JP2010253000A - Radiation irradiation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system to irradiate an irradiation object with a dose of radiation according to the plan by removing the uneven distributions of irradiated ion beam among the regions of respiratory phases with a finite-width caused by the irradiation object movements. <P>SOLUTION: The radiation irradiation system includes a radiation generator 1 to generate radiation, a radiation dose measuring device to measure the radiation dose projected from the radiation generator, a movement measuring device 212 to measure the position of the irradiation object, and a controller to control the start and stop of radiation projection from the radiation generator 1. This radiation irradiation system divides the position of the radiation object into a plurality of regions, based on the information of target irradiation position, radiation dose from the radiation dose measuring device and the position of irradiation object from the movement measuring device, determines whether each of the divided regions has attained the target radiation dose, and controls the start or stop of radiation irradiation so that radiation can be irradiated to the region determined not to have attained the target dose yet. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radiation irradiation system for irradiating an irradiation target with particle beams such as electromagnetic waves such as X-rays, electron beams, neutron beams, proton beams, and carbon beams.

  In radiation therapy, an affected part of a patient such as cancer is irradiated with an ion beam (a charged particle beam such as a proton beam, a helium beam, or a carbon beam), an electromagnetic wave such as an X-ray, an electron beam, or a neutron beam. Regardless of the radiation used, basically, while suppressing the dose to normal cells, the dose is focused on the cancer cells in the target affected area, and the cancer cells are killed intensively to achieve a therapeutic effect. obtain.

  Taking an ion beam as an example, a method for forming a dose distribution by a radiation irradiation system will be described.

  An ion beam irradiation system used for this type of treatment includes an ion accelerator, a beam transport system, and an irradiation field forming device mounted on a rotating gantry. The ion beam accelerated by the ion accelerator is transported to the irradiation field forming apparatus through the beam transport system. The ion beam is formed in the shape of the affected area by the irradiation field forming device. The rotating gantry can irradiate the target with ion beams from any direction of 360 °. Hereinafter, the direction toward the affected area in the body by irradiating the ion beam is referred to as the deep direction, and the direction perpendicular thereto is referred to as the transverse direction.

The typical three-dimensional size of the affected area is a few cm cubic. The typical thickness of the ion beam taken out from the accelerator is a few millimeters. That is, the range in which the ion beam can be irradiated in the horizontal direction is several mm, which is generally smaller than the size of the affected area in the horizontal direction.

  When an ion beam is incident on a substance, most of the kinetic energy is released just before stopping and forms a dose distribution having a maximum called a Bragg peak. The energy of the ion beam is adjusted, the Bragg peak is approximately coincident with the position in the deep direction of the affected part, and a dose is given to the affected part in a concentrated manner. Depending on the ion species and energy, the Bragg peak is typically several millimeters in depth. That is, it is generally smaller than the size of the affected part in the depth direction.

  Therefore, in order to uniformly irradiate the affected area with ion beams, it is necessary to expand the dose distribution both in the lateral direction and in the deep direction.

Scanning irradiation methods and scatterer irradiation methods are known as methods for expanding the dose distribution of ion beams in the horizontal direction. In the scanning irradiation method, a scanning electromagnet is provided in the irradiation field forming device, the ion beam relatively thin compared with the target affected part is deflected in the lateral direction, and the ion beam is discretely or continuously arranged, and the target This is a method of irradiating so as to fill in (FIG. 1A). The scatterer irradiation method includes an ion beam scatterer in the irradiation field forming device, which scatters the ion beam, typically expands to a few tens of centimeters, and uses a collimator that matches the lateral shape of the target. It is the method of irradiating. When irradiating an ion beam to a large target in the lateral direction so that it exceeds the ion beam expansion performance of the scatterer, change the position of the target in the lateral direction by irradiating the ion beam, and then irradiate the ion beam again to determine the dose distribution. There is also known a method of forming a dose distribution of one desired size by repeating a procedure of forming and arranging a plurality of dose distributions side by side. This is known as a patch irradiation method (FIG. 1B).

  In order to form a dose distribution with a target size in the deep direction, there is a method of irradiating ion beams with a plurality of energies. In other words, the target is irradiated with an ion beam accelerated to a desired energy with an ion accelerator, and the target is irradiated again with an ion beam accelerated to another energy to form Bragg peaks with different depths. Are overlapped to form a SOBP (Spread Out Bragg Peak) and a planned deep dose distribution (FIG. 1C). Instead of changing the energy of the ion beam emitted from the ion accelerator, it is also possible to provide an energy absorber on the beam line and change the ion beam energy by changing its thickness. You may combine the acceleration energy in an ion accelerator, and an energy absorber. Note that, even when an ion beam having a constant energy is incident, an ion beam having a plurality of energy components can be generated by passing through a ridge filter or an RMW (Range Modulation Wheel) to form an SOBP.

  Using a rotating gantry, the dose distribution in the deep direction can be expanded to a target size. For example, a large high dose region can be formed in the depth direction by irradiating ion beams from two opposite directions and connecting the end points of the respective dose distributions (FIG. 1 (d)). At this time, the energy may be changed for each direction using an ion accelerator or an energy absorber. Further, the dose distribution may be expanded in the depth direction using a ridge filter or RMW.

  In the above, for the sake of convenience, the expansion of the dose distribution to the target size has been described separately in the lateral direction and the deep direction. However, both may be expanded simultaneously. For example, as is known as discrete spot scanning irradiation, when a three-dimensional target is divided into minute areas called spots, and each spot is irradiated with an ion beam of each planned dose, In addition, the individual dose distributions are combined in the deep direction to expand the dose distribution to the target size.

  Furthermore, both can be combined. For example, as known as multi-port irradiation, there is a method of using a rotating gantry to irradiate a target with ion beams from a plurality of directions and combining them to form a desired dose distribution. Like IMRT (Intensity Modulated Radiation Therapy), IMPT (Intensity Modulated Proton Therapy), and finally, X-rays and ion beams are irradiated from multiple directions while changing the intensity. There is a method for forming a desired dose distribution. These are none other than combining the individual dose distributions mixed in the lateral direction and the deep direction, and expanding the dose distribution to the target size.

  Hereinafter, the individual dose distributions shown above for constituting the target-sized dose distribution to be finally formed will be referred to as dose distribution elements.

  The dose distribution is expanded to the target size by various methods as described above. However, when the target affected part is a liver or the like, the affected part may move irregularly due to physiological movements such as breathing and heartbeat. For this reason, if radiation is irradiated without considering the movement of the target, a desired amount of radiation may not be irradiated, and a planned dose distribution may not be formed. Therefore, when breathing phase is within the permissible range, the breathing phase detection device such as a laser distance meter is used to measure the distance to the body surface and so on. A dose distribution is formed as planned by irradiating only ion beams. For convenience, the description is limited to the detection of the phase of respiration, but the phase of a physiological motion such as a heartbeat may be detected. Similarly, the following description is limited to the respiratory phase, but the physiological motion phase may be detected.

  Patent Document 1 discloses an acceleration device that accelerates and emits a particle beam to a predetermined energy, an irradiation device that irradiates the particle beam emitted from the acceleration device in a plurality of times, and the intensity of the particle beam emitted from the accelerator. Discloses a particle beam irradiation system including an accelerator intensity modulation device that modulates the respiration and a respiratory change monitoring device that monitors the respiratory change of an irradiation target. This particle beam irradiation system divides an irradiation target in a beam traveling direction, and irradiates a particle beam for each divided scan region. In Patent Document 1, the intensity of the particle beam emitted from the accelerator is modulated based on the respiratory fluctuation detected by the respiratory fluctuation monitoring apparatus, or scanning is performed in a gate period in which the amount of displacement of the periodic fluctuation of the irradiation target is within a predetermined phase. By irradiating, irradiation of particle beam according to the plan is realized.

JP 2008-154627 A

  In the conventional respiratory synchronous irradiation, the following problems exist. That is, when performing respiration-synchronized irradiation, a region having a certain finite width of respiration phase is set. And while maintaining the state which can irradiate an ion beam immediately, a respiration phase is also detected, and an ion beam is irradiated to a target only when a respiration phase exists within the width of the set respiration phase. However, since the respiration is irregular, the actually irradiated ion beam is in the set absorption phase region, but within that range, the respiration phase is not always irradiated uniformly. For example, the set finite width There is a possibility that the ion beam is irradiated at the end of the respiratory phase.

  A dose distribution obtained when the affected part moving due to breathing or the like is irradiated with an ion beam will be described with reference to FIG.

  When the target moves in the deep direction with respiration, the depth of the dose distribution formed at each moment changes if the ion beam is biased and irradiated within the finite-width respiration phase region due to the above phenomenon. A dose distribution unevenly distributed on the deeper side or the shallower side than the dose distribution is finally obtained. Because respiration is irregular, for each individual dose distribution that is a component of the target large dose distribution, whether the dose distribution shifts to the deep side or the shallow side is determined by the respiratory phase at the time of beam irradiation. Control is difficult (FIG. 2 (a)).

  When the target moves in the lateral direction with respiration, it is assumed that the ion beam is irradiated in a biased manner within the finite-width respiration phase region due to the above situation. Then, since the horizontal position of the dose distribution formed at each moment changes, a dose distribution unevenly distributed on the left side or the right side of the planned dose distribution is finally obtained. In this case as well, for each individual dose distribution that is a component of the target-size dose distribution, whether the dose distribution is shifted to the left or right is determined by the respiratory phase at the time of beam irradiation. It is difficult (FIG. 2 (b)).

  For this reason, when the dose distribution elements are combined to form a target-sized dose distribution, the dose distribution actually formed will differ from the planned dose distribution at the boundary between the depth direction, the lateral direction, or a combination of both. there is a possibility.

  Accordingly, an object of the present invention is to obtain a dose distribution as planned even at the boundary between dose distribution elements when a target-size dose distribution is formed.

  A feature of the present invention that achieves the above object is that a radiation generation device that generates radiation, a dose measurement device that measures a dose of radiation emitted from the radiation generation device, and a variation measurement device that measures the position of an irradiation target; And a control device that controls the start and stop of the emission of radiation from the radiation generation device, and this control device uses the target irradiation position information, the dose information from the dose measurement device, and the irradiation target position information from the variation measurement device. Based on each of the divided areas obtained by dividing the irradiation position of the irradiation target, it is determined whether the target dose has been reached, and the emission start and the emission stop are performed so that the divided areas that have not reached the target dose are irradiated with radiation. Is to control. In this way, the target dose of radiation is set in advance for each divided region, the respiratory phase is measured during irradiation, and the radiation is irradiated only when the respiratory phase does not reach the target value. The uneven distribution of the ion beam irradiated every time can be eliminated, and the dose distribution region that is difficult to control can be reduced at the end of the dose distribution element in the depth direction, the lateral direction, or both directions. By applying this irradiation method for each dose distribution element, it becomes possible to obtain a dose distribution as planned at the boundary even when a plurality of dose distribution elements are combined.

  ADVANTAGE OF THE INVENTION According to this invention, the uneven distribution of the ion beam irradiation in the finite-width respiration phase area | region which arises due to the movement of irradiation object can be eliminated, and the dose distribution according to the plan can be formed with respect to irradiation object .

It is a schematic diagram of the expansion method of various dose distributions, (a) Lateral dose distribution obtained by scanning irradiation method, (b) Lateral dose distribution obtained by patch method, (c) Ejected from ion accelerator The dose distribution in the depth direction obtained by irradiating while changing the energy of the ion beam, and (d) the dose distribution in the depth direction obtained by irradiating the ion beam from two directions with the rotating gantry. It is a schematic diagram showing a dose distribution when an affected part moves due to breathing or the like, and shows (a) a dose distribution in the depth direction and (b) a dose distribution in the lateral direction. It is a conceptual diagram showing the whole structure of the ion beam therapy apparatus which is one Example of this invention. It is a conceptual diagram which shows the irradiation field forming apparatus with which the ion beam therapy apparatus which is one Example of this invention is equipped. It is a conceptual diagram showing the structure of the irradiation control system with which the ion beam therapy apparatus which is one Example of this invention is equipped. It is a conceptual diagram of the data table stored in the phase area | region determination apparatus memory which is a component of this invention. It is a conceptual diagram of the data table stored in the target value memory which is a component of this invention. It is a figure which shows the initial ion beam irradiation by this invention, (a) The figure which shows the relationship of the extraction permission signal with respect to a patient position signal, and an extraction beam signal, (b) The target dose and irradiated dose for every respiration phase area are shown (C) It is a figure which shows dose distribution in the depth direction. It is a figure which shows the ion beam irradiation of the middle period by this invention, (a) The figure which shows the relationship between the extraction permission signal with respect to a patient position signal, and an extraction beam signal, (b) The target dose and irradiated dose for every respiration phase area are shown (C) It is a figure which shows dose distribution in the depth direction. It is a figure which shows the late ion irradiation by this invention, (a) The figure which shows the relationship of the extraction permission signal with respect to a patient position signal, and an extraction beam signal, (b) The figure which shows the target dose and irradiated dose for every respiration phase area | region (C) It is a figure which shows dose distribution in the depth direction. It is a figure which shows the relationship of the apparatus which comprises the ion beam therapy apparatus which is one Example of this invention. It is a conceptual diagram which shows the irradiation field forming apparatus with which the ion beam therapy apparatus which is 2nd Embodiment of this invention is equipped. It is a figure which shows the dose distribution of the horizontal direction at the time of irradiating an ion beam with the ion beam therapy apparatus which is 2nd Embodiment of this invention. It is a conceptual diagram which shows the irradiation field forming apparatus with which the ion beam irradiation apparatus which is 3rd Embodiment of this invention is equipped. It is a figure which shows the dose distribution of the horizontal direction at the time of irradiating an ion beam with the ion beam irradiation apparatus which is 3rd Embodiment of this invention. It is a conceptual diagram which shows the irradiation field forming apparatus with which the ion beam irradiation apparatus which is 4th Embodiment of this invention is equipped. It is a figure which shows the dose distribution of the depth direction at the time of irradiating an ion beam with the ion beam irradiation apparatus which is 4th Embodiment of this invention. It is a conceptual diagram which shows the irradiation field forming apparatus with which the ion beam irradiation apparatus which is 5th Embodiment of this invention is equipped. It is a conceptual diagram which shows the irradiation field forming apparatus with which the ion beam irradiation apparatus which is 6th Embodiment of this invention is equipped. The conceptual diagram at the time of irradiating an ion beam with the ion beam irradiation apparatus which is 6th Embodiment of this invention is shown, (a) The conceptual diagram at the time of irradiating an ion beam with respect to an affected part, (b) Lateral dose It is a figure which shows distribution, (c) It is a figure which shows dose distribution of a depth direction.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

(Embodiment 1)
FIG. 3 is a schematic diagram of an overall configuration of an ion beam therapy apparatus that is a radiotherapy apparatus of the present embodiment. FIG. 4 is a diagram showing details of the internal structure of the irradiation field forming apparatus 200 described in the embodiment. FIG. 5 is a diagram showing details of the internal structure of the irradiation control system 300 described in the present embodiment. As an example of the radiation generating apparatus, an ion beam therapy apparatus is described as an embodiment, but it may be an apparatus that irradiates other radiation such as X-rays.

  As shown in FIG. 3, the ion beam therapy apparatus according to the present embodiment irradiates an affected area 210 a of a patient 210 positioned on a patient support apparatus (bed apparatus) 211 with an ion beam. The ion beam therapy apparatus includes an ion beam generator 1, a central controller 100, an irradiation field forming apparatus 200, and an irradiation control system 300. The ion beam generator 1 generates ions, accelerates them to desired energy, and supplies the ion beam to the irradiation field forming device 200. The irradiation field forming apparatus 200 forms the supplied ion beam according to the target shape. The irradiation control system 300 controls ion beam irradiation by the ion beam generator 1 according to the progress of irradiation. The central control device 100 performs cooperative control of the respective devices.

  The internal configuration of each device and the operation thereof will be described in detail below.

  The ion beam generator 1 includes an ion source 2, a front stage accelerator 3, a low energy beam transport system 4, a synchrotron 5, and a high energy beam transport system 13.

  Ions generated by the ion source 2 are accelerated by the pre-accelerator 3 and supplied to the synchrotron 5 through the low energy beam transport system 4. The synchrotron 5 accelerates while circulating the ion beam, and includes an accelerating device 6, an extraction high-frequency application device 7, and an extraction deflector 12 on the orbit, and the extraction high-frequency application device 7 includes the extraction high-frequency application electrode 8. (Not shown). The emission high-frequency applying device 7 is supplied with power from the emission high-frequency power source 9 via the open / close switch 11. The open / close switch 11 is connected to the central controller 100 and the irradiation control system 300, and opens and closes according to the command. A high frequency is applied to a high frequency acceleration cavity provided in the acceleration device 6 to accelerate the ion beam. After the ion beam is accelerated to a desired energy (for example, 50 to 250 MeV), high-frequency power from the extraction high-frequency power source 9 is applied to the ion beam by the extraction high-frequency application electrode 8 via the closed open / close switch 11. . As a result, the ion beam that has stably circulated in the synchrotron 5 is shifted to an unstable state, and is emitted to the high energy beam transport system 13 through the extraction deflector 12. When the ion beam is emitted, the currents guided to the quadrupole electromagnet and the deflection electromagnet provided in the synchrotron 5 are held at a constant set value, and the stability limit is also kept almost constant.

  The high energy beam transport system 13 and the irradiation field forming apparatus 200 are mounted on the rotating gantry 14. By adjusting the rotation angle of the rotating gantry 14, the patient 210 can be irradiated with ion beams from a desired direction. The ion beam taken out from the synchrotron 5 is transported to the high energy beam transport system 13, passes through the irradiation field forming device 200, and is irradiated onto the target.

  In addition, although the example which comprised the synchrotron as the center was shown as the ion beam generator 1, the method using a cyclotron is also considered.

  The details of the irradiation field forming apparatus 200 will be described with reference to FIG. The irradiation field forming device 200 expands the ion beam generated by the ion beam generator 1 according to the shape of the affected part 210 a of the patient 210 positioned on the patient support device 211. The irradiation field forming apparatus 200 includes a casing 201. In the casing 201, an incident ion beam monitor 202, a scanning electromagnet 203, a dose monitor 204, a post-scanning ion beam position monitor 205, a range shifter 206, a range shifter insertion mechanism 207, a bolus 208, a collimator. 209. A respiratory phase measuring device 212 is installed in the treatment room. The respiration phase measuring device 212 measures the respiration phase of the patient 210 and measures the fluctuation of the target affected area 210a.

  The incident ion beam monitor 202 measures the position of the ion beam incident on the irradiation field forming apparatus 200 and monitors whether it is within the allowable position. That is, the incident ion beam monitor 202 outputs the position information to the irradiation control system 300 when measuring the position of the ion beam. The irradiation control system 300 determines whether the position of the received ion beam is within a predetermined allowable range. The energy of the incident ion beam is adjusted by the synchrotron 5. If the ion beam position exceeds an allowable value for some reason, such as a component failure, the irradiation control system 300 transmits an ion beam irradiation stop signal to the central control device 100 (the signal line is not shown in the figure) and receives the signal. The central controller 100 opens the open / close switch 11 and immediately stops the irradiation of the ion beam.

  Next, the ion beam reaches the scanning electromagnet 203. The ion beam is deflected by the excitation magnetic field generated by the scanning electromagnetic magnet 203 in accordance with the lateral direction of the affected part shape. When the irradiation control system 300 controls the excitation amount of the scanning electromagnet 203, the deflection amount of the ion beam is changed and the irradiation position in the horizontal direction is changed. Here, the horizontal direction indicates a direction perpendicular to the traveling direction of the ion beam.

  Next, the ion beam reaches the dose monitor 204 and the ion beam position monitor 205 after scanning. The dose monitor 204 measures the ion beam dose, and the post-scan ion beam position monitor 205 measures the position of the ion beam after deflection. The dose monitor 204 outputs the measured ion beam dose information to the irradiation control system 300. Further, the post-scanning ion beam position monitor 205 outputs the measured ion beam position information to the irradiation control system 300. Similar to the incident ion beam monitor 202, the irradiation control system 300 determines whether the ion beam irradiation amount and the ion beam position are within the allowable range. When these received values are out of the allowable range, the irradiation control system 300 transmits an ion beam irradiation stop signal to the central control device 100 (signal lines are not shown in the figure). When the central controller 100 receives the ion beam irradiation stop signal, it immediately stops the ion beam irradiation.

  Next, the ion beam passes through the range shifter 206 mounted on the range shifter insertion mechanism 207. The role of the range shifter insertion mechanism 207 is to insert a range shifter 206 corresponding to the depth of the affected part 210a to be a target and change the energy of the ion beam. In accordance with the central controller 100 (signal lines are not shown in the figure), a plurality of range shifters 206 are arranged on the ion beam trajectory, and the irradiation of the ion beam with a desired energy is realized together with the acceleration by the synchrotron 5. Although FIG. 4 shows a binary type in which a plurality of plate-shaped range shifters 206 having a plurality of thicknesses are combined and inserted, a plurality of wedge-shaped range shifters may be overlapped to change the thickness through which ion beams are transmitted.

  The bolus 208 is formed by excavating a resin block body, for example, and has a structure in which the resin passage thickness changes according to the incident position of the ion beam. As a result, the energy of the ion beam after passing through the bolus 208 can be changed for each incident position, and the reaching depth of the ion beam is matched with the shape of the affected part 210a in the depth direction. This may be realized by changing the deflection amount with the scanning electromagnet 203 and further changing the energy by combining the acceleration of the ion beam by the synchrotron 5 and the energy attenuation by the range shifter 206. In this case, the bolus 208 can be omitted. .

  The collimator 209 includes a hole corresponding to the lateral contour of the affected part 210a in the plate-like ion beam shield, so that only the ion beam that has passed through the hole among the ion lines expanded in the lateral direction is affected. Irradiate 210a. Thereby, the horizontal shape of the affected part 210a and the horizontal shape of the ion beam to be irradiated are matched. The amount of deflection of the ion beam may be adjusted by the scanning electromagnet 203 to match the horizontal shape, and in this case, the collimator 209 can be omitted. The collimator 209 is usually processed according to the shape of the affected part 210a in the lateral direction, and is exchanged for each affected part 210a. By using a multi-leaf collimator as the collimator 209 and moving the leaf to match the shape of the affected part 210a in the lateral direction, the labor of processing and replacement may be saved.

  The respiratory phase measuring device 212 measures the respiratory phase, detects a change in the affected part 210a, and transmits a patient position signal to the irradiation control system 300. Specifically, a method of calculating the position of an affected area by analyzing a photograph taken using X-rays or ultrasound, a method of measuring fluctuations of the body surface using a laser distance meter, a body with an acceleration sensor attached to the body surface How to measure the variation of the table, how to measure the patient's exhalation and inspiratory flow, how to attach a band to the patient's chest and measure the change in chest circumference, how to extract the contraction of the muscle strength of the chest using electrodes, Etc. are also conceivable. In addition, although the embodiment has been described as representative of the measurement of the respiratory phase, it may be a fluctuation measuring device that measures the fluctuation of the irradiation target, as shown in the specific example, a method for directly measuring the fluctuation of the affected area, A method is conceivable in which the fluctuation of the affected part is estimated by measuring the fluctuation of the part linked to the affected part.

  The ion beam that has passed through the device is irradiated onto the affected area 210a of the patient 210 positioned on the patient support device 211, and forms a dose distribution. In the present embodiment, the scanning electromagnet 203 provided in the irradiation field forming apparatus 200 forms a dose distribution in a plane perpendicular to the traveling direction of the ion beam, and the range shifter 206 provided in the irradiation field forming apparatus 200 is provided. A dose distribution is formed in the direction of ion beam travel (depth direction from the body surface). The scanning electromagnet 203 deflects the ion beam in the lateral direction and irradiates the beam, so that the dose distribution can be formed over a wide range by combining the Gaussian dose distribution. In the present embodiment, the amount of excitation of the scanning electromagnet 203 is controlled to irradiate the target irradiation position in the horizontal direction, and the thickness of the range shifter 206 is controlled to control the ion irradiation to the target irradiation position in the deep direction. Irradiate.

  The details of the irradiation control system 300, which is a control device that realizes the present embodiment and controls the emission and stop of radiation, will be described with reference to FIG. The irradiation control system 300 opens and closes the open / close switch 11 using the respiratory phase measured by the respiratory phase measuring device 212 and the ion beam passage amount signal measured by the dose monitor 204 in order to form a planned dose distribution. Further, the irradiation control system 300 includes a phase region determination device 301, a sorting device 303, a multichannel counter 304, an open / close signal generation device 309, an irradiation completion signal generation device 310, and an interlock signal generation device 311.

  The phase region determination device 301 includes a phase region determination device memory 302, and is connected to the central control device 100, the respiratory phase measuring device 212, and the irradiating respiratory phase region memory 307. As shown in FIG. 6, the phase region determination device memory 302 stores the respiratory phase range acquired from the central control device 100 with the respiratory phase being θ. Using this, during the irradiation with the ion beam, the respiratory phase measured by the respiratory phase measuring device 212 is converted into the respiratory phase region (assumed to be converted into the respiratory phase region i), and the result is stored in the respiratory phase region memory 307 during irradiation. Record. Further, the region number determined by the phase region determination device 301 may be stored in the phase region determination device memory 302 and referred to by the distribution device 303 and the comparison device 312 as appropriate.

  The sorter 303 is connected to a breathing phase region memory 307 during irradiation, a dose distribution element memory 308 during irradiation, a dose monitor 204, and a multi-channel counter 304. The in-irradiation respiratory phase area memory 307 is connected to the central controller 100, and dose distribution elements during irradiation are sequentially recorded (assuming that the dose distribution element j is irradiated). The distribution device 303 reads information on the respiratory phase region i and the dose distribution element j recorded in the phase region determination device memory 302 and the irradiating respiratory phase region memory 307, and the ion beam irradiation measured by the dose monitor 204 according to the information. The amount is added to the corresponding multi-channel counter 304-i, j. In parallel therewith, a multi-channel counter 304-S, j may be provided, and the dose measured by the dose monitor 204 may be counted independently in correspondence with the dose distribution element j regardless of the phase region.

The open / close signal generation device 309 is connected to the respiratory phase area memory 307 during irradiation, the dose distribution element memory 308 during irradiation, the multichannel counter 304, the target value memory 305, and the open / close switch 11. As shown in FIG. 7, the target value memory 305 records the target value C (i, j) of the ion beam dose for each respiratory phase region i and dose distribution j acquired from the central controller 100. The open / close signal generation device 309 also records an allowable value ΔC (i, j) (not shown in the figure). The target value and the permissible value itself are calculated by the treatment planning device 102 and recorded in the central control device 100. Although details will be described later, the basic operation of the open / close signal generation device 309 includes a respiratory phase region i obtained from the irradiation respiratory phase region memory 307 and a dose distribution j during ion beam irradiation acquired from the irradiation respiratory phase region memory 307. Multi-channel counter 304-i, j
And the target value 305-i, j. Thereafter, the open / close signal generator 309 opens / closes the switch 11 when the measured count value exceeds (target value) + (allowable value), that is, when it exceeds C (i, j) + ΔC (i, j). To stop the ion beam irradiation. Further, the open / close signal generation device 309 irradiates the ion beam with the open / close switch 11 closed when (target value) − (allowable value), that is, C (i, j) −ΔC (i, j) has not been reached. Control to do.

  Details of the progress of ion beam irradiation using the present embodiment are schematically shown in three periods of an initial period (FIG. 8), an intermediate period (FIG. 9), and a late period (FIG. 10). Although the example which divided the respiratory phase area | region into 3 for the description was shown, what is necessary is just to divide into several. The dose distribution in the depth direction is shown as an example of the dose distribution as in the Bragg curve, but the same effect as in this embodiment can be obtained even when the dose distribution in the horizontal direction is targeted. Initially, as shown in FIG. 8B, since the irradiation amount of the ion beam has not reached the target value in any three respiratory phases, the respiratory phase measured by the respiratory phase measuring device 212 is in the emission permission phase region. If there is, an ion beam is irradiated (FIG. 8A). When ion beam irradiation is continued, irradiation of the target amount is completed in a certain respiratory phase. For example, as shown in FIG. 9B, it is assumed that a target amount of ion beam is irradiated in the respiratory phase region 2, and this is the middle period. In the middle period, the ion beam is irradiated only when the target region has not yet been irradiated in the phase region, that is, when the respiratory phase regions 1 and 3 have a respiratory phase (FIG. 9A). Further, the irradiation of the ion beam further progresses. For example, as shown in FIG. 10B, it is assumed that the target amount of the ion beam is also irradiated in the respiratory phase region 3, and this is the latter period. In the latter period, the ion beam is irradiated only when the respiratory phase region 1 is reached (FIG. 10A). Upon completion of this irradiation, ion beam irradiation in this dose distribution is completed. This procedure is performed for all dose distribution elements.

  The irradiation completion signal generation device 310 is connected to the breathing phase region memory 307 during irradiation, the dose distribution element memory 308 during irradiation, the multichannel counter 304, the target value memory 305, and the open / close switch 11. The irradiation completion signal generation device 310 determines whether or not the target amount of ion beam irradiation has been completed in all respiratory phase regions, and when completed, opens the open / close switch 11 and completes the ion beam irradiation.

  The interlock signal generation device 311 is connected to the breathing phase region memory 307 during irradiation, the dose distribution element memory 308 during irradiation, the multichannel counter 304, the target value memory 305, and the open / close switch 11. The interlock signal generation device 311 determines whether or not the ion dose that has been irradiated in all respiratory phase regions is within an allowable range. If the allowable range is exceeded for some reason, the open / close switch 11 is opened and the ion beam irradiation is immediately stopped.

  The display device 306 displays the ion beam irradiation amount for each respiratory phase region. The display device 306 is connected to the multi-channel counter 304 and the target value memory 305, and sequentially displays these values during ion beam irradiation to inform the driver of the progress of ion beam irradiation. Further, the display device 306 may be connected to the central control device 100 to display the irradiation parameters. Moreover, you may display the ratio of the ion beam irradiation amount for every respiration phase area | region, and the total ion beam irradiation amount. As a result, it is possible to inform the driver of the ion beam therapy system that the irradiation is proceeding evenly.

  FIG. 11 shows the mutual relationship of the individual devices constituting the present embodiment, centering on the irradiation control system 300.

  When a treatment start signal is generated by the central control device 100, the synchrotron 5, the phase region determination device 301, the distribution device 303, the open / close signal generation device 309, the irradiation completion signal generation device 310, and the interlock signal generation device 311 Operation starts and ion beam irradiation is started. In the irradiation dose distribution element memory 308, the central controller 100 constantly updates the dose distribution element j currently being irradiated.

  The role of the phase region determination device 301 is to convert the respiratory phase measured by the respiratory phase measuring device 212 into a phase region during irradiation. First, the phase region determination device 301 captures the relationship between the phase region and the irradiation phase region, that is, the table of both ends of the phase region number and the respiratory phase, from the central controller 100 to the phase region determination device memory 302. Next, the phase input from the respiratory phase measuring device 212 is converted into the irradiation phase region according to the above table. The conversion result is recorded in the breathing phase area memory 307 during irradiation. This procedure is repeated during treatment irradiation, and the respiratory phase area currently being irradiated is always recorded in the respiratory phase area memory 307 during irradiation.

  The role of the sorter 303 is to sort the ion beam dose measured by the dose monitor 204 to the multichannel counter 304 for each respiratory phase region and dose distribution element. First, the sorting device 303 reads the ion beam irradiation area recorded in the breathing phase area memory 307 during irradiation. Next, the dose distribution element j currently being irradiated is fetched from the dose distribution element memory 308 during irradiation. Using these, the ion beam dose input value from the dose monitor 204 is integrated into the corresponding area of the multi-channel counter 304. By repeating this procedure, the multi-channel counter 304 counts the amount of ion beam that has been irradiated for each current phase region and each dose distribution element. In parallel with this, the signal of the dose monitor 204 is not divided in the phase region, but is input to the multi-channel counter 304-S, j, and the ion beam dose of the dose component is counted and used for interlocking. May be.

  The function of the open / close signal generation device 309 is to compare the irradiated ion dose in the region currently being irradiated, that is, the multi-channel counter 304-i, j with the corresponding target ion dose 305-i, j, and the open / close switch 11 The ion beam extraction ON / OFF control from the synchrotron 5 is performed by opening and closing. First, the open / close signal generation device 309 takes in a target value for each area from the target value memory 305. It should be noted that the target value memory 305 is previously fetched from the central controller 100 the ion beam dose target value and the allowable value for each region. Next, the open / close signal generation device 309 selects the ion beam irradiation region i which is currently irradiated with the ion beam from the irradiation respiratory phase region memory 307 and the dose distribution element currently being irradiated from the irradiation dose distribution element memory 308. j is taken in. Then, the target value in the region is compared with the ion beam dose, and if the irradiated ion dose has reached the target value, an open signal (ion beam OFF) is generated, and if not, a closed signal (ion beam ON) is generated. , Transfer and turn on / off the switch 11. Thereby, an ion beam is irradiated only to the area | region where target value is not achieved.

  As described above, the respiratory phase region memory 307 during irradiation and the dose distribution element memory 308 during irradiation may not be provided, and the respiratory phase region i and j for the dose distribution during irradiation may be directly input to individual devices. The data delivery timing of each device becomes complicated.

As irradiation progresses, each region is irradiated with a target amount of ion beam. The role of the interlock signal generating device 311 is to prevent the patient 210 from unnecessary ion beam irradiation in case of an emergency. First, the target value and allowable value for each area and the target value and allowable value for all areas are fetched from the target value memory 305. As described above, the target value memory 305 previously captures the target value and allowable value for each area, and the target value and allowable value for all areas from the central controller 100. Next, the irradiated ion beam irradiation amount of the entire region is fetched from the multi-channel counter 304 for each region. The multichannel counter 304-S, j counts the total amount of irradiation with ion beams for each dose distribution element. Therefore, if the ratio of the multichannel counter 304-i, j and the multichannel counter 304-S, j is taken, the ratio of the ion beam irradiated to the region i can be calculated. If the count value of the multi-channel counter 304-S, j is equal to or smaller than the target value S + the allowable value S, if it exceeds, an ion beam irradiation stop signal is generated and transferred to the central controller 100. The same applies to individual regions. In addition, it is also confirmed that the ratio of the ion beam irradiation amount of each region obtained from the multi-channel counter 304 is within the target ratio R _i ± ΔR _i , and if it is outside, the ion beam irradiation amount is biased. In this case as well, an ion beam irradiation stop signal may be generated and transferred to the central controller 100. Receiving the ion beam irradiation stop signal, the central controller 100 generates an ion beam irradiation stop command (signal lines are omitted) for each device. By taking in the current ion beam dose from the multi-channel counter 304 and repeatedly confirming that the dose itself and its ratio are within an allowable range, highly reliable ion beam irradiation is realized.

  The role of the irradiation completion signal generation device 310 is to determine whether or not a target amount of ion beam has been irradiated in the entire region, and to generate an irradiation completion signal when the irradiation is completed. First, target values for each phase region and dose distribution element are fetched from the target value memory 305. Next, the irradiated ion dose is taken from the multichannel counter 304. Then, the target value and the irradiated ion dose are compared for each region. If the target value is reached in all regions, the irradiation completion signal generation device 310 generates an irradiation completion signal in the central control device 100. If there is a region where the target value is not reached in at least one region, the ion beam irradiation is incomplete and the ion beam irradiation is continued. When the central controller 100 receives the irradiation completion signal, an ion beam irradiation completion signal is generated for each device (signal line omitted), and the termination process is performed. Thereby, ion beam irradiation is completed.

  According to this embodiment, even if the target fluctuates, the uneven distribution of ion beam irradiation in the respiratory phase region can be eliminated. For this reason, when a desired dose distribution is formed by combining a plurality of dose distribution elements, the dose distribution can be controlled even at the boundary, and a planned dose distribution can be formed.

  According to the present embodiment, by eliminating the uneven distribution of ion beam irradiation in the finite-width respiratory phase region caused by movement of the target such as respiration, the dose distribution elements are combined, The dose distribution at the boundary when forming can be formed as planned. Therefore, a dose distribution as planned can be formed. Furthermore, since a distribution as planned can be obtained at the boundary where individual dose distribution elements are combined, a large dose distribution can be easily formed because a large number of dose distribution elements can be connected.

  In the present embodiment, when the irradiation target moves in the horizontal direction, target irradiation position information based on the excitation amount of the scanning electromagnet 203, dose information from the dose measuring device, and irradiation target from the respiratory phase measuring device 212 which is a variation measuring device. Based on the position information, the integrated irradiation amount in a fine divided area obtained by dividing the target irradiation position into a plurality of parts is obtained. The irradiation control system 300 compares the integrated irradiation amount for each divided region (three regions in this embodiment) with the target irradiation amount stored in the target value memory 305, and the irradiation amount in this divided region is the target irradiation. Determine if the amount has been reached. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In this embodiment, when the irradiation target moves in the deep direction, target irradiation position information based on the thickness information of the range shifter 206 that is an energy adjustment device, dose information from the dose measurement device, and a respiratory phase measurement that is a variation measurement device Based on the position information of the irradiation target from the device 212, the integrated irradiation amount in a fine divided area obtained by dividing the target irradiation position into a plurality of parts is obtained. The irradiation control system 300 compares the integrated irradiation amount for each divided region (three regions in this embodiment) with the target irradiation amount stored in the target value memory 305, and the irradiation amount in this divided region is the target irradiation. Determine if the amount has been reached. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In the present embodiment, the dose distribution in the depth direction is formed by changing the energy of the ion beam by changing the thickness of the range shifter 206 provided on the ion beam track of the irradiation field forming apparatus 200. It is also possible to change the energy by combining a plurality of range shifters 206 and acceleration by the synchrotron 5. The ion beam energy emitted from the synchrotron 5 is adjusted by changing the acceleration of the ion beam circulating around the synchrotron 5, and the range shifter 2 is arranged on the beam trajectory through which the ion beam passes to change the ion beam energy. In the case of energy change by the combination to be performed, the target irradiation position in the deep direction is determined by these combinations. In this case, the same effect as that of the present embodiment can be obtained.

(Embodiment 2)
Hereinafter, an ion beam therapy apparatus that is a radiation therapy apparatus according to another embodiment of the present invention will be described with reference to FIGS. 12 and 13.

  The ion beam therapy apparatus according to the present embodiment has a configuration in which the irradiation field forming apparatus 200 is replaced with the irradiation field forming apparatus 200A in the ion beam therapy apparatus according to the first embodiment. The irradiation field forming apparatus 200A includes a scanning electromagnet 203 and a dose monitor 204 on the beam trajectory as shown in FIG. In the present embodiment, the scanning electromagnet 203 provided in the irradiation field forming apparatus 200A forms a dose distribution in a plane perpendicular to the traveling direction of the ion beam, and changes the energy of the ion beam emitted from the synchrotron 5. By doing so, a dose distribution in the traveling direction of ion beams (depth direction from the body surface) is formed. In this embodiment, the amount of excitation of the scanning electromagnet 203 is controlled to irradiate the target irradiation position in the horizontal direction with the ion beam, and the energy of the ion beam circulating around the synchrotron 5 is changed to change the target in the deep direction. Irradiate an ion beam to the irradiation position.

  A scanning electromagnet 203 and a dose monitor 204 are mounted in the casing 201. After the ion beam is deflected by the scanning electromagnet 203, the dose is measured by the dose monitor 204 and reaches the affected area 210a. A respiratory signal is measured by the respiratory phase measuring device 212. In accordance with a command from the central controller 100, ion beams are irradiated with a target scanning amount and irradiation amount for each spot. The dose measurement result by the dose monitor 204 and the respiration signal by the respiration phase measuring device 212 are transferred to the irradiation control system 300.

  Pay attention to the case of irradiating the spot j with an ion beam. When the ion beam is irradiated, the position of the affected part 210a changes due to physiological movement such as respiration. However, since the irradiation amount of the ion beam is managed for each respiratory phase by the irradiation control system 300 described above, a constant dose distribution can be obtained at the end of the lateral dose distribution without depending on the respiratory pattern. For example, as shown in FIG. 13, when a uniform target dose value is set for each respiratory phase, the distribution is wider than the dose distribution obtained when the target is completely stationary. In FIG. 13, the dotted line represents the lateral dose distribution when the target is stationary, and the solid line represents the lateral dose distribution obtained when this embodiment is applied.

  Consider a case in which a larger dose distribution is formed together with the dose distribution by the adjacent spot. As described above, a constant dose distribution is formed even at the end of each dose distribution. Therefore, the planned dose distribution can be obtained even when the end portions of the dose distributions to be formed overlap each other at an intermediate position between adjacent spots. Therefore, even when a dose distribution having a size corresponding to the affected area 210a is formed, a dose distribution as planned can be obtained in the vicinity of the boundary between spots.

  According to the present embodiment, as shown in FIG. 13, a constant dose distribution can be formed particularly at the end portion without depending on the breathing pattern.

  In the present embodiment, when the irradiation target moves in the lateral direction, as in the first embodiment, target irradiation position information based on the excitation amount of the scanning electromagnet 203, dose information from the dose measurement device, and a respiratory phase that is a variation measurement device. Based on the position information of the irradiation target from the measuring instrument 212, an integrated irradiation amount in a fine divided area obtained by dividing the inside of the target irradiation position is obtained. The irradiation control system 300 compares the integrated dose for each divided area with the target dose stored in the target value memory 305, and determines whether the dose in this divided area has reached the target dose. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In the present embodiment, when the irradiation target moves in the deep direction, the target irradiation position information based on the energy information of the ion beam accelerated by the synchrotron 5, the dose information from the dose measurement device, and the respiratory phase that is the variation measurement device Based on the position information of the irradiation target from the measuring instrument 212, an integrated irradiation amount in a fine divided area obtained by dividing the inside of the target irradiation position is obtained. The irradiation control system 300 compares the integrated dose for each divided area with the target dose stored in the target value memory 305, and determines whether the dose in this divided area has reached the target dose. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In this embodiment, the same effect as that of the first embodiment can be obtained.

(Embodiment 3)
Hereinafter, an ion beam therapy apparatus that is a radiation therapy apparatus according to another embodiment of the present invention will be described with reference to FIGS. 14 and 15.

  The ion beam therapy apparatus according to the present embodiment has a configuration in which the irradiation field forming apparatus 200 is replaced with the irradiation field forming apparatus 200B in the ion beam therapy apparatus according to the first embodiment. As shown in FIG. 14, the irradiation field forming device 200 </ b> B includes a dose distribution forming device 213 and a dose monitor 204 on the beam trajectory. In the present embodiment, the dose distribution forming device 213 provided in the irradiation field forming device 200B forms a dose distribution in a plane perpendicular to the traveling direction of the ion beam, and the energy of the ion beam emitted from the synchrotron 5 Is changed to form a dose distribution in the direction of travel of the ion beam (depth direction from the body surface). Moreover, in this embodiment, the example which forms the dose distribution of a horizontal direction by moving the patient support apparatus 211 to a horizontal direction is shown. In the present embodiment, the amount of ion beam emitted from the synchrotron 5 is changed by irradiating the target irradiation position in the lateral direction with the ion beam by controlling the movement amount (installation position) of the patient support device 211. An ion beam is irradiated to the target irradiation position in the deep direction.

A dose distribution forming device 213 and a dose monitor 204 are mounted in the casing 201.
The dose distribution forming device 213 only needs to be able to form a dose distribution in the lateral direction, and a plurality of methods such as a scatterer method, a wobbler method, and a scanning method can be considered. The patient 210 is positioned on the patient support device 211, and the patient support device 211 is driven laterally. After the dose distribution is formed in the lateral direction by the dose distribution forming device 213, the ion beam is measured by the dose monitor 204 and reaches the affected area 210a. A respiratory signal is measured by the respiratory phase measuring device 212. In accordance with a command from the central controller 100, the ion beam is irradiated with a target dose for each position j of the patient support device 211. The dose measurement result by the dose monitor 204 and the respiration signal by the respiration phase measuring device 212 are transferred to the irradiation control system 300.

  Pay attention to the case where the ion beam is irradiated at the position j. When the ion beam is irradiated, the position of the affected part 210a varies due to physiological movement such as respiration. However, since the irradiation control system 300 manages ion beam irradiation for each breathing phase, a planned dose distribution can be obtained at the end of the lateral dose distribution regardless of the breathing pattern. For example, as shown in FIG. 15, when a uniform target value is set for each respiratory phase, the distribution is wider than the dose distribution obtained when the target is completely stationary. In FIG. 15, the dotted line indicates the horizontal dose distribution when the target is stationary, and the solid line indicates the horizontal dose distribution obtained when the present embodiment is applied.

  Attention is paid to a case where a dose distribution formed by driving the patient support device 211 to a plurality of positions is combined to form a large distribution of the affected area. As described above, the end of the dose distribution formed at each position is constant. Therefore, as shown in FIG. 14, the planned dose distribution can be obtained even in the region where the end portions of the respective dose distributions formed at the positions of the adjacent patient support devices 211 overlap. Therefore, even when the movement of the patient support device 211 and the irradiation of the ion beam are repeated so that the size of the affected area 210a is reached, a dose distribution as planned can be obtained even in the vicinity of each dose distribution boundary.

  According to the present embodiment, as shown in FIG. 15, a constant dose distribution can be formed at the end without depending on the breathing pattern.

  In the present embodiment, when the irradiation target moves in the horizontal direction, target irradiation position information based on the movement amount of the patient support apparatus 211 in the horizontal direction (lateral installation position), dose information from the dose measurement apparatus, and variation measurement Based on the position information of the irradiation target from the respiratory phase measuring device 212 which is a device, the integrated irradiation amount in a fine divided region obtained by dividing the target irradiation position into a plurality is obtained. The irradiation control system 300 compares the integrated irradiation amount for each divided region (three regions in this embodiment) with the target irradiation amount stored in the target value memory 305, and the irradiation amount in this divided region is the target irradiation. Determine if the amount has been reached. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In the present embodiment, when the irradiation target moves in the deep direction, the target irradiation position information based on the energy information of the ion beam accelerated by the synchrotron 5, the dose information from the dose measurement device, and the respiratory phase that is the variation measurement device Based on the position information of the irradiation target from the measuring instrument 212, an integrated irradiation amount in a fine divided area obtained by dividing the inside of the target irradiation position is obtained. The irradiation control system 300 compares the integrated dose for each divided area with the target dose stored in the target value memory 305, and determines whether the dose in this divided area has reached the target dose. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In this embodiment, the same effect as that of the first embodiment can be obtained.

  In this embodiment, the dose distribution forming device 213 is installed in the irradiation field forming device 200B. However, the ion beam irradiation position is fixed without installing the dose distribution forming device 213, and the patient support device 211 is moved in the lateral direction. It may be a method of forming a dose distribution in the lateral direction by moving to.

(Embodiment 4)
Hereinafter, an ion beam therapy apparatus which is a radiation therapy apparatus according to another embodiment of the present invention will be described with reference to FIGS. 16 and 17.

  The ion beam therapy apparatus according to the present embodiment has a configuration in which the irradiation field forming apparatus 200 is replaced with an irradiation field forming apparatus 200C in the ion beam therapy apparatus according to the first embodiment. As shown in FIG. 16, the irradiation field forming device 200 </ b> C includes a dose distribution forming device 213, a dose monitor 204, and a range shifter 206 on the beam trajectory. In the present embodiment, the dose distribution forming device 213 provided in the irradiation field forming device 200C forms a dose distribution in a plane perpendicular to the traveling direction of the ion beam, and the range shifter provided in the irradiation field forming device 200C. 206 forms a dose distribution in the traveling direction of the ion beam (depth direction from the body surface). In this embodiment, by controlling the dose distribution forming device 213 (for example, controlling the excitation amount of the wobbler electromagnet), the target irradiation position in the horizontal direction is irradiated with the ion beam, and the thickness of the range shifter 206 is controlled. An ion beam is irradiated to the target irradiation position in the deep direction.

  In the casing 201, a dose distribution forming device 213, a dose monitor 204, and a range shifter insertion mechanism 207 are mounted. The thickness of the range shifter 206 to be inserted on the particle beam trajectory is changed by the range shifter insertion mechanism 207. The irradiation amount of the ion beam is measured by the dose monitor 204, and after the energy is attenuated according to the thickness of the range shifter 206, the ion beam reaches the affected part 210a. The dose distribution reaches layer j according to the energy of the ion beam incident on the affected part 210a. A respiratory signal is measured by the respiratory phase measuring device 212. The ion beam is irradiated with a beam of a target amount determined for each layer in accordance with a command from the central controller 100, and a dose measurement result from the dose monitor 204 and a respiratory signal from the respiratory phase measuring device 212 are transferred to the irradiation control system 300. Is done.

  Attention is paid to the case of irradiating the ion beam reaching layer j. When irradiating an ion beam, the depth of the affected part 210a in the body of the patient 210 varies due to physiological movement such as respiration. However, since irradiation is managed for each respiratory phase by the above-described irradiation control system 300, a planned dose distribution can be obtained even near the Bragg peak of the dose distribution in the depth direction, regardless of the respiratory pattern. For example, as shown in FIG. 17, when a uniform target value is set for each respiratory phase, the dose distribution obtained when the target is completely stationary becomes a distribution in which the depth distribution is expanded in the depth direction. In FIG. 17, the dotted line shows the dose distribution in the deep part when the target is stationary, and the solid line shows the dose distribution in the deep part obtained when the present embodiment is applied.

  Attention is paid to the case where the ion beam is irradiated while changing the thickness of the range shifter 206, Bragg peaks are formed at a plurality of depths, and a dose distribution is formed by combining them. As described above, the dose distribution near the Bragg peak formed by the thickness of each range shifter 206 is constant. Therefore, when a dose distribution is formed by combining adjacent Bragg peaks, such as when forming SOBP, a dose distribution as planned can be obtained smoothly even in a portion where dose distributions between a plurality of Bragg peaks overlap. . Therefore, even when layers corresponding to the size of the affected area 210a are combined, a dose distribution as planned can be obtained in the vicinity of the boundary.

  According to the present embodiment, as shown in FIG. 17, a constant dose distribution can be formed in the vicinity of the black peak, not depending on the breathing pattern.

  In this embodiment, when the irradiation target moves in the horizontal direction, target irradiation position information based on the dose distribution forming device 213, dose information from the dose measuring device, and irradiation target from the respiratory phase measuring device 212 which is a variation measuring device. Based on the position information, the integrated irradiation amount in a fine divided region obtained by dividing the inside of the target irradiation position is obtained. The irradiation control system 300 compares the integrated irradiation amount for each divided region (three regions in this embodiment) with the target irradiation amount stored in the target value memory 305, and the irradiation amount in this divided region is the target irradiation. Determine if the amount has been reached. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In this embodiment, when the irradiation target moves in the deep direction, target irradiation position information based on the thickness information of the range shifter 206 that is an energy adjustment device, dose information from the dose measurement device, and a respiratory phase measurement that is a variation measurement device Based on the position information of the irradiation target from the device 212, the integrated irradiation amount in a fine divided area obtained by dividing the target irradiation position into a plurality of parts is obtained. The irradiation control system 300 compares the integrated irradiation amount for each divided region (three regions in this embodiment) with the target irradiation amount stored in the target value memory 305, and the irradiation amount in this divided region is the target irradiation. Determine if the amount has been reached. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In this embodiment, the same effect as that of the first embodiment can be obtained.

(Embodiment 5)
Hereinafter, an ion beam therapy apparatus that is a radiation therapy apparatus according to another embodiment of the present invention will be described with reference to FIG.

  The ion beam therapy apparatus according to the present embodiment has a configuration in which the irradiation field forming apparatus 200 is replaced with an irradiation field forming apparatus 200D in the ion beam therapy apparatus according to the first embodiment. As shown in FIG. 18, the irradiation field forming apparatus 200D includes a scanning electromagnet 203 and a dose monitor 204 on the beam trajectory. In this embodiment, the scanning electromagnet 203 provided in the irradiation field forming apparatus 200D forms a dose distribution in a plane perpendicular to the traveling direction of the ion beam, and changes the energy of the ion beam emitted from the synchrotron 5. By doing so, a dose distribution in the traveling direction of ion beams (depth direction from the body surface) is formed. In the present embodiment, the amount of excitation of the scanning electromagnet 203 is controlled to irradiate the target irradiation position in the horizontal direction with the ion beam, and the energy of the ion beam circulating around the synchrotron 5 is changed to change the target in the deep direction. Irradiate an ion beam to the irradiation position.

The ion beam accelerated to a predetermined energy by the ion beam generator 1 is transported to the irradiation field forming device 200. The apparatus constituting the irradiation field forming apparatus 200 is mounted in the casing 201. A scanning electromagnet 203 and a dose monitor 204 are mounted in the casing 201. The ion beam reaches the affected part 210a after the dose is measured by the dose monitor 204, and a dose distribution is formed up to the layer j corresponding to the energy accelerated by the ion beam generator 1. A respiratory signal is measured by the respiratory phase measuring device 212. The ion beam is irradiated with a target amount of beam determined for each layer in accordance with a command from the central controller 100.
The dose measurement result by the dose monitor 204 and the respiration signal by the respiration phase measuring device 212 are transferred to the irradiation control system 300.

  Attention is paid to the case of irradiating the ion beam reaching layer j. When irradiating an ion beam, the depth of the affected part 210a in the body of the patient 210 varies due to physiological movement such as respiration. However, since irradiation is managed for each respiratory phase by the above-described irradiation control system 300, a dose distribution as planned can be obtained particularly near the Bragg peak of the dose distribution in the depth direction. Therefore, the situation is the same as in Example 4 (FIG. 17), and a dose distribution as planned can be obtained even when layers corresponding to the size of the affected area 210a are combined.

  According to the present embodiment, a constant dose distribution can be formed in the vicinity of the black peak, not depending on the breathing pattern.

  In this embodiment, when the irradiation target moves in the lateral direction, target irradiation position information based on the excitation amount of the scanning electromagnet 203, dose information from the dose measuring device, and irradiation from the respiratory phase measuring device 212 which is a variation measuring device. Based on the target position information, the integrated irradiation amount in a fine divided region obtained by dividing the target irradiation position into a plurality is obtained. The irradiation control system 300 compares the integrated dose for each divided area with the target dose stored in the target value memory 305, and determines whether the dose in this divided area has reached the target dose. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In the present embodiment, when the irradiation target moves in the deep direction, the target irradiation position information based on the energy information of the ion beam accelerated by the synchrotron 5, the dose information from the dose measurement device, and the respiratory phase that is the variation measurement device Based on the position information of the irradiation target from the measuring instrument 212, an integrated irradiation amount in a fine divided area obtained by dividing the inside of the target irradiation position is obtained. The irradiation control system 300 compares the integrated dose for each divided area with the target dose stored in the target value memory 305, and determines whether the dose in this divided area has reached the target dose. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In this embodiment, the same effect as that of the first embodiment can be obtained.

(Embodiment 6)
Hereinafter, an ion beam therapy apparatus that is a radiation therapy apparatus according to another embodiment of the present invention will be described with reference to FIGS. 19 and 20.

  The ion beam therapy apparatus according to the present embodiment has a configuration in which the irradiation field forming apparatus 200 is installed in the rotating gantry 14 in the ion beam therapy apparatus according to the first embodiment. In the present embodiment, an example is shown in which a rotating gantry 14 is used as an apparatus for combining dose distributions, and a dose distribution as planned is formed by irradiating a beam from a plurality of gantry angles and combining the dose distributions. In the present embodiment, the target irradiation position is irradiated with the ion beam by changing and controlling the angle of the rotating gantry 14 that irradiates the ion beam.

  The irradiation field forming apparatus 200 is mounted on the rotating gantry 14 as shown in FIG. By rotating the rotating gantry 14, the affected part 210a can be irradiated with ion beams from a plurality of directions. The irradiation field forming device 200 includes a casing 201, and a dose distribution forming device 213 and a dose monitor 204 are mounted. The ion beam reaches the affected area 210a after the dose distribution is formed by the dose distribution forming device 213 and the dose is measured by the dose monitor 204. A dose distribution corresponding to the ion beam incident angle corresponding to the rotation angle j of the rotating gantry 14 is formed. A respiratory signal is measured by the respiratory phase measuring device 212. The ion beam is irradiated with a target amount of beam determined for each rotation angle of the rotating gantry 14 according to a command from the central controller 100. The dose measurement result by the dose monitor 204 and the respiration signal by the respiration phase measuring device 212 are transferred to the irradiation control system 300.

  Attention is paid to the case where the ion beam is irradiated at the rotation angle j. When the ion beam is irradiated, the position of the affected part 210a varies due to physiological movement such as respiration. However, since the irradiation control system 300 manages ion beam irradiation for each respiratory phase, a dose distribution as planned can be obtained at the end of the dose distribution in the lateral and depth directions regardless of the respiratory pattern. It is done. For example, as shown in FIG. 20, when a uniform target value is set for each respiratory phase, the dose distribution obtained when the target is completely stationary becomes a wide distribution.

  Attention is paid to the case where the dose distribution is formed by combining the dose distributions when the rotating gantry 14 is rotated and the beam is irradiated from a plurality of angles. As described above, the end of the dose distribution formed at each angle is constant as described above. Therefore, the dose distribution as planned can be obtained even in the region where the ends of the respective dose distributions overlap. Therefore, even when the rotation of the rotating gantry 14 and the irradiation of the ion beam are repeated so as to form a dose distribution having the size of the affected part 210a, a dose distribution as planned can be obtained even in the vicinity of the boundary of each dose distribution. .

  In the present embodiment, when the irradiation target moves in the lateral direction and / or the deep direction, the target irradiation position information based on the angle information of the rotating gantry 14, the dose information from the dose measuring device, and the respiratory phase measuring device which is a variation measuring device Based on the position information of the irradiation target from 212, an integrated irradiation amount in a fine divided area obtained by dividing the target irradiation position into a plurality of parts is obtained. The irradiation control system 300 compares the integrated dose for each divided area with the target dose stored in the target value memory 305, and determines whether the dose in this divided area has reached the target dose. By irradiating the ion beam to the divided area that has not reached the target irradiation dose and controlling the ion beam irradiation to stop at the divided area that has reached the target irradiation dose, the ion beam irradiation can be performed as planned. Is possible.

  In this embodiment, the same effect as that of the first embodiment can be obtained.

  In this embodiment, the dose distribution is formed by changing the target irradiation position by changing the rotation angle of the rotating gantry 14, but the energy of the ion beam emitted from the synchrotron 5 can be changed, The energy may be changed by a combination of changing the energy of the ion beam by installing a range shifter on the beam trajectory of the beam and changing its thickness.

  In the first to sixth embodiments, the scanning electromagnet 203 or the dose distribution forming device 213 is used to form a predetermined dose distribution by superimposing a Gaussian dose distribution in a direction perpendicular to the traveling direction of the ion beam. A uniform high-dose region in the lateral direction may be formed by a wobbler method or a scatterer irradiation method. In this case, a larger dose distribution can be formed as compared with the case where the irradiation field forming device is used to form the irradiation at once.

DESCRIPTION OF SYMBOLS 1 Ion beam generator 2 Ion source 3 Previous stage accelerator 4 Low energy beam transport system 5 Synchrotron 6 Accelerator 7 Ejection high frequency application device 8 Ejection high frequency application electrode 9 Ejection high frequency power supply 10 Signal synthesizer 11 Open / close switch 12 Extraction Deflector 13 High energy beam transport system 14 Rotating gantry 100 Central control device 101 Central control device memory 102 Treatment planning device 200 Irradiation field forming device 201 Casing 203 Scanning electromagnet 204 Dose monitor 205 Scanning ion beam position monitor 206 Range shifter 207 Range shifter insertion mechanism 208 Bolus 209 Collimator 210 Patient 210a Affected part 211 Patient support device 212 Respiration phase measuring device 300 Irradiation control system 301 Phase region determination device 302 Phase region determination device memory 303 Distribution device 304 Chi-channel counter 305 target value memory 306 display device 307 during irradiation respiratory phase region memory 308 during irradiation dose distribution component memory 309 OFF signal generator 310 irradiation completion signal generator 311 interlock signal generator

Claims (12)

A radiation generator for generating radiation;
A dose measuring device for measuring a dose of the radiation emitted from the radiation generating device;
A fluctuation measuring device for measuring the position of the irradiation target;
A control device for controlling start and stop of emission of the radiation from the radiation generation device;
The control device includes:
Based on the target irradiation position information, the dose information from the dose measuring device, and the position information of the irradiation target from the fluctuation measuring device, whether the target dose has been reached for each of the divided areas obtained by dividing the irradiation position of the irradiation target And the emission start and the emission stop are controlled so as to irradiate the radiation to the divided area that has not reached the target dose. The control device includes:
Based on the target irradiation position information, the dose information from the dose measurement device, and the position information from the dose measurement device, an integrated dose of the radiation for each of the divided regions is obtained, and the integrated dose reaches the target dose 2. The radiation irradiation system according to claim 1, wherein control is performed such that emission of the radiation is stopped in a divided region and the radiation is emitted in the divided region that has not reached the target dose.   The radiation irradiation according to claim 2, further comprising a safety device that stops emission of the radiation from the radiation generation device when position information of an irradiation target from the dose measuring device is out of an allowable range. system.   4. The radiation according to claim 2, further comprising a safety device that stops emission of the radiation from the radiation generation device when an accumulated dose of the radiation for each of the divided regions is out of an allowable range. Irradiation system. The control device includes:
The radiation irradiation system according to claim 1, further comprising a storage device that stores a target dose for each divided region. The storage device stores a target dose for the entire area to be irradiated,
The control device obtains a dose ratio for each layer region based on the target dose for the entire region and the integrated dose for each layer region, and from the radiation generation device when the dose ratio exceeds an allowable value The radiation irradiation system according to claim 2, wherein emission of the radiation is stopped.   The radiation irradiation system according to claim 1, wherein the target irradiation position information is target irradiation position information with respect to a traveling direction of the radiation based on energy of the radiation. An energy adjustment device arranged on the trajectory of the radiation to change the energy of the radiation passing through;
The radiation irradiation system according to claim 7, wherein the target irradiation position information is target irradiation position information in a traveling direction of the radiation based on thickness information of the energy adjustment device. An accelerator for accelerating and emitting the radiation;
The radiation irradiation system according to claim 7, wherein the target irradiation position information is target irradiation position information in a traveling direction of the radiation based on energy information of the radiation emitted from the accelerator. A scanning electromagnet for deflecting the radiation passing therethrough,
2. The radiation irradiation system according to claim 1, wherein the target irradiation position information is target irradiation position information in a direction orthogonal to the radiation traveling direction based on an excitation amount of the scanning electromagnet. A bed apparatus on which the radiation irradiation target is placed;
The radiation irradiation system according to claim 1, wherein the target irradiation position information is target irradiation position information in a direction orthogonal to the radiation traveling direction based on position information of the installed bed apparatus. A rotating gantry for changing the irradiation angle of the radiation;
The radiation irradiation system according to claim 1, wherein the target irradiation position information is target irradiation position information of the radiation based on angle information of the rotating gantry.

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