power from the high-frequency power supply 91 to the high-frequency application electrode 93 is stopped, the energy of the ion beam becomes within the stability limit, the emission of the ion beam from the synchrotron 12 is stopped, and the emission of the ion beam to the patient is stopped.

[0090] The scan controller 41 has a delay timer (not shown) for the purpose of waiting until the synchrotron 12 responds to the beam stop instruction from the accelerator controller 40 (the beam completely stops). The trigger signal output in step S310 is input as an instruction signal for starting the delay timer (step S314).

[0091] When the elapsed time after the start becomes a predetermined set time, a delay time reached signal is output (step S315).

[0092] The scan controller 41 reads out the count value of the pulses output from the dose monitor 6A counted by the counter 41B in step S316 on the condition that the delay time reaches the signal and the input of the delay timer start instruction signal. However, instead of waiting for the set time of the delay timer to elapse, an electromagnet or the like on the beam delivery system 4 can be used to stop the beam reaching the patient 30.

[0093] Next, it is determined whether the irradiation dose at this point is below the set value (step S325). If it is not below the set value, it becomes "No" and proceeds to S317.

[0094] In step S317, the scan controller 41 uses the read count value to perform various actual value determinations in order to confirm whether various actual values of the point irradiated on the patient 30 are within the pre-planned range. If it is determined to be abnormal, it becomes "No" and an abnormal signal is output to the central control device 100 (step S318). On the other hand, if it is determined to be a normal value in step S317, it becomes "Yes", the count value is output to the central control device 100 as actual irradiation dose information, and the point irradiation is ended.

[0095] Here, among the various actual values, there are items whose calculation accuracy deteriorates significantly due to the small irradiation dose at this point. Therefore, an irradiation dose is set in advance for each actual value. When the irradiation dose at this point is below the set value, it becomes "Yes" in step S325, and the determination of this actual value is skipped (step S326), and the irradiation of the point is ended.

[0096] Thereby, even for points with a small irradiation dose, it is possible to prevent false detection caused by deteriorated calculation accuracy and continue irradiation. In addition, for the points where the above beam emission skip (step S322) occurs, if it is determined to be "Yes" in step S325, they also become the objects of determination skip. If the irradiation dose is below the set value for each actual value, this determination skip is applied, so there is also a possibility that multiple points will continuously become determination skips.

[0097] Here, in order to monitor the irradiation dose for which the determination has been skipped, the irradiation dose of the point for which the determination has been skipped is recorded in units of the skipped actual value, and this value (cumulative irradiation dose) is compared with the threshold set before irradiation (step S327). If this value is below the threshold (if it is "Yes" in step S327), it is determined that the cumulative irradiation dose is small enough that continuing the treatment without performing the determination will not affect safety, and the point irradiation is ended and proceeds to Figure 2 step S208.

[0098] On the other hand, when this value exceeds the threshold (when the result in step S327 is "No"), it is determined that continuing the treatment without performing the cumulative irradiation dose determination would reduce safety. Thus, an abnormality processing signal is output (step S318), and the process does not proceed to step S208. When the beam is being emitted, a beam emission stop signal is output (step S207), and a series of beam irradiations are interrupted. When determination skipping is continuously performed, the irradiation doses at these points are cumulated and recorded as the cumulative irradiation dose.

[0099] With this function, the irradiation dose of determination skipping is always monitored to prevent a reduction in treatment safety due to this determination skipping. Instead of monitoring the irradiation dose, the number of determination skippings can also be monitored. The recorded value of the irradiation dose or the number of times can be reset when its safety has been confirmed.

[0100] In addition, regarding the case where beam emission is skipped (step S322), similarly to the above, from the viewpoint of treatment safety, the number of skippings and the irradiation dose at the points where beam emission is skipped can also be monitored.

[0101] Figure 4 The graph 400 shows a timing chart of the irradiation dose when four consecutive points such as the (j - 1)-th point, the j-th point, the (j + 1)-th point, and the (j + 2)-th point are irradiated. Figure 4 The graph 400 of FIG. 10 is an example when monitoring the cumulative irradiation dose 401 with the start of the first irradiation as the starting point for the irradiation dose of each point.

[0102] As described above, after the beam emission stop signal is output from the scan controller 41, a response delay may occur until the opening / closing switch 92 is actuated by the accelerator controller 40 and the ion beam emission from the synchrotron 12 actually stops. On the other hand, after the beam emission stop signal ( Figure 4 stop instruction) is output, until the state changes from the beam-on state 411 to the beam-off state 412 in Figure 4 and the ion beam emission actually stops ( Figure 4 period (A): 413), the irradiation dose based on the ion beam emitted from the synchrotron 12 is measured by the dose monitor 6A and cumulated by the counter 41B. Let this be the irradiation dose (B) xx (xx indicates the point number at which the irradiation dose caused by the accelerator response delay is measured) 402. (B) xx The value of (B) varies according to the beam current value.

[0103] Regarding Figure 4 the relationship between the travel of the points in Figure 2 and the cumulative irradiation dose 401, it will be specifically described in association with the flowcharts described in FIGS. 2 and 3.

[0104] After the actual stop of the ion beam emission, as the processing of step S209 and step S205, the scan controller 41 reads out the current value data and the target irradiation dose data for the next irradiation position (point) from the memory 41A. In step S301, a setting instruction for the count value corresponding to the target irradiation dose is output to the counter 41B. Then, the counter 41B sets the target count value for the next irradiation position in step S302. Moreover, the scan electromagnets 5A and 5B are controlled according to the current setting instruction output in step S303, so that the irradiation position of the ion beam moves to the next point. According to the beam emission start signal in step S305, the ion beam emission from the synchrotron 12 starts again.

[0105] At this time, the irradiation dose (count value) for the next point includes not only the irradiation dose based on the measured value of the dose monitor 6A after the ion beam emission starts again, but also Figure 4 the irradiation dose (B) xx .

[0106] For example, Figure 4 the irradiation dose for the j-th point becomes the value obtained by setting the irradiation dose (B) j-1 : 402 measured during the period (A) for the (j - 1)-th point as the initial value and accumulating the irradiation dose after the beam emission starts again to this initial value. Then, when the irradiation dose for the j-th point reaches the target value for this point ( Figure 4 the irradiation dose indicated by the "j th -th point target irradiation dose 403"), the scan controller 41 outputs a beam emission stop signal to the accelerator controller 40. The accelerator controller 40 makes the on-off switch 92 perform an opening operation to stop the ion beam emission from the synchrotron 12. However, actually, during the period from when the beam emission stop signal is sent from the scan controller 41 until the ion beam irradiation actually stops, within the period (A): 414 of the j-th point, the ion beam is irradiated at the irradiation dose (B) j : 404 at this point. The irradiation dose during this period is further accumulated as the initial value when irradiating the next (j + 1)-th point, and the same is repeated hereafter.

[0107] As described above, by controlling based on the irradiation dose by the scan controller 41, during the irradiation of each point, the ion beam is always irradiated at this point until the sum of the irradiation dose (B) xx during the response delay period (A) generated during the irradiation of the previous point and the irradiation dose at this point becomes the target irradiation dose at this point.

[0108] Here, as in Figure 4 the (j + 1)-th point, considering (j + 1) thThe point with a target exposure of 405 is extremely small.

[0109] In this case, after irradiating the j-th point with the j th point target exposure of 403, it is determined whether the target count value corresponding to the (j + 1) th target exposure of 405 is greater than the irradiation amount (B) of the ion beam between the periods (A): 414 of the j-th point j : 404 at the time point when the corresponding count value is large (beam emission start signal output determination: step S321), it becomes a situation where the target exposure of this point has been exceeded (the target count value has been exceeded). At this time, at the (j + 1)-th point, the scan controller 41 determines "no" in step S321 and does not output the beam emission start signal, skipping the (j + 1)-th point (step S322).

[0110] A function for monitoring whether it is the timing allowed to skip can also be installed immediately before step S322, which can prevent unexpected skipping. In addition, as described above, the condition established in step S304 of the (j + 1)-th point can also be added to the execution conditions of step S322.

[0111] After that, after the processing after the beam emission stop (steps S316 and later), it proceeds to the next point (here, the (j + 2)-th point). In addition, for the skipped point, since the actual value of the irradiation amount is zero, it is "yes" in step S325 above, and the step S317 for determining the counter actual value is also skipped. (step S326)

[0112] As described above, through the actual value determination skip function (hereinafter referred to as skip function A) of step S326 and the point irradiation skip function (hereinafter referred to as skip function B) of step S322, it is possible to perform irradiation of small-dose points (points with a target exposure of zero or extremely small). These functions are collectively referred to as the skip point function.

[0113] As described above, with the particle beam irradiation system of this embodiment that has introduced the skip point function, the following effects are obtained.

[0114] By introducing this function, at the time point of outputting the beam emission start signal, even in the case where the target exposure of this point has been exceeded, or in the case of points with small-dose irradiation to cope with accelerator response delay or complex shapes and dose distributions, it is possible to continue treatment through the skip function that maintains sufficient safety, and the irradiation will not be interrupted due to errors and thus treatment can continue.

[0115] In addition, assuming that in the case where the irradiation amount of this point is infinitely small due to various conditions, or Figure 4 of (B) xx:Even when the values of 402 and 404 increase suddenly, it is possible to prevent irradiation interruption by applying this function. As a result, during treatment planning, there is no need to consider small-dose points during irradiation, thereby improving the efficiency of treatment planning and also enabling an improvement in treatment quality.

[0116] In addition, it is possible to relax the restriction on the lower limit value of the irradiation dose per point that can be used during treatment, and it is possible to perform flexible treatment (irradiation of complex shapes and dose distributions) regardless of the irradiation dose per point.

[0117] Moreover, as described above, regarding ensuring safety by introducing this function, safety is ensured by installing a monitoring function for the irradiation dose or the number of times for the points to which skip function A is applied. To further improve safety, the monitoring function of skip function B can also be used.

[0118] In addition, it is presumed that the points to which this function is applied are less than 1% of the whole during one treatment. Therefore, regarding the introduction of this function, it is a function that can be introduced while suppressing the impact on treatment to a minimum, and the current treatment quality can be maintained.

[0119] Example 2

[0120] Next, a particle beam irradiation system according to a second embodiment of the present invention will be described. The particle beam irradiation system of this embodiment has the same structure as the particle beam irradiation system 150 described in Example 1, so the description of the overall structure will be omitted. In the particle beam irradiation system of this embodiment, instead of the method of controlling the start and stop of beam emission for each point described in Example 1, its major feature is that it is possible to start and stop beam emission at an arbitrary timing, and the control sequence of the scan controller 41 is different from that of the particle beam irradiation system 150 of Example 1.

[0121] Figure 5 Flowcharts of the scan controller 41 and the accelerator controller 40 of this embodiment and their cooperation are shown. For the steps that perform the same processing as the flowcharts described in Example 1 Figure 2 the same step numbers are assigned to the steps.

[0122] As the initial setting value at the start of irradiation set in step S251, in addition to the items described in Example 1, k as the beam stop point number is also set. According to this setting, after the irradiation at point number k is completed, the beam is stopped. In addition, multiple k values can be set.

[0123] Step S255 and step S350 respectively correspond to Figure 2 steps S205 and S300 of the flowchart of Example 1. In addition, other initial settings and processes are the same as those of Figure 2 the flowchart of Example 1.

[0124] Figure 6 shows the details of steps S255 and S350 executed by the scan controller 41 of this embodiment. Figure 5 of step S255 and S350.

[0125] As described above, in this embodiment, multiple points are irradiated without stopping the beam. Therefore, for the first point where the beam emission starts, the beam emission starts through the same steps as in Embodiment 1 (steps S301 to S304), but in the points where the beam has not been stopped from the previous point, there is no need to output a beam emission start signal (step S305). That is, in step S323 before outputting the beam emission start signal, it is confirmed that the beam is emitting (whether the beam has not been stopped at the previous point), and if the determination is "yes", the process proceeds to step S309.

[0126] After that, when the actual count value becomes equal to or greater than the target count value, the process proceeds to step S324 to confirm whether this point is a point where the beam emission stops. Specifically, it is confirmed whether the point number j is the same as the pre-set point number k. If "yes", the process proceeds to steps S310, S312, S314, and S315 that perform the same beam emission stop process as in Embodiment 1.

[0127] After that, when the beam stop signal is output in step S312, when the delay timer that starts operating in S314 has passed the set value in S315, the process proceeds to step S316. In this embodiment, an electromagnet or the like can also be used instead of the above delay timer to stop the beam reaching the patient 30.

[0128] On the other hand, if the determination in step S324 is "no", it means that this point is a point where the beam emission does not stop, and the beam stop process is not performed and the process proceeds to step S316. In addition, steps S316, S317, S318 and steps S325, S326, S327 are the same as in Embodiment 1.

[0129] On the other hand, in the points where the beam has been temporarily stopped from the previous point, if the determination in step S323 is "no", the process proceeds to step S321 and subsequent processes for performing the beam emission start process. Steps S321, S305, and S322 for performing the beam emission start process are the same as the processes described in Embodiment 1. After entering step S322, the process proceeds to step S316, so that the beam stop signal is not output again in the state where the beam has stopped.

[0130] A consideration method for the skip point function of this embodiment will be described.

[0131] As used in Embodiment 1 Figure 4As described, the skip function B is only applicable to the exposure amount (B) caused by the response delay at a certain point xx when it exceeds the target exposure amount of the next point. As described above, this (B) xx is generated due to the response delay of the accelerator. Therefore, for points where the beam emission does not stop, the value of (B) xx is zero.

[0132] Therefore, in this embodiment, the skip function B is only effective for points where the beam emission stopped at the previous point and starts at this point. Other points without the beam emission start process (judged as "yes" in Figure 6 step S323) are outside the scope of this skip function B. In addition, regarding the skip function A, all points are targets regardless of the start and stop of the beam emission.

[0133] In addition, for points that are the targets of this skip function B, similar to Embodiment 1, before the beam emission starts ( Figure 6 step S305), a determination is made on whether to skip point irradiation ( Figure 6 step S321). When skipping, enter Figure 6 step S322, and then enter step S316.

[0134] In addition, when the actual value determination is skipped in S326, similar to the description in Embodiment 1, in order to monitor the exposure amount for which the determination was skipped, the exposure amount of the point for which the determination was skipped is recorded in units of the skipped actual value, and this value (cumulative exposure amount) is compared with the threshold set before irradiation (S327). When this value (cumulative exposure amount) is below the threshold (when it is "yes" in S327), it is determined that the cumulative exposure amount is small enough that continuing the treatment without performing the determination will not affect safety, and the point irradiation is ended and enter Figure 5 step S208.

[0135] On the other hand, when this value exceeds the threshold (when it is "no" in S327), it is determined that if the cumulative exposure amount is continued without performing the determination, the safety will be reduced, and instead of entering step S208, a function of interrupting the irradiation (S318) that interrupts a series of beam irradiations is implemented. In addition, when the determination skips are continuously made, the exposure amounts of these points are accumulated and recorded as the cumulative exposure amount.

[0136] With this function, the exposure amount for which the determination is skipped is always monitored to prevent a reduction in the safety of the treatment due to this determination skip. Instead of monitoring the exposure amount, the number of determination skips can also be monitored. The recorded exposure amount or number value can also be reset when its safety is confirmed.

[0137] In addition, in the case where beam extraction is skipped (step S322 ), similarly to the above, the number of skips and the irradiation dose at the point where beam extraction is skipped can also be monitored from the viewpoint of treatment safety.

[0138] exist Figure 7 The same as described in Example 1 is shown in Figure 4 The corresponding chart of the chart 400. Figure 7 The graph shows the following situation: after the (jn)th to (j-1)th points, the jth to (j+n)th points, and the (j+n+2)th point, the beam maintains the open 711 state, and the beam emission is not stopped but the irradiation of the next point is continued, and the beam is turned off 712 between the (j-1)th point and the jth point, and between the (j+n)th point and the (j+n+1)th point.

[0139] and Figure 4 Similarly, Figure 7 This is an example of monitoring the irradiation amount at each point as a cumulative irradiation amount 701 starting from the first irradiation start.

[0140] As described in the first embodiment, after the beam emission stop signal is output from the scanning controller 41, a response delay may occur until the accelerator controller 40 operates the on-off switch 92 to actually stop the emission of the ion beam from the synchrotron 12. Figure 7 After the stop instruction) Figure 7 The period from when the beam-on state 711 changes to when the beam-off state 712 actually stops the ion beam emission ( Figure 7 During the period (A): 713), the irradiation amount based on the ion beam emitted from the synchrotron 12 is measured by the dose monitor 6A and accumulated by the counter 41B.

[0141] Let this be the irradiation amount (B) caused by the accelerator response delay. xx (xx indicates the point number where the irradiation dose caused by the accelerator response delay was measured). In addition, (B) xx The value of varies according to the beam current value.

[0142] about Figure 7 The relationship between the movement of the points in and the cumulative exposure 701 is the same as that in Figure 5 The flowchart described in 6 is linked and described in detail.

[0143] After the actual stop of the continuous ion beam emission, as the processing of step S209 and step S205, the scan controller 41 reads out the current value data and the target irradiation dose data for the next irradiation position (point) from the memory 41A. In step S301, a setting instruction for the count value corresponding to the target irradiation dose is output to the counter 41B. Then, the counter 41B sets the target count value for the next irradiation position in step S302. Moreover, according to the current setting instruction output in step S303, the scan electromagnets 5A and 5B are controlled so that the irradiation position of the ion beam moves to the next point. According to the beam emission start signal in step S305, the emission of the ion beam from the synchrotron 12 is started again.

[0144] At this time, the irradiation dose (count) of the point where irradiation starts not only includes the irradiation dose based on the measured value of the dose monitor 6A after the ion beam emission starts again, but also includes Figure 7 the irradiation dose (B) xx .

[0145] For example, Figure 7 the irradiation dose of the j-th point becomes the value obtained by setting the irradiation dose (B) j-1 measured in the last period (A) 713 during the irradiation periods of the (j - n)-th to (j - 1)-th points as the initial value and accumulating the irradiation dose after the beam emission starts again to this initial value.

[0146] Then, for the j-th to (j + n)-th points irradiated continuously next, when the irradiation dose of each point reaches the target count value for each point set in step S302, it is determined in step S324 whether the irradiated point number has reached the beam stop point number (k) set in step S251.

[0147] If the determination result is that the beam stop point number (k) has been reached (yes in step S324), a trigger signal is output from the counter 41B to the scan controller 41 in step S310. The scan controller 41 that receives this trigger signal sends a beam emission stop signal to the accelerator controller 40 in step S312, and the accelerator controller 40 makes the opening and closing switch 92 perform an opening operation to stop the emission of the ion beam from the synchrotron 12.

[0148] In Figure 7 this case, for the j-th to (j + n - 1)-th points, if it is determined as "no" in S324, the beam stop process is not performed and the process proceeds to step S316, and then to the next point irradiation.

[0149] On the other hand, when the (j+n)th target count value is reached, that is, when the jth to (j+n)th target irradiation cumulative value starting beam emission is reached (in Figure 7 In the th ~(j+n) th When the irradiation amount represented by the point target irradiation amount 703” is reached, it is determined as “yes” in step S324.

[0150] However, in reality, from the time when the scanning controller 41 issues a beam emission stop signal until the irradiation of the ion beam is actually stopped, in the last period (A): 714 of the period during which the jth point to the (j+n)th point are irradiated, the point is irradiated with the irradiation amount (B) j+n : 704 irradiates with an ion beam. The irradiation amount during this period is further accumulated as the initial value for the next point irradiation starting from the (j+n+1)th point, and the same method is repeated thereafter.

[0151] As described above, by performing control based on the irradiation amount by the scanning controller 41, in each continuous spot irradiation, the ion beam is always irradiated to the continuous spot irradiation area until the irradiation amount (B) during the response delay period (A) generated in the previous continuous spot irradiation is less than xx Until the total value of the irradiation amount of the continuous spot irradiation becomes the target irradiation amount of the continuous spot irradiation area.

[0152] Here, if Figure 7 As in the case of the (j+n+1)th point, consider the initial point when irradiation is started again, i.e., (j+n+1) th Point target: A point at which the irradiation amount 705 is extremely small.

[0153] At this time, for the first point in the continuous irradiation, that is, the (j+n+1)th point, after the (j)th point in the continuous irradiation of the immediately preceding point has been irradiated, th ~(j+n) th After the point target irradiation amount 703 is irradiated, the (j+n+1)th point is determined. th Is the target count value corresponding to the target irradiation amount 705 greater than (j)? th ~(j+n) th Period (A) during the spot irradiation period: Ion beam irradiation dose in 714 (B) j+n : At the time point when the count value corresponding to 704 is large (beam emission start signal output determination: step S321), the target irradiation amount at that point has been exceeded (the target count value has been exceeded). At this time, the scanning controller 41 determines "No" in step S321 at the (j+n+1)th point, does not output the beam emission start signal, and skips the (j+n+1)th point (step S322).

[0154] It is also possible to install a function for monitoring the timing that allows skipping immediately before step S322, so as to prevent unexpected skipping. In addition, as described above, it is also possible to add, to the progression condition of step S322, the condition that holds in step S304 for consecutive points starting from the (j + n + 1)-th point.

[0155] After that, through the processing after beam emission stop (steps S316 and later), it progresses to the next consecutive point (here, the (j + n + 2)-th point). Regarding the skipped points, since the actual value of the irradiation dose is zero, it is "Yes" in the above step S325, enters step S326, and also skips step S317 for the actual value of the skip determination counter.

[0156] As described above, in the same manner as the description in Embodiment 1, through the actual value determination skip function in step S326 (hereinafter referred to as skip function A) and the point irradiation skip function in step S322 (hereinafter referred to as skip function B), it is possible to perform irradiation of small-dose points (points with a target irradiation dose of zero or very small). These functions are collectively referred to as the skip point function.

[0157] As used Figure 7 As described, skip function B is only applicable to the case where the irradiation dose (B) xx exceeds the target irradiation dose of the next point. As described above, this (B) xx is generated due to the response delay of the accelerator. Therefore, for points where the beam emission is not stopped, the value of (B) xx is zero.

[0158] Thus, in this embodiment, skip function B is only effective for points where the beam emission stopped at the previous point and starts at this point, and other points not accompanied by the beam emission start process (judged as "Yes" in Figure 6 step S323) are outside the scope of this skip function B. Skip function A targets all points regardless of the start and stop of beam emission.

[0159] In addition, for points that are the target of this skip function B, in the same manner as in Embodiment 1, before the beam emission starts ( Figure 6 step S305), a determination of whether to skip point irradiation ( Figure 6 step S321) is performed. In the case of skipping, it progresses to Figure 6 step S322, and then progresses to step 324.

[0160] As described above, in the particle beam irradiation system of this embodiment in which the skip point function is introduced, the following effects similar to those of Embodiment 1 are obtained: at the time point when the output beam emission start signal is output, even when the target irradiation dose at that point is exceeded, or in the case of a small-dose irradiation point for coping with accelerator response delay or complex shape and dose distribution, the treatment can be continued by the skip function that maintains sufficient safety, and the irradiation will not be interrupted due to an error, thus enabling the treatment to continue.

[0161] In addition, it is assumed that in the case where the irradiation dose at this point is infinitesimal due to various conditions, or Figure 7 in (B) of xx : when the values of 702 and 704 increase suddenly, the irradiation interruption can also be prevented by applying this function. Thus, during treatment planning, small-dose points do not need to be considered during irradiation, thereby improving the efficiency of treatment planning and enabling the improvement of treatment quality.

[0162] In addition, the restriction on the lower limit value of the irradiation dose per point that can be used during treatment can be relaxed, and flexible treatment (irradiation of complex shapes and dose distributions) independent of the irradiation dose per point can be performed.

[0163] Moreover, as described above, regarding ensuring safety by introducing this function, safety is ensured by installing a monitoring function for the irradiation dose or number of times for the points to which Skip Function A is applied. To further improve safety, the monitoring function of Skip Function B can also be used.

[0164] In addition, it is presumed that the points to which this function is applied account for less than 1% of the whole during one treatment. Therefore, regarding the introduction of this function, it is a function that can be introduced while minimizing the impact on treatment and can maintain the current treatment quality.

[0165] Symbol Explanation

[0166] 1 Charged particle beam generation device

[0167] 4 Beam delivery system

[0168] 5A, 5B Scanning electromagnets (charged particle beam scanning devices)

[0169] 6A Dose monitor (irradiation dose detection device)

[0170] 6B Position monitor

[0171] 8 Deflector for emission

[0172] 9 High-frequency application device

[0173] 10 Acceleration device

[0174] 11 Pre - charged particle beam generation device (linear accelerator)

[0175] 12 Synchrotron (accelerator)

[0176] 15 Irradiation device

[0177] 17, 23, 24 Deflection electromagnet

[0178] 18, 21, 22 Quadrupole electromagnet

[0179] 29 Treatment table

[0180] 30 Patient

[0181] 40 Accelerator / delivery system controller

[0182] 41 Scan controller

[0183] 41A Memory

[0184] 41B Counter

[0185] 62 Beam path

[0186] 91 High - frequency power supply

[0187] 92 On - off switch

[0188] 93 High - frequency application electrode

[0189] 100 Central control device

[0190] 140 Treatment planning device.

Claims

1. A particle beam irradiation system, comprising: A charged particle beam generation unit that generates a charged particle beam; An irradiation unit including a scanning electromagnet and a dose monitor, wherein, The scanning electromagnet irradiates the irradiation target with the charged particle beam generated by the charged particle beam generation unit in a point-by-point manner, and the dose monitor measures the irradiation dose of the charged particle beam; A scan controller that generates a signal for starting or stopping the irradiation of the charged particle beam that the irradiation unit irradiates to the irradiation target; and An accelerator / transport system controller that receives the signal for starting or stopping the irradiation of the charged particle beam output from the scan controller, and starts or stops the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit, Characterized in that When the accelerator / transport system controller that receives the signal for stopping the irradiation of the charged particle beam has stopped the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit, and when the irradiation dose measured by the dose monitor at the point where the charged particle beam has been irradiated after the signal for stopping the irradiation is output from the scan controller exceeds the target irradiation dose of the next point where the charged particle beam has been irradiated, it is determined that the irradiation of the charged particle beam to the next point is skipped, thereby controlling the accelerator / transport system controller.

2. A particle beam irradiation system, comprising: A charged particle beam generation unit that generates a charged particle beam; The irradiation unit includes a scanning electromagnet and a dose monitor, wherein, The scanning electromagnet irradiates multiple points of the irradiation target with the charged particle beam generated by the charged particle beam generation unit in a point-by-point manner, and the dose monitor measures the irradiation dose of the charged particle beam; A scan controller that generates a signal for starting or stopping the irradiation of the charged particle beam that the irradiation unit irradiates to the irradiation target; and An accelerator / transport system controller that receives the signal for starting or stopping the irradiation of the charged particle beam output from the scan controller, and starts or stops the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit, Characterized in that The scan controller controls the accelerator / transport system controller to continuously irradiate the charged particle beam to the multiple points. When the total irradiation dose of the multiple points of the continuous irradiation measured by the dose monitor reaches a predetermined irradiation dose, a signal for stopping the irradiation of the charged particle beam is output to the accelerator / transport system controller. When the irradiation dose measured by the dose monitor after outputting the stop signal exceeds the target irradiation dose of the first point among the next multiple points of continuous irradiation of the multiple points of the continuous irradiation, it is determined that the irradiation of the charged particle beam to the first point is skipped, thereby controlling the accelerator / transport system controller.

3. The particle beam irradiation system according to claim 1 or 2, characterized in that When the measured value of the exposure dose of the charged particle beam at the point irradiated with the charged particle beam measured by the dose monitor is greater than a preset amount, the scan controller determines the normality / abnormality of the measured value. When the measured value is less than the preset amount, the scan controller skips the determination of the normality / abnormality of the measured value.

4. The particle beam irradiation system according to claim 3, wherein The scan controller compares the accumulation of the measured value at the point where the determination of the normality / abnormality of the measured value has been skipped with a preset threshold value. When the accumulation of the measured value is greater than the threshold value, the scan controller controls the accelerator / transport system controller to interrupt the irradiation of the charged particle beam.

5. A control method for a particle beam irradiation system, wherein the particle beam irradiation system measures the exposure dose while irradiating a plurality of points of an irradiation target from an irradiation unit with a charged particle beam generated by a charged particle beam generation unit in sequence, and starts or stops the irradiation of the charged particle beam according to a signal output from a scan controller. Characterized in that When the exposure dose of the charged particle beam at one of the plurality of points measured by the dose monitor reaches a predetermined exposure dose, a signal for stopping the irradiation of the charged particle beam is output from the scan controller to the accelerator / transport system controller. When the exposure dose measured by the dose monitor after the output of the stop signal exceeds the target exposure dose of the next point irradiated with the charged particle beam, it is determined that the irradiation of the charged particle beam to the next point is skipped, and the accelerator / transport system controller is controlled.

6. A control method for a particle beam irradiation system, wherein the particle beam irradiation system continuously irradiates a plurality of points of an irradiation target from an irradiation unit with a charged particle beam generated by a charged particle beam generation unit while measuring the exposure dose by a dose monitor, and starts or stops the irradiation of the charged particle beam according to a signal output from a scan controller. Characterized in that When the total exposure dose of the charged particle beam at the plurality of points of the continuous irradiation measured by the dose monitor reaches a predetermined exposure dose, a signal for stopping the irradiation of the charged particle beam is output from the scan controller to the accelerator / transport system controller. When the exposure dose measured by the dose monitor after the output of the stop signal exceeds the target exposure dose of the first point of the next continuous irradiation of the plurality of points of the continuous irradiation, it is determined that the irradiation of the charged particle beam to the first point is skipped, and the accelerator / transport system controller is controlled.

7. The control method for a particle beam irradiation system according to claim 5 or 6, wherein In the scan controller, when the measured value of the exposure dose of the charged particle beam at the point irradiated with the charged particle beam measured by the dose monitor is greater than a preset amount, the normality / abnormality of the measured value is determined. When the measured value is less than the preset amount, the determination of the normality / abnormality of the measured value is skipped.

8. The control method of the particle beam irradiation system according to claim 7, characterized in that in the scanning controller, the accumulation of the measured values at the points where the determination of normal / abnormal of the measured values is skipped is compared with a preset threshold value. When the accumulation of the measured values is greater than the threshold value, the accelerator / transport system controller is controlled to interrupt the irradiation of the charged particle beam.

9. A control device for a particle beam irradiation system The particle beam irradiation system includes: a charged particle beam generation unit that generates a charged particle beam; an irradiation unit that sequentially point-irradiates a plurality of points of an irradiation target with the charged particle beam generated by the charged particle beam generation unit, and a dose monitor that monitors the irradiation dose of the charged particle beam irradiated from the irradiation unit, characterized in that the control device includes: a scanning controller that generates a signal for starting or stopping the irradiation of the charged particle beam irradiated by the irradiation unit to the irradiation target; and an accelerator / transport system controller that receives a signal for stopping the irradiation of the charged particle beam from the scanning controller and starts or stops the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit, when the irradiation dose of the charged particle beam at one of the plurality of points measured by the dose monitor reaches a predetermined irradiation dose, the scanning controller outputs a signal for stopping the irradiation of the charged particle beam to the accelerator / transport system controller. When the irradiation dose measured by the dose monitor after the output of the stop signal exceeds the target irradiation dose of the next point irradiated with the charged particle beam, it is determined that the irradiation of the charged particle beam to the next point is skipped, and the accelerator / transport system controller is controlled.

10. A control device for a particle beam irradiation system The particle beam irradiation system includes: a charged particle beam generation unit that generates a charged particle beam; an irradiation unit that continuously irradiates a plurality of points of an irradiation target with the charged particle beam generated by the charged particle beam generation unit; and a dose monitor that monitors the irradiation dose of the charged particle beam irradiated from the irradiation unit, characterized in that the control device includes: a scanning controller that generates a signal for starting or stopping the irradiation of the charged particle beam irradiated by the irradiation unit to the irradiation target; and an accelerator / transport system controller that receives a signal for stopping the irradiation of the charged particle beam from the scanning controller and starts or stops the emission of the charged particle beam from the charged particle beam generation unit to the irradiation unit, When the total irradiation dose of the charged particle beam at the plurality of points of the continuous irradiation measured by the dose monitor reaches a predetermined irradiation dose, the scanning controller outputs a signal to stop the irradiation of the charged particle beam to the accelerator / conveyor system controller. When the irradiation dose measured by the dose monitor after the output of the stop signal exceeds the target irradiation dose of the first point among the plurality of points of the next continuous irradiation of the plurality of points of the continuous irradiation, it is determined that the irradiation of the charged particle beam to the first point is skipped, and the accelerator / conveyor system controller is controlled.

11. The control device of the particle beam irradiation system according to claim 9 or 10, characterized in that when the measured value of the irradiation dose of the charged particle beam at the point where the charged particle beam is irradiated, measured by the dose monitor, is greater than a preset amount, the scanning controller determines the normality / abnormality of the measured value, and when the measured value is less than the preset amount, the determination of the normality / abnormality of the measured value is skipped.

12. The control device of the particle beam irradiation system according to claim 11, characterized in that the scanning controller compares the accumulation of the measured value at the point where the determination of the normality / abnormality of the measured value is skipped with a preset threshold, and when the accumulation of the measured value is greater than the threshold, controls the accelerator / conveyor system controller to interrupt the irradiation of the charged particle beam.

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