JP6232472B2 - Particle beam therapy system - Google Patents

Description

  The present invention relates to a particle beam therapy apparatus for irradiating an affected area of a patient with a particle beam, and in particular, particle beam therapy for imaging a target using X-ray irradiation in a treatment time including an irradiation preparation period and an irradiation period of a particle beam. Relates to the device.

It is important to confirm the position of the affected part in the particle beam therapy system in order to form a dose distribution that matches the shape of the affected part.
In particular, there is a method of irradiating a particle beam in synchronization with respiration by measuring the movement of the chest in order to improve the dose distribution accuracy for an affected part that moves with movement of the body such as respiration.

  Japanese Patent Application Laid-Open No. 2004-228688 describes a technique for capturing a CT image for treatment planning using a CT apparatus in advance and determining a region to be irradiated with particle beams using the CT image.

JP 2011-217902 A

Regarding the measurement of the affected part position, if the affected part position can be imaged in real time during the treatment time, the affected part position can be confirmed more accurately.
However, if an attempt is made to confirm the position of the affected area using an X-ray imaging device during the treatment time, the irradiated X-rays are scattered by the patient's body, etc., which may cause an error in particle beam dose management. It has been found by the present inventors that there is sex.

Specifically, errors can occur as follows.
X-rays irradiated during the treatment time are scattered by the patient's body and the like. The X-rays scattered at this time are incident on a dose measuring device installed in the irradiation field forming device depending on the direction of scattering. However, since the dose measuring instrument cannot distinguish between the scattered X-rays and the particle beam irradiated to the affected part, the incident of the scattered X-rays is measured as the incident particle beam.
For this reason, it has become clear that it is difficult to correctly measure the dose of particle beams, and it may be difficult to maintain high dose management accuracy and dose distribution accuracy of particle beams. .
In particular, in spot scanning in which an affected area is divided into a plurality of spots and a particle beam is irradiated for each spot, the influence of scattered X-rays is increased, so that it is necessary to pay more attention to the above-described problem.

  The present invention relates to a particle beam therapy apparatus capable of performing a dose management of a particle beam with high accuracy in a particle beam therapy apparatus that performs imaging of an affected area by X-ray irradiation during a treatment time including an irradiation preparation period and an irradiation period of a particle beam. An object is to provide an apparatus.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present invention includes a plurality of means for solving the above-mentioned problems. To give an example, a particle beam therapy apparatus, which generates a particle beam, and the particle beam with respect to a target. Irradiation field forming device for irradiating the target, a dose measuring device provided at a position where the particle beam passes, an X-ray imaging device for imaging the position of the target by irradiating X-rays, and the dose measuring device A control device that performs control for excluding the measurement result of the scattered X-rays derived from the X-ray imaging device from the measurement result of, and the control device includes a counter that integrates signals output from the dose measuring device, A subtracting arithmetic unit that is connected in series with the counter and subtracts the scattered X-ray dose value from an integrated value output from the counter, and an integrated value of the counter and a calculation result in the subtracting arithmetic unit Less And having a storage unit also stores either, at least.

  According to the present invention, when X-rays are irradiated during the treatment time, the X-ray measurement results are excluded from the measurement results of the dose measuring instrument installed at the position where the particle beam in the irradiation field forming apparatus passes. Therefore, the scattered X-rays can be distinguished from the particle beams, and the dose measurement of the particle beams can be performed correctly. Therefore, the dose management of the particle beam can be performed with high accuracy.

It is a figure which shows schematic structure of the particle beam therapy apparatus which is one Embodiment of this invention. It is a figure which shows schematic structure in the treatment room which comprises the particle beam therapy apparatus which is one Embodiment of this invention. X-ray irradiation, timing of particle beam irradiation, and X-ray imaging control unit output when the progress of the next spot of particle beam is stopped a certain time before X-ray irradiation during particle beam irradiation by the particle beam therapy system It is a figure which shows the timing of the signal to perform. It is the schematic of an example of a structure of the irradiation field forming apparatus, X-ray imaging device, and control apparatus which comprise the particle beam therapy apparatus in one Embodiment of this invention. It is a block diagram which shows the other example of the outline of the particle beam therapy apparatus which is one Embodiment of this invention. It is a figure which shows an example of the conditions which determine whether particle beam irradiation is implemented in the particle beam therapy apparatus in one Embodiment of this invention. It is a block diagram which shows the other example of the outline of the particle beam therapy apparatus which is one Embodiment of this invention. It is a figure which shows an example of the conditions which determine whether particle beam irradiation is implemented in the particle beam therapy apparatus in one Embodiment of this invention. It is the schematic of another example of the structure of the irradiation field forming apparatus, X-ray imaging device, and control apparatus which comprise the particle beam therapy apparatus in one Embodiment of this invention. When the particle beam irradiation is performed by the particle beam therapy apparatus, the timing of the X-ray irradiation and the particle beam irradiation and the X-ray imaging control unit and the irradiation control unit in the case where the particle beam irradiation is stopped simultaneously with the start of the X-ray irradiation are output. It is a figure which shows the timing of a signal. It is the schematic of another example of the structure of the irradiation field forming apparatus, X-ray imaging device, and control apparatus which comprise the particle beam therapy apparatus in one Embodiment of this invention. It is the schematic of another example of the structure of the irradiation field forming apparatus, X-ray imaging device, and control apparatus which comprise the particle beam therapy apparatus in one Embodiment of this invention. It is the schematic of another example of the structure of the irradiation field forming apparatus, X-ray imaging device, and control apparatus which comprise the particle beam therapy apparatus in one Embodiment of this invention.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  The particle beam therapy system of the present embodiment uses a discrete spot scanning method that can divide the affected area into small three-dimensional regions called spots and can concentrate the dose suitably on those spots. To do. Further, the particle beam includes proton beam, neutron beam, carbon beam and the like.

  Furthermore, in particle beam therapy, irradiation with particle beams having different energies may be performed so that a desired dose distribution is formed on the affected area. In order to carry out such treatment, it is necessary to interrupt the irradiation at one end and generate particle beams having different energies using the particle beam generator during that time. In particle beam therapy, the time during which such particle beams having different energies are generated is also treated as the time required for therapy. Therefore, in the following description, the time for irradiating the particle beam and the time for preparing the particle beam to be irradiated are combined to be the treatment time.

Example 1
A particle beam therapy system according to a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram showing a schematic configuration of a particle beam therapy apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of a treatment room constituting the particle beam therapy apparatus according to an embodiment of the present invention. 3 shows the timing of X-ray irradiation, particle beam irradiation, and the X-ray imaging control unit when the progress of the next spot of the particle beam is stopped a certain time before X-ray irradiation during particle beam irradiation by the particle beam therapy system. FIG. 4 is a schematic diagram illustrating an example of configurations of an irradiation field forming device, an X-ray imaging device, and a control device that constitute a particle beam therapy system according to an embodiment of the present invention.

  As shown in FIG. 1, the particle beam therapy system 100 generally includes a particle beam generator 101, a particle beam transport system 6, a treatment room 105, and a control device 400.

The particle beam generation apparatus 101 is generally configured by an ion source, a pre-accelerator 1 such as a linac, and a synchrotron 2 that is an accelerator.
When performing particle beam therapy, first, charged particles generated by an ion source are supplied to the pre-stage accelerator 1. The front stage accelerator 1 accelerates these charged particles and then supplies them to the synchrotron 2. The synchrotron 2 that has received the charged particles from the former accelerator 1 further accelerates the charged particles to a predetermined energy to generate a charged particle beam (particle beam). The synchrotron 2 includes a high-frequency quadrupole electromagnet that changes the stability limit of the particle beam and an RF kicker 4 that increases the betatron oscillation amplitude of the particle beam by applying a high frequency in order to take out the circulating particle beam.
Although the synchrotron 2 is taken as an example of the accelerator, an accelerator that does not require the pre-stage accelerator 1 such as a cyclotron may be used instead of the synchrotron 2.

  The particle beam transport system 6 generally has a particle beam path, a quadrupole electromagnet, a deflection electromagnet 3, and a high-speed steerer 5. The particle beam path formed by the particle beam transport system 6 communicates the particle beam generator 101 with an irradiation field forming device 102 provided in a treatment room described later. The particle beam generated by the particle beam generator 101 is transported to the treatment room via the particle beam transport system 6.

In the treatment room 105, as shown in FIG. 2, an irradiation field forming apparatus 102 for irradiating a target with a particle beam, an X-ray imaging apparatus 103 for confirming the position of an affected part, and a patient are moved to a position suitable for irradiation. A couch (bed) 104 is installed for this purpose.
The treatment room 105 may be provided integrally with a gantry that can be rotated using a motor or the like. When the irradiation field forming device 102 and a part of the particle beam transport system 6 are installed on such a gantry, it becomes possible to perform treatment of the patient from any direction by rotating the gantry, and from one direction. Can carry out effective treatment even for the affected part which is difficult to be irradiated.

Returning to FIG. 1, the irradiation field forming apparatus 102 is provided with two scanning electromagnets 7 and a dose measuring device 8.
The particle beam carried through the particle beam transport system 6 is irradiated between the scanning electromagnets 7 and the dose measuring device 8. When the irradiated particle beam passes between the scanning electromagnets 7 excited in accordance with the treatment plan, the path is bent by the electromagnetic force so as to form an irradiation field suitable for the shape of the affected part. Scanned in the direction.
The dose measuring device 8 is installed between the scanning electromagnet 7 and the patient in order to measure the irradiation dose at a position closer to the patient, and measures the dose of the particle beam passing through the dose measuring device 8. Dose management is performed using this measured value.

The X-ray imaging apparatus 103 includes X-ray generation apparatuses 9a and 9b that generate imaging X-rays that can be irradiated with pulses, and X-ray receivers 11a and 11b that detect the generated X-rays.
In the X-ray generators 9a and 9b, the irradiation timing is controlled by the X-ray imaging control unit 405. As shown in FIG. 1, each device is installed so that imaging can be performed from two axial directions. That is, the X-ray generator 9a and the X-ray receiver 11a are arranged so as to face each other across the area where the patient is installed, and the X-ray receiver 11a is installed on the irradiation field forming apparatus 102 side. The X-ray generator 9b and the X-ray receiver 11b are arranged so as to face each other across the area where the patient is installed, like the pair of X-ray generator 9a and the X-ray receiver 11b. An X-ray receiver 11b is installed on the irradiation field forming apparatus 102 side. At this time, the line segment connecting the X-ray generator 9a and the X-ray receiver 11a and the line segment connecting the X-ray generator 9b and the X-ray receiver 11b intersect in the region where the patient is installed. Installed.
Note that the X-ray imaging apparatus 103 may be arranged so as to perform imaging from one axial direction, or may be arranged by reversing the arrangement of the X-ray generation apparatus and the X-ray receiver.

The control device 400 controls the devices that constitute the particle beam generator 101, the particle beam transport system 6, the rotating gantry, the irradiation field forming device 102, the X-ray imaging device 103, and the like described above.
As shown in FIG. 1, the control device 400 includes control units such as a central control unit 401, a particle beam generation device 101, a particle beam transport system 6, a rotating gantry, an irradiation field forming device 102, and an X-ray imaging device. 103 is configured to exchange signals with each other. In the control device 400, there are a central control unit 401, an accelerator control unit 402, a transport system control unit 403, an irradiation control unit 404, an X-ray imaging control unit 405, a couch control unit 406, and a gantry control unit 407 as respective control units. In addition, a storage unit 409 for storing various parameters, an input unit for inputting various parameters, and the like are provided.

  The control device 400 of this embodiment performs control such as interlock by the central control unit 401. In addition, each device of the particle beam generator 101 is controlled by the accelerator controller 402, and each device of the particle beam transport system 6 is controlled by the transport system controller 403. Further, the irradiation control unit 404 controls the irradiation field forming apparatus 102, and the X-ray imaging control unit 405 controls the X-ray imaging apparatus 103. Each device of the couch 104 is controlled by the couch control unit 406, and the rotating gantry is controlled by the gantry control unit 407.

  In the control device 400, the X-ray imaging control unit 405 performs control to separate the particle beam irradiation timing and the X-ray irradiation timing.

  Further, the control device 400 performs calculation processing for removing the contribution of scattered X-rays from the measurement result of the dose measuring device 8 in the irradiation control unit 404.

Next, details of control in the X-ray imaging control unit 405 of the control device 400 will be described with reference to FIG.
As shown in FIG. 3A, the X-ray imaging control unit 405 performs X-ray irradiation (pulse irradiation) in a pulsed manner at a constant time interval, as shown in FIG. Signals are output to the line generators 9a and 9b. In addition, the X-ray imaging control unit 405 performs spot progress with respect to the irradiation control unit 404 from the end of X-ray irradiation until a predetermined time (next spot progress stop time) before the next X-ray irradiation. Output permission signal. As shown in FIG. 3 (C), the irradiation control unit 404 performs the irradiation of the particle beam as shown in FIG. 3 (B) while the spot advance permission signal is being input, and during irradiation. The transport system control unit 403 and the accelerator control unit 402 are controlled so that the irradiation position of the particle beam is updated from the spot to the spot to be irradiated next. When the input of the spot advance permission signal is interrupted, the irradiation controller 404 outputs a spot advance stop signal to the transport system controller 403 and the accelerator controller 402. The transport system control unit 403 that has received the spot advance stop signal is installed in the particle beam transport system 6 so that the irradiation position of the particle beam is not updated from the spot being irradiated to the spot to be irradiated next. An excitation signal is transmitted to the existing high speed steerer 5. Further, the accelerator control unit 402 that has received the spot advance stop signal outputs a stop signal to the RF kicker 4.

  As described above, the control device 400 receives the pre-pulse signal transmitted from the X-ray imaging control unit 405 and blocks the particle beam transport to the irradiation field forming device 102, whereby the particle beam irradiation timing and the X-ray irradiation Control to separate the irradiation timing is performed.

Next, the configuration and control details of the irradiation control unit 404 will be described with reference to FIG.
As shown in FIG. 4, the irradiation control unit 404 has a dose management system 408 that removes the contribution of scattered X-rays from the measurement result of the dose meter 8.
The dose management system 408 includes a dose measuring device 8 that measures particle beams and X-rays and outputs an electrical signal, an integration counter 13 that integrates signals from the dose measuring device 8, and a period during which no particle beam is irradiated. A-αB is calculated based on the integration value A output from the integration counter 15 and the integration value B output from the integration counter 15 and the integration value B output from the integration counter 15. A subtraction operation unit 16 and a dose expiration determination unit 14 for determining whether a planned dose has been irradiated are schematically configured. Calculation results from the integration counter 13, the subtraction integration counter 15, and the subtraction operation unit 16 are stored in the storage unit 409.
The constant α used in the subtracting calculation unit 16 is a coefficient for setting A−αB = 0 when the particle beam is not irradiated, and is calculated before the particle beam therapy system is operated. This α is 1 in this embodiment.

  The calculation processing performed by the dose management system 408 will be described separately for the case where X-rays are irradiated (particle beam irradiation is stopped) and the case where particle beams are irradiated (X-ray irradiation is stopped). .

First, a case where pulse irradiation is performed in order to image the affected part position using the X-ray generators 9a and 9b will be described.
While X-rays are being emitted from the X-ray generators 9a and 9b, the irradiated X-rays are scattered in various directions depending on the human body or other factors. Since the dose measuring device 8 arranged in the irradiation field forming apparatus 102 is operated regardless of whether the particle beam irradiation is performed or stopped, the scattered X-rays are transported by the particle beam transport system 6. Measure without distinguishing from particle beam. The particle beam or X-ray measured by the dose measuring device 8 is converted into an electrical signal, and the integration counter 13 and the subtraction integration counter 15 that have received this signal integrate the signals. If the integration value of the integration counter 13 is A and the integration value of the subtraction integration counter 15 is B, the integration values A and B from the integration counter 13 and the subtraction integration counter 15 are respectively sent to the subtraction operation unit (subtraction unit) 16. The subtraction calculation unit 16 calculates A−αB. The calculation result in the subtraction calculation unit 16 is output to the dose expiration determination unit 14 that determines whether the irradiation dose has reached the planned value, and dose management is performed to determine whether a predetermined dose has been irradiated.

  Next, the case where X-ray pulse irradiation is stopped and particle beam irradiation is performed will be described.

  Since the particle beam passes through the dose measuring device 8 when being irradiated, the dose measuring device 8 measures the particle beam passing therethrough. The dose measuring device 8 outputs an electrical signal according to the measured particle beam, and both the integration counter 13 and the subtraction integration counter 15 receive this signal. At this time, the integration counter 13 integrates the signal, but the subtraction integration counter 15 operates only while X-ray irradiation is performed, so that the signal is not integrated, and the integration value B of the subtraction integration counter 15 is 0. Become. The integrated values A and B of the integrating counters 13 and 15 are output to the subtracting calculation unit 16 where A-αB is calculated (B = 0), and the same calculation as in X-ray pulse irradiation is performed. The

  As described above, the dose management system 408 according to the present embodiment acquires the measurement value derived from the scattered X-rays using the subtraction integration counter 15. Therefore, the integrated value derived from the scattered X-rays can be subtracted from the integrated value of the dose measuring device 8, and the measured value based on the actual irradiation amount of the particle beam can be acquired.

  The subtraction integration counter 15 is configured to operate only when X-ray irradiation is being performed. However, a signal output in response to excitation of the high-speed steerer 5 is used to control this operation. This is because the irradiation stop time of the particle beam is equal to the time during which the high-speed steerer 5 installed in the particle beam transport system 6 is excited, and the X-ray irradiation is performed during that period. This is because the integration of signals at the time of X-ray irradiation can be selectively performed using a signal indicating the above.

  According to the particle beam therapy system of the present embodiment, the following effects can be obtained.

First, since the particle beam irradiation timing and the X-ray irradiation timing are controlled to be separated by the X-ray imaging control unit 405 of the control device 400, the dose measuring device 8 measures both irradiations at the same time. Thus, erroneous measurement of dose due to counting of scattered X-rays can be avoided. Further, since the progress of the next spot of the particle beam is stopped for a predetermined time before the X-ray irradiation, a high-speed blocking mechanism for blocking the particle beam at high speed is unnecessary, and the apparatus can be simplified.
Furthermore, a dose management system 408 provided in the irradiation control unit 404 of the control device 400 obtains a measurement value based on particle beam irradiation by subtracting the integrated value derived from scattered X-rays from the integrated value of the dose measuring device 8. Therefore, the dose management of the particle beam can be performed more accurately.

In addition, in the particle beam therapy system according to the present embodiment, high-accuracy dose management is possible even when irradiation is temporarily interrupted due to the patient's movement during the treatment time and then treatment is resumed. Can continue.
For example, consider a case where the affected area moves greatly due to the movement of the patient in particle beam therapy. When such a situation occurs, irradiation is interrupted. When resuming irradiation, it is necessary to set the position of the patient again using X-ray imaging. At this time, if the dose measuring device 8 erroneously measures the scattered component of X-rays irradiated for position setting, there is a possibility that an error may occur in dose management before and after the irradiation is interrupted. However, according to the present embodiment, since the timing of particle beam irradiation and X-ray irradiation can be measured separately and dose measurement values derived from particle beams can be obtained, such errors do not occur and irradiation is interrupted. Even if there is, high-precision dose management can be continued.

  Although the timing at which the transport system control unit 403 transmits the excitation signal to the high-speed steerer 5 is the timing at which the pre-pulse signal from the X-ray imaging control unit 405 is received, the control device 400 stops the irradiation of the particle beam. The timing may be stored, and the particle beam irradiation timing and the X-ray irradiation timing may be separated.

  Further, the signal for operating the subtraction integration counter 15 may be any signal that can know the state in which the emission of the particle beam is stopped. Therefore, for example, a stop signal of the RF kicker 4 related to beam emission installed in the synchrotron 2 or an excitation stop signal of a high-speed quadrupole electromagnet may be used.

(Example 2)
Next, a second embodiment of the particle beam therapy system according to the present invention will be described with reference to FIGS. FIG. 5 is a block diagram showing another example of the outline of a particle beam therapy system according to an embodiment of the present invention. FIG. 6 shows whether particle beam irradiation is performed in the particle beam therapy system according to an embodiment of the present invention. It is a figure which shows an example of the conditions which determine these.

The particle beam therapy system 100G of Example 2 shown in FIG. 5 is a control device in which the central control unit 401 provided in the control device 400 of the particle beam therapy system 100 of Example 1 shown in FIG. 1 is replaced with the central control unit 401G. 400G is provided.
Specifically, the central control unit 401G in the control device 400G of the particle beam therapy system 100G of the present embodiment is repeated a plurality of times within the treatment time in addition to the control function performed by the central control unit 401 of the first embodiment. It is configured to calculate a predicted time from emission of a spot to stop, and to control particle beam irradiation based on the predicted time.
In the present embodiment, description of the same configuration and function as in the first embodiment will be omitted, and different portions will be described in detail.

When the central control unit 401G starts irradiation of a spot, the central control unit 401G calculates an estimated time t from the emission of the spot to the stop. Next, the central control unit 401G determines whether or not the particle beam irradiation timing and the X-ray irradiation timing overlap before the irradiation of the spot is completed based on the previously calculated predicted time t.
For example, as shown in FIG. 6, it is determined that the irradiation timing of the particle beam and the irradiation timing of the X-ray do not overlap with each other. The spot group α in (B1) and (B2) and the spot β1 in (B1) are irradiated with the particle beam. Thus, the accelerator controller 402 and the transport system controller 403 are controlled. On the other hand, in the spot β2 shown in (B2), since it is determined that the particle beam irradiation timing and the X-ray irradiation timing overlap, the accelerator control unit 402 and the transport system control unit 403 are controlled not to irradiate the particle beam. .

Here, the particle beam irradiation amount for each spot takes various values, and the average beam current in the spot varies within a certain range. The spot irradiation time is determined by this combination. For this reason, in this embodiment, the next step is performed with a margin so that the particle beam and the imaging X-ray irradiation can be separated even when the largest particle beam irradiation amount and the average beam current in the lowest spot are combined. The stop stop time for the spot is set.
In addition to the combination of the largest particle beam irradiation amount and the average beam current in the lowest spot, there is an extra stop time for the next spot. Therefore, the advance stop time to the next spot may be set smaller than when the largest particle beam irradiation amount and the average beam current in the lowest spot are combined. Even with this setting, the particle beam and the imaging X-ray irradiation can be separated at almost all timings.
In any case, the effect exhibited by Example 1 can be obtained with a shorter extension of treatment time.

  In order to calculate the predicted time, it is necessary to obtain the average beam current in the spot. Methods for obtaining the average beam current include, for example, a method using a value calculated in advance based on a model, a method using a measured value of the beam current of an irradiated spot, and the like.

(Example 3)
Next, a third embodiment of the particle beam therapy system according to the present invention will be described with reference to FIGS. FIG. 7 is a block diagram showing another example of the outline of a particle beam therapy system according to an embodiment of the present invention. FIG. 8 shows whether particle beam irradiation is performed in the particle beam therapy system according to one embodiment of the present invention. It is a figure which shows an example of the conditions which determine these.

In the particle beam therapy system 100H of the present embodiment shown in FIG. 7, the central control unit 401 provided in the control device 400 of the particle beam therapy system 100 of Example 1 is replaced with the control device 400H replaced by the central control unit 401H. Have.
Specifically, the central control unit 401H in the control device 400H of the particle beam therapy system 100H of the present embodiment is repeated a plurality of times within the treatment time in addition to the control function performed by the central control unit 401 of the first embodiment. While measuring the time from the exit of each spot to the stop, the measurement of the time being measured is used to control the irradiation of the particle beam.
In the present embodiment, description of the same configuration and function as in the first embodiment will be omitted, and different portions will be described in detail.

The central control unit 401H compares the measured value with the determination time stored in advance in the storage unit 409 while measuring the time from the start of emission to the stop of irradiation at each spot when the spot progresses. . This determination time is set to be smaller than the progress stop time to the next spot.
And when measurement time is short compared with determination time like the spot group (alpha) shown to FIG. 8 (B), spot progress is continued, without adding special control newly.
On the other hand, when it is determined that the measurement time is longer than the determination time, as in the case of the spot β shown in FIG. 8B, the control for increasing the particle beam current extracted from the particle beam generator 101 immediately. I do. For example, the particle beam is generated again from the ion source and the particle beam that circulates around the synchrotron 2 is increased, or the output of the RF kicker 4 for taking out the circulating particle beam is increased. In order to implement the above, a signal is output to the accelerator control unit 402 and the transport system control unit 403.

  In this embodiment, when the spot measurement time is longer than the set time, the control is performed to increase the particle beam current, so that the spot can be advanced while keeping the spot irradiation time short. For this reason, the spot continues to travel with a shorter spot irradiation time compared to the progress stop time to the next spot, and a time margin is provided by the processing for separating the particle beam and the imaging X-ray irradiation. In other words, the effect achieved by the first embodiment can be obtained with higher reliability.

Example 4
Next, a fourth embodiment of the particle beam therapy system according to the present invention will be described with reference to FIG. FIG. 9 is a schematic diagram of another example of the configuration of the irradiation field forming device, the X-ray imaging device, and the control device constituting the particle beam therapy system according to the embodiment of the present invention.

The particle beam therapy system according to the present embodiment has a configuration in which the dose management system 408 of the irradiation control unit 404 provided in the control device 400 in the particle beam therapy system 100 according to the first embodiment is replaced with a dose management system 408A. .
Specifically, as shown in FIG. 9, the dose management system 408A in the irradiation control unit 404A of the control device 400A of the present embodiment is an integration for subtraction provided in the dose management system 408 of the first embodiment shown in FIG. The counter 15 and the subtraction operation unit 16 are not provided. This dose management system 408A is provided in an irradiation control unit 404A provided in the control device 400A. In the present embodiment, description of the same configuration and function as in the first embodiment will be omitted, and different portions will be described in detail.

  Also in the present embodiment, the control device 400A performs control for separating the particle beam irradiation timing and the X-ray irradiation timing in the X-ray imaging control unit 405.

As shown in FIG. 9, the dose management system 408A of the present embodiment includes an integration counter 13A that integrates signals from the dose measuring device 8, and a dose expiration determination unit 14 that determines whether a planned dose has been irradiated. It is roughly structured. The integration counter 13A is directly connected to the dose expiration determination unit 14.
The integration counter 13A is configured to integrate signals from the dose measuring device 8 only during a period during which the particle beam is irradiated.

  The calculation processing of the dose management system 408A of the present embodiment will be described separately for the case where X-rays are irradiated and the case where particle beams are irradiated.

First, a case where pulse irradiation is performed in order to image the affected part position from the X-ray generator 9 will be described.
Since the dose measuring device 8 is operating regardless of whether the execution of the particle beam irradiation is stopped, the scattered X-rays are measured. An electrical signal is output from the dose measuring device 8 to the integrating counter 13A according to the scattered X-rays measured at this time, but the signal is not integrated because the integrating counter 13A is stopped. Therefore, 0 is output as the integration signal A to the dose expiration determination unit 14.

  On the other hand, when the X-ray pulse irradiation is stopped and the particle beam irradiation is performed, the integration counter 13A integrates the electric signal output from the dose measuring device 8 according to the particle beam measurement. The integrated value A of the integrated counter 13A is output to the dose expiration determining unit 14, and the dose expiration determining unit 14 determines whether the irradiation dose has reached the planned value.

  As described above, the dose management system 408A of the present embodiment acquires the measurement value derived from the particle beam because the integration counter 13A integrates the signal output from the dose measuring device 8 only during the irradiation period of the particle beam. Can do.

  In order to operate the integration counter 13A only while the particle beam irradiation is performed, a signal output while the high-speed steerer 5 is excited is used as an off signal of the integration counter 13A.

  According to the present embodiment, in addition to the effects achieved by the first embodiment, the subtraction integration counter 15 and the subtraction operation unit 16 are not required, so that the device configuration of the dose management system can be simplified.

(Example 5)
Next, a fifth embodiment of the particle beam therapy system according to the present invention will be described with reference to FIG. FIG. 10 shows the X-ray irradiation, the timing of particle beam irradiation, the X-ray imaging control unit, and the irradiation control unit when the particle beam irradiation is stopped simultaneously with the start of the X-ray irradiation at the time of particle beam irradiation by the particle beam therapy system. It is a figure which shows the timing of the signal which outputs.

The particle beam therapy system according to the present embodiment has a configuration in which the control device 400 is replaced with the particle beam therapy system 100 according to the first embodiment.
In the control apparatus 400 of Example 1, it controls so that irradiation of a particle beam may be stopped for the fixed time before starting X-ray irradiation. On the other hand, in the control apparatus of the present embodiment, the X-ray irradiation and the particle beam irradiation are controlled to be separated without providing this fixed time. That is, the particle beam therapy system according to the present embodiment has the same configuration as the particle beam therapy system 100 according to the first embodiment, but the control method by the controller is different between the two.

  A description will be given of the control by the control device of the present embodiment, which is different from the control device 400 of the first embodiment. Note that description of matters common to the first embodiment is omitted.

In this embodiment, the X-ray imaging control unit 405 of the control device is irradiated with the next X-ray after the X-ray irradiation is completed, as shown in FIGS. 10 (A), (B), and (C). In the meantime, a spot advance permission signal is output to the irradiation controller 404. The irradiation control unit 404 controls the transport system control unit 403 and the accelerator control unit 402 so as to continue the particle beam irradiation while the spot advance permission signal is input. When the input of the spot advance permission signal is interrupted, the irradiation controller 404 outputs a spot advance stop signal to the transport system controller 403 and the accelerator controller 402 as shown in FIG. . Receiving this spot advance stop signal, the transport system control unit 403 transmits an excitation signal to the high-speed steerer 5 installed in the particle beam transport system 6 in order to stop the irradiation of the particle beam. Further, the accelerator control unit 402 that has received the spot advance stop signal outputs a stop signal to the RF kicker 4.
Thus, since the particle beam therapy apparatus of a present Example has stopped irradiation of particle beam at the time of X-ray pulse irradiation being started, it can isolate | separate particle beam irradiation and X-ray irradiation.

  The basic configuration and operation of the dose management system of this embodiment are the same as those of the first embodiment. The difference from the first embodiment is that an X-ray irradiation start signal is used to operate the subtraction integration counter 15. In this embodiment as well, a signal to be output while the high-speed steerer 5 is excited can be used for the operation of the subtraction integration counter 15.

  In addition to achieving the same effect as in the first embodiment, this embodiment does not require a certain amount of time to separate the particle beam from the imaging X-ray irradiation. Can be stopped.

(Example 6)
Next, a sixth embodiment of the particle beam therapy system according to the present invention will be described.

The particle beam therapy system according to the present embodiment has a configuration in which the control device 400A is replaced with the particle beam therapy system according to the fourth embodiment.
That is, the control device 400A of the fourth embodiment is controlled so as to stop the particle beam irradiation a certain time before starting the X-ray irradiation, but the control device of the present embodiment is the same as the control device of the fifth embodiment. Control is performed so that X-ray irradiation and particle beam irradiation are separated without providing a certain period of time. That is, the particle beam therapy system of the present embodiment has the same configuration as the particle beam therapy system of Example 4, but the control method by the controller is different between them.

  The dose management system of the present embodiment has the same configuration as the dose management system 408A of the fourth embodiment shown in FIG. The difference between the dose management system of the present embodiment and the dose management system 408A of the fourth embodiment is that an X-ray irradiation start signal is used as a signal for stopping the operation of the integration counter 13.

  According to the present embodiment, it is possible to minimize the extension of the treatment time, and since the subtraction integration counter 15 and the subtraction operation unit 16 are not required, the apparatus configuration of the dose management system can be simplified.

(Summary of Example 1-6)
As described above, the particle beam therapy system according to the first to sixth embodiments described above separates the irradiation timing of the particle beam from the timing of X-ray pulse irradiation using the control device, and measures the dose measuring device 8. It is characterized by having a dose management system that calculates a measurement value derived from a particle beam by subtracting a measurement value derived from scattered X-rays from the value. By having such a feature, the measurement timings of the particle beam and the scattered X-ray are separated, and the overlapping of the measurement periods can be eliminated. Further, the measurement value derived from the particle beam can be acquired from the measurement value of the dose measuring device 8.
As a result, it is possible to confirm the position of the affected area in real time by using X-ray pulse irradiation while realizing high dose management accuracy and dose distribution accuracy of the particle beam.
In particular, in a particle beam therapy system that employs an irradiation method that requires dose management in a minute area unit such as a discrete spot scanning method, the present invention can eliminate measurement errors derived from an X-ray imaging apparatus. Examples 1-6 make a significant contribution.

  In addition, although the particle beam therapy apparatus of each Example shall use the discrete spot scanning method, an irradiation control apparatus and a dose management system are not limited to this, The wobbler irradiation method using a raster scanning method or a scatterer The present invention can also be applied to a particle beam therapy apparatus using the above. The particle beam irradiation timing and the X-ray pulse irradiation timing are separated from each other by stopping the update of the particle beam irradiation position with a fixed time margin or by forcibly stopping the particle beam irradiation. Therefore, the particle beam irradiation method has the same effect even if it is not limited to spot scanning.

  By the way, as a particle beam therapy apparatus capable of confirming the position of an affected area in real time during treatment time using X-rays while realizing high-precision dose management accuracy and dose distribution accuracy, it has features different from the above embodiments. The following examples are also conceivable. Examples of these will be described below.

(Example 7)
Next, a seventh embodiment of the particle beam therapy system according to the present invention will be described with reference to FIG. FIG. 11 is a schematic diagram of another example of the configuration of the irradiation field forming device, the X-ray imaging device, and the control device that constitute the particle beam therapy system according to the embodiment of the present invention.

  As shown in FIG. 11, the dose management system 408D of the irradiation controller 404D in the control device 400D of the particle beam therapy apparatus according to the present embodiment is the irradiation of the control device 400 of the particle beam therapy apparatus 100 shown in FIG. In addition to the configuration shown in the dose management system 408 of the control unit 404, a scattered X-ray dose measuring device (second dose measuring device) 17 for measuring scattered X-rays, and a scattered X-ray integration for integrating the measured values And a counter 18.

In the particle beam dose measurement in the particle beam therapy system of the present embodiment, the accumulated value derived from scattered X-rays measured by the scattered X-ray dose meter 17 is subtracted from the accumulated value obtained from the dose meter 8. Will be implemented.
Specifically, the signal output from the dose measuring device 8 is integrated by the integrating counter 13, and the signal output from the scattered X-ray dose measuring device 17 is integrated by the scattered X-ray integrating counter 18. The The integrated value A of the integrated counter 13 and the integrated value B of the scattered X-ray integrated counter 18 are output to the subtracting calculation unit 16 where A-αB is calculated. The calculation result of A−αB in the subtraction calculation unit 16 is output to the dose expiration determination unit 14 that determines whether the irradiation dose has reached the planned value.

The present embodiment includes a scattered X-ray dose measuring device 17 that measures scattered X-rays and a scattered X-ray integration counter 18 that integrates the signals thereof, so that particle beams and imaging X-rays can be obtained. There is no need to separate the irradiation timing. Therefore, particle beam irradiation control, dose management system, and the like can be simplified.
The particle beam irradiation method may be the raster scanning described above, and the X-ray irradiation may not be limited to pulse irradiation.

(Example 8)
Next, an eighth embodiment of the particle beam therapy system according to the present invention will be described with reference to FIG. FIG. 12 is a schematic diagram of another example of the configuration of the irradiation field forming device, the X-ray imaging device, and the control device that constitute the particle beam therapy system according to the embodiment of the present invention.
In the eighth embodiment, the scattered X-ray dose measuring instrument 17 shown in the seventh embodiment and the scattered X-ray integrating counter 18 that accumulates the signals are used for the scattered X-rays measured by the dose measuring instrument 8. Is replaced with a scattered X-ray simulation device 19 that outputs to the subtraction operation unit 16.

In the dose management system 408G in the irradiation control unit 404G in the control apparatus 400G of the particle beam therapy system according to the present embodiment, as shown in FIG. 12, the scattered X-ray simulation apparatus is calculated from the integrated value of the signal output from the dose measuring device 8. The dose measurement of the particle beam is performed by subtracting the integrated value of the signal output from 19.
In using the scattered X-ray simulation device 19, a background measurement is performed in which the X-rays for imaging are irradiated in advance and the scattered X-ray dose is measured before treatment. The scattered X-ray simulation device 19 outputs a simulated signal of scattered X-rays in conjunction with X-ray irradiation based on the background measurement result. For example, only during the X-ray irradiation period, the scattered X-ray simulation device 19 outputs a simulation signal to the subtraction operation unit 16.

  According to the present embodiment, the same effect as that of the seventh embodiment can be obtained without providing a configuration including the scattered X-ray dose measuring device 17 and the scattered X-ray integrating counter 18 for measuring scattered X-rays.

Example 9
Next, a ninth embodiment of the particle beam therapy system according to the present invention will be described with reference to FIG. FIG. 13 is a schematic diagram of another example of the configuration of the irradiation field forming device, the X-ray imaging device, and the control device that constitute the particle beam therapy system according to the embodiment of the present invention.

  In this embodiment, the scattered X-ray simulation apparatus described in the eighth embodiment is incorporated into the dose management system described in the first embodiment.

  As shown in FIG. 13, the particle beam therapy system according to the present embodiment is configured such that a subtraction integration counter 15 and a scattered X-ray simulation device 19 are connected to a subtraction operation unit 16 via an input switch 20. .

  The input switching unit 20 provided in the dose management system 408F in the irradiation control unit 404F of the control device 400F of the present embodiment switches the acquisition source of the signal output to the subtraction calculation unit 16 according to the irradiation state of the particle beam. That is, for the period during which the particle beam is irradiated, the input switching unit 20 simulates the scattered X-ray among the integrated value b2 input from the scattered X-ray simulator 19 and the integrated value b1 input from the subtracting counter 15. The integrated value b2 output from the device 19 is output as an output value B to the subtraction operation unit 16. On the other hand, the input switcher 20 integrates the integration input from the subtraction integration counter 15 during a period in which a signal indicating that the high-speed steerer 5 is excited, that is, a period in which no particle beam is irradiated. The value b1 is output as the output value B to the subtraction operation unit 16. Then, in the subtracting calculation unit 16, the calculation process of A−αB is performed as in the first embodiment and the calculation result is output to the dose expiration determination unit 14.

  In this embodiment, the dose measurement of the particle beam is performed as follows. The integrated value b1 is input from the subtracting integration counter 15 and the integrated value b2 is input from the scattered X-ray simulator 19 to the input switcher 20. Depending on the irradiation state of the particle beam, one of the integrated values b1 and b2 is output as an output value B to the subtraction operation unit 16, and the subtraction operation unit 16 performs an arithmetic process.

  According to the present embodiment, it is not always necessary to separate the irradiation timing of the particle beam and the X-ray. Further, the control system can be simplified and the treatment time is not extended. Further, since the scattered X-rays are measured using the dose measuring instrument 8, the dose management accuracy is further improved as compared with the eighth embodiment.

(Other)
In addition, this invention is not restricted to said embodiment, A various deformation | transformation and application are possible.

  For example, in Example 1, etc., the control for separating the particle beam irradiation timing and the X-ray irradiation timing in the X-ray imaging control unit 405 in the control device 400 and the measurement result of the dose measuring device 8 in the irradiation control unit 404 The calculation processing for removing the contribution of scattered X-rays from the above may be executed independently.

  In the ninth embodiment, a configuration including the scattered X-ray dose measuring device 17 and the scattered X-ray integration counter 18 shown in the seventh embodiment can be provided instead of the subtraction integration counter 15. In this case, during the period of irradiation with the particle beam, the input switching unit 20 simulates the scattered X-ray among the integrated value input from the scattered X-ray simulation device 19 and the integrated value input from the scattered X-ray integration counter 18. The integrated value output from the device 19 is output to the subtraction operation unit 16. On the other hand, during the period when the particle beam is not irradiated, the integrated value input from the scattered X-ray integration counter 18 can be output to the subtraction operation unit 16.

  Further, the configuration in which the control units of the control device 400 are connected in parallel and the signals are directly output to the related control units has been described. However, the configuration of the control device is not limited to this, and for example, the central control unit can control each control unit. It can also be configured to control in an integrated manner.

1 ... Pre-stage accelerator,
2 ... Synchrotron,
3 ... Bending electromagnet,
4 ... RF kicker,
5 ... High-speed steerer,
6 ... Particle beam transport system,
7 ... Scanning magnet,
8 ... Dose measuring device,
9a, 9b ... X-ray generator,
11a, 11b ... X-ray receiver,
13, 13A ... Integration counter,
14: Dose expiration determination unit,
15 ... Subtraction counter,
16: Subtraction operation unit (subtraction unit),
17 ... Dosimeter for scattered X-rays (second dose meter),
18 ... Integrated counter for scattered X-rays,
19 ... scattered X-ray simulator
20: Input selector,
100, 100G, 100H ... particle beam therapy device,
101 ... Particle beam generator,
102 ... Irradiation field forming device,
103 ... X-ray imaging apparatus,
104 ... Couch (bed),
105 ... treatment room,
400, 400A, 400D, 400E, 400F, 400G, 400H ... control device,
401, 401G, 401H ... Central control unit,
402: Accelerator control unit,
403 ... Transport system control unit,
404, 404A, 404D, 404E, 404F ... irradiation control unit,
405 ... X-ray imaging control unit,
406 ... Couch control unit,
407 ... Gantry control unit,
408, 408A, 408D, 408E, 408F ... Dose management system,
409: Storage unit.

Claims (9)

  A particle beam therapy device,
  A particle beam generator for generating particle beams;
  An irradiation field forming device for irradiating the target with the particle beam;
  A dose meter provided at a position through which the particle beam passes;
  An X-ray imaging apparatus that images the position of the target by irradiating X-rays;
  A control device that performs control to exclude the measurement result of the scattered X-rays derived from the X-ray imaging device from the measurement result of the dose measuring instrument,
  The controller is
    A counter for accumulating signals output from the dosimeter,
    A subtracting arithmetic unit that is connected in series with the counter and subtracts the scattered X-ray dose value from the integrated value output from the counter;
    A storage unit that stores at least one of the integrated value of the counter and the calculation result of the subtraction calculation unit;
  A particle beam therapy system.   The particle beam therapy system according to claim 1, wherein
  The control device further includes means for outputting a value corresponding to the scattered X-ray dose to the subtraction operation unit.
  A particle beam therapy system.   The particle beam therapy system according to claim 2, wherein
  The means is the counter that integrates signals output from the dose measuring device during a period in which the irradiation of the particle beam is stopped.
  A particle beam therapy system.   In the particle beam therapy system according to any one of claims 1 to 3,
  The irradiation method of the particle beam by the irradiation field forming device is a scanning irradiation method,
  The control device permits the change of the irradiation position in the scanning irradiation method during a period from the end of the X-ray irradiation to a predetermined time before the next X-ray irradiation, and the irradiation position after the elapse of the period. Control changes to stop
  A particle beam therapy system.   In the particle beam therapy system according to any one of claims 1 to 3,
  The irradiation method of the particle beam by the irradiation field forming device is a scanning irradiation method,
  The control device permits the change of the irradiation position in the scanning irradiation method during a period from the end of the X-ray irradiation to a predetermined time before the next X-ray irradiation, and the particle beam after the elapse of the period. Control to stop irradiation immediately
  A particle beam therapy system.   The particle beam therapy system according to claim 2, wherein
  A second dose measuring device installed at a position different from the particle beam passing line;
  The means is a subtraction integration counter that is connected in series to the subtraction operation unit, integrates signals output from the second dose measuring device, and outputs an integration result to the subtraction operation unit.
  A particle beam therapy system.   The particle beam therapy system according to claim 2, wherein
  The means is connected in series to the subtraction operation unit, and outputs a simulated value of a scattered X-ray signal derived from the X-ray imaging apparatus measured by the dose measuring device to the subtraction operation unit. It is a simulation device
  A particle beam therapy system.   The particle beam therapy system according to claim 2, wherein
  The means includes an accumulation counter for subtraction for accumulating signals output from the dose measuring device, and an X-ray storing a simulated value of a scattered X-ray signal derived from the X-ray imaging device measured by the dose measuring device. A simulation device,
  The control device is connected to the subtraction integration counter and the X-ray simulation device so as not to output the output of either the subtraction integration counter or the X-ray simulation device to the subtraction operation unit. It further has an input switching unit to control
  A particle beam therapy system.   In the particle beam therapy system according to any one of claims 1 to 8,
  The control device further includes a dose expiration determination unit that determines whether or not a planned dose has been irradiated based on a signal output from the subtraction calculation unit.
  A particle beam therapy system.

Images