JP2009050468A - Charged particle beam irradiation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charged particle beam irradiation system which accurately measures vertical dose distributions of particle beam relative to the particle beam advancing direction within an irradiation object, and thus improves accuracy of controlling vertical irradiation dose relative to the particle beam advancing direction at each position within the irradiation object and secures desired dose distributions. <P>SOLUTION: The charged particle beam irradiation system has a two-dimensional dose monitor 212 and an irradiation controlling apparatus 300. A dose counter apparatus 304a measures an added dose for each region of a monitor plane of the two-dimensional dose monitor 212 by independently cumulative doses measured for each region of the monitor plane. A comparing section 306 outputs a control signal for stopping beam irradiation when the cumulative dose measured for each region of the monitor plane reaches a target dose predetermined for each region of the monitor plane so as to stop beam irradiation to a region reaching its target dose. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a charged particle beam irradiation system, and in particular, a charge suitable for application to a particle beam therapy apparatus that irradiates and treats a diseased site as an irradiation target with a charged particle beam (ion beam) such as protons and carbon ions. The present invention relates to a particle beam irradiation system.

  2. Description of the Related Art A treatment method is known in which an affected area of a patient such as cancer is irradiated with a charged particle beam (ion beam) such as protons and carbon ions. The charged particle beam irradiation system used for this treatment is composed of, for example, a rotary irradiation apparatus including an ion beam generator including an ion source, a pre-stage accelerator, a circular accelerator, a beam transport system, and an irradiation field forming apparatus. ing. A circular accelerator accelerates an ion beam that circulates along a circular orbit to a target energy and then emits the ion beam, and transports the ion beam to an irradiation field forming apparatus through a beam transport system. The irradiation field forming device shapes the dose distribution of the ion beam according to the shape of the affected area of the patient and irradiates the affected area.

  As a circular accelerator, for example, as disclosed in Patent Document 1, means for circulating an ion beam along a circular orbit, means for increasing the betatron oscillation amplitude of the ion beam within the resonance stability limit, and circulating the ion beam A synchrotron having an exit deflector that is taken out of orbit is known. By increasing the betatron oscillation amplitude of the ion beam, the ion beam is moved out of the stability limit and emitted from the synchrotron to the beam transport system.

  Usually, the beam emitted from the accelerator has a Gaussian distribution in a direction perpendicular to the traveling direction (hereinafter referred to as a lateral direction), and the beam size is about 1 to 5 mm. Usually, the affected area has a larger size in the lateral direction. Therefore, in order to effectively irradiate an ion beam across the entire affected area, a large and uniform dose of the affected area in the lateral direction is large. A distribution needs to be formed.

  From this point of view, as a conventional ion beam irradiation system, for example, as described in Non-Patent Document 1, a beam having a Gaussian distribution shape is scanned in a circular or zigzag shape by a scanning electromagnet in a horizontal direction, and a uniform dose region is obtained. A method of forming is known. Among them, the wobbler method forms a dose distribution with high uniformity in the center by setting the beam size and the beam scanning radius to optimum values. Patent Document 2 describes a method of forming a uniform dose distribution by scanning a beam in a Lissajous shape.

Japanese Patent No. 2596292 JP 2006-208200 A REVIEW OF SCIENTIFIC INSTRUMENTS Vol.64 No.8 (August 1993; P2084-2089)

  In the above prior art, the amount of beam emitted from the accelerator is not always constant, and there is a possibility that the beam emission amount may change over time while scanning the beam. In some cases, uniform irradiation is impossible within the planned irradiation dose. In order to avoid such a situation, the beam scanning speed is made sufficiently faster than the time change of the beam intensity, and the irradiation area is scanned many times, so that the change of the beam emission amount is temporally averaged. There is a need to. However, even in that case, since there was no means capable of accurately measuring the dose distribution of the scanned beam in real time, it was not possible to control the irradiation dose based on the measurement result of the dose distribution, and the desired dose at the end of irradiation. Whether or not a distribution is obtained becomes a stochastic event, and as a result, it is difficult to ensure a desired dose distribution.

  An object of the present invention is to accurately measure the dose distribution in the direction perpendicular to the charged particle beam traveling direction in the irradiation target, and as a result, each position in the direction perpendicular to the charged particle beam traveling direction in the irradiation target. It is an object of the present invention to provide a charged particle beam irradiation system that can improve the control accuracy of the irradiation dose and can ensure a desired dose distribution.

  A feature of the present invention that achieves the above-described object is that a charged particle beam generator that accelerates and emits a charged particle beam (ion beam), and scanning that scans the charged particle beam emitted from the charged particle beam generator. In a charged particle beam irradiation system having an electromagnet and a beam irradiation device that irradiates an irradiation target with the charged particle beam that has passed through the scanning electromagnet, the charged beam that is provided in the beam irradiation device and scanned by the scanning electromagnet A monitor plane in which the scanning range of the particle beam is divided into a plurality of areas, a two-dimensional dose monitor capable of measuring an irradiation dose independently for each area of the monitor plane, and the monitor plane of the two-dimensional dose monitor The dose measured for each area is input, and this measured dose is integrated independently for each area of the monitor plane and integrated for each area of the monitor plane. A region where the amount of the measured dose is measured and the integrated dose measured for each region of the monitor plane reaches a target dose set in advance for each region of the monitor plane, a control signal is output to stop beam irradiation, and the region reaches the target dose And an irradiation control device for stopping the beam irradiation to.

  In this way, the two-dimensional dose monitor and the irradiation control device are provided. In the irradiation control device, the dose measured for each monitor plane region of the two-dimensional dose monitor is integrated independently for each monitor plane region, and the monitor plane region By measuring the integrated dose every time, the dose distribution in the direction perpendicular to the charged particle beam traveling direction in the irradiation target can be accurately measured. In addition, when the accumulated dose measured for each area on the monitor plane reaches the target dose set in advance for each area on the monitor plane, a control signal for stopping beam irradiation is output and the target dose is reached. By stopping the beam irradiation to the target area, irradiation control reflecting the measurement result of the irradiation dose becomes possible, and the control accuracy of the irradiation dose at each position in the direction perpendicular to the charged particle beam traveling direction in the irradiation target is improved. The desired dose distribution can be ensured.

  In addition, the present invention is characterized in that the irradiation control device counts a measured dose for each region of the monitor plane input from the two-dimensional dose monitor for each region of the monitor plane, and the dose counter device. A storage device that includes a first storage unit that stores the dose counted by each region of the monitor plane as the integrated dose, and a second storage unit that stores the target dose for each region of the monitor plane; and An irradiation area determination device that inputs an excitation current command value at that time and identifies an area corresponding to the excitation current command value at that time of the scanning magnet among a plurality of areas on the monitor plane as a measurement area, The dose counter device is identified by the irradiation region determination device out of the measured dose for each region of the monitor plane input from the two-dimensional dose monitor By selecting only measured dose of the serial measurement area is to count.

As a result, even if erroneous measurement due to noise or the like occurs in an area other than the beam irradiation area on the monitor plane of the two-dimensional dose monitor, the influence of such erroneous measurement is eliminated, and accurate measurement of irradiation dose is possible. In addition, the present invention is characterized in that the irradiation region determination device has a center of a beam irradiation region corresponding to an excitation current command value of the scanning electromagnet among the plurality of regions on the monitor plane. The region is identified as a central measurement region, and a plurality of regions located around the central measurement region and constituting a part of the beam irradiation region are identified as simultaneous measurement regions, and the dose counter device includes the two-dimensional dose Of the measured dose for each region of the monitor plane input from the monitor, the central measurement region and the simultaneous measurement region identified by the irradiation region determination device It is to select and count the dose.

  As a result, a scatterer is provided in the irradiation forming device, and the lateral distribution of the charged particle beam is expanded by the scatterer, so that the irradiation dose can be accurately measured even when the beam diameter is larger than the width of the divided area of the monitor plane. can do.

  In addition, the present invention is characterized in that the irradiation control device calculates an integrated dose of the measurement region (center measurement region) identified by the irradiation region determination device among the integrated doses for each region stored in the first storage unit. And a first irradiation management device that outputs a control signal for stopping the beam irradiation when the accumulated dose reaches the target dose when compared with the target dose selected and stored in the second storage unit. .

  Thus, by selectively irradiating the charged particle beam only to the region where the integrated dose has not reached the target dose, the dose distribution in the direction perpendicular to the beam traveling direction can be controlled. In addition, even in a region that is being irradiated with a charged particle beam, the beam irradiation dose can be controlled in real time by stopping beam irradiation on that region as soon as the target dose is reached. Can be increased.

  In addition, the present invention is characterized in that, in the integrated dose for each region stored in the first storage unit, the integrated dose of the measurement region identified by the irradiation region determination device is the second storage unit. A second irradiation management device that reads out whether or not the target dose stored in (1) is reached and outputs a control signal for stopping the beam irradiation when the accumulated dose has reached the target dose; When at least one of the management device and the second irradiation management device outputs a control signal for stopping the beam irradiation, the control device has an output device that outputs a beam emission OFF signal to the charged particle beam generation device.

  As a result, when the cumulative dose of the region corresponding to the update of the excitation current command value has reached the target dose, even if a signal for commanding beam irradiation is output due to a malfunction of the first irradiation management device, Since the second irradiation management device outputs a control signal for stopping the beam irradiation and the output device outputs a beam emission OFF signal, erroneous irradiation of the charged particle beam is reliably prevented, and high safety is ensured.

  In addition, the present invention is characterized in that the second irradiation management device is configured such that the accumulated dose for each region stored in the first storage unit reaches the target dose stored in the second storage unit in all regions of the monitor plane. In this case, an energy update command is output and a control signal for stopping the beam irradiation is output to the output device.

  As a result, when the integrated dose reaches the target dose in all areas, even if a signal for instructing beam irradiation is output due to a malfunction of the first irradiation management device, the second irradiation management device performs beam irradiation. Since the control signal for stopping is output and the output device outputs the beam extraction OFF signal, erroneous irradiation of the charged particle beam is reliably prevented, and high safety is ensured.

  Further, the present invention is characterized in that the second irradiation management device includes the integrated dose of the measurement region identified by the irradiation region determination device and the second dose of the integrated dose for each region stored in the first storage unit. According to the comparison result with the target dose stored in the storage unit, the control unit outputs either the control signal for commanding the beam irradiation or the control signal for stopping the beam irradiation to the output device, and commands the beam irradiation. When the control signal is output, the control signal for stopping the beam irradiation is output a predetermined time before the center measurement region identified by the irradiation region determination device moves to the next region.

  As a result, while the central measurement area does not reach the target dose, the target dose is suppressed while suppressing the beam irradiation amount to the peripheral simultaneous measurement area even when the peripheral simultaneous measurement area reaches the target dose. Beam irradiation can be performed on the central measurement region that does not reach the center, and the irradiation accuracy can be improved.

  In addition, a feature of the present invention is that the storage device further includes a third storage unit that records that the integrated dose has reached the target dose for each area of the monitor plane, and the first irradiation management unit includes: When the integrated dose in the measurement region identified by the irradiation region determination device reaches the target dose stored in the second storage unit, a control signal for stopping the beam irradiation is output, and at the same time, the integrated dose becomes the target dose. The second irradiation management device records the measurement region identified by the irradiation region determination device out of the integrated dose for each region stored in the first storage unit. It is to read from the third storage device whether or not the integrated dose has reached the target dose stored in the second storage unit.

  As a result, the second irradiation management device can instantly read whether or not the integrated dose in the measurement region identified by the irradiation region determination device has reached the target dose by simply referring to the record in the third storage device. , The reliability of control accuracy is improved.

  Further, according to the present invention, the charged particle beam generating device emits a charged particle beam by a beam extraction start command after the charged particle beam is accelerated to a desired energy, and is generated by one acceleration operation. The synchrotron is configured to stop the emission of the charged particle beam by a beam extraction stop command when a time period during which the beam extraction can be performed, and the irradiation control device inputs the beam extraction start command and the beam extraction stop command, and And a first beam scanning management device that outputs an excitation current command value update command, a scanning control start command, and a scanning control end command for the scanning electromagnet in synchronization with a start command and a beam extraction stop command.

  Thus, after the beam extraction from the charged particle beam generator is stopped by the beam extraction stop command, the charged particle beam is accelerated to a desired energy, and when the beam extraction and the beam irradiation to the affected area are restarted by the beam extraction start command, the scanning electromagnet Without beam excitation, beam irradiation can be resumed from the position where beam irradiation was stopped when beam extraction was stopped, thereby facilitating area management.

  In addition, the present invention is characterized in that the irradiation control device uses the irradiation region determination device among the integrated doses stored in the first storage unit every time the excitation current command value of the scanning electromagnet is updated. If the cumulative dose in the region to which beam irradiation is performed following the identified measurement region has reached the target dose stored in the second storage unit, and if the cumulative dose has reached the target dose , A control for searching for a region that has not reached the shortest target dose from the measurement region identified by the irradiation region determination device, outputting an update command for an excitation current command value corresponding to this region, and stopping the beam irradiation When at least one of the second beam scanning management device that outputs a signal, and the irradiation management device and the second beam scanning management device outputs a control signal for stopping the beam irradiation, the load In further comprising an output device for outputting the beam extraction OFF signals to the particle beam generator.

  As a result, when the accumulated dose in the next beam irradiation area reaches the target dose, the measurement area immediately moves to the shortest area that has not reached the target dose, so the measurement area reaches the target dose. The waiting time until moving to an unoccupied area is eliminated, and the irradiation time (treatment time) can be shortened. Further, it is possible to prevent erroneous beam irradiation while moving to an area where the target dose has not been reached.

  Further, the present invention is characterized in that the irradiation control device has a dose counter device having a number of counters smaller than the number of divided areas of the monitor plane as the dose counter device, and input from the two-dimensional dose monitor. A first multiplexer that selects a measurement dose corresponding to the measurement region identified by the irradiation region determination device from measurement doses for each region of the monitor plane, and transmits the measurement dose to the counter of the dose counter device; and The second multiplexer is configured to transmit and store the dose counted by the counter in a memory area corresponding to the measurement area identified by the irradiation area determination device in the memory area of the first storage unit.

  As a result, the number of counters in the dose counter device can be reduced, and the manufacturing cost can be reduced.

  In addition, the present invention is characterized in that the beam irradiation device expands a beam diameter of the charged particle beam emitted from the charged particle beam generator more than a division width of the plurality of regions of the monitor plane. A plurality of energy regions are formed on the charged particle beam emitted from the apparatus and the charged particle beam generator, and a plurality of Bragg peaks formed in the depth direction are overlapped, so that it is uniform in the depth direction. An energy distribution enlarging device that forms a dose distribution, and the second irradiation management device of the irradiation control device has an integrated dose for each region stored in the first storage unit in all regions of the monitor plane. When the target dose stored in the second storage unit is reached, an energy update command is output.

  This makes it possible to accurately measure the dose distribution not only in the direction perpendicular to the charged particle beam traveling direction within the irradiation target but also in the charged particle beam traveling direction (depth direction within the irradiation target), thereby improving the control accuracy of the irradiation dose. be able to.

  In addition, a feature of the present invention is that it further includes a display device that displays a measured dose for each area of the monitor plane.

  Thus, the driver can check the progress of beam irradiation.

  According to the present invention, it is possible to accurately measure the dose distribution in the direction perpendicular to the traveling direction of the charged particle beam in the irradiation target. As a result, the control accuracy of the irradiation dose at each position in the direction perpendicular to the charged particle beam traveling direction in the irradiation target can be increased, and a desired dose distribution can be ensured.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
<Embodiment 1>
FIG. 1 is a diagram showing an overall configuration of a charged particle beam irradiation system (particle beam therapy system) according to a first embodiment of the present invention.

  The charged particle beam irradiation system of this embodiment irradiates an affected part 218 (see FIG. 2) of a patient 216 fixed to a treatment bed 217 with an ion beam (a charged particle beam such as a proton beam or a carbon beam). And an ion beam generator 1, a high energy beam transport system 11, an irradiation field forming device 200 (beam irradiation device), a central control device 100 and an irradiation control device 300. The central controller 100 provides information necessary for treatment (irradiation beam energy, irradiation angle (gantry rotation angle), scanning electromagnet pattern, scatterer type, ridge filter type, range shifter insertion, which is presented from a treatment planning device (not shown). Quantity etc.) is stored in the memory, and on the basis of the treatment information, nozzle equipment parameters such as equipment type, installation position, and set values are selected, and accelerator operation parameters such as beam energy and beam intensity pattern are selected. , To control equipment constituting the charged particle beam irradiation system. The nozzle device parameters are transmitted from the central control device 100 to the irradiation control device 300 and set in the irradiation field forming device 200. The accelerator operation parameters are set in the equipment constituting the ion beam generator 1.

  The ion beam generator 1 is an apparatus for generating an ion beam 2 having a desired beam energy, and includes a pre-stage accelerator 3, a low energy beam transport system 4, and a synchrotron 5. The ion beam 2 is accelerated to the incident energy to the synchrotron 5 by the pre-stage accelerator 3, and is supplied to the synchrotron 5 through the low energy beam transport system 4.

  As shown in FIG. 1, the synchrotron 5 emits a plurality of electromagnets (not shown) and an acceleration device (not shown) located on its orbit, an emission high-frequency electrode 6, an emission high-frequency oscillator 10, and the like. The device 13 is configured. The ion beam 2 orbiting the orbit of the synchrotron 5 is accelerated to a desired energy (for example, 70 to 250 MeV) by applying a high frequency voltage to an acceleration cavity provided in the acceleration device. After the ion beam 2 is accelerated to a desired energy, an extraction high-frequency voltage output from the extraction high-frequency oscillator 10 is applied to the extraction high-frequency electrode 6 so that the ion beam 2 is emitted from the synchrotron 5 to the high-energy beam transport system 11. Is done. At this time, the beam irradiation is stopped by the interlock signal from the central controller 100 so that the high-frequency voltage applied to the extraction high-frequency electrode 6 can be applied only in a state in which the patient 216 can be safely irradiated. The interlock switch 8 and the exit gate switch 9 for stopping the beam irradiation in response to the beam irradiation stop condition during the irradiation control by the irradiation control signal from the irradiation control device 300 are used as a high-frequency voltage transmission line. It is installed above. In the present embodiment, the interlock signal for controlling the interlock switch 8 is output from the central control device 100, but the safety system interlock that specially monitors the operating conditions of the devices constituting the particle beam therapy system. A control device (not shown) may be prepared separately, and the interlock switch 8 may be controlled by the safety system interlock control device.

  The high energy beam transport system 11 connects the synchrotron 5 and the irradiation field forming device 200, and the ion beam 2 emitted from the synchrotron 5 is supplied to the irradiation field forming device 200 by the high energy beam transport system 11. At this time, the beam is often supplied through the rotating gantry 12 that allows the affected area 218 of the patient 216 to be irradiated from an arbitrary angle. The ion beam 2 supplied from the ion beam generator 1 is supplied to the irradiation field forming apparatus 200 in this way.

  Details of the irradiation field forming apparatus 200 will be described with reference to FIG. The irradiation field forming device 200 is a device that shapes the ion beam generated by the ion beam generator 1 according to the shape of the affected part 217a of the patient 216. The irradiation field forming apparatus 200 includes beam scanning electromagnets 202 and 202, a scatterer 206, a ridge filter 208, a range shifter 210, a dose monitor 212, a bolus 214, and a collimator 215.

  The scanning electromagnets 202 and 202 scan the irradiation position of the beam in time to form a uniform dose distribution in the lateral direction of the affected area 218. The scanning electromagnets 202 and 202 are provided with scanning electromagnet power supplies 219 and 219 and a scanning electromagnet power supply controller 220. The scanning electromagnets 202 and 202 are, for example, a pair of electromagnets that scan in the orthogonal transverse direction, and are configured to scan the beam in two orthogonal directions in a plane perpendicular to the beam traveling direction. The scanning electromagnet power supplies 219 and 219 supply current to the pair of scanning electromagnets 202 and 202 to generate a magnetic field and deflect the beam. Since the amount of deflection of the beam is determined by the excitation current to be supplied, it is possible to irradiate the beam at an arbitrary point in the lateral direction by adjusting the excitation current. The scanning electromagnets 202 and 202 are supplied with the current set from the scanning electromagnet power supply controller 220 by the scanning electromagnet power supplies 219 and 219. In the present embodiment, the scanning electromagnet power supply control device 220 is provided independently of the irradiation control device 300, but the function of the scanning electromagnet power supply control device 220 may be provided in the irradiation control device 300.

  The scatterer 206 is for expanding the lateral distribution of an ion beam by a phenomenon of ion scattering by a substance (beam diameter expanding device). The scatterer 206 broadens the beam to a Gaussian distribution. The scatterer 206 is generally composed of a substance having a large atomic number, such as tungsten, which has little energy loss with respect to the amount of scattering. The scatterer 206 may be a mixture of a plurality of substances, and may be configured by stacking a plurality of plate members having different thicknesses to change the total thickness in the ion beam traveling direction. In the present embodiment, the scatterer 206 is arranged on the downstream side of the scanning electromagnets 202 and 202, but it can also be arranged on the upstream side.

  The ridge filter 208 forms a wide and uniform dose distribution by forming a plurality of energy regions in the beam and superimposing a plurality of Bragg peaks formed in the depth direction (energy distribution expansion device). It is. The ridge filter 208 includes a plurality of wedge-shaped structures 208a and a wedge-shaped structure support 208b. Openings are formed between adjacent wedge-shaped structures 208a. The wedge-shaped structure 208a has a plurality of planar regions arranged stepwise, and the thicknesses from the bottom surface of the ridge filter 208 to the planar regions in the beam axis direction are different. The wedge-shaped structure 208a is formed so that the thickness in the axial direction increases stepwise from the openings located on both sides toward the planar region at the highest position in the axial direction. That is, in the ridge filter 208, the thickness of the portion through which the ion beam passes changes according to the beam passage position. As a result, the beam energy after passing through the ridge filter 208 is changed, and the Bragg peaks are formed at different depths corresponding to the respective beam energies, so that it is uniform over a wide region having a desired depth within the affected area 216a. An irradiation field can be formed. The ridge filter 208 reduces the difference in energy distribution at the lateral position by reducing the width in the direction in which the thickness of the wedge-shaped structure 208a is different and mitigating the difference in beam energy depending on the passing position. The ridge filter 208 may be provided with a scattering compensator in order to compensate for the difference in the amount of ion beam scattering caused by the difference in thickness up to each planar region. In the present embodiment, the ridge filter 208 is configured to include a plurality of wedge-shaped structures 208a having a plurality of deformed regions arranged in a step shape, but may be configured to have different thicknesses. In addition, in order to compensate for the amount of beam scattering due to the difference in thickness of the wedge-shaped structure 208a, a scattering compensator having a different thickness in the direction in which the wedge-shaped structure 208a is different may be attached to the ridge filter 208.

  The range shifter 210 matches the maximum range of the ion beam with the maximum depth of the affected area 216a. The range shifter 210 is generally composed of a material having a small atomic number such as a resin having a small beam scattering amount with respect to energy loss. Since the energy is lost when the ion beam passes through the range shifter 210, the maximum range of the ion beam can be reduced. Thereby, the maximum range of the ion beam can be matched with the affected part 216a. The range shifter 210 is configured by stacking a plurality of plate members having different thicknesses, and the total thickness in the ion beam traveling direction can be changed by combining the plate members. Further, the acceleration energy of the ion beam by the synchrotron 5 may be reduced without using the range shifter 210, or the energy of the ion beam may be lost by the high energy beam transport system 16.

  Through the above process, the ion beam scanned in the lateral direction and expanded in the depth direction is incident on the dose monitor 212, and the amount of the beam that has passed through is measured. If the dose monitor 212 is arranged on the downstream side of the beam, the ion beam passage amount immediately before irradiation of the affected part 216a can be measured. If the dose monitor 212 is arranged on the upstream side of the beam, for example, on the upstream side of a device that changes the energy of the ion beam such as the ridge filter 208 and the range shifter 210, it is time-consuming to calculate and correct the output signal from the dose monitor 212 due to the difference in energy. Save.

  The bolus 214 is formed by excavating a resin block body, for example, and the resin passage thickness of the beam changes according to the beam incident position in the lateral direction. Thereby, the energy of the ion beam after passing through the bolus 214 can be changed for each incident position, and the arrival depth of the ion beam is matched with the shape in the depth direction of the affected part 216a. The collimator 215 is composed of a radiation shield and forms a through hole corresponding to the affected part 216a. The collimator 215 irradiates the affected part 216a only with the ion beam that has passed through the through-hole among the beams expanded in the horizontal direction. The bolus 214 and the collimator 215 are usually processed in accordance with the shape of the affected area 216a and are exchanged for each affected area 216a. By using a multi-leaf collimator as the collimator 215 and moving the leaf to match the shape of the affected part 216a in the lateral direction, the labor of processing and replacement may be saved.

  An irradiation control system including a scanning electromagnet power supply control device 220, a dose monitor 212, and an irradiation control device 300 that realizes the present invention will be described with reference to FIG.

  First, in the present embodiment, beam scanning by the scanning electromagnets 202 and 202 is performed independently of irradiation control. Therefore, excitation data (Ix_data, Iy_data) (explained later), excitation data update cycle and scanning control command, which are excitation current command values of the pair of scanning electromagnets 202, 202, are transmitted from the central control device 100 to the scanning electromagnet power supply control device 220. . The scan control command includes a scan control start command and a scan control end command. When the scanning control start command is transmitted from the central controller 100, the scanning electromagnet power controller 220 transmits excitation data (Ix_data) to each scanning electromagnet power source 219 at the excitation data update period transmitted from the central controller 100. , Iy_data) is updated and output (self-running scanning control). The scanning electromagnet power source 219 outputs an excitation current (Ix, Iy) based on the excitation data to the scanning electromagnet 202. When the scanning control start command is transmitted from the central control device 100, an extraction start command is output from the central control device 100 to the extraction device 13 of the synchrotron 5 at the same time or immediately after that, and the excitation current (Ix , Iy) is output to the scanning electromagnet 202, the ion beam emitted from the synchrotron 5 and supplied to the irradiation field forming apparatus 200 is scanned by the magnetic field generated between the magnetic poles of the scanning electromagnet 202 by this excitation current. Is done. The scanned beam is irradiated to the affected area while passing through the dose monitor 212. The dose monitor 212 is a two-dimensional dose monitor (multi-channel type dose monitor) that measures and outputs an irradiation dose for each divided region (described later), and the measurement result is a measured dose signal 224 for each divided region. Is transmitted to the irradiation control device 300. When the scanning control end command is transmitted from the central control device 100, the scanning electromagnet power control device 220 stops updating and outputting the excitation data (Ix_data, Iy_data) for each scanning electromagnet power source 219. When the scanning control end command is transmitted from the central control device 100, the central control device 100 outputs an output stop command to the extraction device 13 of the synchrotron 5 at the same time or immediately before it, and at least the scanning electromagnet power control device 220. However, when the update and output of the excitation data (Ix_data, Iy_data) are stopped by the scanning control end command, the beam irradiation is also stopped.

  Here, as described above, in the scanning electromagnets 202 and 202, the beam deflection amount is determined by the excitation current to be supplied. Therefore, by adjusting the excitation current, the beam is irradiated to any point in the lateral direction. be able to. Therefore, updating the excitation data (Ix_data, Iy_data) for each scanning electromagnet power supply 219 means updating the measurement area of the dose monitor 212 by updating the irradiation position of the beam. In addition, the scanning electromagnet power supply control device 220 updates the excitation data of the scanning electromagnet power supplies 219 and 219 in the excitation data update period, and the integrated dose in all the regions for one layer of the affected area to be irradiated becomes the target dose. The excitation data is repeatedly updated until it reaches, and one layer is scanned a plurality of times.

  The irradiation control device 300 includes a control processor 301, an irradiation region determination unit 302 (irradiation region determination device), an irradiation management unit 303 (second irradiation management device), a dose counter device 304 (dose counter device), and an irradiation control memory device 305. (Storage device), comparator 306 (first irradiation management device), counter control unit 307 (dose counter device), comparator control unit 308 (first irradiation management device), and AND circuit 309 (output device) .

  A control processor 301 of the irradiation control apparatus 300 controls transmission data between the central control apparatus 100 and the irradiation control apparatus 300 in an integrated manner. The memory 301 of the control processor 301 stores the target dose value (FIG. 5C) for each region of the two-dimensional dose monitor 212 corresponding to the total irradiation beam energy used for irradiation treatment, and excitation used by the irradiation region determination unit 302. Table data (FIGS. 5A and 5B) for converting the irradiation area from the data (excitation current command value) is stored. In addition, the control processor 301 is connected to the memory device 305 and the irradiation region determination unit 302 used for managing the irradiation dose by means capable of data communication, thereby transmitting data necessary for treatment transmitted from the central control device 100. Easy to save and update.

  The memory device 305 used for managing the irradiation dose includes an integrated dose memory 305a, a target dose memory 305b, and an irradiation management memory 305c, and secures a plurality of memory areas in accordance with the number of monitor plane areas of the two-dimensional dose monitor 212. (Described later). In addition, the access to the plurality of memory areas of these memories 305a, 305b, and 305c can easily realize dose management of each area by adopting an address structure that allows access to the same area in parallel.

  The irradiation region determination unit 302 stores table data (FIGS. 5A and 5B) for converting the irradiation region from the excitation data transmitted from the control processor 301. The irradiation region determination unit 302 includes a scanning electromagnet. Each time the power supply controller 220 updates the excitation data (Ix_data, Iy_data) set in the scanning electromagnet power supplies 219, 219 (that is, every time the measurement area is updated), the excitation data is paralleled with the scanning electromagnet power supplies 219, 219. When an irradiation area centered on the center of gravity of the irradiation beam is identified as a center measurement area 222a (described later), and the ion beam diameter (beam diameter) is larger than the division width of the monitor plane area of the two-dimensional monitor 212 Simultaneously includes a plurality of regions around the central measurement region 222a including a beam irradiation position (beam irradiation region) on the monitor plane. It identifies as measurement area | region 223 (after-mentioned). At this time, since the deflection amount (scanning amount) with respect to the excitation amount of the scanning electromagnet 202 differs depending on the energy of the irradiation beam, when the ion beam is irradiated by dividing the depth direction of the affected part 216a into a plurality of layers, the irradiation beam Every time the energy of is updated, the data for converting the irradiation area is updated. This data update is performed by an energy update command (described later) given from the irradiation management unit 303 to the control processor 301.

  The dose counter device 304 has the same number of counters 304a as the area of the 2D dose monitor 212 prepared for each area of the 2D dose monitor 212, and the measurement transmitted from the 2D dose monitor 212 during the irradiation treatment. The dose signal 224 is input, and the measurement dose for each region is continuously counted. Here, the dose counter device 304 is connected to the counter control unit 307, and the counter control unit 307 sends a central measurement region 222 a and a simultaneous measurement region 223 (ion beam diameter ( The beam diameter) is smaller than the division width of the monitor plane area of the two-dimensional monitor 212, and only the central measurement area 222a) is input. Of the measured dose for each monitor plane area input from the two-dimensional dose monitor 212 The dose counter 212 is controlled to select and count only the measurement dose corresponding to the central measurement region 222a and the simultaneous measurement region 223. The dose value (accumulated dose) counted by the dose counter device 304 is sequentially transmitted to the accumulated dose memory 305a, stored, and updated. As described above, the counter control unit 307 is provided, and only the measurement dose corresponding to the simultaneous measurement region 223 identified by the irradiation region determination unit 302 is selected, counted, and integrated. Even if an erroneous measurement due to noise or the like occurs in a region other than the central measurement region 222a or the simultaneous measurement region 223 on the plane, the influence of such an erroneous measurement is eliminated, and the irradiation dose can be accurately measured. In addition, by providing the integrated dose memory 305a, sequential access from the control processor 301 is possible, and processing such as data transmission to the central control device 100 and the display device 320 and data storage can be easily performed.

  The comparator 306 sequentially compares the measurement value stored in the integrated dose memory 305a and the target dose stored in the target dose memory 305b for each region. The comparator 306 is connected to the irradiation region determination unit 302 via the comparator control unit 308, and the comparator control unit 308 inputs information on the center measurement region or 222 a corresponding to the beam centroid position from the irradiation region determination unit 302. Then, among the measured values (integrated doses) stored in the integrated dose memory 305a, only the integrated dose in the region corresponding to the central measurement region 222a is selected and compared with the target dose stored in the target dose memory 305b. The comparator 306 is controlled. As a result of the comparison, when the integrated value of the measured dose does not reach the target dose, a beam ON signal (for example, a signal of high level) that is a control signal for instructing beam irradiation to the AND circuit 309 is output, and the measured dose When the integrated value has reached the target dose, the comparator 306 outputs a beam OFF signal (for example, a level low signal) that is a control signal for stopping the beam irradiation to the AND circuit 309, and at the same time, in the irradiation management memory 305c. Write data indicating that the target dose has been reached for the area. Further, as a result of the comparison, even if the integrated value of the measured dose does not reach the target dose and the beam ON signal is output, the integrated dose in the region corresponding to the central measurement region 222a during the ion beam irradiation When the target dose is reached, the comparator 306 immediately outputs a beam OFF signal to the AND circuit 309. When the AND circuit 309 receives the beam ON signal from the comparator 306, the AND circuit 309 outputs a beam emission ON gate signal as a beam irradiation control command to the extraction device 13 of the synchrotron 5, thereby causing the irradiation field forming device 200 to perform the beam irradiation. . When the AND circuit 309 receives the beam OFF signal from the comparator 306, it outputs a beam output OFF gate signal to the extraction device 13 of the synchrotron 5, whereby the irradiation field forming device 200 stops the beam irradiation. Thus, whenever the excitation data (Ix_data, Iy_data) set in the scanning electromagnet power sources 219 and 219 is updated (every time the measurement area is updated), the irradiation of the ion beam to the area where the integrated dose reaches the target dose is stopped. Then, by selectively irradiating the ion beam only to the region where the accumulated dose does not reach the target dose, the dose distribution in the direction perpendicular to the beam traveling direction can be controlled. In addition, even in the area where the ion beam is being irradiated, the irradiation of the ion beam to the area is stopped as soon as the target dose is reached. Can be increased. The comparison of the integrated value of the target dose and the measured dose and the beam irradiation control are sequentially performed until the target dose is reached in all regions while scanning the beam. Further, scanning is performed a plurality of times until the integrated dose in all the regions reaches the target dose for one layer of the affected part to be irradiated.

  The irradiation management unit 303 updates the excitation data (Ix_data, Iy_data) set in the scanning electromagnet power sources 219 and 219 (updates the measurement region), and sets the beam center of gravity position every time the irradiation region determination unit 302 captures the excitation data. The target dose reachability in the corresponding central measurement region 222a (whether or not the integrated dose in the central measurement region 222a has reached the target dose) is read from the irradiation management memory 305c, and beam irradiation to the region that has reached the target dose is stopped. The control signal is output. In addition, the irradiation management unit 303 outputs an energy update signal when the accumulated dose reaches the target dose in all regions and an output of a control signal for stopping the beam irradiation, and when the target dose is reached at all energies. An irradiation completion signal and a control signal for stopping the beam irradiation are output.

  First, each time the excitation data is updated, the irradiation management unit 303 inputs information on the central measurement region or 222a corresponding to the beam center of gravity position from the irradiation region determination unit 302, and the accumulated dose in the central measurement region 222a reaches the target dose. Is read from the corresponding area of the irradiation management memory 305c, and when the integrated dose has not reached the target dose, a beam ON signal (for example, a signal having a high level) that is a control signal for instructing beam irradiation. When the integrated dose reaches the target dose, the beam OFF signal, which is a control signal for stopping the beam irradiation, is output to the AND circuit 309.

  The AND circuit 309 configures an AND logic with the output from the irradiation management unit 303 and the output from the comparator 306, and when both outputs are beam ON signals (for example, level high signals), the synchrotron 5 A gate signal (beam irradiation control signal) for beam extraction ON is output to the extraction device 13, and at other times (at least one of the output from the irradiation management unit 303 and the output from the comparator 306 is a beam OFF signal (for example, level Low) ), The gate signal for turning off the beam emission is output to the emission device 13 of the synchrotron 5. When the beam emission ON gate signal is output from the AND circuit 309, the extraction device 13 of the synchrotron 5 closes the switch 9, supplies the ion beam to the irradiation field forming device 200, and the AND circuit 309 turns off the beam emission OFF. When the gate signal is output, the switch 9 is opened to stop the extraction of the ion beam, and the beam irradiation is stopped.

  In the irradiation treatment to the affected part by beam scanning, irradiation is performed by changing the energy of the irradiation beam in accordance with the depth of the affected part 216a in the body. In the present embodiment, the energy width is expanded by the ridge filter 208 in accordance with the depth of the affected area, but even when the ridge filter 208 is used, in order to increase the irradiation accuracy in the depth direction, the affected area is The body depth direction of 216a is divided into a plurality of layers, and the beam energy supplied from the ion beam generator 1 is changed. When the ridge filter 208 is not used, it is necessary to divide the in-vivo depth direction of the affected part 216a into a plurality of layers and change the beam energy supplied from the ion beam generator 1. Therefore, when the target dose is reached in all regions in the layer where the affected area is present, the irradiation management unit 303 transmits an energy update signal to the central control device 100 via the control processor 301, and the energy update signal is transmitted to the scanning electromagnet power source. Output to the controller 220. When the central controller 100 receives the energy update signal, the central controller 100 changes the control parameter of the beam energy supplied from the ion beam generator 1, and supplies the irradiation device 200 with a beam of energy that matches the next irradiation layer. The scanning electromagnet power supply control device 220 stops the scanning excitation once in response to the input of the energy update signal, updates the energy excitation data matched to the next irradiation layer, and then starts the scanning excitation. At this time, the excitation data update process of the scanning electromagnet power supply controller 220 may be commanded from the central controller 100 that has received the energy update signal.

  The irradiation management unit 303 also outputs a beam OFF signal (for example, a signal of level Low) to the AND circuit 309 even when the integrated dose reaches the target dose in all regions.

  Furthermore, the irradiation management unit 303 outputs an irradiation completion signal to the central control device 100 after confirming that the target dose has been reached for all the layers of the affected part 216a. The central control apparatus 100 ends the irradiation treatment to the affected area by the irradiation completion signal. At this time, when beam irradiation is planned from another angle, the irradiation angle is changed by rotating the rotating gantry 14 to a desired angle, and control according to the above-described series of processing is started. The irradiation management unit 303 also outputs a beam OFF signal (for example, a level low signal) to the AND circuit 309 when it is confirmed that the target dose has been reached for all the layers of the affected part 216a.

  In this way, the beam OFF signal is output when the cumulative dose in the corresponding area when the excitation data is updated reaches the target dose, and the beam OFF signal is output when the cumulative dose reaches the target dose in all areas. By executing the output of the beam OFF signal when the target dose is reached for all energies, if the accumulated dose in the area corresponding to the update of the excitation data reaches the target dose in all areas, Even if the output of the comparator 306 is switched to the beam ON signal due to some malfunction after each of the accumulated doses reaches the target dose and reaches the target dose for all energies, the AND circuit Since 309 continues to output the beam extraction OFF gate signal, erroneous irradiation of the ion beam is reliably prevented, and high safety can be ensured.

  The two-dimensional dose monitor 212 used in this embodiment will be described in detail. The two-dimensional dose monitor 212 divides a monitor plane perpendicular to the beam traveling direction as shown in FIG. 4 into mxn regions 222 at equal intervals a in the XY direction, and independently measures dose in each region 222. Is a possible dose monitor. In this specification, these areas 222 are called “measurement areas”. The position of the measurement region 222 can be expressed by, for example, a coordinate system (Ax, Ay) in which the Oz point of the upper left corner of the drawing is the origin of the coordinate axis. By adopting such a two-dimensional dose monitor 212, it becomes possible to accurately measure a dose corresponding to an arbitrary measurement region 222 (Ax, Ay) in two dimensions.

  As described above, the center of gravity of the irradiation beam with respect to the excitation current (Ix, Iy) of each scanning electromagnet 202 can be identified by the irradiation region determination unit 302. In the present embodiment, a measurement region 222 (Ax, Ay) is defined with respect to the center of gravity position of the irradiation beam, and the dose measurement result of each measurement dose signal 224 of the two-dimensional dose monitor 212 is managed. Specifically, as shown in FIGS. 5A and 5B, two scan positions corresponding to the scan range are set based on the scan position range corresponding to the set scan excitation current of the scan magnet in each of the X direction and the Y direction. The center measurement area 222a and the simultaneous measurement area 223 of the dimension dose monitor 212 are associated with each other. At this time, since the amount of deflection of the center of gravity of the beam due to the excitation current of the scanning magnet varies depending on the energy of the irradiation beam, the table data shown in FIGS. 5A and 5B is prepared for each energy of the irradiation beam. It is necessary to keep. The table data prepared for each energy is stored in the region determination unit 302, and these pieces of information are preloaded from the central control device 100 to the memory of the control processor 301 of the irradiation control device 300 before the start of irradiation treatment. .

  In addition, the method for setting the target dose in each region is performed in the same manner as the association of the measurement region 222 with the excitation current of the scanning electromagnet 202. Specifically, as shown in FIG. 5C, each target dose D and its allowable value ΔD (D ± ΔD) are set for the central region (Ax_i, Ay_j) of the measurement region 222. Each target dose D and its allowable value ΔD are stored in the target dose memory 305b.

  In the present embodiment, the irradiation area determination unit 302 is connected to each of the memories 305a, 305b, and 305c of the memory device 305 by a memory bus, and thereby irradiation control is performed according to the update of excitation data for the scanning electromagnets 202 and 202. Simultaneously with updating of the memory address of the measurement area 222 shown in FIGS. 5A and 5B stored in the irradiation area determination unit 302 of the apparatus 300, the memories 305a, 305b, The data stored in 305c can be accessed. That is, it is possible to manage the identification of the central measurement region 222a and the simultaneous measurement region 223 corresponding to the excitation current of the scanning electromagnet 202 and access to memories used for irradiation control such as the integrated dose memory 305a, target dose memory 305b, and irradiation management memory 305c. It is.

  Here, the correspondence of the measurement region 222 (Ax, Ay) to the excitation current (Ix, Iy) of the scanning electromagnet 202 will be described. As shown in FIG. 4, the beam scans through the center of the measurement region 222. In this embodiment, scanning is performed in the X direction. Further, the measurement region 222 on the dose monitor 212 is divided by the width a in both the X direction and the Y direction. On the other hand, in the present invention, the irradiation field forming apparatus 200 is provided with the scatterer 206 and the lateral distribution of the ion beam is expanded, so that the beam diameter φB is larger than the width a of the measurement region 222 (φB> a )is doing. This is because when each of the measurement areas 222 is irradiated with a beam being scanned discretely (the extraction of the ion beam from the synchrotron 5 is stopped, and the excitation current of the scanning magnet is updated in this state to change the irradiation position. The beam diameter φB may be smaller than the width a of the measurement region 222, but the beam is continuously scanned. This is because if the beam diameter φB is smaller than the width a of the measurement region 222, there is a possibility that the irradiation cannot be performed uniformly on the Y-direction plane. On the other hand, since the beam diameter φB is larger than the width “a” of the measurement region 222, the beam is also irradiated to the region that protrudes from the measurement region 222 corresponding to the center of the irradiated beam. Therefore, when measuring the dose, it is necessary to simultaneously measure the measurement region 222 corresponding to the beam center and the surrounding measurement region 222. Therefore, in the present embodiment, the dose is measured simultaneously in each of the measurement region 222 (center measurement region 223a) corresponding to the beam center and the surrounding measurement region 222 (simultaneous measurement region 223).

  The selection of the measurement region 222 when scanning in the X direction will be described. As shown in FIG. 5A, the excitation current range in the X direction is divided corresponding to the scanning range of each measurement region 222 (start position and end position of each measurement region 222). By this division correspondence, the measurement region 222a at the beam center is associated with the excitation current. Next, a peripheral measurement area corresponding to the measurement area 222a at the beam center is set. In the present embodiment, as shown in FIG. 4, when the number of surrounding measurement regions is eight regions surrounding the beam center measurement region 222a (Ax_i, Ay_j) having the beam diameter φB, the beam center measurement region 222a ( Before and after (Ax_ (i−1) and Ax_ (i + 1)) are set as the simultaneous measurement region 223. That is, when the beam center reaches a certain measurement region 222, the measurement region 222 in the irradiation range before and after the beam diameter φB is applied is simultaneously measured. Similarly, in the Y direction, the simultaneous measurement region 223 is set in the peripheral measurement region 222 corresponding to the measurement region 222a at the beam center as in the X direction. That is, when one measurement region 222 (center measurement region 222a) is designated, each measurement region 222 shown in FIG. 5C is designated by designating the measurement region 222 in the X direction and the measurement region 222 in the Y direction. The target irradiation beam amount (D) and its allowable value (ΔD) are read. When scanning the beam in the X direction, there is no change in the beam position in the Y direction. Therefore, as the simultaneous measurement region 223 in the Y direction, the measurement region 222 in the upper and lower irradiation ranges where the beam diameter φB is applied may be simultaneously measured.

When irradiation is performed by discretely scanning the beam, the control method for the simultaneous measurement region 223 described above may be used. However, when the beam is continuously scanned and irradiated, control of the simultaneous measurement region is complicated. . Here, a method of controlling the simultaneous measurement region when the beam is continuously scanned will be described with reference to FIG. FIG. 6 is an enlarged view around the measurement region 222a at the beam center in FIG. Consider a case in which scanning is continuously performed from point P to point Q in a region (Ax_i, Ay_j) where the beam center is located. Assume that the center of the irradiation beam is scanned from point P to point Q by Δx in the X direction. By scanning this Δx, at the position of the point P, eight regions (simultaneous measurement region width: 3a × 3a) around the region 222a (Ax_i, Ay_j) are set as the simultaneous measurement region 223a. 3, the number of measurement regions 222 to which the beam diameter φB is applied increases by three (Ax_i + 2 region 223b in the figure). In this case, it is necessary to increase the simultaneous measurement region (add the region 223b to the region 223a) in order to manage the irradiation beam amount with high accuracy. The condition for adding the simultaneous measurement region 223b can be indicated by the beam diameter φB and the simultaneous measurement region width na (indicated by n = 3 in FIG. 6). When the amount of change for adding the simultaneous measurement region 223b is Δx, it is expressed by Equation 1.

That is, when the beam center moves by Δx from the center position of the measurement region 222 (here, the center position in each measurement region 222 is indicated by (2na−a) / 2), the simultaneous measurement region 223a Furthermore, the desired dose measurement can be performed by adding the adjacent simultaneous measurement region 223b. When the beam is further scanned from the point P to the point R by Δx ′, the simultaneous measurement region 223 transitions to eight simultaneous measurement regions centered on (Ax_i + 1, Ay_j). The transition condition Δx ′ of the simultaneous measurement region at this time is expressed by Equation 2.

In accordance with the update of the excitation current of the scanning electromagnets 202 and 202, when the condition of Δx and Δx ′ is satisfied with respect to the center position of the measurement region 222, the control for changing the simultaneous measurement region 223 is performed. This makes it possible to appropriately measure the irradiation amount of the beam irradiated to each measurement region 222 during treatment irradiation.

  When the above-described control is performed, if the central measurement area 222a does not reach the target dose, but reaches the target dose in the peripheral simultaneous measurement area 223, the central measurement does not reach the target dose. It is assumed that the beam irradiation to the region 222a becomes difficult. As a cause of such a phenomenon, when a beam is irradiated around each measurement region 222, a slight irradiation amount is accumulated in the peripheral region, and depending on the measurement region 222, a deviation of the irradiation amount with respect to the target dose may be caused. Occurrence can occur. Further, since the time from the output of the beam extraction OFF (stop) command (gate signal) of the AND circuit 309 in the irradiation control device 300 to the actual stop of the beam emission in the synchrotron 5 is a finite value, the beam emission is There is a possibility that the beam is irradiated to the adjacent measurement region 222 slightly before the beam actually stops after the output of the OFF command. When such a slight irradiation is repeated, there is a possibility that the measurement value of each measurement region 222 is integrated and exceeds the allowable value. As these countermeasures, in the present embodiment, the beam irradiation time is shortened when the target dose is reached in an area having the simultaneous measurement area 223 located around the center measurement area 222a.

  FIG. 7 shows a timing chart of the beam irradiation control in the adjacent irradiation region when the beam is scanned and irradiated from the region i-1 to the region i + 1. FIG. 7A is a timing chart of the beam irradiation control when the irradiation time of the irradiation beam is not shortened, and FIG. 7B is a diagram of the beam irradiation control when the irradiation time of the irradiation beam is shortened according to this embodiment. It is a timing chart. As shown in FIG. 7A, when the irradiation dose reaches the target dose in the regions (region i ± 1) at both ends of the irradiation region i, the beam emission gate signal is turned on in the irradiation region of the region i. And OFF in the irradiation area of the area i ± 1. If the control transition time from beam ON to OFF (time from beam output OFF (stop) command output until beam output is actually stopped) is TOFF, the beam is placed in the next adjacent region i + 1 for the time TOFF. Will be irradiated. On the other hand, as shown in FIG. 7B, considering the control transition time TOFF from the beam ON to OFF, the beam is emitted earlier by the control transition time TOFF before the beam moves from the region i to the region i + 1. By turning off the gate signal, beam irradiation to the adjacent region i + 1 can be suppressed.

  In the present embodiment, ON / OFF control of such a beam emission gate signal is performed by the irradiation management unit 303 of the irradiation control device 300. That is, as described above, the irradiation management unit 303, when updating the excitation data, every time the irradiation region determination unit 302 takes in the excitation data, the target in the center measurement region 222a corresponding to the beam barycentric position from the irradiation region determination unit 302. The dose reachability is read from the irradiation management memory 305c, and a control signal (beam ON signal) for stopping the beam irradiation on the region that has reached the target dose is output. The irradiation management unit 303 outputs a beam OFF signal when a time obtained by subtracting the control transition time TOFF from the scanning time Tscan for each region, which is the excitation data update cycle, after the beam ON signal is output to the region that has reached the target dose. Output. Since the AND circuit 309 configures an AND logic with the output from the irradiation management unit 303 and the output from the comparator 306, the output from the irradiation management unit 303 is output even if the output beam ON signal is output from the comparator 306. When switched to the beam OFF signal, a gate signal for beam extraction OFF is output to the extraction device 13 of the synchrotron 5. As a result, before the beam moves from the region i to the region i + 1, the gate signal of the beam extraction OFF is output earlier by the time TOFF (before the time TOFF of the next beam extraction ON gate signal is output), and the center measurement is performed. Even if the region 222a does not reach the target dose, and the peripheral simultaneous measurement region 223 reaches the target dose, the target dose is reduced while suppressing the beam irradiation amount to the peripheral simultaneous measurement region 223. Beam irradiation to the central measurement region 222a that has not reached can be performed, and irradiation accuracy can be improved.

  The display device 320 (see FIG. 3) is connected to the central control device 100 via the control processor 301, and is set by the scanning electromagnet power control device 220. The scanning electromagnet power source 202 shown in FIGS. Displays excitation data. Further, the display device 320 is connected to the memory device 305 via the control processor 301, and the integrated dose value for each region measured by the dose monitor 212 and stored in the integrated dose memory 305a is stored in the target dose memory 305b in FIG. By sequentially displaying the target value for each region shown in c) and the target dose reachability for each region stored in the irradiation management memory 305c (whether or not the integrated dose has reached the target dose) during beam irradiation, the beam Inform the driver of the progress of irradiation. In addition, the total dose counter value, irradiation parameters, and used devices in all areas may be displayed. When the irradiation parameters and used devices are displayed, the driver can easily grasp the beam irradiation conditions. Further, a ratio between the ion beam irradiation amount and the total ion beam irradiation amount for each region may be displayed. As a result, the driver can be informed that the irradiation is proceeding evenly.

  According to the present embodiment configured as described above, the following effects can be obtained.

  (1) In the present embodiment, a two-dimensional dose monitor 212 and an irradiation control device 300 are provided. In the irradiation control device 300, a dose measured for each monitor plane region of the two-dimensional dose monitor 212 is displayed for each monitor plane region. Therefore, the dose distribution in the direction perpendicular to the traveling direction of the charged particle beam (ion beam) in the affected area 216a to be irradiated is accurately measured. Can do. In addition, when the accumulated dose measured for each area on the monitor plane reaches the target dose set in advance for each area on the monitor plane, a control signal for stopping beam irradiation is output and the target dose is reached. The irradiation control to reflect the measurement result of the irradiation dose becomes possible because the beam irradiation to the selected area is stopped, and the control accuracy of the irradiation dose at each position in the direction perpendicular to the charged particle beam traveling direction in the irradiation target is improved. And a desired dose distribution can be ensured.

  (2) The irradiation control apparatus 300 integrates the dose counted by the dose counter device 304 and the dose counter device 304 that counts the measured dose for each monitor plane region input from the two-dimensional dose monitor 212. A memory 305 (storage device) including an integrated dose memory 305a (first storage unit) that stores a dose as a dose for each region of the monitor plane and a target dose memory 305b (second storage unit) that stores a target dose for each region of the monitor plane And the excitation data (excitation current command value) at that time of the scanning electromagnets 202 and 202 are input, and the region corresponding to the excitation data at that time of the scanning electromagnets 202 and 202 is measured region 222a among the plurality of regions on the monitor plane. , 223 and an irradiation region determination unit 302 (irradiation region determination device), and a dose counter device 304 includes: Of Measurement dose for each area of the monitor plane input from the dimension dose monitor 212, counted by selecting only measured dose of the irradiation area determination unit 302 measurement region 222a, 223 identified by.

As a result, even if an erroneous measurement due to noise or the like occurs in an area other than the beam irradiation area on the monitor plane of the two-dimensional dose monitor 212, the influence of such an erroneous measurement is eliminated, and the irradiation dose is accurately measured. (3) The irradiation area determination unit 302 is positioned at the center of the beam irradiation area corresponding to the excitation data (excitation current command value) at that time of the scanning electromagnets 202 and 202 among the plurality of areas on the monitor plane. The region to be measured is identified as the central measurement region 222a, and a plurality of regions that are located around the central measurement region and constitute a part of the beam irradiation region are identified as the simultaneous measurement region 223. Of the measured dose for each monitor plane area input from the monitor 212, the central measurement area 222a and the central measurement area 222a identified by the irradiation area determination unit 302 are displayed. The measurement dose in the simultaneous measurement region 223 is selected and counted.

  As a result, the irradiation forming apparatus 200 is provided with a scatterer 206, and the scatterer 206 expands the lateral distribution of the charged particle beam, so that the irradiation dose can be reduced even when the beam diameter is larger than the width of the divided area of the monitor plane. It can measure with high accuracy.

  (4) The irradiation control apparatus 300 selects the target integrated dose in the central measurement region 222a identified by the irradiation region determination unit 302 among the integrated doses stored in the integrated dose memory 305a (first storage unit). A comparator 306 and a comparator control unit 308 (first irradiation) that output a control signal for stopping beam irradiation when the accumulated dose reaches the target dose, compared with the target dose stored in the dose memory 305b (second storage unit). Management device).

  Thus, by selectively irradiating the charged particle beam only to the region where the integrated dose has not reached the target dose, the dose distribution in the direction perpendicular to the beam traveling direction can be controlled. In addition, even in a region that is being irradiated with a charged particle beam, the beam irradiation dose can be controlled in real time by stopping beam irradiation on that region as soon as the target dose is reached. Can be increased.

  (5) The irradiation control apparatus 300 uses the integrated dose of the central measurement region 222a identified by the irradiation region determination unit 302 among the integrated doses stored in the integrated dose memory 305a as the target dose stored in the target dose memory 305b. The irradiation management unit 303 (second irradiation) that reads whether or not it has reached from the irradiation management memory 305c (third storage unit) and outputs a control signal for stopping the beam irradiation when the integrated dose has reached the target dose. When at least one of the first irradiation management device (comparator 306 and comparator control unit 308) and the second irradiation management device (irradiation management unit 303) outputs a control signal for stopping beam irradiation, An AND circuit 309 (output device) that outputs a beam extraction OFF signal to the synchrotron 5 (charged particle beam generator);

  As a result, when the accumulated dose in the region corresponding to the update of the excitation data (excitation current command value) has reached the target dose, beam irradiation should be commanded due to malfunction of the comparator 306 and the comparator control unit 308. Even if a signal to output is output, the irradiation management unit 303 outputs a control signal for stopping the beam irradiation, and the AND circuit 309 outputs a beam emission OFF signal. Safety is ensured.

  (6) The irradiation management unit 303 outputs an energy update command when the integrated dose for each region stored in the integrated dose memory 305a reaches the target dose stored in the target dose memory 305b in all regions on the monitor plane. The control signal for stopping the beam irradiation is output to the AND circuit 309.

  As a result, when the integrated dose reaches the target dose in all regions, even if a signal for instructing beam irradiation is output due to malfunction of the comparator 306 and the comparator control unit 308, the irradiation management unit 303 Since the control signal for stopping the beam irradiation is output and the AND circuit 309 outputs the beam extraction OFF signal, erroneous irradiation of the charged particle beam is surely prevented, and high safety is ensured.

  (7) The irradiation management unit 303 includes the integrated dose of the central measurement region 222a identified by the irradiation region determination unit 302 among the integrated doses stored in the integrated dose memory 305a and the target dose stored in the target dose memory 305b. Depending on the comparison result, when either a control signal for instructing beam irradiation or a control signal for stopping beam irradiation is output to the AND circuit 309 and a control signal for instructing beam irradiation is output, the irradiation area is determined. A control signal for stopping the beam irradiation is output a predetermined time TOFF before the center measurement region 222a identified by the unit 302 moves to the next region.

  As a result, while the central measurement area does not reach the target dose, the target dose is suppressed while suppressing the beam irradiation amount to the peripheral simultaneous measurement area even when the peripheral simultaneous measurement area reaches the target dose. Beam irradiation can be performed on the central measurement region that does not reach the center, and the irradiation accuracy can be improved.

  (8) The memory 305 (storage device) further includes an irradiation management memory 305c (third storage unit) that records that the integrated dose has reached the target dose for each area of the monitor plane, and the irradiation management unit 303 When the integrated dose in the central measurement region 222a identified by the region determination unit 302 reaches the target dose stored in the target dose memory 305b, a control signal for stopping beam irradiation is output and at the same time, the integrated dose has reached the target dose Are stored in the irradiation management memory 305c, and the comparator 306 and the comparator control unit 308 include the integrated dose of the central measurement region 222a identified by the irradiation region determination unit 302 among the integrated doses stored in the integrated dose memory 305a. Reads from the irradiation management memory 305c whether or not the target dose stored in the target dose memory 305b has been reached.

  Thereby, the comparator 306 and the comparator control unit 308 simply refer to the record in the irradiation management memory 305c, and whether or not the integrated dose in the central measurement region 222a identified by the irradiation region determination unit 302 has reached the target dose. Can be read instantaneously, and the reliability of control accuracy is improved.

  (9) The irradiation field forming apparatus 200 (beam irradiation apparatus) is a scatterer 206 (beam diameter expanding apparatus) that expands the beam diameter of the charged particle beam emitted from the synchrotron 5 to be larger than the divided width of a plurality of regions on the monitor plane. ) And a plurality of energy regions are formed on the charged particle beam emitted from the synchrotron 5, and a plurality of Bragg peaks formed in the depth direction are overlapped to form a uniform dose distribution in the depth direction. The comparator 306 and the comparator control unit 308 of the irradiation control device 300 are integrated for each region stored in the integrated dose memory 305a in all regions on the monitor plane. When the dose reaches the target dose stored in the target dose memory 305b, an energy update command is output.

  This makes it possible to accurately measure the dose distribution not only in the direction perpendicular to the charged particle beam traveling direction within the irradiation target but also in the charged particle beam traveling direction (depth direction within the irradiation target), thereby improving the control accuracy of the irradiation dose. be able to.

  (10) The present embodiment further includes a display device 320 that displays the measured dose for each area of the monitor plane.

Thus, the driver can check the progress of beam irradiation.
<Embodiment 2>
A second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram showing a configuration of an irradiation control apparatus in the charged particle beam irradiation system (particle beam therapy apparatus) of the present embodiment.

  In the present embodiment, the central control device 100 is configured to send only the excitation data (Ix_data, Iy_data) of the scanning electromagnets 202 and 202 to the scanning electromagnet power supply control device 220, and instead, the beam scanning management in the irradiation control device 300A. Unit 311 (first and second beam scanning management devices) is provided, and a data update command and a scanning control command (scanning control start command and scanning control end command) are transmitted from beam scanning management unit 311 to scanning magnet power supply control device 220. . The beam scanning management unit 311 is connected to the AND circuit 309A, and the beam scanning management unit 311 outputs a beam irradiation control signal (beam ON signal or beam OFF signal) to the AND circuit. It is possible to control ON / OFF of the beam emission from the synchrotron 5. The other configuration is the same as the irradiation control apparatus 300 in the first embodiment shown in FIG.

  In the first embodiment, the scanning electromagnet power supply control device 220 performs self-running scanning control based on the excitation data update period transmitted from the central control device, whereas in this embodiment, the beam scanning management unit. 311 generates an excitation data update command and a scanning control command (a scanning control start command and a scanning control end command) based on the beam irradiation state signal transmitted from the central controller 100 and transmits it to the scanning electromagnet power controller 220. Here, the beam irradiation state signal is, for example, an extraction start command output from the central controller 100 to the extraction device 13 of the synchrotron 5 after the ion beam is accelerated to a desired energy in the synchrotron 5 or the extraction. After the start command is output, the synchrotron from the central control device 100 after the irradiation time (the time during which the ion beam generated by one acceleration operation can be emitted and irradiated) elapses based on the beam energy and the emission amount in the synchrotron 5 has elapsed. 5 is a signal including an output stop command output to the output device 13. The scanning electromagnet power supply control device 220 updates the output of excitation data (Ix_data, Iy_data) to the scanning electromagnet power supplies 219 and 210 only at the time of beam irradiation based on the data update instruction and the scanning control instruction. The excitation data 210 is updated. Accordingly, the position of the beam scanned by the scanning electromagnets 202 and 202 can be controlled by the irradiation control device 300A, and the management of the beam barycentric position at the time of beam irradiation, that is, the measurement region 222 is facilitated. That is, by outputting an excitation data update command, a scanning control start command, and a scanning control end command in synchronization with the beam extraction start command and the beam extraction stop command output to the extraction device 13 of the synchrotron 5, the scanning electromagnet power control is performed. The apparatus 220 updates the excitation data of the scanning electromagnet power sources 219 and 219 only during beam irradiation, and scan start position (scan start area of the dose monitor 212), irradiation start position (irradiation start area of the dose monitor 212), and scan end position. (Scanning end area of the dose monitor 212) and irradiation end position (irradiation end area of the dose monitor 212) can be made to coincide with each other. Thereby, after the beam extraction from the synchrotron 5 is stopped by the beam extraction stop command, the ion beam 2 is accelerated to a desired energy, and the beam extraction from the synchrotron 5 and the beam irradiation to the affected part are restarted by the beam extraction start command. The scanning electromagnet power supply control device 220 resumes the ion beam irradiation from the position where the beam irradiation was stopped when the beam extraction was stopped, without performing the sky control of the scanning electromagnet power supplies 219 and 219 (no excitation of the scanning electromagnets 202 and 202) Thus, the measurement area 222 can be easily managed.

  Further, when irradiation control proceeds from the start of irradiation treatment and only a region that has not reached the target dose is irradiated, in the case of the first embodiment, the scanning electromagnet power supply control device 220 is self-running scanning control. Since the beam irradiation stops and waits until the beam reaches a desired scanning position, the irradiation time must be long. In this embodiment, such a problem is solved by installing the beam scanning management unit 311.

  That is, the beam scanning management unit 311 is connected to the irradiation region determination unit 302 and the memory device 305, and can access both the irradiation region determination unit 302 and the irradiation management memory 305c of the memory device 305. The beam scanning management unit 311 updates the excitation data (Ix_data, Iy_data) set in the scanning electromagnet power sources 219 and 219 (the measurement region is updated), and the irradiation region determination unit 302 captures the excitation data each time the excitation data is acquired. The target dose reachability (whether or not the integrated dose has reached the target dose) in the measurement region 222 where the beam irradiation is performed next to the center measurement region 222a corresponding to the beam center of gravity position identified by the unit 302 is determined from the irradiation management memory 305c. When the next measurement region 222 has reached the target dose, the current center of gravity of the beam identified by the irradiation region determination unit 302, that is, the region that has not reached the shortest target dose is searched for. Then, the beam scanning management unit 311 transmits a data update signal for setting the next beam irradiation region as the region to the scanning electromagnet power supply control device 220, and the scanning electromagnet power supply control device 220 is excited based on the data update signal. The data (Ix_data, Iy_data) is updated, and the scanning electromagnet power supply 219 outputs the excitation current (Ix, Iy) based on the excitation data to the scanning electromagnet 202. As a result, since the measurement region 222 immediately moves to the shortest region that has not reached the target dose, there is no waiting time until the measurement region 222 reaches the region that has not reached the target dose, and the irradiation time (treatment time) can be shortened. it can.

On the other hand, when moving the measurement region 222, the beam scanning management unit 311 determines excitation data of the scanning electromagnets 202 and 202, outputs a beam irradiation control signal of beam OFF to the AND circuit 309A, and outputs from the synchrotron 5 When the beam emission is stopped and then the movement of the measurement region 222 is completed, a beam irradiation control signal for turning on the beam is output to the AND circuit 309A. This makes it possible to prevent erroneous beam irradiation when the scanning position is moved to the target measurement region 222. The other effects are the same as those in the first embodiment.
<Embodiment 3>
A third embodiment of the present invention will be described with reference to FIG. FIG. 9 is a diagram showing a configuration of an irradiation control apparatus in the charged particle beam irradiation system (particle beam therapy apparatus) of the present embodiment.

  In the first embodiment, the dose counter device 304 prepares the same number of counters 304a in accordance with the measurement channels (the number of divided areas or the number of measurement areas) of the two-dimensional dose monitor 212. While it is possible to control in parallel, it is necessary to prepare as many counters 304a as the number of measurement channels, and the cost of the irradiation control apparatus 300 tends to increase. On the other hand, in the present invention in which the beam is scanned and irradiated, the lateral distribution of the ion beam is expanded by the scatterer 206 provided in the irradiation field forming apparatus 200. The expanded beam diameter φB is a two-dimensional dose monitor. Since the area is not so large as to enclose the entire area 212, the substantially irradiated area (the central measurement area and the simultaneous measurement area) is a few areas of all measurement channels as shown in FIGS. 4 and 6. Therefore, in the present embodiment, the dose counter device 304B of the irradiation control device 300B has a counter 304a smaller than the number of measurement channels of the two-dimensional dose monitor 212, for example, the maximum of the total of the central measurement region 222a and the simultaneous measurement region 223. It is assumed that there are a number of counters 304a (12 in the case of FIG. 6), a multiplexer between the measured dose signal 224 from the two-dimensional dose monitor 212 and the dose counter 304B, and between the dose counter 304B and the integrated dose memory 305a. 313 and 314 are provided, and these multiplexers 313 and 314 are connected to the irradiation region determination unit 302 via the multiplexer control unit 307B.

  Excitation data output from the scanning electromagnet power supply controller 220 is taken into the irradiation region determination unit 302, and the center measurement region 222a and the simultaneous measurement region 223 are selected. Based on the selected information, the target data addresses of the integrated dose memory 305a, the target dose memory 305b, and the irradiation management memory 305c are indicated. In parallel with the designation of the memory address, the irradiation region determination unit 302 sends the address information to the multiplexer control unit 307B as selection information for the central measurement region 222a and the simultaneous measurement region 223, and the multiplexer control unit 307B receives the selection information. Based on the above, the multiplexer 313 is controlled, and the measured dose signal 224 corresponding to the memory address at that time is selected from the measured dose signals 224 output from the two-dimensional dose monitor 212 and transmitted to the counter 304B. Further, the multiplexer control unit 307B controls the multiplexer 314 based on the selection information, selects a memory area corresponding to the memory address at that time among the memory areas of the integrated dose memory 305a, and stores the counter 304B in these memory areas. Send the count value and save the total. In this way, by controlling the multiplexers 313 and 314 corresponding to the memory addresses, data transmission that is consistent with the central measurement region 222a and the simultaneous measurement region 223 is realized between the dose measurement signal 224, the dose counter 304B, and the integrated dose memory 305a. Is possible.

  With the configuration described above, the number of counters 204a of the dose counter device 304B can be reduced, and the manufacturing cost can be reduced.

1 is a diagram illustrating an overall configuration of a charged particle beam irradiation system (particle beam therapy system) according to a first embodiment of the present invention. It is a figure which shows the detail of the irradiation field forming apparatus with which the charged particle beam irradiation system of the 1st Embodiment of this invention is equipped. It is a figure which shows the structure of the irradiation control system containing the scanning magnet power supply control apparatus with which the charged particle beam irradiation system of the 1st Embodiment of this invention is equipped, a dose monitor, and an irradiation control apparatus. It is a figure which shows the relationship of the center measurement area | region and simultaneous measurement area | region with respect to the concept of the measurement area | region of the two-dimensional dose monitor with which the charged particle beam irradiation system of the 1st Embodiment of this invention is equipped, and an irradiation beam diameter. It is a figure which shows the table data preserve | saved at the irradiation area | region determination part with which the irradiation control apparatus of the charged particle beam irradiation system of the 1st Embodiment of this invention is equipped, and target dose memory, FIG. FIG. 5B shows the relationship between the excitation current range in the direction and the scanning range, and the relationship between them and the central measurement region and the simultaneous measurement region, and FIG. FIG. 5C shows the relationship between the measurement region and the simultaneous measurement region, and the relationship between the central region of the measurement region 222, the target dose D, and its allowable value ΔD (D ± ΔD). The relationship between the central measurement region and the simultaneous measurement region with respect to the irradiation beam diameter of the two-dimensional dose monitor of the charged particle beam irradiation system according to the first embodiment of the present invention and the change of the central measurement region and the simultaneous measurement region due to beam movement are shown. FIG. It is a timing chart of the beam irradiation control in the adjacent irradiation area | region at the time of scanning and irradiating a beam from the area | region i-1 to the area | region i + 1. It is a figure which shows the whole structure of the charged particle beam irradiation system (particle beam therapy apparatus) of the 2nd Embodiment of this invention. It is a figure which shows the whole structure of the charged particle beam irradiation system (particle beam therapy apparatus) of the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ion beam generator 2 ... Ion beam (charged particle beam)
3 ... Pre-stage accelerator 4 ... Low energy beam transport system 5 ... Synchrotron (charged particle beam generator)
6... High frequency electrode 7 for output. Power amplifier 8. Switch 9 for interlock. 9 Switch for output gate 10. High frequency oscillator for output 11... High energy beam transport system 12. Irradiation field forming device (beam irradiation device)
202 ... Scanning electromagnet 206 ... Scattering body (beam diameter expanding device)
208 ... Ridge filter (energy distribution expansion device)
210 ... Range shifter 212 ... Two-dimensional dose monitor 214 ... Bolus 215 ... Collimator 216 ... Patient 216a ... Diseased part 217 ... Treatment bed 219 ... Scanning magnet power supply 220 ... Scanning magnet power supply control device 222 ... Measurement area 222a ... Central measurement area 223, 223a, 223b ... simultaneous measurement regions 300, 300A, 300B ... irradiation control device 301 ... control processor 302 ... irradiation region determination unit (irradiation region determination device)
303 ... Irradiation management unit (second irradiation management device)
304, 304B ... Dose counter device 305 ... Irradiation control memory device (storage device)
306 ... Comparator (second irradiation management device)
307 ... Counter control unit (dose counter device)
308 ... Comparator control unit (second irradiation management device)
309, 309A ... AND circuit (output device)
311: Beam scanning management unit (first and second beam scanning management devices)
313, 314: Multiplexer.
320 ... Display device

Claims (16)

A charged particle beam generator that accelerates and emits a charged particle beam; and a scanning electromagnet that scans the charged particle beam emitted from the charged particle beam generator, and the charged particle beam that passes through the scanning electromagnet In a charged particle beam irradiation system comprising a beam irradiation device for irradiating an irradiation target,
A monitor plane provided in the beam irradiation apparatus and having a charged particle beam scan range scanned by the scanning magnet divided into a plurality of areas, and the irradiation dose can be measured independently for each area of the monitor plane A two-dimensional dose monitor;
Input a dose measured for each area of the monitor plane of the two-dimensional dose monitor, and integrate this measured dose independently for each area of the monitor plane to measure the accumulated dose for each area of the monitor plane, When the accumulated dose measured for each area of the monitor plane reaches a target dose set in advance for each area of the monitor plane, a control signal for stopping beam irradiation is output, and beam irradiation to the area that has reached the target dose is performed. A charged particle beam irradiation system comprising: an irradiation control device for stopping. The irradiation control device includes:
A dose counter device for counting the measured dose for each area of the monitor plane input from the two-dimensional dose monitor for each area of the monitor plane;
A storage device including a first storage unit that stores the dose counted by the dose counter device for each region of the monitor plane as the integrated dose, and a second storage unit that stores the target dose for each region of the monitor plane;
The integrated dose for each region stored in the first storage unit is compared with the target dose stored in the second storage unit, and a control signal for stopping the beam irradiation is output when the integrated dose reaches the target dose. The charged particle beam irradiation system according to claim 1, further comprising a first irradiation management device. The irradiation control device includes:
A dose counter device for counting the measured dose for each area of the monitor plane input from the two-dimensional dose monitor for each area of the monitor plane;
A storage device including a first storage unit that stores the dose counted by the dose counter device for each region of the monitor plane as the integrated dose, and a second storage unit that stores the target dose for each region of the monitor plane;
An irradiation region determination device that inputs an excitation current command value of the scanning electromagnet at that time, and identifies a region corresponding to the excitation current command value of the scanning electromagnet among the plurality of regions of the monitor plane as a measurement region; Have
The dose counter device selects and counts only the measurement dose of the measurement region identified by the irradiation region determination device from the measurement dose for each region of the monitor plane input from the two-dimensional dose monitor. The charged particle beam irradiation system according to claim 1. The irradiation area determination device identifies, as a central measurement area, an area where the center of the beam irradiation area corresponding to the current excitation current command value of the scanning electromagnet is located among the plurality of areas on the monitor plane, and A plurality of regions that are located around the central measurement region and constitute a part of the beam irradiation region are identified as simultaneous measurement regions,
The dose counter device selects and counts the measured doses in the central measurement region and the simultaneous measurement region identified by the irradiation region determination device among the measured doses for each region of the monitor plane input from the two-dimensional dose monitor. The charged particle beam irradiation system according to claim 5. The irradiation control device includes:
A dose counter device for counting the measured dose for each area of the monitor plane input from the two-dimensional dose monitor for each area of the monitor plane;
A storage device including a first storage unit that stores the dose counted by the dose counter device for each region of the monitor plane as the integrated dose, and a second storage unit that stores the target dose for each region of the monitor plane;
An irradiation region determination device that inputs an excitation current command value of the scanning electromagnet at that time, and identifies a region corresponding to the excitation current command value of the scanning electromagnet among the plurality of regions of the monitor plane as a measurement region; ,
Of the integrated doses stored in the first storage unit, the integrated dose of the measurement region identified by the irradiation region determination device is selected and compared with the target dose stored in the second storage unit. The charged particle beam irradiation system according to claim 1, further comprising: a first irradiation management device that outputs a control signal for stopping the beam irradiation when a dose reaches the target dose. The irradiation region determination device identifies, as a central measurement region, a region where the center of the beam irradiation region corresponding to the current excitation current command value of the scanning electromagnet is located among the plurality of regions on the monitor plane,
The first irradiation management device selects the accumulated dose of the central measurement region identified by the irradiation region determination device from the accumulated doses for each region stored in the first storage unit, and saves it in the second storage unit 4. The charged particle beam irradiation system according to claim 3, wherein a control signal for stopping the beam irradiation is output when the integrated dose reaches the target dose in comparison with the target dose. The irradiation control device includes:
A dose counter device for counting the measured dose for each area of the monitor plane input from the two-dimensional dose monitor for each area of the monitor plane;
A storage device including a first storage unit that stores the dose counted by the dose counter device for each region of the monitor plane as the integrated dose, and a second storage unit that stores the target dose for each region of the monitor plane;
An irradiation region determination device that inputs an excitation current command value of the scanning electromagnet at that time, and identifies a region corresponding to the excitation current command value of the scanning electromagnet among the plurality of regions of the monitor plane as a measurement region; ,
Compared with the target dose stored in the second storage unit by selecting only the integrated dose of the measurement region identified by the irradiation region determination device from the integrated dose for each region stored in the first storage unit, A first irradiation management device that outputs a control signal for stopping the beam irradiation when an accumulated dose reaches the target dose;
Whether or not the cumulative dose of the measurement region identified by the irradiation region determination device among the cumulative doses for each region stored in the first storage unit has reached the target dose stored in the second storage unit. A second irradiation management device that reads and outputs a control signal to stop the beam irradiation when the accumulated dose reaches the target dose;
An output device for outputting a beam emission OFF signal to the charged particle beam generator when at least one of the first irradiation management device and the second irradiation management device outputs a control signal for stopping the beam irradiation; The charged particle beam irradiation system according to claim 1. The irradiation region determination device identifies, as a central measurement region, a region where the center of the beam irradiation region corresponding to the current excitation current command value of the scanning electromagnet is located among the plurality of regions on the monitor plane,
The first irradiation management device selects the accumulated dose of the central measurement region identified by the irradiation region determination device from the accumulated doses for each region stored in the first storage unit, and saves it in the second storage unit Output a control signal to stop the beam irradiation when the accumulated dose reaches the target dose,
The second irradiation management device is configured such that, out of the integrated doses for each region stored in the first storage unit, the integrated dose of the central measurement region identified by the irradiation region determination device is stored in the second storage unit. 8. The charged particle beam irradiation system according to claim 7, wherein whether or not the dose has been reached is read, and if the integrated dose has reached the target dose, a control signal for stopping the beam irradiation is output.   The second irradiation management device outputs an energy update command when the integrated dose for each region stored in the first storage unit reaches the target dose stored in the second storage unit in all regions of the monitor plane. The charged particle beam irradiation system according to claim 7, wherein a control signal for stopping the beam irradiation is output to the output device.   The second irradiation management device includes an integrated dose of the measurement region identified by the irradiation region determination device and a target dose stored in the second storage unit among the integrated doses stored in the first storage unit for each region. According to the comparison result, when outputting either the control signal for instructing the beam irradiation to the output device and the control signal for stopping the beam irradiation, and outputting the control signal for instructing the beam irradiation, 9. The charged particle beam irradiation according to claim 8, wherein a control signal for stopping the beam irradiation is output a predetermined time before a time point when the central region identified by the irradiation region determination device moves to the next region. system. The storage device further includes a third storage unit that records that the integrated dose has reached the target dose for each area of the monitor plane,
The first irradiation management unit outputs a control signal for stopping the beam irradiation when the integrated dose in the measurement region identified by the irradiation region determination device reaches the target dose stored in the second storage unit. , Recording that the cumulative dose has reached the target dose in the third storage device,
The second irradiation management device includes the target dose stored in the second storage unit by the integrated dose of the measurement region identified by the irradiation region determination device among the integrated doses stored in the first storage unit. 11. The charged particle beam irradiation system according to claim 7, wherein whether or not the light beam has reached has been read from the third storage device. 11. The charged particle beam generator emits a charged particle beam according to a beam extraction start command after the charged particle beam is accelerated to a desired energy, and has a time during which the charged particle beam generated by one acceleration operation can be emitted. When it has passed, it is a synchrotron that stops the emission of the charged particle beam by a beam extraction stop command,
The irradiation control device includes:
A dose counter device for counting the measured dose for each area of the monitor plane input from the two-dimensional dose monitor for each area of the monitor plane;
A storage device including a first storage unit that stores the dose counted by the dose counter device for each region of the monitor plane as the integrated dose, and a second storage unit that stores the target dose for each region of the monitor plane;
An irradiation region determination device that inputs an excitation current command value of the scanning electromagnet at that time, and identifies a region corresponding to the excitation current command value of the scanning electromagnet among the plurality of regions of the monitor plane as a measurement region; ,
Of the integrated doses stored in the first storage unit, the integrated dose of the measurement region identified by the irradiation region determination device is selected and compared with the target dose stored in the second storage unit. An irradiation management device that outputs a control signal to stop the beam irradiation when a dose reaches the target dose; and
The beam extraction start command and the beam extraction stop command are input, and an update command for the excitation current command value of the scanning electromagnet, a scan control start command, and a scan control end command are issued in synchronization with the beam extraction start command and the beam extraction stop command. The charged particle beam irradiation system according to claim 1, further comprising: a first beam scanning management device that outputs. The irradiation control device includes:
Each time the excitation current command value of the scanning electromagnet is updated, out of the accumulated doses for each area stored in the first storage unit, the area for performing beam irradiation next to the measurement area identified by the irradiation area determination device Read whether or not the accumulated dose has reached the target dose stored in the second storage unit, and if the accumulated dose has reached the target dose, the shortest from the measurement region identified by the irradiation region determination device A second beam scanning management device that searches for an area that has not reached the target dose, outputs an excitation current command value update command corresponding to the area, and outputs a control signal for stopping the beam irradiation;
An output device for outputting a beam emission OFF signal to the charged particle beam generator when at least one of the irradiation management device and the second beam scanning management device outputs a control signal for stopping the beam irradiation; The charged particle beam irradiation system according to claim 12. The irradiation control device includes:
A dose counter device for counting the measured dose for each area of the monitor plane input from the two-dimensional dose monitor for each area of the monitor plane, the dose having a number of counters smaller than the number of divided areas of the monitor plane A counter device;
A storage device including a first storage unit that stores the dose counted by the dose counter device for each region of the monitor plane as the integrated dose, and a second storage unit that stores the target dose for each region of the monitor plane;
An irradiation region determination device that inputs an excitation current command value of the scanning electromagnet at that time, and identifies a region corresponding to the excitation current command value of the scanning electromagnet among the plurality of regions of the monitor plane as a measurement region; ,
Compared with the target dose stored in the second storage unit by selecting only the integrated dose of the measurement region identified by the irradiation region determination device from the integrated dose for each region stored in the first storage unit, An irradiation management device that outputs a control signal for stopping the beam irradiation when an accumulated dose reaches the target dose; and
A measurement dose corresponding to the measurement region identified by the irradiation region determination device is selected from the measurement doses for each region of the monitor plane input from the two-dimensional dose monitor, and transmitted to the counter of the dose counter device. A multiplexer,
A second multiplexer for transmitting and storing the dose counted by the counter of the dose counter device in a memory region corresponding to the measurement region identified by the irradiation region determination device in the memory region of the first storage unit; The charged particle beam irradiation system according to claim 1. The beam irradiation device includes:
A beam diameter enlarging device for enlarging a beam diameter of the charged particle beam emitted from the charged particle beam generator more than a divided width of the plurality of regions of the monitor plane;
By forming a plurality of energy regions on the charged particle beam emitted from the charged particle beam generator and superimposing a plurality of Bragg peaks formed in the depth direction, a uniform dose distribution in the depth direction can be obtained. An energy distribution expansion device to be formed;
The irradiation control device includes:
A dose counter device for counting the measured dose for each area of the monitor plane input from the two-dimensional dose monitor for each area of the monitor plane;
A storage device including a first storage unit that stores the dose counted by the dose counter device for each region of the monitor plane as the integrated dose, and a second storage unit that stores the target dose for each region of the monitor plane;
The integrated dose for each region stored in the first storage unit is compared with the target dose stored in the second storage unit, and a control signal for stopping the beam irradiation is output when the integrated dose reaches the target dose. A first irradiation management device;
A second irradiation management device that outputs an energy update command when the accumulated dose for each region stored in the first storage unit in all the areas of the monitor plane reaches the target dose stored in the second storage unit; The charged particle beam irradiation system according to claim 1, comprising:   The charged particle beam irradiation system according to claim 1, further comprising a display device that displays a measured dose for each area of the monitor plane.

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