Patent Application
20240362783
Embodiments of the present invention relate to a medical image processing device, a treatment system, a medical image processing method, and a storage medium.
Radiation therapy is a treatment method for destroying a lesion in a body of a patient by irradiating the lesion with radiation. In this case, it is necessary for radiation to be accurately radiated to a position of the lesion. This is because a normal tissue inside a body of the patient may be influenced when the normal tissue is irradiated with the radiation. To this end, when the radiation therapy is performed, first, computed tomography (CT) is performed in advance and a position of the lesion in the body of the patient is ascertained in three dimensions in a treatment planning stage. A direction of radiation irradiation or intensity of the irradiation radiation is planned to reduce irradiation toward normal tissue, based on the ascertained position of the lesion. Thereafter, in a treatment stage, a position of the patient is matched with that of the patient in the treatment planning stage, and the lesion is irradiated with radiation according to an irradiation direction or irradiation intensity planned in the treatment planning stage.
In aligning the patient in the treatment stage, three-dimensional CT data is virtually disposed in a treatment room, and a position of a movable bed in the treatment room is adjusted so that a position of the patient actually laid on a bed matches a position of the three-dimensional CT data. More specifically, two images including a three-dimensional CT image of the patient captured in a state where the patient lies on the bed and a three-dimensional CT image captured at the time of treatment planning are collated (3D-3D positioning) so that a deviation in a position of the patient between the two images is obtained. The bed is moved based on the deviation in the position of the patient obtained through the image collation, and a position of a lesion or bone inside a body of the patient is aligned with that at the time of the treatment plan. Thereafter, two images including an X-ray fluoroscopic image of the inside of the body of the patient captured in a state where the patient lies on the bed and a digitally reconstructed radiograph (DRR) image obtained by virtually reconstructing the X-ray fluoroscopic image from the 3D CT image captured at the time of treatment planning are compared or collated with each other (3D-2D positioning) when necessary, positioning is approved, and the lesion is irradiated with radiation.
However, in the related art, since a DRR image reconstructed from the 3D CT image captured at the time of treatment planning is generally collated with the X-ray fluoroscopic image, the CT image captured in the treatment stage may not be effectively utilized for positioning of the patient in some cases.
Hereinafter, a medical image processing device, a treatment system, a medical image processing method, and a storage medium of the embodiment will be described with reference to the drawings.
A medical image processing device according to an embodiment includes a first image acquirer, s second image acquirer, a 3D-3D positioning executer, and a display controller. The first image acquirer acquire a first three-dimensional fluoroscopic image, the first three-dimensional fluoroscopic image being a three-dimensional fluoroscopic image of a patient captured in a first stage. The second image acquirer acquires a second three-dimensional fluoroscopic image, the second three-dimensional fluoroscopic image being a three-dimensional fluoroscopic image of the patient captured in a second stage after the first stage. The 3D-3D positioning executer executes 3D-3D positioning for calculating a first shift amount between the first three-dimensional fluoroscopic image and the second three-dimensional fluoroscopic image. The display controller causes the display device to display a first DRR image generated from the second three-dimensional fluoroscopic image corrected based on the first shift amount, and a two-dimensional fluoroscopic image of the patient.
The bed 12 is a movable treatment table that fixes a subject (patient) P who receives treatment using radiation, for example, in a laid state by a fixing tool or the like. The bed 12 moves in a state where the patient P is fixed inside the annular CT photographing device 16 having an opening according to the control of the bed controller 14. The bed controller 14 controls a translation mechanism and a rotation mechanism provided in the bed 12 to align a position of the patient to an irradiation position according to a movement amount signal output from the medical image processing device 100. The translation mechanism can drive the bed 12 in three axial directions, and the rotation mechanism can rotate the bed 12 around three axes. That is, the bed controller 14 controls, for example, the translation mechanism and the rotation mechanism of the bed 12 to move the bed 12 with six degrees of freedom. A degree of freedom at which the bed controller 14 controls the bed 12 may not be the six degrees of freedom, and may be a degree of freedom (for example, four degrees of freedom) lower than the six degrees of freedom or a degree of freedom (for example, eight degrees of freedom) higher than the six degrees of freedom. The bed 12 is installed to be able to be moved to both a position where photographing using the CT photographing device 16 is executed and a position where irradiation of a treatment beam B using the treatment beam irradiation gate 18 is performed when the positions are different.
The CT photographing device 16 is an imaging device for performing three-dimensional computed tomography. The CT photographing device 16 includes a plurality of radiation sources disposed inside a circular (gantry) opening, and radiates radiation for seeing through the inside of the body of the patient P from each radiation source. That is, the CT photographing device 16 radiates the radiation from a plurality of positions around the patient P. The radiation radiated from each radiation source in the CT photographing device 16 is, for example, X-rays. The CT photographing device 16 detects the radiation irradiated from the corresponding radiation source, passing through the inside of the body of the patient P, and reaching a plurality of radiation detectors disposed inside the circular opening using the radiation detectors. The CT photographing device 16 generates a CT image of the inside of the body of the patient P based on the magnitude of the energy of the radiation detected by each radiation detector. The CT image of the patient P generated by the CT photographing device 16 is a three-dimensional digital image in which a magnitude of a degree of radiation attenuation at each location inside the body is expressed as a digital value. The CT photographing device 16 outputs the generated CT image to the medical image processing device 100. The photography of the inside of the body of the patient P in the CT photographing device 16, that is, the irradiation of the radiation from each radiation source or the generation of the CT image based on the radiation detected by each radiation detector is controlled, for example, by a photography controller (not shown). The CT photographing device 16 is an example of a “first imaging device”.
The treatment beam irradiation gate 18 irradiates radiation for destroying a tumor (lesion), which is a treatment target site present in the body of the patient P, as the treatment beam B. The treatment beam B is, for example, an X-ray, a y ray, an electron beam, a proton beam, a neutron beam, or a heavy particle beam. The treatment beam B is radiated linearly from the treatment beam irradiation gate 18 to the patient P (more specifically, a tumor in the body of the patient P). The irradiation of the treatment beam B at the treatment beam irradiation gate 18 is controlled by, for example, a treatment beam irradiation controller (not shown). In the treatment system 1, the treatment beam irradiation gate 18 is an example of an “irradiator.”
In the radiation therapy, the treatment plan is made in a situation in which a treatment room is simulated. That is, in the radiation therapy, an irradiation direction, intensity, or the like when the patient P is irradiated with the treatment beam B is planned through a simulation of a state where the patient P is laid on the bed 12 in the treatment room. Specifically, an irradiation target location is specified by a doctor for the CT image, or such processing is performed automatically. To this end, information such as a parameter representing an angle of the bed 12 or a body position (such as lying on one's back or face down) of the patient in the treatment room is assigned to the CT image at a treatment planning stage. This is also true for the CT image captured immediately before the radiation therapy or the CT image captured at the time of previous radiation therapy. That is, the parameter representing the angle of the bed 12 or the body position of the patient at the time of photographing is assigned to the CT image obtained by photographing the inside of the body of the patient P using the CT photographing device 16.
The medical image processing device 100 outputs the movement amount signal for moving the bed 12 to the bed controller 14 to align the position of the patient P to the same body position as in the time of the treatment plan. That is, the medical image processing device 100 outputs to the bed controller 14 a movement amount signal for moving the patient P to a position and at a posture where a tumor or tissue to be treated can be appropriately irradiated with the treatment beam B in the radiation therapy.
The display device 200 displays images for presenting various types of information in the treatment system 1 to a radiation therapist (such as a doctor) who uses the treatment system 1, including during positioning of the patient P in the medical image processing device 100. The display device 200 displays various images such as the CT image or X-ray fluoroscopic image output by the medical image processing device 100, or an image obtained by superimposing various types of information on these images. Here, examples of the various types of information include patient information (age, sex, height, weight, or the like), image capturing conditions (photographing part, presence or absence of a contrast agent, tube voltage, tube current, or the like), image capturing date and time, and the body position of the patient (head-up position, feet-up position, or the like). The display device 200 is, for example, a display device such as a liquid crystal display (LCD). The radiation therapist can obtain information when the radiation therapy is performed using the treatment system 1 by visually confirming the image displayed on the display device 200. The treatment system 1 may be configured to include a user interface such as an operator (not shown) operated by the radiation therapist, and to allow various functions executed by the treatment system 1 to be manually operated.
The radiation source 20-1 radiates radiation r-1 for seeing through the inside the body of the patient P from a predetermined angle. The radiation source 20-2 radiates radiation r-2 for seeing through the inside the body of the patient P from a predetermined angle different from that of the radiation source 20-1. The radiation r-1 and the radiation r-2 are, for example, X-rays.
The radiation detector 30-1 detects the radiation r-1 radiated from the radiation source 20-1, passing through the inside of the body of the patient P, and reaching the radiation detector 30-1, and generates an X-ray fluoroscopic image of the inside of the body of the patient P according to a magnitude of energy of the detected radiation r-1. The radiation detector 30-2 detects the radiation r-2 radiated from the radiation source 20-2 and passing through the inside of the body of the patient P, and generates an X-ray fluoroscopic image of the inside of the body of the patient P according to a magnitude of energy of the detected radiation r-2. The radiation detector 30 includes X-ray detectors disposed in a two-dimensional array, and generates a digital image in which the magnitude of the energy of the radiation r that reaches each X-ray detector is expressed as a digital value, as the X-ray fluoroscopic image. The radiation detector 30 is, for example, a flat panel detector (FPD), an image intensifier, or a color image intensifier. In the following description, each radiation detector 30 is assumed to be an FPD. The radiation detector 30 (FPD) outputs each generated X-ray fluoroscopic image to the medical image processing device 100. In
The various components shown in
Hereinafter, the medical image processing device 100 of the embodiment will be described.
Some or all of components of the medical image processing device 100 are realized by, for example, a hardware processor such as a central processing unit (CPU) executing a program (software). Some or all of these components may be realized by hardware (circuit; including circuitry) such as a large scale integration (LSI), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a graphics processing unit (GPU), or may be realized by collaboration between software and hardware. Some or all of functions of these components may be realized by a dedicated LSI. The program may be stored in a storage device (a storage device including a non-transitory storage medium) such as a read only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), or a flash memory included in the medical image processing device 100 in advance, or may be stored in a removable storage medium (non-transitory storage medium) such as a DVD or CD-ROM and installed in the HDD or flash memory included in the medical image processing device 100 when the storage medium is mounted on a drive device included in the medical image processing device 100. The program may be downloaded from another computer device via a network and installed in the HDD or flash memory included in the medical image processing device 100.
The first image acquirer 110 acquires a first image regarding the patient P before treatment and parameters (and/or treatment plan data) associated with the first image. The first image is, for example, a three-dimensional CT image representing a three-dimensional shape of the inside of the body of the patient P, which is photographed by the CT photographing device 16 in the treatment planning stage when the radiation therapy is performed. The first image is used for a determination of a direction (a path including an inclination, a distance, or the like) or intensity of the treatment beam B to be radiated to the patient P in the radiation therapy. The first image is an example of a “first three-dimensional fluoroscopic image.”
The second image acquirer 120 acquires a second image of the patient P immediately before the start of the radiation therapy and parameters associated with the second image. The second image is, for example, a three-dimensional CT image representing the three-dimensional shape of the inside of the body of the patient P photographed by the CT photographing device 16 in order to align the body position of the patient P at the time of irradiation with the treatment beam B in the radiation therapy (that is, to perform positioning). That is, the second image is an image captured by the CT photographing device 16 immediately before the treatment beam B is radiated from the treatment beam irradiation gate 18. In this case, the first image and the second image are captured at different times, but methods of capturing the image are the same. The second image is an example of a “second three-dimensional fluoroscopic image.”
The 3D-3D positioning executer 130 performs 3D-3D positioning processing for aligning the position of the patient P when the radiation therapy is performed, based on the first image acquired by the first image acquirer 110 and the second image acquired by the second image acquirer 120. More specifically, for example, the medical image processing device 100 calculates a three-dimensional shift amount (hereinafter referred to as a “first shift amount” in some cases) between the first image acquired by the first image acquirer 110 and the second image acquired by the second image acquirer 120, and aligns the positions between the first image and the second image by correcting the second image by the calculated first shift amount. In this case, the medical image processing device 100 may output a movement amount signal for moving the bed 12 on which the patient is laid and fixed, by the first shift amount to the bed controller 14, and the bed controller 14 may move the bed 12 by the first shift amount. Furthermore, when the CT photographing device 16 and the treatment beam irradiation gate 18 are installed at positions apart from each other, the medical image processing device 100 may output a movement amount signal for moving the bed 12 by an amount obtained by adding the first shift amount to a distance between the CT imaging position and the irradiation position to the bed controller 14, and the bed controller 14 may move the bed 12 by the amount obtained by adding the first shift amount to the distance.
In the related art, generally, when positioning of the patient is performed in the radiation therapy, a DRR image generated from a CT image captured in the treatment planning stage is collated with an X-ray fluoroscopy image captured in the treatment stage (3D-2D positioning), and the bed 12 is moved by the specified shift amount so that positioning is performed. On the other hand, as shown in
The 3D-2D positioning executer 140 executes the 3D-2D positioning processing for collating the DRR image generated from the second image with the X-ray fluoroscopic image of the patient captured in the treatment stage. More specifically, the 3D-2D positioning executer 140 calculates a three-dimensional shift amount (hereinafter referred to as a “second shift amount” in some cases) between the DRR image generated from the second image corrected by the first shift amount and the X-ray fluoroscopic image of the patient captured after the bed 12 on which the patient is laid and fixed is moved by the first shift amount. For example, when the calculated second shift amount is smaller than a threshold value, the radiation therapist approves the positioning. On the other hand, when the calculated second shift amount is equal to or larger than the threshold value, the bed controller 14 moves the bed 12 by the calculated second shift amount, and captures the X-ray fluoroscopic image of the patient again, and the 3D-2D positioning executer 140 executes the 3D-2D positioning processing again using the captured X-ray fluoroscopic image. The processing is repeated, and finally, the positioning is approved by the radiation therapist.
The 3D-2D positioning executer 140 is also configured to execute the 3D-2D positioning processing for collating the DRR image generated from the first image with the X-ray fluoroscopic image of the patient, in addition to the 3D-2D positioning processing for collating the DRR image generated from the second image with the X-ray fluoroscopic image of the patient. More specifically, the 3D-2D positioning executer 140 calculates a three-dimensional shift amount (hereinafter referred to as a “third shift amount” in some cases) between the DRR image generated from the first image and the captured X-ray fluoroscopic image of the patient. In this case, the captured X-ray fluoroscopic image of the patient may be an image captured after the bed 12 is moved by the first shift amount as described above, or may be an image captured after the bed 12 is moved by an amount obtained by adding the first shift amount to the distance between the CT imaging position and the irradiation position when the CT photographing device 16 and the treatment beam irradiation gate 18 are installed at positions apart from each other. The radiation therapist approves the positioning, for example, when the calculated third shift amount is smaller than a threshold value. On the other hand, when the calculated third shift amount is equal to or greater than the threshold value, the bed controller 14 moves the bed 12 by the calculated third shift amount, captures the X-ray fluoroscopic image of the patient again, and the 3D-2D positioning executer 140 executes the 3D-2D positioning processing again using the captured X-ray fluoroscopic image. The process is repeated, and the positioning is finally approved by the radiation therapist.
The series of processes executed by the 3D-3D positioning executer 130 and the 3D-2D positioning executer 140 described above is not limited to positioning before the radiation therapy, and can also be applied to verify the positioning after treatment using the CT image captured after the radiation therapy, for example. Specifically, first, the CT image of the patient is captured by the CT photographing device 16 immediately after the treatment beam B is radiated. Next, the 3D-3D positioning executer 130 performs 3D-3D positioning processing between the captured CT image and the CT image captured in the treatment planning stage. Thereafter, the 3D-2D positioning executer 140 may generate a DRR image based on the shift amount specified through the 3D-3D positioning processing, and perform 3D-2D positioning between the generated DRR image and the X-ray fluoroscopic image at the time of positioning approval. It is possible to verify the positioning using this 3D-3D positioning or the shift amount specified by the 3D-2D positioning. Thus, the “second stage” is a concept including both immediately before the radiation therapy (that is, the treatment stage) and immediately after the radiation therapy.
The display controller 150 causes the display device 200 to display various types of information processed by the medical image processing device 100. For example, the display controller 150 may cause the display device 200 to display the DRR image generated from the second image corrected by the first shift amount and the X-ray fluoroscopic image of the patient together. When the DRR image is generated from the first image, the display controller 150 may also cause the display device 200 to display the DRR image and the X-ray fluoroscopic image of the patient together. Further, for example, the display controller 150 may cause the display device 200 to display an execution result of the 3D-3D positioning processing or an execution result of the 3D-2D positioning processing. Further, for example, the display controller 150 may cause the display device 200 to display an interface (IF) that receives a designation regarding whether to generate the DRR image based on one (or both) of the first image or the second image and execute the 3D-2D positioning processing after execution of the 3D-3D positioning.
In
A region R3 represents an execution result of the 3D-3D positioning processing performed before the 3D-2D positioning processing is executed. A region R4 represents an execution result of the 3D-2D positioning processing using the DRR image generated from the second image. Thus, the display device 200 displays the execution result of the 3D-3D positioning processing and the execution result of the 3D-2D positioning processing together, thereby making it possible for the radiation therapist to confirm whether the patient has been positioned appropriately.
First, the first image acquirer 110 acquires the first image of the patient P captured by the CT photographing device 16 in the treatment planning stage (step S100). Next, the bed controller 14 moves the bed 12 to the CT imaging position (step S102). Next, the second image acquirer 120 acquires the second image of the patient P captured by the CT photographing device 16 in the CT photographing device (step S104).
Next, the 3D-3D positioning executer 130 performs 3D-3D positioning processing for aligning the position of the patient P when the radiation therapy is performed, based on the first image acquired by the first image acquirer 110 and the second image acquired by the second image acquirer 120 (step S106). Next, the bed controller 14 moves the bed 12 by the first shift amount specified through the 3D-3D positioning processing (step S108).
After the bed 12 is moved, the medical image processing device 100 captures the X-ray fluoroscopic image of the patient P using the X-ray photographing device (step S110). Next, the 3D-2D positioning executer 140 performs the 3D-2D positioning processing for calculating the second shift amount between the DRR image generated from the second image corrected by the first shift amount and the X-ray fluoroscopic image (step S112).
Next, the medical image processing device 100 determines whether the positioning has been approved by the radiation therapist (step S114). More specifically, the medical image processing device 100 may determine whether the positioning has been manually approved by the radiation therapist on an interface (IF) on the display device 200, or may automatically determine the approval of the positioning by determining whether the calculated second shift amount is within the threshold value.
When a determination is made that the positioning has been approved by the radiation therapist, the medical image processing device 100 confirms the positioning and ends the processing of this flowchart. On the other hand, when a determination is made that the positioning has not been approved by the radiation therapist, the bed controller 14 moves the bed 12 by the second shift amount specified by the 3D-2D positioning processing (step S116) and returns the processing to step S110 again.
Through the processing of the flowchart, the medical image processing device 100 corrects the second image using the first shift amount specified through the 3D-3D positioning processing, and executes the 3D-2D positioning processing, based on the DRR image generated from the corrected second image and the X-ray fluoroscopic image obtained by photographing the patient P after the bed is moved by the first shift amount. This makes it possible to effectively utilize the CT images captured in the treatment stage for positioning of the patient.
In the processing of the flowchart in
Next, a flow of the processing that is executed by the medical image processing device 100 will be described with reference to
First, the first image acquirer 110 acquires the first image of the patient P photographed by the CT photographing device 16 in the treatment planning stage (step S200). Next, the bed controller 14 moves the bed 12 to the CT imaging position (step S202). Next, the second image acquirer 120 acquires the second image of the patient P captured by the CT photographing device 16 in the CT photographing device (step S204).
Next, the 3D-3D positioning executer 130 performs 3D-3D positioning processing for aligning the position of the patient P when the radiation therapy is performed, based on the first image acquired by the first image acquirer 110 and the second image acquired by the second image acquirer 120 (step S206). Next, the bed controller 14 moves the bed 12 by the first shift amount specified through the 3D-3D positioning processing (step S208).
After the bed 12 is moved, the medical image processing device 100 uses the X-ray photographing device to capture the X-ray fluoroscopic image of the patient P (step S210). Next, the medical image processing device 100 receives a designation regarding whether or not to the 3D-2D positioning processing using the second image is performed, through the interface (IF) on the display device 200 (step S212). When a determination is made that the 3D-2D positioning processing using the second image is performed, the 3D-2D positioning executer 140 performs 3D-2D positioning processing for calculating the second shift amount between the DRR image generated from the second image corrected by the first shift amount and the X-ray fluoroscopic image (step S214). On the other hand, when a determination is not made that the 3D-2D positioning processing using the second image is performed, the 3D-2D positioning executer 140 performs 3D-2D positioning processing for calculating the third shift amount between the DRR image generated from the first image and the X-ray fluoroscopic image (step S216). In this case, in step S214 and/or step S216, the display controller 150 causes the display device 200 to display the DRR image and the X-ray fluoroscopic image together.
Next, the medical image processing device 100 determines whether the positioning has been approved by the radiation therapist (step S218). More specifically, the medical image processing device 100 may determine whether the positioning has been manually approved by the radiation therapist in the interface (IF) on the display device 200, or may automatically determine the approval of the positioning by determining whether the calculated second shift amount or third shift amount is within the threshold value.
When a determination is made that the positioning has been approved by the radiation therapist, the medical image processing device 100 confirms the positioning and ends the processing of this flowchart. On the other hand, when a determination is made that the positioning is not approved by the radiation therapist, the bed controller 14 moves the bed 12 by the second or third shift amount specified through the 3D-2D positioning processing (step S220), and returns the processing to step S210 again.
Through the processing of the flowchart, the medical image processing device 100 receives a designation regarding execution of the 3D-2D positioning processing using the second image corrected by the first shift amount specified through the 3D-3D positioning processing or execution of the 3D-2D positioning processing using the first image, and determines which 3D-2D positioning processing is executed depending on the designation of the radiation therapist. This makes it possible to improve convenience for the radiation therapist.
In the processing of the flowchart in
According to at least one embodiment described above, the medical image processing device 100 corrects the second image using the first shift amount specified through the 3D-3D positioning processing, and executes the 3D-2D positioning processing based on the DRR image generated from the corrected second image and the X-ray fluoroscopic image obtained by photographing the patient P after moving the bed by the first shift amount. This makes it possible to effectively utilize the CT images captured in the treatment stage for positioning of the patient.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-041522 | Mar 2022 | JP | national |
The present application claims priority based on Japanese Patent Application No. 2022-041522 filed Mar. 16, 2022 and PCT/JP2023/005223 filed Feb. 15, 2023, the contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2023/005223 | Feb 2023 | WO |
| Child | 18770331 | US |
