JP6895757B2 - Radiation therapy system and patient positioning system - Google Patents

Description

Embodiments of the present invention relate to a radiotherapy system and a patient positioning system.

As a technique of radiotherapy, it is confirmed whether or not the patient and the device or the devices (for example, a pedestal and a sleeper) interfere with each other at the time of treatment planning. For this reason, it is important where the patient is placed on the bed. Confirmation of interference is performed by an interference simulator. The interference simulator determines the presence or absence of interference based on the input device and the position of the patient. The position of the device can be uniquely determined from the set value at the time of treatment planning, but the position on the bed of the patient is mainly visually determined by the medical staff such as a doctor or a radiologist based on the position of the patient's isocenter. ing. If the patient cannot be placed at the exact position of the value input by the interference simulator during radiotherapy, the pre-confirmation result by the interference simulator cannot be reproduced, and the patient and the device may interfere with each other. In addition, since the reference position of the patient with respect to the sleeper is unclear, it takes a lot of time to arrange the patient.

Japanese Unexamined Patent Publication No. 2009-226015 JP-A-2007-236729 Japanese Unexamined Patent Publication No. 2009-369 Japanese Unexamined Patent Publication No. 2012-10759 Japanese Unexamined Patent Publication No. 2015-157011

An object of the embodiment is to provide a radiotherapy system and a patient position confirmation system capable of arranging a patient in an accurate position on a bed in radiotherapy or the like.

The radiotherapy system according to the present embodiment optically photographs the irradiation unit for irradiating radiation, the bed on which the patient is placed, and the patient placed on the bed during radiotherapy or medical imaging. An optical imaging unit that generates a first optical image, and a first position calculation unit that calculates the first relative position of the patient with respect to the bed during the radiotherapy based on the first optical image. A second position calculation unit that calculates the second relative position of the patient with respect to the berth at the time of the radiotherapy planning based on the second optical image of the patient placed on the berth at the time of the radiotherapy planning. A difference calculation unit for calculating the difference between the first relative position and the second relative position, and a display unit for displaying the difference at the time of the radiotherapy.

FIG. 1 is a diagram showing a configuration of a radiotherapy system according to the present embodiment. FIG. 2 is a diagram showing the appearance of a radiotherapy device installed in a treatment room. FIG. 3 is a diagram showing an installation mode of the radiotherapy device, the X-ray computed tomography device, the optical imaging device, and the relative position display device of FIG. 1 in the treatment room. FIG. 4 is a diagram showing a typical processing flow of the radiotherapy system according to the present embodiment. FIG. 5 is a plan view of the patient placed on the bed in step SA2 of FIG. FIG. 6 is a diagram showing an example of calculating the position of the patient's reference point (patient's relative position) with respect to the bed's reference point, which is performed by the relative position calculation device in step SA3 of FIG. FIG. 7 is a diagram showing a calculation example of the rotation angle (patient relative angle) of the patient reference axis with respect to the reference axis of the bed, which is performed by the relative position calculation device in step SA3 of FIG. FIG. 8 is a diagram showing a typical flow of the patient position confirmation process performed by the patient position confirmation system in step SA7 of FIG. FIG. 9 is a diagram showing a guide image of the difference in the body axis direction generated by the relative position calculation device in step SB4 of FIG. FIG. 10 is a diagram showing a guide image of the difference in the minor axis direction generated by the relative position calculation device in step SB4 of FIG. FIG. 11 is a diagram showing a guide image of the difference in the rotation direction generated by the relative position calculation device in step SB4 of FIG. FIG. 12 is a diagram showing an example of projection of a guide image by the relative position display device in step SB5 of FIG.

Hereinafter, the radiotherapy system and the patient position confirmation system according to the present embodiment will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a radiotherapy system 100 according to the present embodiment. As shown in FIG. 1, the radiotherapy system 100 according to the present embodiment includes a patient position confirmation system 1, a treatment planning device 3, a radiotherapy device 5, a medical diagnostic imaging device 7, and an interference simulator 9.

The patient position confirmation system 1 is a system for confirming the position of the patient with respect to the bed during radiotherapy or image taking. The time of radiation therapy according to the present embodiment refers to a period from the arrangement (setup) of the patient on the bed to the end of irradiation of radiation by the radiation therapy device 5. The time of image taking according to the present embodiment refers to the period from the arrangement (setup) of the patient on the bed to the end of the medical image taking by the medical image diagnostic apparatus 7.

As shown in FIG. 1, the patient position confirmation system 1 includes an optical imaging device 11, a relative position calculation device 13, and a relative position display device 15.

The optical imaging device 11 optically photographs a patient placed on a bed to generate an optical image. The generated optical image depicts the patient resting on the berth. The optical image is composed of, for example, a plurality of pixels arranged in a two-dimensional manner, and each pixel is assigned an RGB value or a gray value according to the color of the subject corresponding to the pixel. The optical imaging device 11 optically photographs the patient placed on the bed at both the treatment planning and the radiotherapy or the imaging, and generates an optical image. The optical image generated at the time of treatment planning is referred to as a reference optical image, and the optical image generated at the time of radiotherapy or image taking is referred to as a target optical image. The time of treatment planning according to the present embodiment refers to the time of medical image taking performed before, during, or after the image taking of the medical image for treatment planning. As the optical photographing device 11, for example, an optical camera is used. The optical imaging device 11 is installed in, for example, a radiotherapy room. The reference optical image and the target optical image are transmitted to the relative position calculation device 13.

The relative position calculation device 13 is, for example, a general-purpose computer or workstation. For example, the relative position calculation device 13 is installed in a management room or the like adjacent to the treatment room. The relative position calculation device 13 includes an input device, a display, a communication device, and a storage device included in a general-purpose computer or workstation. The storage device is a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or an integrated circuit storage device that stores a reference optical image and a target optical image transmitted from the optical imaging device 11. .. Further, the relative position calculation device 13 has a processor such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit) and a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The processor realizes the reference relative position calculation function 131, the target relative position calculation function 133, the difference calculation function 135, and the guide image generation function 137 by executing the position confirmation program stored in the memory.

In the reference relative position calculation function 131, the relative position calculation device 13 calculates the relative position of the patient with respect to the bed at the time of treatment planning based on the reference optical image. Hereinafter, the relative position of the patient with respect to the sleeper may be referred to as a relative position. In particular, the relative position of the patient with respect to the bed at the time of treatment planning will be referred to as the reference relative position.

In the target relative position calculation function 133, the relative position calculation device 13 calculates the relative position of the patient with respect to the bed during radiotherapy or image taking based on the target optical image. The calculated relative position will be referred to as the target relative position.

In the difference calculation function 135, the relative position calculation device 13 calculates the difference between the reference relative position calculated by the reference relative position calculation function 131 and the target relative position calculated by the target relative position calculation function 133.

In the guide image generation function 137, the relative position calculation device 13 generates an image expressing the difference calculated by the difference calculation function 135. The generated image serves as a guide for confirming the position of the patient with respect to the bed, and is therefore referred to as a guide image. The guide image is transmitted to the relative position display device 15.

The relative position display device 15 displays the difference calculated by the difference calculation function 135. Specifically, the relative position display device 15 displays the guide image generated by the guide image generation function 137 at the time of radiotherapy or image taking. As the relative position display device 15, any device such as a display, a projector, a spatial imaging display device, or the like that can display a guide image may be used. Hereinafter, in order to specifically explain the description of the present embodiment, the relative position display device 15 is assumed to be a projector. The relative position display device 15 is installed in the treatment room.

The treatment planning device 3 is a computer that creates a treatment plan for the patient by using the medical image generated by the medical image diagnostic device 7 and the reference relative position calculated by the relative position calculation device 13. Specific examples of the treatment plan include the irradiation site, dose distribution, irradiation direction, and the like. Information about the treatment plan (hereinafter referred to as treatment plan information) is transmitted to the radiotherapy device 5 and the interference simulator 9.

The radiotherapy device 5 and the medical diagnostic imaging device 7 are communicably connected to the treatment planning device 3. For example, the radiotherapy device 5 and the medical diagnostic imaging device 7 are installed in the treatment room, and the treatment planning device 3 is installed in the management room.

FIG. 2 is a diagram showing the appearance of the radiotherapy device 5 installed in the treatment room. The radiotherapy device 5 is a device for the purpose of radiotherapy, and treats a patient by irradiating the patient with radiation according to treatment plan information. As shown in FIG. 2, the radiotherapy device 5 has a pedestal 51 and a sleeper 53. The gantry 51 has a pedestal 511 that rotatably supports the irradiator 513 around the rotation axis Z. The irradiator 513 irradiates the radiation according to the treatment plan information. Specifically, the irradiator 513 forms an irradiation field with a multi-division diaphragm (multi-leaf collimator), and adjusts the irradiation amount of radiation according to the irradiation field. When the treatment site is irradiated with radiation, the treatment site disappears or shrinks. A display 515 is provided on the base 511. Various information such as treatment plan information is displayed on the display 515. Further, a guide image may be displayed on the display 515. As shown in FIG. 2, the sleeper 53 has a base 531 and a top plate 533. The base 531 movably supports the top plate 533. The patient is placed on the top plate 533.

The medical image diagnostic device 7 is a device that captures a medical image of a patient to be treated. For example, at the time of treatment planning, the medical image diagnostic apparatus 7 performs medical imaging on a patient to generate a three-dimensional medical image about the patient or a four-dimensional medical image which is a time-series three-dimensional medical image. Before the start of radiation during radiotherapy, the medical diagnostic imaging apparatus 7 generates a three-dimensional or four-dimensional medical image for confirming the position of the patient with respect to the bed. The medical image diagnostic apparatus 7 may be any modality such as an X-ray computed tomography apparatus, an X-ray angio apparatus, a PET (positron emission tomography) apparatus, a SPECT (single photon emission CT) apparatus, a magnetic resonance imaging apparatus, or the like. Hereinafter, for the sake of specific description, it is assumed that the medical image diagnostic apparatus 7 is an X-ray computed tomography apparatus.

As described above, the radiotherapy apparatus 5, the X-ray computed tomography apparatus 7, the optical imaging apparatus 11, and the relative position display apparatus 15 are installed in the treatment room. FIG. 3 is a diagram showing an installation mode of the radiotherapy device 5, the X-ray computed tomography device 7, the optical imaging device 11, and the relative position display device 15 in the treatment room. As shown in FIG. 3, the radiotherapy apparatus 5 and the X-ray computed tomography apparatus 7 have a Z-axis as a common rotation axis between the gantry 51 of the radiotherapy apparatus 5 and the gantry of the medical diagnostic imaging apparatus 7. Will be installed. Further, a sleeper 53 is installed between the radiotherapy device 5 and the X-ray computed tomography apparatus 7, and the radiotherapy apparatus 5 and the X-ray computed tomography apparatus 7 share the sleeper 53.

As shown in FIG. 3, the optical imaging device 11 is installed at a position where the patient placed on the sleeper 53 can be photographed. For example, the optical imaging device 11 is suspended at a predetermined position on the ceiling of the treatment room where the imaging field of view is not obstructed by the gantry 51 or the like. The relative position display device 15 is installed at a position where a guide image can be projected onto the patient placed on the bed 53. For example, the relative position display device 15 is suspended at a predetermined position on the ceiling of the treatment room where the guide image is not obstructed by the gantry 51 or the like.

The form of installation of the radiotherapy device 5, the X-ray computed tomography device 7, the optical imaging device 11, and the relative position display device 15 in the treatment room is not limited to the example shown in FIG. For example, the X-ray computed tomography apparatus 7 may be incorporated in the radiotherapy apparatus 5. In this case, in addition to the irradiator 513, an X-ray tube and a plane detector are attached to the gantry 51 with the rotation axis Z axis interposed therebetween. Cone beam CT imaging is performed by repeating irradiation and detection of X-rays while the X-ray tube and the plane detector rotate around the Z-axis of the rotation axis. Further, although the optical imaging device 11 and the relative position display device 15 are suspended from the ceiling, they may be provided on the wall surface of the treatment room, or may be attached to the radiotherapy device 5 or the X-ray computed tomography apparatus 7. You may. Further, the optical imaging device 11 may be carried by a medical worker or the like.

As shown in FIG. 1, the interference simulator 9 determines the presence or absence of interference between the radiotherapy device 5, the X-ray computed tomography device 7, and the patient. The interference simulator 9 is, for example, a general purpose computer or workstation. For example, the interference simulator 9 is installed in a management room or the like adjacent to the treatment room. The interference simulator 9 includes an input device, a display, a communication device, and a storage device included in a general-purpose computer or workstation. The storage device is a storage device such as an HDD, an SSD, or an integrated circuit storage device. Further, the interference simulator 9 has a processor such as a CPU and a GPU and a memory such as a ROM and a RAM. The processor realizes the interference determination function 91 and the relative position correction function 93 by executing the interference check program stored in the memory.

In the interference determination function 91, the interference simulator 9 is based on the reference relative position, treatment plan information, and the mechanism information of the radiotherapy device 5 or the X-ray computed tomography device 7, and the patient placed at the reference relative position is the radiotherapy device. It is determined whether or not it interferes with 5 or the X-ray computed tomography apparatus 7. Specifically, the interference simulator 9 stores in advance information on the structure of the gantry 51 and the sleeper 53 of the radiotherapy device 5 and information on the movable range of the structure in the storage device or the like. Hereinafter, information on the structure and information on the movable range of the structure will be referred to as mechanism information. Similarly, the interference simulator 9 stores the mechanism information of the X-ray computed tomography apparatus 7 in the above-mentioned storage device or the like in advance. The mechanism information can be obtained from the mechanism design data (CAD: Computer-Aided Design) relating to the radiotherapy apparatus 5 and the X-ray computed tomography apparatus 7. The interference simulator is provided by the mechanisms provided by the radiotherapy device 5 or by the X-ray computed tomography device 7 based on the treatment plan information and the mechanism information of the radiotherapy device 5 or the X-ray computed tomography device 7. It is also possible to determine whether or not the mechanisms interfere with each other.

In the relative position correction function 93, when the interference determination function 91 determines that the patient interferes with the radiotherapy device 5 or the X-ray computed tomography device 7, the interference simulator 9 corrects the reference relative position to a position where the patient does not interfere. .. The corrected reference relative position is transmitted to the relative position calculation device 13 and the treatment planning device 3 and used as the reference relative position.

Hereinafter, an operation example of the radiotherapy system 100 according to the present embodiment will be described in detail.

FIG. 4 is a diagram showing a typical processing flow of the radiotherapy system 100 according to the present embodiment. As shown in FIG. 4, the processing phase of the radiotherapy system 100 is divided into a treatment planning phase and a radiotherapy phase.

In the treatment planning phase, the X-ray computed tomography apparatus 7 first CT scans the patient placed on the bed 53 in the treatment room and generates a CT image (treatment plan image) for the patient (step SA1). The treatment plan image is transmitted to the treatment plan device 3.

When step SA1 is performed, the optical imaging device 11 optically photographs the patient placed on the bed 53 in the treatment room to generate a reference optical image (step SA2).

FIG. 5 is a plan view of the patient P placed on the bed 53. In step SA2, the patient P lies on the bed 53 in the position and posture of the bed 53 assumed at the time of radiation therapy. Patient P will be placed on the bed 53 so as to reproduce the position and posture during radiotherapy. The optical imaging device 11 optically photographs the patient P according to an imaging instruction by a medical worker or the like to generate a reference optical image. The photographing instruction may be executed, for example, by pressing a button provided on the optical photographing device 11, or may be executed by operating an input device provided on the relative position calculation device 13 or the like.

When step SA2 is performed, the relative position calculation device 13 executes the reference relative position calculation function 131 (step SA3). In step SA3, the relative position calculation device 13 calculates the reference relative position based on the reference optical image. The reference relative position is the position of the patient's reference point with respect to the reference point of the bed 53 (hereinafter referred to as the patient relative position) and the rotation angle of the patient's reference axis with respect to the reference axis of the sleeper 53 (hereinafter referred to as the patient relative angle). Specified by at least one of.

FIG. 6 is a diagram showing a calculation example of the position (patient relative position) of the patient's reference point with respect to the reference point of the sleeper 53. As shown in FIG. 6, the reference optical image I1 has an image region (hereinafter referred to as a sleeper region) R53 relating to the sleeper and an image region (hereinafter referred to as the patient region) RP relating to the patient P.

As shown in FIG. 6, as the patient relative position, for example, the distance from the edge of the top plate to the patient P with respect to the long axis direction of the sleeper 53 is calculated. In this case, the relative position calculation device 13 specifies the reference point P1 of the patient region RP in the long axis direction and the reference point P2 on the edge of the sleeper region R53. The reference point P1 and the reference point P2 are defined as parts that can be visually recognized from the outside. The reference point P1 is specified, for example, at the crown of the patient area RP. The reference point P1 such as the crown may be specified by performing image processing on the reference optical image, or may be specified by the user via an input device. The reference point P2 is set to a point on the edge of the sleeper region R53 at the shortest distance from the reference point P1. The reference point P2 such as the edge portion may be specified by performing image processing on the reference optical image, or may be specified by the user via an input device. When the reference points P1 and P2 are specified, the relative position calculation device 13 measures the distance D1 between the reference points P1 and the reference points P2. The distance D1 is calculated by, for example, multiplying the number of pixels between the reference point P1 and the reference point P2 in the reference optical image by the distance in the real space per pixel. The measured distance D1 is used as the patient relative position.

As shown in FIG. 6, as the relative position of the patient, the shortest distance of the patient P is calculated from the edge of the top plate in the horizontal axis direction of the bed 53. In this case, the relative position calculation device 13 specifies the reference point P3 of the patient region RP in the horizontal axis direction and the reference point P4 of the sleeper region R53 in the minor axis direction. The reference point P3 and the reference point P4 are defined as parts that can be visually recognized from the outside. The reference point P3 is specified, for example, on the shoulder of the patient area RP. The reference point P3 such as the shoulder portion may be specified by performing image processing on the reference optical image, or may be specified by the user via an input device. The reference point P4 is set to, for example, a point on the edge of the sleeper region R53 at the shortest distance from the reference point P3. The reference point P4 such as the edge may be specified by performing image processing on the reference optical image, or may be specified by the user via an input device. When the reference points P3 and P4 are specified, the relative position calculation device 13 measures the distance D2 between the reference points P3 and the reference point P4. The measured distance D2 is used as the patient relative position.

The reference point that defines the relative position of the patient is not limited to the above position, and may be set to any position as long as the relative position of the patient with respect to the bed 53 can be defined. For example, the reference points P1 and P3 of the patient area RP may be set at the foot, shoulder, isocenter, or the like. Further, the reference points P2 and P4 of the sleeper area R53 may be set to points other than the points on the edge of the sleeper area R53, or may be set to the image area of the external device attached to the sleeper area 53. .. Examples of the external device include a fixture for patient P and the like.

FIG. 7 is a diagram showing a calculation example of the rotation angle (patient relative angle) of the patient reference axis with respect to the reference axis of the sleeper 53. The reference axis RA1 of the sleeper 53 is set to, for example, the long axis of the sleeper 53, and the reference axis RA2 of the patient P is set to, for example, the body axis of the patient P. The relative position calculation device 13 specifies the reference axis RA1 of the sleeper region R53 and the reference axis RA2 of the patient region RP by image processing. For example, the relative position calculation device 13 approximates the patient region RP to an ellipse and sets the long axis of the elliptical shape to the reference axis RA2. The reference axis RA1 and the reference axis RA2 may be designated by the user via an input device. When the reference axis RA1 and the reference axis RA2 are specified, the relative position calculation device 13 calculates the rotation angle A1 of the reference axis RA2 with respect to the reference axis RA1. The rotation angle A1 is calculated by, for example, the angle between the reference axis RA1 and the reference axis RA2 centered on the intersection of the reference axis RA1 and the reference axis RA2. The measured rotation angle A1 is used as a patient relative angle.

The reference axis that defines the patient relative angle is not limited to the above axis, and may be set to any axis as long as the relative position of the patient P with respect to the bed 53 can be defined. For example, the patient reference axis RA2 may be set to the long axis of the leg, the long axis of the arm, the long axis of the torso, and the long axis of the head. The patient relative angle may be calculated not only based on one of the plurality of reference axes, but also for each of the plurality of reference axes.

As the reference relative position, both the above-mentioned patient relative position and the patient relative angle may be calculated, or only one of them may be calculated. The reference relative position of the calculation target can be arbitrarily selected by the user via the input device.

Further, in the above example, it is assumed that the entire patient P is visualized on the optical image, but the present embodiment is not limited to this. For example, if the reference point is included in the imaging field of view, only a part of the patient P may be visualized in the optical image.

When step SA3 is performed, the treatment planning device 3 creates a treatment plan (step SA4). Specifically, the treatment planning device 3 uses the reference relative position calculated in step SA3 and the treatment planning image to generate treatment planning information such as dose distribution, treatment site, and irradiation direction.

When step SA4 is performed, the interference simulator 9 executes the interference determination function 91 (step SA5). In step SA5, the interference simulator 9 determines the presence or absence of interference between the radiotherapy device 5 and the patient. Specifically, in the interference simulator 9, the patient P is placed at the reference relative position calculated in step SA3 based on the reference relative position and the mechanism information, and the radiation therapy device is set at an irradiation angle corresponding to the irradiation direction. When the gantry 51 of 5 is arranged, it is determined whether or not the patient P interferes with the gantry 51. The presence or absence of interference is determined by using, for example, the CAD implemented in the interference simulator 9. In order to determine the presence or absence of interference with higher accuracy, the physique information of the patient P may be used in addition to the reference relative position of the patient P. As the physique information, body measurement values such as height, chest circumference, abdominal circumference, and weight of patient P are used. Further, a three-dimensional model of the patient P may be used as the physique information. The physique information is registered in the interference simulator 9 in advance.

When it is determined in step SA5 that there is interference (step SA5: yes), the interference simulator 9 executes the relative position correction function 93 (step SA6). In step SA6, the interference simulator 9 corrects the reference relative position. Specifically, the interference simulator 9 recalculates the reference relative position of the patient P who can avoid the interference under the fixed irradiation angle of the gantry 51 and the absolute position of the bed 53. When the reference relative position after recalculation and the reference relative position before recalculation are a predetermined minute amount, the interference simulator 9 updates the reference relative position with the reference relative position after recalculation. If the reference relative position after recalculation and the reference relative position before correction are not a predetermined minute amount, the treatment plan is performed again.

If it is determined in step SA4 that there is no interference (step SA5: none) or step SA6 is performed, the treatment planning phase ends.

Next, we move on to the radiation therapy phase. In the radiotherapy phase, patient P is first placed on the bed 53. At this time, the patient P is positioned with respect to the bed 53 so as to match the reference relative position in step SA2. In the positioning of the patient P, the patient position confirmation process is performed by the patient position confirmation system 1.

FIG. 8 is a diagram showing a typical flow of the patient position confirmation process performed by the patient position confirmation system 1 in step SA7 of FIG. As shown in FIG. 8, first, the optical imaging device 11 optically photographs the patient placed on the bed 53 to generate a target optical image (step SB1). For example, the optical imaging device 11 performs optical imaging triggered by an imaging instruction from a medical professional or the like. The photographing instruction may be given, for example, by pressing a button provided on the optical photographing device 11, or may be given by operating an input device provided on the relative position calculation device 13.

When step SB1 is performed, the relative position calculation device 13 executes the target relative position calculation function 133 (step SB2). In step SB2, the relative position calculation device 13 calculates the target relative position of the patient with respect to the sleeper 53 based on the target optical image. The method of calculating the target relative position is the same as the method of calculating the reference relative position in step SA3.

When step SB2 is performed, the relative position calculation device 13 executes the difference calculation function 135 (step SB3). In step SB3, the relative position calculation device 13 calculates the difference between the reference relative position calculated in step SA3 and the target relative position calculated in step SB2. The difference includes the distance and direction from the target relative position to the reference relative position. For example, when the patient relative position with respect to the long axis direction of the sleeper 53 is calculated as the reference relative position and the target relative position, when the reference relative position is 5 cm and the target relative position is 7 cm, the distance is 2 cm and the direction is the target. The direction from the relative position to the reference relative position, that is, the direction toward the tip of the bed 53 on the patient's head side. When the patient relative position with respect to the horizontal axis direction of the sleeper 53 is calculated as the reference relative position and the target relative position, when the reference relative position is 1 cm and the target relative position is 2 cm, the distance is 1 cm and the direction is from the target relative position. This is the direction toward the reference relative position, that is, the direction toward the left-hand side edge of the sleeper 53. When the patient relative angle is calculated as the reference relative position and the target relative position, when the reference relative angle is + 5 ° and the target relative angle is + 3 °, the rotation angle is 2 ° and the rotation direction is the reference relative from the target relative angle. The direction toward the angle, that is, the direction toward the minor axis of the sleeper 53.

In step SB3, the relative position calculation device 13 executes the guide image generation function 137 (step SB4). In step SB4, the relative position calculation device 13 generates a guide image based on the difference calculated in step SB3. For example, guide images are generated for each type of relative position.

FIG. 9 is a diagram showing a difference guide image IP1 in the major axis direction, FIG. 10 is a diagram showing a difference guide image IP2 in the minor axis direction, and FIG. 11 is a diagram showing a difference guide image IP3 in the rotation direction. It is a figure which shows. As shown in FIG. 9, the guide image IP1 includes a numerical value indicating the difference value of the distance in the major axis direction and a mark indicating the direction from the target relative position to the reference relative position. For example, in the case of FIG. 9, the difference value (distance) is 2 cm, and the direction is toward the tip of the bed 53 on the patient's head side. As shown in FIG. 10, the guide image IP2 includes a numerical value indicating the difference value of the distance in the minor axis direction and a mark indicating the direction from the target relative position to the reference relative position. In the case of FIG. 10, the difference value (distance) is 1 cm, and the direction is toward the edge of the bed 53 on the left hand side of the patient. As shown in FIG. 11, the guide image IP3 includes a numerical value indicating a difference value between the target relative angle and the reference relative angle, and a mark indicating the direction from the target relative angle to the reference relative angle. In the case of FIG. 11, the difference value (rotation angle) is 2 °, and the rotation direction is the direction toward the minor axis of the sleeper 53.

When step SB4 is performed, the relative position display device 15 displays the guide image generated in step SB4 (step SB5). For example, the relative position display device 15 projects a guide image triggered by a projection instruction from a medical worker or the like. The projection instruction may be given, for example, by pressing a button provided on the relative position display device 15, or may be given by operating an input device provided on the relative position calculation device 13.

FIG. 12 is a diagram showing an example of projection of a guide image by the relative position display device 15. As shown in FIG. 12, the relative position display device 15 projects the guide image IP1, the guide image IP2, and the guide image IP3 generated in step SB4 onto the patient P lying on the bed 53. At this time, the relative position display device 15 projects the guide images IP1, IP2, and IP3 by matching the marks indicating the directions included in the guide images IP1, IP2, and IP3 with the directions in the real space. By projecting the guide images IP1, IP2 and IP3 on the patient P, the medical staff can visually recognize the guide images IP1, IP2 and IP3 without diverting the line of sight from the patient P. By looking at the guide images IP1, IP2 and IP3, the medical staff can recognize the direction in which the patient P should be moved and the distance to be moved. This makes it possible to easily and reliably place the patient P in the reference relative position. For example, in the case of FIG. 12, the patient P is moved 2 cm toward the patient's head side, 1 cm toward the patient's left hand side, and 2 ° toward the minor axis of the sleeper 53. As a result, the relative position at the time of radiation therapy can be matched with the relative position at the time of treatment planning.

As a result, the patient position confirmation process (step SA7) performed by the patient position confirmation system 1 in step SA7 of FIG. 4 is completed.

In the above example, the guide image is assumed to be generated for each type of the patient's relative position with respect to the bed 53. However, this embodiment is not limited to this. For example, a guide image showing all the calculated relative positions in one frame may be generated.

As shown in FIG. 4, when the patient position confirmation process (step SA7) is performed, the interference check by the actual machine is performed (step SA8). The interference check by the actual machine is a method of confirming the presence or absence of interference by actually moving the gantry 51 and the sleeper 53 in the same manner as in the case of irradiation.

When it is confirmed in step SA8 that there is no interference, the radiotherapy apparatus 5 starts irradiation of radiation (step S8). For example, when it is confirmed in step SA8 that there is no interference, the medical staff or the like inputs an irradiation start instruction via an input device. The radiation therapy device 5 starts irradiation of radiation when the irradiation start instruction is input. Since the relative position of the patient P coincides with the relative position at the time of the treatment plan, it is possible to irradiate the anatomical site according to the treatment plan.

As a result, the processing of the radiation therapy system 100 according to the present embodiment of FIG. 4 is completed.

In the above embodiment, the optical imaging device 11 performs optical imaging in a single shot in step SB1. However, this embodiment is not limited to this. For example, the optical imaging device 11 may generate a target optical image by performing optical imaging at regular intervals or continuously. In this case, the process is immediately repeated from steps SB2 to SB5 each time the target optical image is generated. Since a guide image reflecting the current position of patient P is projected immediately, it is easier and more precise to match the relative position of patient P with respect to the bed 53 with the relative position of patient P with respect to the bed 53 at the time of treatment planning. Can be done.

Further, in the above embodiment, it is assumed that the number of optical photographing devices 11 is one. However, this embodiment is not limited to this. That is, a plurality of optical photographing devices 11 may be provided. For example, in order to generate optical images having a plurality of different shooting angles, it is preferable that the optical shooting device 11 is provided at each of the plurality of positions corresponding to the plurality of shooting angles. As a result, the patient P can be reliably optically photographed without being obstructed by the radiotherapy device 5 or the like. In this case, the relative position calculation device 13 can calculate the relative position based on the optical image in which the patient P is drawn without being obstructed by the radiotherapy device 5 among the optical images of a plurality of imaging angles. Become.

Further, the above embodiment has been described by exemplifying the arrangement of the patient P on the bed 53 at the time of radiotherapy. However, this embodiment is not limited to this. That is, this embodiment can also be applied at the time of medical imaging performed by the medical image diagnostic apparatus 7 before the start of irradiation or after the end of irradiation. Hereinafter, this embodiment will be described. Before the start of irradiation or after the end of irradiation, the medical image diagnostic apparatus 7 may perform medical imaging of patient P. Also in this case, the patient P needs to be placed at the same position with respect to the bed 53 as at the time of treatment planning. The patient position confirmation system 1 according to the present embodiment can perform the processing and the like shown in FIG. 8 at the time of medical imaging performed by the medical diagnostic imaging apparatus 7 before the start of irradiation or after the end of irradiation. Thereby, the position of the patient P with respect to the bed 53 at the time of the medical imaging can be easily and surely arranged at the position of the patient P with respect to the bed 53 at the time of treatment planning.

As described above, the patient position confirmation system 1 and the radiotherapy system 100 according to the present embodiment include an optical imaging device 11, a relative position calculation device 13, and a relative position display device 15. The optical imaging device 11 optically photographs the patient P placed on the bed 53 at the time of radiotherapy or medical image acquisition to generate a target optical image. The relative position calculation device 13 calculates the target relative position of the patient P with respect to the bed 53 at the time of radiotherapy or image taking based on the target optical image. The relative position calculation device 13 calculates the reference relative position of the patient P with respect to the bed 53 at the time of radiation therapy planning based on the reference optical image of the patient P placed on the bed 53 at the time of radiation therapy planning. The relative position calculation device 13 calculates the difference between the target relative position and the reference relative position. The relative position display device 15 displays the difference at the time of radiotherapy or medical image taking.

With the above configuration, the patient position confirmation system 1 and the radiotherapy system 100 according to the present embodiment support the placement of the patient P on the bed 53 based on the relative position of the patient P with respect to the bed 53. Specifically, the patient position confirmation system 1 and the radiotherapy system 100 calculate and display the difference between the target relative position at the time of radiotherapy or medical imaging and the reference relative position at the time of treatment planning. A user such as a medical worker places the patient P at a position at the time of treatment planning according to the displayed difference. In the present embodiment, since the patient P is arranged by using the relative position of the patient P with respect to the bed 53, the reference of the arrangement is clear as compared with the case where the patient P is arranged by using the absolute value. Therefore, the patient P can be easily and quickly placed at the target position.

Further, the radiotherapy system 100 according to the present embodiment performs a treatment plan based on the reference relative position calculated by the relative position calculation device 13. Therefore, the radiation therapy system 100 can create a highly reliable treatment plan as compared with the conventional case in which the position of the patient P with respect to the bed 53 is visually determined. In addition, the accuracy of confirming the presence or absence of interference by the interference simulator 9 is also improved.

Thus, according to the present embodiment, the patient can be placed at an accurate position on the bed 53 in radiation therapy or the like.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Patient position confirmation system, 3 ... Treatment planning device, 5 ... Radiation therapy device, 7 ... Medical imaging device (X-ray computed tomography device), 9 ... Interference simulator, 11 ... Optical imaging device, 13 ... Relative position calculation Device, 15 ... Relative position display device, 51 ... Stand, 53 ... Sleeper, 91 ... Interference determination function, 93 ... Relative position correction function, 100 ... Radiation therapy system, 131 ... Reference relative position calculation function, 133 ... Target relative position calculation Function, 135 ... Difference calculation function, 137 ... Guide image generation function, 511 ... Base, 513 ... Irradiator, 515 ... Display, 513 ... Base, 533 ... Top plate.

Claims (6)

Irradiation part that irradiates radiation and
The bed on which the patient is placed and
An optical imaging unit for generating a first optical image of the patient is placed in the radiotherapy at Oite the bed in optical imaging,
A first position calculation unit that calculates the first relative position of the patient with respect to the bed during the radiotherapy based on the first optical image.
A second position calculation unit that calculates the second relative position of the patient with respect to the bed at the time of the radiation therapy planning based on the second optical image of the patient placed on the bed at the time of the radiation therapy planning. ,
A determination unit for determining whether or not the patient placed at the second relative position interferes with the radiotherapy device, and a determination unit.
When it is determined that the patient interferes with the radiotherapy device, a correction unit that corrects the second relative position to a position where the patient does not interfere, and a correction unit.
A difference calculation unit that calculates the difference between the first relative position and the corrected second relative position,
A display unit that displays the difference during the radiotherapy, and a display unit that displays the difference.
Radiation therapy system equipped with. The radiotherapy system according to claim 1, wherein the display unit includes a projector that projects an image expressing the difference onto the body surface of the patient. The first position calculation unit calculates the distance between the reference position of the bed and the reference position of the patient depicted in the first optical image as the first relative position.
The second position calculation unit calculates the distance between the reference position of the bed and the reference position of the patient depicted in the second optical image as the second relative position.
The radiation therapy system according to claim 1. The first position calculation unit calculates the rotation angle and rotation direction of the reference axis of the patient with respect to the reference axis of the bed depicted in the first optical image as the first relative position.
The second position calculation unit calculates the rotation angle and rotation direction of the patient's reference axis with respect to the reference axis of the bed depicted in the second optical image as the second relative position.
The radiation therapy system according to claim 1. Or the determination unit, based on the mechanism information of the second optical image and treatment planning and radiotherapy equipment, wherein the patient disposed second relative position from interfering with the radiation therapy equipment It determines whether,請Motomeko 1 radiotherapy system according. Radiation therapy sometimes Oite, an optical imaging unit for generating a first optical image of a patient placed on the bed in optical imaging,
A first position calculator for calculating a first relative position of the patient to the couch definitive during the radiation therapy based on the first optical image,
A second position calculation unit that calculates the second relative position of the patient with respect to the bed at the time of the radiation therapy planning based on the second optical image of the patient placed on the bed at the time of the radiation therapy planning. ,
A determination unit for determining whether or not the patient placed at the second relative position interferes with the radiotherapy device, and a determination unit.
When it is determined that the patient interferes with the radiotherapy device, a correction unit that corrects the second relative position to a position where the patient does not interfere, and a correction unit.
A difference calculation unit that calculates the difference between the first relative position and the corrected second relative position,
A display unit that displays the Oite the difference at the time of the radiation therapy,
A patient positioning system equipped with.

Images