JP6450165B2 - Charged particle beam apparatus, charged particle beam irradiation position specifying apparatus, and charged particle beam irradiation position specifying method - Google Patents

Description

  The present invention relates to a charged particle beam apparatus, a charged particle beam irradiation position specifying apparatus, and a charged particle beam irradiation position specifying method, and more particularly to a charged particle beam apparatus suitable for specifying an irradiation target position irradiated with a charged particle beam, and The present invention relates to a charged particle beam irradiation position specifying device and a charged particle beam irradiation position specifying method.

  In order to actually measure the irradiation range of the charged particle beam to be irradiated with a charged particle beam apparatus used for cancer treatment and record it, Patent Document 1 discloses that when the emitted charged particle beam irradiates the target, An invention is described in which an acoustic signal generated from the sensor is detected by a detector, and the actual irradiation location is recorded by obtaining the actual irradiation location by a calculation means based on the detected acoustic signal.

JP-A-10-52509

  The number of cancer deaths and morbidity continues to increase, and there is an urgent need to establish treatment methods. There are three main treatment methods: surgery, radiation therapy, and chemotherapy. In recent years, the techniques of radiation therapy and chemotherapy have been remarkably improved.

  Chemotherapy is expected to provide efficient treatment and reduce side effects by developing molecularly targeted drugs that can determine and act on cancer cells at the molecular level. The side effects of chemotherapy are caused by acting on normal cells other than the target cancer cells, and the symptoms and burden on the body differ depending on the type of medication and patient.

  Radiation therapy is expected to be equally efficient and reduce side effects by developing technology that concentrates high doses in the desired irradiation range. Side effects of radiation therapy can occur when cells other than the target cancer cells are irradiated, and symptoms such as inflammation are known when side effects occur. However, most of the side effects of radiation therapy are temporary, and the burden on the body is considered to be very light compared to chemotherapy. Therefore, in radiotherapy, it is important that the position and shape of the cancer and the position and shape of the high-dose region of radiation coincide with each other with high accuracy.

  In the conventional charged particle beam apparatus, irradiation treatment with high accuracy is performed by positioning so that the position of the affected part of the patient, the irradiation position of the charged particle beam, and the irradiation range coincide before the irradiation treatment. In addition, by measuring the irradiation position and irradiation range of the charged particle beam and leaving the irradiation position and irradiation range of the treatment irradiation in the record, further higher accuracy can be expected.

  One method for accurately measuring the irradiation position and irradiation range is a method using a phenomenon in which an acoustic signal is generated from the irradiation position when a charged particle beam is irradiated onto a target such as a living body or metal. This method is described in, for example, Patent Document 1 described above.

  Here, the speed of sound when propagating through fat is about 1450 [m / s], the speed of sound when propagating through blood, muscle, and organs is about 1530 to 1630 [m / s], and the speed of sound propagating through bone is About 2700-4100 [m / s] etc., it will be slightly different depending on the tissue and shape constituting the body and the individual person or organism.

  Further, as shown in FIG. 16, a refraction phenomenon in accordance with the relationship shown in the following equation 1 occurs when Vi is a medium sound speed in medium i, Vii is a medium sound speed in medium ii, θi is an incident angle, and θt is a refraction angle. (Snell's law).

  Vi × sin (θt) = Vii × sin (θi) (Formula 1)

  For this reason, when obtaining from simple geometric calculation based on sensor arrangement information and time distribution information where the acquired acoustic signal reaches the sensor, assuming that the tissue of the human body is uniform as in Patent Document 1 described above, There is a possibility that an error of several millimeters may occur between the irradiation position obtained by calculation and the actual irradiation position due to the difference in sound velocity due to the tissue of the human body and the Snell's law.

  An object of the present invention is to provide a charged particle beam apparatus, a charged particle beam irradiation position specifying apparatus, and a charged particle beam irradiation position specifying method capable of accurately measuring an irradiation position.

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-described problems. For example, an accelerator that accelerates and emits a charged particle beam, and an irradiation device that irradiates the charged particle beam emitted from the accelerator, A control device for controlling the accelerator and the irradiation device; and an elastic wave measurement device having a plurality of sensors capable of detecting elastic waves generated at rest of the charged particle beam irradiated by the irradiation device at a plurality of positions; An elastic wave measurement control device that controls the operation of the elastic wave measurement device, a storage unit that stores waveform data of the elastic wave measured by the sensor of the elastic wave measurement device, and an object to be irradiated with the charged particle beam a database to hold the information required to create a virtual model placed required information and virtual measurement points to create the measurement profile or model composition sensor arrangement, this A model is created using model creation necessary information held in a database, and the charged particle is obtained by performing time-dependent computation on the model using the waveform data stored in the storage unit as an input value. An elastic wave measurement processing device that calculates the irradiation position of the beam, and the elastic wave measurement processing device creates a virtual model using the virtual model creation necessary information and virtually arranges the measurement on the virtual model. A virtual acquisition waveform is newly obtained at the position of the point, and the irradiation position of the charged particle beam is calculated by performing time-dependent calculation using the virtual acquisition waveform data as an input value .

  According to the present invention, the position irradiated with the charged particle beam can be measured with high accuracy and recorded.

It is a figure which shows an example of the functional block diagram of the charged particle beam apparatus of the 1st Embodiment of this invention. It is a figure which shows an example of the functional block diagram of the charged particle beam irradiation position specific | specification apparatus of 1st Embodiment. It is a figure which shows an example of the sensor suitable for the elastic wave measurement in the charged particle beam apparatus of 1st Embodiment. It is a figure which shows another example of the sensor suitable for the elastic wave measurement in the charged particle beam apparatus of 1st Embodiment. It is a figure which shows another example of the sensor suitable for the elastic wave measurement in the charged particle beam apparatus of 1st Embodiment. It is a flowchart which shows an example of the flow of the treatment scheme using the charged particle beam apparatus of 1st Embodiment. It is a flowchart which shows an example of the flow of an elastic wave measurement and process in the charged particle beam irradiation position specifying method of the 1st Embodiment of this invention. It is a schematic diagram which shows an example of the process of the acquisition data in the charged particle beam irradiation position specifying method of 1st Embodiment. It is an example of the schematic diagram of the two-dimensional tomographic model used in the charged particle beam irradiation position specifying method of the first embodiment. It is an example of the schematic diagram of the three-dimensional model used in the charged particle beam irradiation position specification method of 1st Embodiment. It is a figure which shows an example of the database for every structure | tissue required for the elastic wave analysis in the charged particle beam irradiation position specifying method of 1st Embodiment. It is a flowchart which shows an example of the flow of an elastic wave measurement and process in the charged particle beam irradiation position specifying method of the 2nd Embodiment of this invention. It is a schematic diagram which shows an example of the process of the acquisition data in the charged particle beam irradiation position specifying method of 2nd Embodiment. It is a flowchart which shows an example of the flow of an elastic wave measurement and process in the charged particle beam irradiation position specifying method of the 3rd Embodiment of this invention. It is a schematic diagram which shows an example of the process of the acquisition data in the charged particle beam irradiation position specifying method of 3rd Embodiment. It is a schematic diagram of the outline of Snell's law showing refraction of elastic waves.

  Embodiments of a charged particle beam apparatus, a charged particle beam irradiation position specifying apparatus, and a charged particle beam irradiation position specifying method of the present invention will be described below with reference to the drawings.

<First Embodiment>
A first embodiment of a charged particle beam device, a charged particle beam irradiation position specifying device, and a charged particle beam irradiation position specifying method of the present invention will be described with reference to FIGS.

  1 is a block diagram of a charged particle beam apparatus according to the present embodiment, FIG. 2 is a block diagram of an elastic wave measuring apparatus, FIGS. 3 to 5 are examples of sensors suitable for elastic wave measurement, and FIG. 6 is a flowchart showing a treatment scheme. FIG. 7, FIG. 7 is a flowchart showing an elastic wave measurement / processing method, FIG. 8 is a schematic diagram showing processing of acquired data, FIG. 9 is a schematic diagram of a two-dimensional tomographic model, and FIG. 10 is a schematic diagram of a three-dimensional model. Reference numeral 11 is an example of a database for each tissue necessary for elastic wave analysis.

  First, the configuration and role of a general irradiation apparatus and the measurement apparatus of the present invention will be described with reference to FIG.

  In FIG. 1, a charged particle beam apparatus performs treatment by irradiating an affected part of an irradiated body (patient) 212 fixed to a treatment bed in a treatment room with a charged particle beam, and generates and accelerates a charged particle beam. An irradiation system 100 for transporting and irradiating, a measurement system 200 for measuring a charged particle beam irradiated to the irradiated object 212, an elastic wave measurement control device 250, an elastic wave measurement processing device 260, an elastic wave measurement result holding device 270, X It comprises a line measurement control / processing device 300, an irradiated object information acquisition device 400, an irradiation control device 500, an irradiation planning device / irradiation maintenance device 600, and the like.

  The irradiation system 100 includes an accelerator 110, a beam transport system 120, a gantry 130, and an irradiation field forming device / irradiation nozzle 140.

  The accelerator 110 accelerates the charged particle beam and emits it to the beam transport system 120. Examples of the type of the accelerator 110 include a synchrotron, a cyclotron, and a linear accelerator. The charged particle beam accelerated by this accelerator and irradiated to the irradiation object 212 includes protons, heavy particle ions such as carbon having a heavier mass than protons, and neutrons.

  The beam transport system 120 is connected to the downstream side of the accelerator 110 and connects the accelerator 110 to the gantry 130 and the irradiation field forming device / irradiation nozzle 140.

  The gantry 130 is configured to be rotatable around an isocenter (not shown), and determines a beam irradiation angle. The rotation angle of the gantry 130 can change the irradiation angle of the charged particle beam with which the irradiated object 212 is irradiated.

  The irradiation field forming device / irradiation nozzle 140 is a device that irradiates the charged particle beam emitted from the accelerator 110. For example, when the irradiation method is a spot scanning method, the upstream is sequentially from the upstream side in the traveling direction of the charged particle beam. A beam monitor, scanning magnet, dose monitor and downstream beam monitor are positioned along the beam path. The irradiation field forming device / irradiation nozzle 140 forms a scanning beam irradiation field.

  The charged particle beam irradiation method by the irradiation field forming device / irradiation nozzle 140 is not limited to the spot scanning method in which the emission of the particle beam is stopped for each spot described above, but the raster scanning method in which the emission of the particle beam is not stopped, Various methods such as a scatterer method in which a beam diameter is enlarged with a scatterer when the beam is irradiated in accordance with the shape and then the peripheral part is shaved with a collimator to shape the beam can be employed.

  The measurement system 200 is a group of devices that measure a charged particle beam irradiated to the irradiation object 212, and includes an X-ray measurement apparatus 230 and an elastic wave measurement apparatus 240 that acquire transmission imaging used for positioning the irradiation object 212. The measurement system 220 includes a bed 210 for fixing the center position of the charged particle beam so as to coincide with the position of the affected area based on the imaging result, and the irradiation object 212 fixed to the bed 210 is aligned.

  The X-ray measurement control / processing apparatus 300 is an apparatus that captures and records a cross section of the irradiated object 212 necessary for creating an irradiation plan for the irradiated object 212, and measures the charged particle beam irradiated object 212. A database 320 that holds information necessary for creating a model of the outer shape, composition, and sensor arrangement, and a control / processing device 310 for organizing and controlling information recorded in the database 320 are provided.

  The irradiated object information acquisition apparatus 400 includes an X-ray CT apparatus and the like, performs tomographic imaging of the irradiated object 212 in advance, and acquires information on the position and shape of the affected area that is the irradiated object 212 and the surrounding tissue. It is a device for doing. The irradiated object information acquiring apparatus 400 outputs the obtained information on the position and shape of the affected part and surrounding tissue to the database 320 of the X-ray measurement control / processing apparatus 300.

  The irradiation control device 500 is connected to the irradiation planning device / irradiation maintenance device 600, the irradiation system 100, and the elastic wave measurement control device 250, and controls the operation of each of these devices. This irradiation control device 500 is based on setting data from the irradiation planning device / irradiation maintenance device 600, setting values of operating parameters for accelerator operation, operating parameters for forming an irradiation field, planned beam positions, and It has a function to calculate set values for beam width and dose. These operating parameters and monitor set values are output from the irradiation control device 500 to the irradiation system 100 and the elastic wave measurement control device 250.

  The irradiation planning apparatus / irradiation maintenance apparatus 600 treats the position / range of the affected area, such as information on the position and shape of the affected area, which is the area to be irradiated 212, and the surrounding tissue acquired by the irradiated object information acquiring apparatus 400 in advance. Irradiation plan information such as necessary irradiation dose and irradiation range is created and stored from the previous and treatment process information. The irradiation plan information includes irradiation data (beam energy information such as energy and energy width of a charged particle beam, irradiation position information such as a nozzle position, a target dose value of a charged particle beam for each irradiation position, and the like). The irradiation planning device / irradiation maintenance device 600 again creates (updates) a new irradiation plan based on the irradiation position information obtained by the elastic wave measurement processing device 260.

  Next, operations of a general irradiation apparatus and the measurement apparatus of the present invention will be described with reference to FIG.

  In FIG. 1, before irradiation, tomographic imaging of the irradiated object 212 is performed in advance by the irradiated object information acquisition device 400, and the position and shape of the affected area, which is the irradiated object 212, and the surrounding tissue are obtained. 320 is recorded. Based on the CT imaging data, the irradiation planning device / irradiation maintenance device 600 creates an irradiation plan.

  Next, in the measurement system 200, transmission imaging is acquired by the X-ray measurement device 230 used for positioning the irradiated object 212, and the bed 210 and the bed are set so that the center position of the charged particle beam coincides with the affected part position from the imaging result. The alignment of the irradiated object 212 fixed to 210 is performed.

  Next, based on the irradiation plan for treatment, the irradiation controller 100 controls the irradiation system 100 to irradiate the affected part with the charged particle beam.

  In the irradiation system 100, particles are accelerated by an accelerator 110, and a charged particle beam incident through the transport system 120 is irradiated from the irradiation field forming device / irradiation nozzle 140 to the irradiated object 212 using the gantry 130. Whether or not a desired position is irradiated is determined by monitoring the trajectory and intensity of the charged particle beam with a monitor installed on the path from when the charged particle beam is transported to when it is emitted.

  In the present invention, an elastic wave measurement device 240, an elastic wave measurement control device 250, an elastic wave measurement processing device 260, and an elastic wave measurement result holding device 270 are added to the above-described irradiation device configuration. These elastic wave measurement device 240, elastic wave measurement control device 250, elastic wave measurement processing device 260 and elastic wave measurement result holding device 270 constitute a charged particle beam irradiation position specifying device 1000.

  Next, the configuration and role of an apparatus for measuring and utilizing these four elastic waves will be described with reference to FIG.

  The elastic wave measuring device 240 is a device for measuring an elastic wave generated when the irradiated charged particle beam is stationary, and can detect an elastic wave generated when the irradiated charged particle beam is stationary at a plurality of positions. Two or more sensors 242 and an elastic wave received by the sensor 242 are converted into electrical signals, then amplified, A / D converted, etc., and acquired as waveform data, and the sensor position detected by the sensor position detector 252 And a drive unit 246 for driving the sensor 242.

  In the sensor 242, a plurality of elements that detect elastic waves are arranged in two dimensions or three dimensions. A specific example of the sensor 242 will be described below.

  Examples of the sensor 242 that detects elastic waves include a hydrophone, an acoustic emission sensor, and an ultrasonic sensor used in medicine and industry.

  Also, as shown in FIGS. 3 to 5, a plurality (N) of elements capable of acquiring an elastic wave signal on the body surface of the irradiated object 212 in order to detect an elastic wave generated when stationary and specify a position. It is desirable to fix the array sensors 242A, 242B, and 242C made of

  For example, the array sensor 242A illustrated in FIG. 3 is an example of a sensor including elements 242A1 distributed two-dimensionally or three-dimensionally on the body surface. The electrical signal from each element measured by the cable 242A2 is output to the receiving device 244.

  An array sensor 242B shown in FIG. 4 is an example of a sensor in which the element 242B1 is embedded in advance and arranged in the upper surface 210A (contact surface with the irradiated body 212) of the bed 210 that fixes the irradiated body 212.

  The articulated array sensor 242C shown in FIG. 5 is a sensor in which a plurality of elements 242C1 are arranged in an articulated mechanism 242C2 that fixes the irradiated object 212 and can detect a slight movement of the irradiated object 212. It is an example.

  Returning to FIG. 2, the elastic wave measurement control device 250 is a device that controls the operation of the elastic wave measurement device 240, and includes a sensor position detection device 252, a synchronization device 254, a waveform information storage device 256, and a drive control device 258.

  The positional relationship between the irradiated object 212 and the element position of the array sensor 242 is important information for obtaining the generation position of the elastic wave. Therefore, the sensor position detection device 252 is a method of geometrically calculating the positional relationship between the irradiated object 212 and the element positions of the array sensor 242 with the array sensor 242 fixed to the bed 210 and using the bed 210 as a reference, FIG. The irradiation object 212 and the array sensor 242 can be obtained by using the information obtained when the X-ray measurement apparatus 230 in the measurement system 220 of the irradiation object 212 performs alignment of the irradiation site of the irradiation object 212. The positional relationship with the element position is detected.

  The synchronization device 254 is a device that outputs a reception start signal to the reception device 244 based on an external signal (irradiation start signal) from the irradiation control device 500, and waveform data is synchronized with the irradiation start timing of the irradiation system 100. The measurement start of the sensor 242 is synchronized with the irradiation start timing so as to be acquired.

  The waveform information storage device 256 stores the elastic wave signal measured by the sensor 242 of the elastic wave measuring device 240 as elastic wave waveform data, and stores the sensor position information detected by the sensor position detecting device 252.

  The drive control device 258 is a device for changing the position of the sensor 242. For example, in the case of using an array sensor 242A as shown in FIG. 3, when there are a plurality of treatment locations such as a tumor being distributed or dispersed in a wide range, the sensor itself is moved so that the elastic wave can be received with higher sensitivity. Is desirable. The drive control device 258 is a device for moving the position of the sensor 242 in such a case.

  The elastic wave measurement processing device 260 is a device for processing the elastic wave measurement result, and is not stored in the database 320 but performs the geometric calculation processing in which the irradiated object 212 is regarded as a homogeneous medium as in the conventional case. By creating a model using the model creation necessary information and performing time-dependent computation on the model using the waveform data stored in the waveform information storage device 256 and the position information of the sensor 242 as input values, This is a device for calculating the irradiation position of the charged particle beam and the irradiation range (irradiation distribution) of the charged particle beam. The elastic wave measurement processing device 260 includes a model creation device 262, an analysis device 264, and an analysis result evaluation device 266.

  The model creation device 262 creates an analysis model for analyzing the elastic wave signal in detail using the irradiated object 212 information in the database 320.

  The analysis device 264 numerically analyzes the elastic wave signal data acquired on the model created by the model creation device 262 to obtain the generation position of the elastic wave.

  The analysis result evaluation device 266 evaluates the analysis result obtained by the analysis device 264.

  Details of the operation of each device of the elastic wave measurement processing device 260 will be described later.

  The elastic wave measurement result holding device 270 is a device that records the irradiation position and irradiation range obtained by the elastic wave measurement processing device 260, and includes an evaluation result holding device 272, a display device 276, and a display screen control device 274. The data stored in the elastic wave measurement result holding device 270 is fed back to the next irradiation plan creation by the irradiation planning device / irradiation maintenance device 600 and utilized.

  The evaluation result holding device 272 stores elastic wave generation position information and distribution obtained by the elastic wave measurement processing device 260.

  The display device 276 displays the generation position and generation range of the elastic wave, which is the irradiation position of the charged particle beam calculated by the elastic wave measurement processing device 260, and the generation position / range 212A of the elastic wave and the irradiation planned position. The range 212B is displayed using the irradiated object 212 information so that it can be visualized and compared.

  The display screen control device 274 is a device for operating the user interface of the display device 276.

  Radiotherapy using the charged particle beam apparatus will be described with reference to FIGS. Radiation therapy is roughly divided into steps as shown in FIG.

  First, it starts at step S000.

  Next, in step S001, an irradiation plan is formulated from various diagnostic results such as CT imaging.

  Next, in step S002, when performing the treatment of the irradiation object 212, the bed 210 is driven to perform irradiation position alignment for adjusting the irradiation position with the irradiation object 212.

  Next, in step S003, the affected part of the irradiation object 212 is irradiated with a charged particle beam.

  After the irradiation in step S003, in step S004, the necessity of re-irradiation is determined by follow-up observation. If re-irradiation is necessary, the process returns to step S001 to re-develop the irradiation plan, and steps S002 to S004 are performed. When a sufficient effect is obtained and re-irradiation is no longer necessary, the process proceeds to step S005 to complete the treatment.

  To implement the measurement of the present invention, the flow shown in FIG. 7 is used. This flow is performed in the step S003 in FIG. The following flow shown in FIG. 7 can be performed during maintenance and adjustment of the apparatus using phantom, water, or the like as the irradiated body 212 for purposes other than the treatment shown in FIG.

  First, in step S100, elastic wave measurement is started using the sensor 242 of the elastic wave measuring device 240. In step S100, measurement is performed at a plurality of positions using a plurality of sensors 242.

  Next, in step S101, reception of elastic waves is started. To start reception, for example, an irradiation start signal is detected as an external signal by the synchronization device 254 shown in FIG. 2, and a reception start signal is output to the reception device 244, and the reception device 244 receives the signal from the sensor 242. Start signal input.

  Next, in step S102, the waveform information is recorded for a certain period of time using the receiving device 244 of the elastic wave measuring device 240.

  Next, in step S103, the elastic wave measurement processing device 260 uses the model creation device 262 to model the measurement external shape, composition, and sensor arrangement of the irradiated object 212 of the charged particle beam based on the sensor position information and CT image information. A is generated, and analysis 1 of the waveform data information of the elastic wave measured in steps S100 to S102 is performed on the model A by the analysis device 264, and the irradiation position and irradiation range of the charged particle beam are specified. Details will be described later.

  Next, in step S <b> 104, the elastic wave measurement processing device 260 processes the analysis result and outputs it to the elastic wave measurement result holding device 270.

  Finally, in step S105, the elastic wave measurement is terminated.

  The analysis algorithm used in the analysis 1 performed in step S103 is an algorithm that mainly analyzes in a time-dependent manner, and includes various algorithms such as a finite integration method and a finite element method. In addition to an algorithm that analyzes in a time-dependent manner, it can also be realized by using a geometric analysis method such as a ray tracing method.

  The model A created by the model creation device 262 in step S103 and used when analyzing the propagation phenomenon of elastic waves is an analysis mesh reflecting human body tissue information. In creating the analysis mesh, CT images and ultrasonic diagnostic images, which are essential items for specifying the affected area of the patient, are used in the formulation of the irradiation plan. In particular, a two-dimensional (2D) CT section 410 including an irradiation target (2D) 212C as shown in FIG. 9 or a 2D CT section 410 as shown in FIG. CT data 410A including the converted irradiation target (3D) 212D indicates that the density of the image indicates the density of tissues such as bone 416, fat / muscle 414, organ 412 and affected area, and so on, and the propagation of precise elastic waves This is effective in creating an analysis model. Furthermore, when the irradiation position and the irradiation range are specified using the array sensors 242A, 242B, and 242C shown in FIGS. 3 to 5, the 3D CT data as shown in FIG. 10 is particularly effective. Further, when creating the propagation analysis model, as shown in FIG. 11, the density of the CT image should correspond to the data necessary for the elastic wave propagation analysis, that is, the density, elastic modulus, and speed of sound. This makes it possible to create an elastic wave propagation analysis model reflecting human tissue. When defining the analysis region, boundary conditions are created using the position of the sensor 242, the shape of the measurement target (patient), the type of bone 416, fat / muscle 414, organ 412, etc. as input information, and the analysis region is meshed To divide. The mesh size of the analysis region may be determined by a method such as input by an operator or using a numerical value set in advance according to the wavelength of the elastic wave detected.

  The model A, analysis 1, and output in each step of FIG. 7 will be described in detail below with reference to FIG.

In step S101 and step S102 in the flow of FIG. 7, N waveforms recorded from the irradiated object 212 are converted to φ ₁ (t),..., Using an array sensor 242 with N elements for detecting elastic waves. _Let φ _N (t) (1 ≦ n ≦ N). The recording start time is started approximately in synchronization with the irradiation timing of the charged particle beam by the synchronization device 254, and the recording time is set to a sufficient time T at which an elastic wave waveform can be acquired.

If the waveform recording is successful, these N waveforms are time-reversed to generate time-reversed waveforms φ ₁ ′ (t),..., Φ _N ′ (t) (1 ≦ n ≦ N), which are analyzed The initial load condition is as follows. The time reversal operation is φ _n ′ (t) = φ _n (T−t).

  In step S103, the time-reversed load condition is numerically calculated using an algorithm such as a finite element method on the model A created by the model creation device 262 based on the CT image, for example. This is called back propagation analysis. In the numerical calculation for performing such propagation analysis, the wavefront traveling from each element can be observed as time passes, and as shown in step S104, each wavefront is focused (overlapped) at a certain time tx, Strength increases. The point where the intensity is observed most strongly is the sound source position (elastic wave generation position), that is, the irradiation position and irradiation range. In order to specify the sound source position, the temporal change in intensity at each pixel of the analysis mesh after analysis may be examined, or may be calculated by correlation processing.

  Next, the effect of this embodiment will be described.

  In the first embodiment of the charged particle beam device, the charged particle beam irradiation position specifying device, and the charged particle beam irradiation position specifying method of the present invention described above, when the emitted charged particle beam irradiates the irradiated object 212, An acoustic signal (elastic wave) generated from the irradiation position is detected by the sensor 242. Further, an analysis model considering the properties of the irradiated object 212 for analyzing the elastic wave signal in detail is created using the information of the irradiated object 212, and the detected elastic wave is numerically analyzed based on the analyzed model. Then, the actual irradiation position and irradiation range are obtained by obtaining the elastic wave generation position.

  As a result, the actual irradiation position and irradiation range of the charged particle beam can be obtained with high accuracy even when the human body has non-homogeneity, and a highly accurate charged particle beam device or charged particle beam suitable for medical use can be obtained. An irradiation position specifying device and a charged particle beam irradiation position specifying method can be provided. In addition, the irradiation position / range can be obtained in real time during adjustment of irradiation control of a charged particle beam or during treatment, and safety and treatment accuracy can be improved.

  Further, since the irradiation plan is updated according to the irradiation position obtained by the elastic wave measurement processing device 260, the irradiation position information / range information in the irradiated object 212 becomes more accurate, and re-irradiation is necessary in step S004. It is possible to further improve the accuracy of the irradiation plan when creating the next irradiation plan in the case of being judged.

  Furthermore, by synchronizing the measurement start of the sensor 242 and the irradiation start timing so as to acquire the waveform data in accordance with the irradiation start timing of the irradiation system 100, it is possible to suppress an enormous number of data.

  In addition, as a model of the measurement outer shape, composition, and sensor arrangement of the irradiated object 212, a model that is made three-dimensional using CT tomographic data and that is given information on sound velocity, density, and elastic constant based on the density distribution of the CT tomographic data. By creating, it is possible to create an elastic wave propagation analysis model reflecting human tissue with higher accuracy, and it is possible to specify irradiation positions and ranges with higher accuracy.

  Moreover, by displaying the generation position of the elastic wave that is the irradiation position of the charged particle beam calculated by the elastic wave measurement processing device 260, it can be displayed as image information together with the irradiation target, and thus the irradiation position based on direct measurement -You will be able to check the range record.

  Further, by visualizing and comparing the generation position of the elastic wave and the irradiation planned position using the irradiated object 212 information, it is easier to check the accuracy of irradiation and the effect of the previous irradiation.

  In addition, the sensor 242 is provided with a plurality of two-dimensional or three-dimensional elements that detect elastic waves, thereby further improving the accuracy of acquiring the elastic wave signal necessary for specifying the position of the elastic wave generated at rest. In addition, the actual irradiation position and irradiation range of the charged particle beam can be obtained with higher accuracy.

  In addition, since the evaluation result holding device 272 for recording the irradiation position obtained by the elastic wave measurement processing device 260 is provided, the data can be recorded and the irradiation position / range recording based on the direct measurement can be more confirmed. It becomes easy.

<Second Embodiment>
A second embodiment of the charged particle beam apparatus, charged particle beam irradiation position specifying apparatus, and charged particle beam irradiation position specifying method of the present invention will be described with reference to FIGS. In the present embodiment, the same components as those in FIGS. 1 to 11 are denoted by the same reference numerals, and description thereof is omitted. The same applies to the following embodiments.
FIG. 12 is a flowchart showing an elastic wave measurement / processing method involving an analysis model change, and FIG. 13 is a schematic diagram showing processing of acquired data when an analysis model change is involved.

  In addition to the method of specifying the sound source position as in the first embodiment, it is preferable to create a more accurate analysis model in order to further increase the accuracy of position specification. This is due to the following reasons.

  In the case of the human body, there are changes in the outer shape due to respiration, changes in the organ 412 due to the dead weight, movements of the person, and the like. If this change is large, the elastic wave measurement can be performed even if the analysis is performed on the model created by utilizing the irradiation object 212 information (CT data) originally possessed in steps S103 and S104 shown in FIGS. It is conceivable that time and position shift occur. This means that the irradiation position and the irradiation range can be specified with higher accuracy by considering such positional deviation.

  Therefore, in this embodiment, the movement of the body surface or the like is monitored, and information such as the outline of the human body and the position of the sensor 242 is updated to perform back propagation analysis.

  Therefore, in the charged particle beam apparatus according to the present embodiment, the database 320 includes the information on the position and shape of the affected area, which is the region to be irradiated 212, and the position and shape of the surrounding tissue, as well as the change in the outer shape of the human body and the outer shape of the human body. It further holds information on the change in the position of the sensor 242 accompanying the change. It is desirable that this change information is also measured in advance by the irradiated object information acquisition device 400, for example.

  Further, the model creation device 262 of the elastic wave measurement processing device 260 creates a change model (model B) using the change model creation necessary information held in the database 320, and uses this change model for the charged particle beam. Calculate the irradiation position.

  Next, the specific processing flow of this embodiment will be described with reference to FIG. 12, and the model A, model B, analysis 1, analysis 2, and output will be described in detail with reference to FIG.

  Steps S100 to S104 and step S105 are the same as those in FIGS.

  After step S104, in step S200, the analysis result evaluation device 266 of the elastic wave measurement processing device 260 determines whether or not a sufficient signal strength at the elastic wave generation position is obtained as an analysis result. In this step S200, for example, it is determined whether or not a peak value peak is obtained in the waveform data obtained by the back propagation analysis in step S103. If it is determined that sufficient signal strength is obtained in step S200, it is determined that the specific accuracy of the elastic wave generation position is sufficiently secured by the processing in steps S100 to S104, and the process proceeds to step S105. Proceed to complete the elastic wave measurement. On the other hand, if it is determined that it has not been obtained, the process proceeds to step S201.

  Next, in step S201, the analysis result evaluation device 266 of the elastic wave measurement processing device 260 determines whether reanalysis is necessary. In this step S200, for example, among the time tx at which the peak value determined in step S200 becomes a peak, the distribution of locations up to XX% (for example, 70%, 50%, etc. is arbitrarily set) of the peak is determined. Evaluate if it is a position. As a result of the evaluation, it is determined whether or not the position of XX% of the peak is an unexpected position or an unexpectedly wide range of distribution / distribution, and whether the center of the discrete / distribution greatly exceeds the original apparatus accuracy. . In this case, it is determined that re-analysis is necessary if the position of the discrete / distribution is unexpectedly wide or unexpectedly wide, and the center of the discrete / distribution greatly exceeds the original device accuracy. If the position or unexpectedly wide range is not discrete or distributed, or if the center of the discrete or distribution does not significantly exceed the original device accuracy, the re-analysis will be judged that the position identification accuracy is sufficiently secured Judge that it is unnecessary. If it is determined in step S201 that reanalysis is unnecessary, the process proceeds to step S105, and the elastic wave measurement is terminated. On the other hand, if it is determined that reanalysis is necessary, the process proceeds to step S202.

  In step S202, the model creation device 262 and the analysis device 264 of the elastic wave measurement processing device 260 create a creation model B in accordance with the change in the outer shape of the human body and the change in the position of the sensor 242. Analysis 2 is performed. In this step, the created model B is a model that more accurately models the situation at the time of elastic wave measurement than the created model A. Analysis 1 and analysis 2 basically use the same time-reversed waveform and analyze with the same algorithm. . Note that the model B may be created in the model creation device 262, for example, by storing in the database 320 information obtained by measuring in advance the change in the outer shape of the human body and the change in the position of the sensor 242 associated therewith.

  Next, in step S203, the elastic wave measurement processing device 260 processes the analysis result, outputs the analysis result in step S202 to the elastic wave measurement result holding device 270, and returns the processing to step S200.

  In step S200, the analysis result evaluation device 266 of the elastic wave measurement processing device 260 determines again whether sufficient signal strength has been obtained. If not, the same determination is repeated in step S201.

  Also in the second embodiment of the charged particle beam apparatus, charged particle beam irradiation position specifying apparatus, and charged particle beam irradiation position specifying method of the present invention, the charged particle beam apparatus and charged particle beam irradiation position of the first embodiment described above. The same effects as those of the specifying apparatus and the charged particle beam irradiation position specifying method can be obtained.

  Further, by calculating the irradiation position of the charged particle beam using the change model, even if a change in the external shape due to respiration, a change in the organ 412 due to its own weight, a human movement, or the like occurs, The analysis of the elastic wave generation position in consideration can be performed, and the irradiation position and irradiation range can be specified with higher accuracy.

  In addition, you may analyze using the creation model B matched with the external shape change of a human body and the change of the sensor position accompanying it from the time of step S103.

<Third Embodiment>
A third embodiment of the charged particle beam apparatus, charged particle beam irradiation position specifying apparatus, and charged particle beam irradiation position specifying method of the present invention will be described with reference to FIGS.
FIG. 14 is a flowchart showing an elastic wave measurement / processing method when data is complemented, and FIG. 15 is a schematic diagram showing processing when acquired data and complemented data are used.

  The sound source position specifying method as in the first embodiment can increase the position specifying accuracy as the acquired waveform data increases. On the other hand, when the bone 416 as shown in FIG. 8 is positioned between the generation position of the elastic wave and the array sensor 242, the elastic wave is almost reflected by the bone 416. May not be detected sufficiently. In addition, due to restrictions on the arrangement of the array sensor 242 depending on the shape of the human body and the shape of the treatment device, there is a possibility that the elastic wave cannot be detected with a sufficient number of elements. When the number of elements that can be detected is limited as described above, the irradiation position and the irradiation range can be specified with sufficient accuracy by considering the virtual elements in the analysis.

  Therefore, in the charged particle beam apparatus according to the present embodiment, the database 320 includes a virtual model in which virtual measurement points are arranged in addition to information on the position and shape of the affected area and surrounding tissue, which are regions to be irradiated 212. It also holds information necessary to create

  In addition, the model creation device 262 of the elastic wave measurement processing device 260 creates a virtual model using the virtual model creation necessary information held in the database 320, and positions of measurement points that are virtually arranged on the virtual model. Then, a virtual acquisition waveform is newly obtained, and the irradiation position of the charged particle beam is calculated by performing time-dependent calculation using the virtual acquisition waveform data as an input value.

  Next, the specific processing flow of the present embodiment will be described with reference to FIG. 14, and Model A, Model B, Model C, Analysis 1, Analysis 2, and Analysis 3 and their respective outputs will be described in detail with reference to FIG.

  Steps S100 to S104 and step S105 are the same as those in FIGS.

  After step S104, the process proceeds to step S200. This step S200 is the same as FIG. 12 and FIG. 13, and if it is determined that sufficient signal strength has been obtained, the process proceeds to step S105. If it is determined that it has not been obtained, the process proceeds to step S201. Proceed.

  The next step S201 is also substantially the same as FIG. 12 and FIG. 13, and if it is determined that reanalysis is unnecessary, the process proceeds to step S105 and the elastic wave measurement is terminated. On the other hand, if it is determined that reanalysis is necessary, the process proceeds to step S300.

In step S300, first, a model C in which virtual measurement points N + 1, N + 2,... Are newly arranged is created by the model creation device 262 of the elastic wave measurement processing device 260, for example, as shown in step S300 in FIG. To do. In this model C, information obtained by selecting a portion where a sensor is not arranged directly above a bone such as the rib (the elastic wave generated by the sensor arrives and actually does not have a sensor) is selected by looking at the CT slice. May be stored in the database 320 and created by the model creation device 262. In step S300, the analysis device 264 of the elastic wave measurement processing device 260 first _sets the mesh in the figure to the pixel _ij and the change in the waveform intensity at a specific pixel of the mesh to ξ _ij (t). Based on the weak signal obtained by analyzing in step S103 and obtained in step S104, still image data in which waves are steadily back-propagating is superimposed in the time direction to generate a specific range (when an elastic wave is generated). The range of the pixel (i, j) in the vicinity of the range, the sound source) is specified, and the intensity change ξ _ij (t) in the pixel in the vicinity of the sound source is calculated from the result of the model A and analysis 1 in step S103.

Next, in step S301, the virtual acquisition waveforms φ _{N + 1} (t), φ _{N + 2} (t),... Are newly obtained by the analysis device 264 of the elastic wave measurement processing device 260 at the positions of N + 1, N + 2,. In step S301, as analysis 3, the intensity change ξ _ij (t) in the pixel near the sound source obtained in step S300 is assumed to be a provisional irradiation position, and the intensity corresponding to the intensity change ξ _ij (t) from this position. Assuming that the elastic wave is generated, the virtual acquired waveform is calculated. It is desirable that this analysis 3 also uses the same algorithm as analysis 1 and analysis 2.

In step S302, the newly acquired virtual acquired waveforms N + 1, N + 2,... Are time-reversed by the analysis device 264 of the elastic wave measurement processing device 260, and the virtual load conditions φ _{N + 1} (t), φ _{N + 2} (t). create.

  Next, similarly, using the analysis 2 by the analysis device 264 of the elastic wave measurement processing device 260 with the model B in step S202, the N waveform load conditions created in step S103 and the virtual condition newly created in step S302. The back propagation analysis with the load condition is performed.

  Thereafter, in step S203, the elastic wave measurement processing device 260 processes the analysis result, outputs the analysis result in step S202 to the elastic wave measurement result holding device 270, returns the processing to step S200, and returns to step S105. Repeat until it reaches.

  Also in the third embodiment of the charged particle beam apparatus, charged particle beam irradiation position specifying apparatus, and charged particle beam irradiation position specifying method of the present invention, the charged particle beam apparatus and charged particle beam irradiation position of the first embodiment described above. The same effects as those of the specifying apparatus and the charged particle beam irradiation position specifying method can be obtained.

  Also, a virtual model in which virtual measurement points are arranged is created, a virtual acquisition waveform is newly obtained on the virtual model at the position of the virtual measurement points, and time is obtained using this virtual acquisition waveform data as an input value. By calculating the irradiation position of the charged particle beam by performing the dependency calculation, there is a case where the elastic wave cannot be sufficiently detected due to the presence of the bone 416, or there are restrictions on the arrangement of the array sensor 242 depending on the human body shape and the treatment device shape Even in the case where the elastic wave cannot be detected with a sufficient number of elements generated in some cases, the irradiation position and irradiation range can be specified with sufficient intensity, and the irradiation position and irradiation range can be specified with high accuracy.

<Others>
In addition, this invention is not limited to said embodiment, Various modifications are included. The above embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the configurations and processes described. It is also possible to replace a part of the configuration / process of an embodiment with the configuration / process of another embodiment, and to add the configuration / process of another embodiment to the configuration / process of an embodiment. Is also possible. In addition, it is possible to add, delete, and replace other configurations and processes for a part of the configurations and processes of each embodiment.

  For example, a charged particle beam can be obtained by calculation with a monitor installed from when the charged particle beam is transported to when it is emitted, so this information can be used to pass the charged particle beam. Position information is obtained in advance, and the stationary position of the charged particle beam can be specified using this information.

100 ... irradiation system,
110 ... Accelerator,
120: Beam transport system,
130 ... Gantry,
140 ... Irradiation field forming device / irradiation nozzle,
200 ... Measurement system,
210 ... Sleeper,
210A ... bed top surface (contact surface with irradiation object),
212 ... Subject to be irradiated,
212A: Elastic wave generation position and range,
212B ... Irradiation plan position / range,
212C ... Irradiation target (2D),
212D ... Irradiation target (3D),
220 ... irradiated object measurement system,
230 ... X-ray measuring device,
240 ... elastic wave measuring device,
242 ... Sensor,
242A ... Array sensor,
242A1 element,
242A2 ... cable,
242B ... Array sensor,
242B1 ... element,
242C ... Articulated array sensor,
242C1 element,
242C2 ... Joint mechanism,
244 ... Receiving device,
246 ... Driving device,
250 ... elastic wave measurement control device,
252 ... Sensor position detection device,
254 ... Synchronizer,
256 ... Waveform information storage device (storage unit),
258 ... Drive control device,
260 ... elastic wave measurement processing device,
262 ... Model creation device,
264 ... analysis device,
266 ... analysis result evaluation device,
270 ... Elastic wave measurement result holding device,
272 ... Evaluation result holding device,
274 ... Display screen control device,
276 ... display device,
300 ... X-ray measurement control / processing device,
310 ... control / processing device,
320 ... database (irradiated object information holding device),
400 ... irradiated object information acquisition device,
410 ... CT cross section,
410A ... CT data,
412 ... organs,
414 ... fat / muscle,
416 ... bones,
500 ... irradiation control device,
600 ... Irradiation planning device / irradiation maintenance device,
1000: Charged particle beam irradiation position specifying device.

Claims (14)

An accelerator that accelerates and emits charged particle beams;
An irradiation device for irradiating a charged particle beam emitted from the accelerator;
A control device for controlling the accelerator and the irradiation device;
An elastic wave measuring device having a plurality of sensors capable of detecting elastic waves generated at a plurality of positions when the charged particle beam irradiated by the irradiation device is stationary;
An elastic wave measurement control device for controlling the operation of the elastic wave measurement device;
A storage unit for storing waveform data of the elastic wave measured by the sensor of the elastic wave measuring device;
A database that holds information necessary for creating a model of measurement outline and composition / sensor arrangement of the charged particle beam to be irradiated , and information necessary for creating a virtual model in which virtual measurement points are arranged ;
A model is created using the model creation necessary information held in the database, and the charge is obtained by performing time-dependent computation on the model using the waveform data stored in the storage unit as an input value. An elastic wave measurement processing device for calculating the irradiation position of the particle beam ,
The elastic wave measurement processing device creates a virtual model using the virtual model creation necessary information, obtains a newly acquired waveform at the position of the measurement point virtually arranged on the virtual model, and acquires the virtual acquired waveform data The charged particle beam apparatus is characterized in that the irradiation position of the charged particle beam is calculated by performing a time-dependent calculation using as an input value . The charged particle beam device according to claim 1.
An irradiation plan device for creating an irradiation plan of the charged particle beam;
This irradiation plan apparatus updates an irradiation plan according to the irradiation position calculated | required with the said elastic wave measurement processing apparatus. The charged particle beam apparatus characterized by the above-mentioned. The charged particle beam device according to claim 1.
The elastic wave measurement control device includes a synchronization device that synchronizes the measurement start and irradiation start timing of the sensor so as to acquire the waveform data in accordance with the irradiation start timing of the irradiation device. apparatus. The charged particle beam device according to claim 1.
The elastic wave measurement processing apparatus uses CT tomographic data as a three-dimensional model of the measurement outline, composition, and sensor arrangement of the irradiated object, and sets the sound velocity, density, and elastic constant based on the density distribution of the CT tomographic data. A charged particle beam device characterized by creating a model with information. The charged particle beam device according to claim 1.
A charged particle beam apparatus, further comprising: a display device that visualizes an irradiation position of the charged particle beam calculated by the elastic wave measurement processing apparatus. The charged particle beam device according to claim 5.
The display device further compares and displays the charged particle beam irradiation position and the charged particle beam irradiation planned position in the irradiation plan. The charged particle beam device according to claim 1.
The charged particle beam apparatus according to claim 1, wherein a plurality of elements for detecting the elastic wave are arranged in two dimensions or three dimensions. The charged particle beam device according to claim 1.
The database further holds information necessary for creating a change model in accordance with a change in the outer shape of the human body and a change in the sensor position accompanying the change in the outer shape of the human body,
The charged particle beam apparatus characterized in that the elastic wave measurement processing apparatus further creates a change model using change model creation necessary information and calculates an irradiation position of the charged particle beam using the change model. The charged particle beam device according to claim 1.
A charged particle beam device, further comprising a recording device that records an irradiation position obtained by the elastic wave measurement processing device. The charged particle beam device according to claim 1.
The elastic wave measurement processing device further calculates an irradiation range of the charged particle beam. An elastic wave measuring device having a plurality of sensors capable of detecting an elastic wave generated when the charged particle beam is stationary at a plurality of positions;
An elastic wave measurement control device for controlling the operation of the elastic wave measurement device;
A storage unit for storing waveform data of the elastic wave measured by the sensor of the elastic wave measuring device;
A database that holds information necessary for creating a model of measurement outline and composition / sensor arrangement of the charged particle beam to be irradiated , and information necessary for creating a virtual model in which virtual measurement points are arranged ;
A model is created using the model creation necessary information held in this database, and on this model, the waveform data stored in the storage unit is used as an input value to perform a time-dependent calculation, An elastic wave measurement processing device for calculating the irradiation position of the charged particle beam ,
The elastic wave measurement processing device creates a virtual model using the virtual model creation necessary information, obtains a newly acquired waveform at the position of the measurement point virtually arranged on the virtual model, and acquires the virtual acquired waveform data The charged particle beam irradiation position specifying device is characterized in that the irradiation position of the charged particle beam is calculated by performing time-dependent calculation using as an input value . A measurement step of measuring elastic waves generated when the charged particle beam is stationary when irradiated with a charged particle beam emitted from an accelerator at a plurality of positions using a plurality of sensors;
A creation step of creating a model of the measurement external shape and composition / sensor arrangement of the charged particle beam to be irradiated;
A calculation step of specifying an irradiation position of the charged particle beam by performing time-dependent calculation using the elastic wave waveform data measured in the measurement step and the model created in the creation step; Yes, and
In the creation step, a virtual model in which virtual measurement points are arranged is created,
In the calculation step, the irradiation position of the charged particle beam is specified using the virtual model . A charged particle beam irradiation position specifying method, characterized in that: The charged particle beam irradiation position specifying method according to claim 1 2,
Wherein in the creating step further creates a change model according to the change in sensor position due to the body contour change or contour change of the body,
In the calculating step, the irradiation position of the charged particle beam is further specified using the change model. A charged particle beam irradiation position specifying method, characterized in that: The charged particle beam irradiation position specifying method according to claim 1 2,
In the measurement step, the reception of elastic waves is started simultaneously with the start of irradiation of the charged particle beam.

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