JP2010233881A - Positioning system for particle beam therapeutic apparatus and particle beam therapeutic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning system for a particle beam therapeutic apparatus improving the safety by producing a simulated image of an irradiated area of a patient which an operator can visually recognize, and to provide a particle beam therapeutic system. <P>SOLUTION: A DRR patient's image 36 is planned by assuming a starting position 21 of particle beam expansion as an X-ray source position 22 in the preparatory stages, and the DRR patient's image 36 is shifted for an error amount of a patient's position computed in a step 110 (image shift operation 42), and a collimator area is extracted from a collimator radiographing image 35 in a step 105, and furthermore, the collimator area is treated by a correction operation to be an image radiographed at the starting position 21 of particle beam expansion (collimator area extraction and correction operation 43), and the corrected collimator area is overlapped on an image of an operated result of the image shift operation 42 and drawn (additional drawing operation 44). It results in that a simulated X-ray image 38 is produced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a positioning system for particle beam therapy apparatus and a particle beam therapy system, and more particularly to a positioning system and particle beam therapy for a particle beam therapy apparatus including an X-ray imaging system in which an X-ray source position is different from a particle beam expansion start position. About the system.

  In cancer treatment with radiation, especially with particle beam therapy using proton beam, carbon beam, etc., it is possible to concentrate a high dose on the affected area of the patient, so that normal cells can be treated without being relatively damaged. . In addition, in order to perform accurate treatment, the position of the collimator that forms the irradiation field, the position of the patient, and the like are confirmed using an X-ray imaging system separately from the therapeutic particle beam.

  In this particle beam treatment, the particle beam is matched to the shape of the affected area of the patient, and a narrow beam is expanded in the direction perpendicular to the beam axis by scattering or scanning to form an irradiation field. This starting point position of the expansion is called a particle beam expansion starting position. For example, in the case of a double scatterer type nozzle, the beam expansion start point is virtually placed between the range modulation wheel for adjusting the beam range and the second scatterer. In the case of a beam scanning nozzle, the beam expansion starting point is virtually placed between the Y-axis scanning magnet and the X-axis scanning electromagnet. At this time, in order to obtain a particle beam parallel to the beam axis as much as possible in the patient affected area, it is possible to increase the distance (hereinafter referred to as SAD, Source Axis Distance) from the particle beam expansion starting position to the isocenter that is the irradiation reference of the patient affected area. It is common.

  A part of the enlarged particle beam used for particle beam therapy is shielded by a collimator, and an unshielded region is an irradiation region to the affected part.

  The X-ray source position in the X-ray imaging system used in the particle beam therapy system is the same as the particle beam expansion starting position so that the irradiation area of the patient affected area and the non-shielding area of the collimator overlap in the X-ray imaging image. Ideally. However, SAD of particle beam is larger than SAD at the time of general X-ray imaging, and X-ray imaging system such as X-ray tube and high-voltage generator if X-ray source position is the same as the particle beam expansion starting position The performance of the components must be improved. Therefore, since it is economically and technically difficult to match the SAD of the particle beam and the SAD of the X-ray, the X-ray source position is placed downstream of the beam axis at the particle beam expansion start position, and the X-ray SAD is placed on the particle beam SAD. The structure is shortened compared to.

  In the particle beam therapy, the confirmation work performed using the X-ray image can be considered to have three items: collimator position confirmation, patient position confirmation, and patient irradiation region confirmation.

  For example, in Patent Document 1, confirmation of a collimator position is created by assuming an actual X-ray source position as an X-ray source position by an X-ray collimator image captured by an X-ray imaging apparatus and a treatment planning apparatus. This is done by comparing the planned collimator contour shape.

  In addition, regarding the confirmation of the patient position, the X-ray patient image captured by the X-ray imaging device and the reconstructed image created by the treatment planning device assuming the actual X-ray source position as the X-ray source position By comparing with.

JP 2007-61438 A

  On the other hand, there have been the following problems regarding the confirmation of the patient irradiation area. Since the captured X-ray image is a wider range than the actual patient irradiation area when the X-ray source is closer to the collimator, the relative relationship between the collimator and the patient is unclear, I can't compare. Therefore, the relative relationship between the collimator and the patient, that is, the patient irradiation area is estimated through the confirmation of the collimator position and the patient position, and the patient irradiation area cannot be directly confirmed. I was unable to respond to the desire to do so or to memorize it as evidence.

  An object of the present invention is to provide a particle beam therapy system positioning system and a particle beam therapy system that can improve safety by creating a simulated image of a patient irradiation region that can be visually recognized by an operator.

  (1) In order to achieve the above object, the present invention provides a snout control device for positioning control of a collimator installed on a snot, a support base control device for positioning control of a support base for supporting a patient, and the snot control device. In the positioning system of the particle beam therapy system, the image processing system includes a CT of a patient, and the image processing system includes: an image processing system that generates positioning information of the collimator to be output to Based on the image, a first reconstructed image (first DRR patient image) that can be assumed to be taken from the particle beam expansion starting position is created, and the first reconstructed image is image-shifted based on the patient position error. An image shift calculation unit for creating two reconstructed images (second DRR patient images), and a first collimator image obtained by X-ray imaging from the X-ray source position Is corrected to a second collimator image that can be assumed to have been taken from the particle beam expansion starting position, and an additional drawing operation for creating a simulated image in which the second reconstructed image and the second collimator image are superimposed Part.

  As described above, since the image processing system includes the image shift calculation unit, the correction calculation unit, and the additional drawing calculation unit, it is possible to create a simulated image that can be assumed to be an image obtained by X-ray imaging at the particle beam expansion starting position. The simulated image allows the operator to visually confirm the patient irradiation area. Thereby, the safety | security improvement of positioning of a particle beam therapy apparatus can be aimed at.

  (2) In the above (1), preferably, the image processing system further includes a display device for displaying the simulated image.

  Thereby, the operator can visually recognize the simulated image of the patient irradiation area.

  (3) In the above (1), preferably, the image processing system further includes a storage device for storing the simulated image.

  Thereby, it can be set as evidence by memorizing a simulation image.

  (4) In the above (1), the image processing system is further included in a calculation result of a simulated image reverse shift calculation unit that reversely shifts the simulated image based on the patient position error and the simulated image reverse shift calculation unit. An error calculation unit for calculating a patient irradiation region error by comparing a corrected collimator region and a reconstructed image (DRR collimator region) of a collimator region created assuming the particle beam expansion starting point position as an X-ray source position; It shall have.

  As a result, it is possible to further improve safety by calculating the error of the patient irradiation region and numerically confirming the patient irradiation region.

  (5) In order to achieve the above object, the present invention provides a snout control device that controls the positioning of a collimator installed in the snot, a support base control device that controls the positioning of a support base that supports a patient, and the snout. In the positioning system of the particle beam therapy system, comprising: the collimator positioning information to be output to the control device; and the image processing system to generate the support table positioning information to be output to the support base control device. A correction calculation unit that corrects the first collimator image obtained by X-ray imaging from the position of the radiation source to a second collimator image that can be assumed to be captured from the particle beam expansion starting position, and the second collimator image is inverted based on the patient position error. The collimator area reverse shift operation unit to shift, and the patient image created assuming the particle beam expansion start position as the X-ray source position. An additional drawing calculation unit that creates a comparative simulation image in which the second collimator image reversely shifted with the reconstructed image (DRR patient image), a correction collimator region included in the comparative simulation image, and a particle beam expansion starting point An error calculation unit that calculates a patient irradiation region error by comparing a reconstructed image (DRR collimator region) of a collimator region created assuming that the position is an X-ray source position.

  As described above, the image processing system includes the correction calculation unit, the collimator region reverse shift calculation unit, and the additional drawing calculation unit, so that a comparative simulated image can be created. Since the comparative simulation image is created for the purpose of comparison with the DRR collimator region, it does not accurately simulate the image when X-ray imaging is performed at the particle beam expansion starting position, but the collimator and patient Is reflected, and the operator can visually confirm the error of the patient irradiation region. Thereby, the safety | security improvement of positioning of a particle beam therapy apparatus can be aimed at.

  Furthermore, safety can be improved by calculating an error of the patient irradiation region and numerically confirming the patient irradiation region.

  (6) In order to achieve the above object, the present invention includes a particle beam generator, a collimator that forms an irradiation field by forming a particle beam from the particle beam generator into an affected part shape, and the collimator. A particle beam irradiation device having a support device for supporting a patient, an X-ray imaging system in which an X-ray source is positioned downstream of a particle beam expansion starting position of the particle beam generation device, and driving the snot A snout control device that controls the positioning of the collimator, a support stand control device that controls the positioning of the support stand by driving the support stand, positioning information of the collimator that is output to the snout control device, and the support stand control An image processing system comprising: an image processing system that generates positioning information for a support that is output to the apparatus, wherein the image processing system is based on a CT image of a patient Then, a first reconstructed image (first DRR patient image) that can be assumed to have been taken from the particle beam expansion starting position is generated, and the second reconstructed image is shifted based on the patient position error. An image shift calculation unit that creates an image (second DRR patient image) and a first collimator image obtained by X-ray imaging from the X-ray source position are corrected to a second collimator image that can be assumed to be acquired from the particle beam expansion starting position. And an additional drawing calculation unit that creates a simulated image obtained by superimposing the second reconstructed image and the second collimator image.

  According to the present invention, it is possible to improve safety by creating a simulated image of a patient irradiation region that can be visually recognized by an operator.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the positioning system of the particle beam therapy apparatus which is 1st Embodiment of this invention with the whole structure of a particle beam therapy apparatus. (A) It is a block diagram of the particle beam irradiation apparatus and X-ray imaging system of a double scatterer system. FIG. 2B is a configuration diagram of a beam scanning particle beam irradiation apparatus and an X-ray imaging system. It is a functional block diagram which shows the arithmetic processing of an image processing system. It is a control flow which shows the arithmetic processing of an image processing system. It is a functional block diagram which shows the arithmetic processing of the image processing system in 2nd Embodiment of this invention.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a configuration diagram showing a positioning system for a particle beam therapy system according to a first embodiment of the present invention, together with the overall configuration of the particle beam therapy system. As shown in FIG. 1, the present embodiment assumes that the present invention is used for a particle beam therapy system equipped with a rotating gantry.

  In FIG. 1, the particle beam therapy system includes a particle beam irradiation device 2, an X-ray imaging system 6, a snowt control device 10, a support control device 12, and an image processing system 7.

  The particle beam irradiation apparatus 2 includes a rotating gantry 3, a particle beam generation apparatus (irradiation nozzle 8), a collimator 5, a snout 9 provided at the tip of the irradiation nozzle 8 and having the collimator 5 installed therein, and a patient 4. And a support base 19 for supporting.

  The X-ray imaging system 6 is for confirming the position of the patient 4 and the position of the collimator 5, and includes an X-ray imaging apparatus (imaging apparatus) 16, two sets of X-ray tube apparatuses 17, and two sets of X-rays. It has an image receiving device 18 (installed so as to be able to take an image from the direction of the irradiation beam and a direction that makes an angle of 90 ° with these). These devices rotate around the isocenter as the rotating gantry 3 rotates. To do.

  The image processing system 7 includes an arithmetic device 13 having a monitor (display device) 13a, an input device 14 such as a keyboard and a mouse, and a medical image server (storage device) 15 in which images used for positioning are stored. is doing.

  The snout control device 10 controls the positioning of the collimator 5 by driving the snout 9 based on the calculation result of the calculation device 13. The support table control device 12 controls the positioning of the patient 4 by driving the support table 19 based on the calculation result of the calculation device 13.

  The medical image server 15 is connected to the treatment planning apparatus 1. The treatment planning apparatus 1 creates a particle beam irradiation plan (referred to as a treatment plan) for each patient and stores the treatment plan information in the medical image server 15.

  FIG. 2 is a configuration diagram of the particle beam irradiation apparatus 2 and the X-ray imaging system 6. A configuration in which the X-ray source 22 is positioned downstream of the particle beam expansion starting position 21, which is a premise of the present invention, will be described with reference to FIG. 2.

  In the case of the double scatterer method shown in FIG. 2A, a range modulation wheel 24 and a second scatterer 25 for adjusting the beam range are installed in the irradiation nozzle 8, and the particle beam expansion starting position 21 is It is virtually placed between the range modulation wheel 24 that adjusts the beam range and the second scatterer 25.

  The particle beam used for the particle beam treatment spreads radially from the particle beam expansion starting position 21, the unnecessary particle beam is blocked by the collimator 5, and the affected part of the patient 4 is determined with reference to the isocenter 23 which is the reference for irradiation. Irradiate. On the other hand, the X-rays used for confirming the collimator 5 position, the patient 4 position, etc. spread radially from the X-ray source position 22 located in the irradiation nozzle 8, and unnecessary collimator 5 blocks the unnecessary X-rays. It passes through the patient 4 and enters the X-ray image receiving device 18.

  Here, since the X-ray source position 22 is downstream of the beam of the particle beam expansion starting point position 21 and appears closer to the source, the apparent size of the patient in the X-ray imaging image is the particle beam. Compared to the case where the enlargement starting position 21 is assumed to be the X-ray source position, the collimator opening appears to further expand.

  In the case of the beam scanning method shown in FIG. 2B, a Y-axis scanning electromagnet 26 and an X-axis scanning electromagnet 27 are installed in the irradiation nozzle 8, and the particle beam expansion starting position 21 is located at the Y-axis scanning electromagnet 26 and X-axis. It is virtually placed between the axial scanning electromagnets 27. The above problem also occurs in this configuration.

  FIG. 3 is a functional block diagram showing arithmetic processing by the arithmetic device 13 of the image processing system 7. FIG. 4 is a control flow showing calculation processing by the calculation device 13 of the image processing system 7. Hereinafter, the positioning procedure of the patient 4 and the collimator 5 performed by the positioning system of the present embodiment will be described with reference to FIGS. This flow is started when there is an appropriate positioning start instruction from the operator (for example, an instruction input from the input device 14).

  First, as a preliminary preparation, a patient is imaged by X-ray CT in order to determine a treatment plan. In the treatment plan, the X-ray CT tomographic image 31 is used to grasp the position and size of the affected area to be irradiated and determine the irradiation direction, irradiation dose, and the like. Further, when creating the treatment plan, an X-ray image is created as a simulation image from the CT image on the treatment planning apparatus 1. This simulation image is an X-ray image (hereinafter referred to as a DRR (Digital Reconstructed Radiograph) image) generated from a CT image. The DRR image is transmitted from the treatment planning apparatus 1 to the image processing system 7 and stored in the medical image server 15.

  Here, the DRR image created conventionally is an image when reconstructed with the same position as the actual X-ray source position 22 as the X-ray source position. This image includes planned collimator contour shape information, and the DRR patient image 32 and the DRR collimator image 33 can be displayed separately from the DRR image.

  Furthermore, in the present invention, an image is created when the particle beam expansion starting position 21 is assumed to be the X-ray source position 22. Similarly, this image also includes collimator contour shape information planned on the assumption that the particle beam expansion starting position 21 is the X-ray source position 22, and separately displays the DDR patient image 36 and the DDR collimator image 37. Can do.

  The DRR images 36 and 37 are stored in the medical image server 15 together with the DRR images 32 and 33 described above.

  After the above preparation is completed, the control flow procedure of FIG. 4 is started.

  First, positioning of the collimator 5 is started (step 101). First, the collimator 5 is installed on the snout 9. At this time, it is determined by a sensor or the like whether the collimator is correctly installed. (Step 102).

  Next, when an operator inputs an instruction to start X-ray imaging using the input device 14 in the image processing system 7, an aperture image in which the contour of the collimator 5 is captured by the X-ray imaging device 16 is captured as a positioning image. When the imaging is completed, the captured positioning image (collimator X-ray captured image 35) is stored in the medical image server 15 in the image processing system 7 from the X-ray imaging device 16 (step 103).

  Next, the DRR collimator image 33 is read from the medical image server 15 and displayed on the monitor 13a. Further, the collimator X-ray captured image 35 stored in step 103 is read from the medical image server 15 and displayed on the monitor 13a. Further, the images 33 and 35 are compared to calculate a collimator position error amount (collimator error calculation 40) (step 104).

  The operator confirms that the calculated collimator position error amount is within the allowable range and proceeds to the next step by performing the end operation. If the calculated collimator position error amount is outside the allowable range, the operator confirms after correcting the collimator position. Exit. The collimator position correction is performed by the snout control device 10 particularly in the rotation direction. Here, in some cases, the collimator shape may be corrected. The method of correcting the collimator shape differs depending on the case where the collimator block is manually corrected, and when there is a multi-leaf collimator, the leaf position is corrected electrically. Further, the process returns to step 103 again, and the operator confirms that the error amount calculated again from the acquisition of the collimator image is within the allowable range, and finishes the operation. In this case, the previously acquired data is discarded, the final image data is used as the collimator X-ray captured image 35, and the error amount at this time is set as the collimator position error amount (step 105).

  When the position confirmation of the collimator 5 is completed, it is determined whether or not the collimator 5 has been removed (step 106). This is because it is necessary to temporarily retract the collimator 5 from the irradiation field so that the collimator 5 does not appear during X-ray imaging in the positioning of the patient 4 described later. When it is detected by the operator that the collimator 5 has been removed from the collimator mounting portion of the snout 9, the collimator positioning is terminated (step 107).

Next, positioning of the patient 4 is started (step 108).
First, the patient 4 is fixed to the support 19 and is roughly positioned by a laser marker (not shown). The laser marker is positioned by irradiating the patient 4 with a laser from a laser generator (not shown) attached to a wall or the like at the time of CT imaging, marking the position, and marking the laser generator during treatment. This is rough rough positioning performed by moving the patient 4 (support base 19) so that the position marked with the fixture fixed at the irradiation point and the body of the patient overlapped with the laser. After the rough positioning is completed, a positioning image of the patient 4 fixed on the support base 19 is taken by the X-ray imaging device 16 according to an X-ray imaging instruction from the operator, and this patient X-ray imaging image 34 is medically treated. Store in the image server 15 (step 109).

  Next, the DRR patient image 32 is read from the medical image server 15 and displayed on the monitor 13a. Further, the patient X-ray captured image 34 stored in step 109 is read from the medical image server 15 and displayed on the monitor 13a. Further, the images 32 and 34 are compared to calculate a patient position error amount (patient position error calculation 41) (step 110).

  If the calculated patient position error amount is within the allowable range, the confirmation is completed and the process proceeds to the next step. If the calculated patient position error amount is outside the allowable range, the confirmation is completed after correcting the patient position. Furthermore, returning to step 109 again, the operator confirms that the error amount calculated again is within the allowable range, starting from the acquisition of the patient X-ray image, and the confirmation operation is completed. In this case, the previously acquired data is discarded, the final image data is used as the patient X-ray image 34, and the error amount at this time is set as the patient position error amount (step 111).

  When the position confirmation of the patient 4 is completed, it is determined whether or not the collimator 5 has been installed again (step 112). This is because it is necessary to restore the collimator temporarily retracted from the irradiation field during X-ray imaging and prepare for irradiation.

  When it is detected by the operator that the collimator 5 is installed at the collimator mounting portion of the snout 9, the positioning of the patient is terminated (step 113).

  The above is a control flow similar to the control flow related to the positioning of the conventional collimator 5 and the positioning of the patient 4, but the control flow related to the confirmation of the patient irradiation area according to the present invention will be described below. In FIG. 3, the portion indicated by a thick line is a processing function according to the present invention, and the portion indicated by a thick line in FIG. 4 is a control flow procedure according to the present invention.

  Confirmation of the patient irradiation area is started (step 114). A feature of the present invention is that a simulated X-ray image 38 that can be assumed to have an X-ray source placed at the particle beam expansion starting position 22 is created (step 115). This image creation procedure will be described mainly with reference to FIG.

  First, in the preparation stage, the DDR patient image 36 planned on the assumption that the particle beam expansion starting position 21 is the X-ray source position 22 is shifted by the amount of patient position error calculated in step 110 (image shift calculation). 42). As a result, a patient X-ray captured image in which the particle beam expansion starting position 21 is assumed to be the X-ray source position 22 is created.

  Next, a collimator region is extracted from the collimator X-ray image 35 in step 105. Further, correction calculation is performed so that the collimator area becomes an image photographed at the particle beam expansion starting position 21 (collimator area extraction and correction calculation 43).

  Finally, the corrected collimator region is drawn on the image that is the calculation result of the image shift calculation 42 (additional drawing calculation 44). Thereby, a simulated X-ray image 38 is created.

  At this time, the patient irradiation region can be displayed more visually and easily by drawing the collimator region actually captured without being transmitted and by drawing the corrected collimator region with the color subjected to the transmission processing.

  Further, the patient irradiation area is confirmed based on the created simulated X-ray image 38 (step 116). In this confirmation, a visual confirmation by the operator is performed. By creating the simulated X-ray image 38, it is possible to visually confirm the patient irradiation region reflecting the actually positioned collimator and the patient position.

  If necessary, a simulated X-ray image 38 is stored in the medical image server 15 as evidence indicating the positional relationship between the collimator 5 and the patient 4 when irradiated.

  On the other hand, a DDR collimator image 37 (planned collimator) planned on the assumption that the particle beam expansion starting position 21 is the X-ray source position 22 and a simulated X-ray image 39 obtained by reverse shifting the simulated X-ray image 38 in the preparation stage. And the error of the patient irradiation area can be calculated. More specifically, the entire simulated X-ray image 38 including the corrected collimator region is returned to the original amount by the shift of the patient position error amount performed in the shift calculation 42 (reverse shift calculation 42a). As a result, the shifted X-ray image returns to the original position, and the error of the patient irradiation region can be calculated by comparing the corrected collimator region included in the simulated X-ray image 39 with the DDR collimator image 37. Yes (patient irradiation area error calculation 45).

  If the calculated patient irradiation area error amount is within the allowable range, the confirmation is finished by the operator's operation (step 117), and all the confirmations are finished (step 118). If it is out of the allowable range, it is determined from the simulated X-ray image 38 whether the collimator position or the patient position is a factor, and the control returns to the collimator positioning start (step 101) or the patient positioning start (step 108) again. Repeat the flow procedure.

  In the above, the calculation processing function of the image shift calculation 42 constitutes an image shift calculation unit that creates a second reconstructed image obtained by shifting the image of the DRR patient image 36 based on the patient position error, and the collimator region extraction and correction calculation 43 The calculation processing function constitutes a correction calculation unit that corrects the collimator X-ray captured image 35 X-rayed from the X-ray source position 22 to a second collimator image that can be assumed to be captured from the particle beam expansion starting position 21. The calculation processing function of the additional drawing calculation 44 constitutes an additional drawing calculation unit that creates a simulated X-ray image 38 in which the second reconstructed image and the second collimator image are superimposed.

  Further, the calculation processing function of the reverse shift calculation 42a constitutes a simulated image reverse shift calculation unit that reverse shifts the simulated X-ray image 38 based on the patient position error, and the calculation processing function of the patient irradiation region error calculation 45 is reverse. Comparing the corrected collimator region included in the simulated X-ray image 39 after the shift and the reconstructed image (DDR collimator image 37) of the collimator region created assuming the particle beam expansion starting point position 21 as the X-ray source position 22 Thus, an error calculation unit for calculating the patient irradiation region error is configured.

  According to the positioning system of the particle beam therapy system of this embodiment described above, the following effects can be obtained. By creating the simulated X-ray image 38, the patient irradiation region can be visually confirmed. Thereby, the safety | security improvement of positioning of a particle beam therapy apparatus can be aimed at. Further, by storing the simulated X-ray image 38 in the medical image server 15, evidence can be obtained. Further, the patient irradiation area can be numerically confirmed by calculating the error of the patient irradiation area.

<Second Embodiment>
Another embodiment of the present invention will be described with reference to FIG. FIG. 5 is a functional block diagram showing arithmetic processing by the arithmetic device 13A (not shown) of the image processing system 7A.

  In the first embodiment, a simulated X-ray image 38 is created, a simulated X-ray image 39 obtained by reverse-shifting the simulated X-ray image 38 and the DDR collimator image 37 are compared, and the error of the patient irradiation region is calculated. In the embodiment, a simulated X-ray image 39 is directly created without creating the simulated X-ray image 38, the simulated X-ray image 39 and the DDR collimator image 37 are compared, and the error of the patient irradiation region is calculated. To do. In addition, the same code | symbol is attached | subjected to what is equivalent to what was shown in FIG. 3 among what is shown in FIG.

  First, a collimator region is extracted from the collimator X-ray captured image 35, and correction calculation is performed so that the collimator region becomes an image photographed at the particle beam expansion start position 21 (collimator region extraction and correction calculation 43). Next, the calculation result of the correction calculation 43 is reverse shifted by the amount of the patient position error (collimator region reverse shift calculation 54). Finally, the collimator region that has been reversely shifted is drawn on the DDR patient image 36 that is planned on the assumption that the particle beam expansion starting position 21 is the X-ray source position 22 at the preparation stage (additional drawing calculation 55). Thereby, a simulated X-ray image 39 for comparison is created.

  Since the simulated X-ray image 39 is created for the purpose of comparison with the DDR collimator image 37 (planned collimator), the image when X-ray imaging is performed at the particle beam expansion starting position 21 is accurately simulated. However, the relative relationship between the collimator 5 and the patient 4 is reflected, and an error in the patient irradiation region can be visually confirmed.

  Similarly to the first embodiment, the simulated X-ray image 39 is stored in the medical image server 15 to provide evidence. The collimator region included in the simulated X-ray image 39 and the DDR collimator image 37 are obtained. By comparing, the error of the patient irradiation area can be calculated (patient irradiation area error calculation 45).

  In the above description, the calculation processing function of the collimator region extraction and correction calculation 43 can be assumed to be that the collimator X-ray captured image 35 acquired by X-ray imaging from the X-ray source position 22 is captured from the particle beam expansion starting position 21. A correction calculation unit that corrects the collimator image is configured, and the calculation processing function of the collimator region reverse shift calculation 54 configures a collimator region reverse shift calculation unit that reverse shifts the correction collimator region based on a patient position error, and additional drawing calculation The calculation processing function 55 is a comparison in which a reconstructed image (DRR patient image 36) of a patient image created on the assumption that the particle beam expansion start position is an X-ray source position and a second collimator image reversely shifted are superimposed. The additional drawing calculation unit for creating the simulated image 39 for the patient, and the calculation processing function of the patient irradiation region error calculation 45 is the complement included in the simulated X-ray image 39 for comparison. An error calculation for calculating a patient irradiation region error by comparing a collimator region and a reconstructed image (DDR collimator image 37) of the collimator region created assuming that the particle beam expansion starting position 21 is the X-ray source position 22 Parts.

  As described above, also in this embodiment, the same effect as that of the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Treatment plan apparatus 2 Particle beam irradiation apparatus 3 Rotating gantry 4 Patient 5 Collimator 6 X-ray imaging system 7 Image processing system 8 Irradiation nozzle
DESCRIPTION OF SYMBOLS 9 SNOT 10 SNOT control apparatus 12 Support stand control apparatus 13 Arithmetic apparatus 13a Display apparatus 14 Input apparatus 15 Medical image server 16 X-ray imaging apparatus (imaging apparatus)
17 X-ray tube device 18 X-ray image receiving device 19 Support base 21 Particle beam expansion starting position 22 X-ray source position 23 Isocenter 24 Range modulation wheel 25 Second scatterer 26 Y-axis scanning electromagnet 27 X-axis scanning electromagnet

Claims (6)

A snout control device for positioning control of a collimator installed in the snout;
A support control device for positioning control of a support for supporting a patient;
In the positioning system of the particle beam therapy apparatus comprising: the collimator positioning information to be output to the snout control device; and the image processing system to generate the positioning information of the support base to be output to the support base control device.
The image processing system includes:
Based on the CT image of the patient, a first reconstructed image (first DRR patient image) that can be assumed to be taken from the particle beam expansion starting position is created, and the first reconstructed image is imaged based on the patient position error. An image shift calculation unit for creating a shifted second reconstructed image (second DRR patient image);
A correction calculation unit that corrects a first collimator image obtained by X-ray imaging from an X-ray source position to a second collimator image that can be assumed to be imaged from the particle beam expansion start position;
A positioning system for a particle beam therapy system, comprising: an additional drawing calculation unit that creates a simulated image obtained by superimposing the second reconstructed image and the second collimator image. In the positioning system of the particle beam therapy system according to claim 1,
The image processing system further includes:
A positioning system for a particle beam therapy system, comprising a display device for displaying the simulated image. In the positioning system of the particle beam therapy system according to claim 1,
The image processing system further includes:
A positioning system for a particle beam therapy system, comprising a storage device for storing the simulated image. In the positioning system of the particle beam therapy system according to claim 1,
The image processing system further includes:
A simulated image reverse shift computing unit that reversely shifts the simulated image based on the patient position error;
The corrected collimator region included in the calculation result of the simulated image reverse shift calculation unit is compared with the reconstructed image (DRR collimator region) of the collimator region created assuming the particle beam expansion starting point position as the X-ray source position. And a positioning system for the particle beam therapy system, comprising an error calculation unit for calculating a patient irradiation region error. A snout control device for positioning control of a collimator installed in the snout;
A support control device for positioning control of a support for supporting a patient;
In the positioning system of the particle beam therapy apparatus comprising: the collimator positioning information to be output to the snout control device; and the image processing system to generate the positioning information of the support base to be output to the support base control device.
The image processing system includes:
A correction calculation unit that corrects the first collimator image captured from the X-ray source position to the second collimator image that can be assumed to be captured from the particle beam expansion starting position;
A collimator region reverse shift operation unit that reversely shifts the second collimator image based on a patient position error;
Addition of creating a comparative simulation image in which the reconstructed image (DRR patient image) of the patient image created assuming the particle beam expansion starting point position as the X-ray source position and the second collimator image reversely shifted are superimposed A drawing operation unit;
The patient irradiation region is compared with the reconstructed image (DRR collimator region) of the collimator region created assuming that the corrected collimator region included in the simulation image for comparison is the X-ray source position as the particle beam expansion starting point position. A positioning system for a particle beam therapy system, comprising: an error calculation unit that calculates an error. A particle beam having a particle beam generator, a collimator that forms an irradiation field by forming a particle beam from the particle beam generator into an affected part shape, a snout on which the collimator is installed, and a support table that supports a patient An irradiation device;
An X-ray imaging system in which an X-ray source is located downstream of a particle beam expansion starting position of the particle beam generator;
A snout control device for controlling the positioning of the collimator by driving the snot;
A support control device for controlling the positioning of the support by driving the support;
In the particle beam therapy system comprising: the collimator positioning information to be output to the snout control device; and the image processing system to generate the support table positioning information to be output to the support base control device.
The image processing system includes:
Based on the CT image of the patient, a first reconstructed image (first DRR patient image) that can be assumed to be taken from the particle beam expansion starting position is created, and the first reconstructed image is imaged based on the patient position error. An image shift calculation unit for creating a shifted second reconstructed image (second DRR patient image);
A correction calculation unit that corrects a first collimator image obtained by X-ray imaging from an X-ray source position to a second collimator image that can be assumed to be imaged from the particle beam expansion start position;
A particle beam therapy system comprising: an additional drawing calculation unit that creates a simulated image in which the second reconstructed image and the second collimator image are superimposed.

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