JP6591229B2 - Patient positioning apparatus, apparatus operating method and program - Google Patents

Description

  Embodiments of the present invention relate to positioning techniques for patients undergoing radiation therapy.

Radiation therapy is a treatment technique that destroys a lesion tissue by irradiating the lesion of a patient with a treatment beam. Therefore, if the treatment beam is not accurately irradiated to the lesion area, there is a risk that even the normal tissue is destroyed.
Therefore, prior to treatment beam irradiation, X-ray CT imaging is performed to acquire data of a three-dimensional image in the patient's body, and the lesion range is three-dimensionally grasped.
Then, based on the three-dimensional image data in the patient body, a treatment plan for determining the irradiation direction and irradiation intensity of the treatment beam is formulated so that the irradiation to the normal tissue is reduced.

  In the treatment beam irradiation stage, the patient's position is adjusted or the patient's bed is moved so that the aim of the treatment beam matches the patient's lesion range derived in the treatment plan. Positioning is performed.

The determination of whether or not this patient positioning has been performed correctly is based on an X-ray projection image obtained by actually capturing the patient with an X-ray imaging unit permanently installed in the radiation treatment system and a three-dimensional image data used in the treatment plan. The reconstructed DRR (Digitally Reconstructed Radiograph) is collated, and based on whether or not the respective lesion ranges match.
On the other hand, for the purpose of reducing the exposure dose of a patient, a technique is known in which an optical camera is used in place of an X-ray imaging unit and a positioning determination is performed using a marker attached to the patient's body surface as a reference point. It has become.

Japanese translation of PCT publication No. 2002-528168 (International publication WO00 / 24333) JP-A-11-197259

  The patient positioning using the optical camera described above is only to determine whether it is appropriate or inappropriate, and when it is determined to be inappropriate, it gives a countermeasure on how to eliminate the deviation amount. It wasn't something that gave me.

  Embodiments of the present invention have been made in consideration of such circumstances, and provide a patient positioning technique capable of positioning a patient accurately in a short time without being exposed to a treatment beam irradiation region. With the goal.

  A patient positioning apparatus according to an embodiment of the present invention includes a first holding unit that holds a surface image obtained by measuring a surface shape of a patient disposed in an irradiation region of a treatment beam, and features of the patient included in the surface image A first identifying unit for identifying a point; a first computing unit for computing a first feature point coordinate in the coordinate system of the irradiation region of the feature point identified from the surface image; and a marker attached to the patient on the surface A detection unit that detects from an image; a marker coordinate calculation unit that calculates a marker coordinate in the coordinate system of the irradiation region of the marker detected from the surface image; and a coordinate conversion of the first feature point coordinate to the marker coordinate A characteristic of the patient calculated based on a conversion parameter deriving unit that derives a conversion parameter, a three-dimensional image obtained by three-dimensionally imaging the patient, and position information of the three-dimensional image that is positioned in the coordinate system of the irradiation region. An acquisition unit that acquires a second feature point coordinate in the coordinate system of the irradiation area of a point, a conversion unit that converts the second feature point coordinate to a target coordinate by the conversion parameter, and a pointer that is projected onto the target coordinate And a control unit.

  Embodiments of the present invention provide a patient positioning technique capable of positioning a patient accurately and in a short time without being exposed to a treatment beam irradiation region.

The block diagram which shows the patient positioning device which concerns on 1st Embodiment of this invention. Explanatory drawing of the calibration method of an optical camera (surface measuring device). The partial enlarged view of the patient arrange | positioned in the irradiation area | region of a beam. The block diagram which shows the patient positioning device which concerns on 2nd Embodiment. The lineblock diagram showing the patient positioning device concerning a 3rd embodiment. The block diagram which shows the patient positioning device which concerns on 4th Embodiment. The flowchart of the patient positioning method or patient positioning program which concerns on each embodiment.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows an outline of a radiotherapy system to which a patient positioning apparatus 10A (10) according to a first embodiment is applied.
In the treatment room 30, a beam irradiation unit 34 that irradiates the patient 32 with a treatment beam controlled by the irradiation control unit 29, a bed 33 that lies the patient 32 in the irradiation region 31, and the surface of the patient 32 is measured. A surface measuring instrument 35, a projector 36 that projects a pointer 44 (FIG. 3) on the surface of the patient 32, and a monitor 37 that displays an image of the patient 32 in real time.

The patient positioning apparatus 10 </ b> A (10) includes a first holding unit that holds the surface image 11 obtained by measuring the surface shape of the patient 32 disposed in the treatment beam irradiation region 31, and patient characteristics included in the surface image 11. A first identification unit 12 that identifies a point 41 (FIG. 3), and a first feature point coordinate P (P ₁ , P) in the coordinate system (XYZ) of the irradiation region of the feature point 41 identified from the surface image 11 P ₂ , P ₃ ), the first calculation unit 13 for calculating the marker 42 attached to the patient 32 from the surface image 11, and the coordinate system of the irradiation area of the marker 42 detected from the surface image 11 A marker coordinate calculation unit 15 for calculating the marker coordinates Q (Q ₁ , Q ₂ , Q ₃ ) in (XYZ) and a conversion parameter W for coordinate conversion of the first feature point coordinates P to the marker coordinates Q are derived. Conversion parameter deriving unit 16 and patient 32 in three dimensions A second holding unit that holds the imaged three-dimensional image 21, a second identification unit 22 that identifies a patient feature point 43 included in the three-dimensional image 21, and a coordinate system (XYZ) of the irradiation region. A third holding unit that holds position information 24 of the three-dimensional image 21 to be positioned (FIG. 3), and a second in the coordinate system (XYZ) of the irradiation region of the feature point 43 identified from the three-dimensional image 21. A second calculation unit 23 that calculates the feature point coordinates R (R ₁ , R ₂ , R ₃ ) based on the position information 24, and the second feature point coordinates R are converted into the target coordinates S (S ₁ , S ₂ by the conversion parameter W). , S ₃ ), and a control unit 26 for controlling the projector 36 so as to project the pointer 44 onto the target coordinates S.

Although the beam irradiation unit 34 in each embodiment is illustrated as being fixed in the treatment room 30, it rotates or translates around the patient 32 in accordance with the posture of the patient 32 and the irradiation direction of the treatment beam. It may move.
The treatment beam is radiation that irradiates the affected tissue such as cancer and kills the cells. Examples of such radiation include X-rays, γ-rays, electron beams, proton beams, neutron beams, and heavy particle beams. Adopted.
In addition, the second holding unit of the three-dimensional image 21, the second identification unit 22, the third holding unit of the position information 24, the second calculation unit 23, which are partitioned by a broken line in the patient positioning apparatus 10A, You may comprise the pre-processing part 20 containing these by another apparatus. In this case, prior to measuring the surface image 11 of the patient 32 in the patient positioning apparatus 10A, the acquisition unit (not shown) acquires the second feature point coordinates R calculated in advance by this separate apparatus. It may be.

The radiotherapy system to which this embodiment is applied varies greatly in scale and form depending on the type of equipment and the treatment beam to be applied. However, any radiation treatment system is common in that a treatment plan is performed prior to irradiation of a treatment beam.
In the treatment plan, CT (Computed Tomography) imaging of a patient is performed in advance in the same posture as that of receiving the treatment beam, and a three-dimensional image 21 of the patient including the affected part is acquired.
Based on the three-dimensional image 21, the radiation amount, irradiation angle, irradiation range, number of times, and the like of the radiation irradiated to the affected area are discussed by the professional staff, and the position information 24 of the patient 32 arranged in the irradiation region 31 is obtained. It is determined.

Then, the patient 32 is positioned in the irradiation region 31 based on the position information 24 determined by this treatment plan. When the patient 32 is positioned on the bed 33, the state is required to be maintained until the irradiation of the treatment beam is completed.
There are several positioning methods and state maintaining methods. In the first embodiment, a case where the patient performs his / her own judgment or a case where the patient's posture is moved according to the judgment of the medical staff will be described.

  The radiotherapy system illustrated in FIG. 1 relates to neutron capture therapy, and a compound containing boron or the like that generates a particle beam (alpha ray) by nuclear reaction with neutrons is preliminarily incorporated into tumor cells. Then, a treatment beam of neutrons is irradiated toward the affected area, and only tumor cells that have taken in a lot of boron are destroyed by alpha rays generated by the nuclear reaction.

The advantage of neutron capture therapy is that alpha rays only fly 10 microns, so that only tumor cells are selectively killed without damaging normal cells.
In neutron capture therapy, the time required for one irradiation of the treatment beam is as long as several minutes to several tens of minutes. Therefore, the patient 32 needs to keep the posture determined by the treatment plan throughout the treatment beam irradiation period. .
On the other hand, in radiation therapy using X-rays and γ-rays, and heavy particle beam therapy using accelerated heavy charged particle beams, the patient's restraint time when irradiating a treatment beam once is more than neutron capture therapy. Is short.

As the surface measuring instrument 35 for measuring the surface image 11 of the patient 32, a plurality of optical cameras 35a and 35b (FIG. 2) are used to take a stereo image of the surface shape of the patient 32, or a laser scanner (not shown) is used for the patient 32. The surface shape of these is laser-scanned.
In addition, in order to reduce the blind spot of the irradiation area 31, it is desirable to arrange three or more surface measuring instruments 35.

  Here, the optical camera detects the visible light reflected from the surface of the patient 32 with a plurality of light receiving sensors arranged in a plane, and obtains a two-dimensional image. From each of two-dimensional images taken by a plurality of optical cameras arranged at different positions, a group of coordinate values representing the surface shape of the patient can be obtained based on the principle of triangulation.

The laser scanner measures the distance by measuring the time that the laser pulse reciprocates between the surface of the patient 32 and the light receiving sensor and the phase difference of the wavelength, and simultaneously measures the direction in which the laser pulse is emitted. A group of coordinate values representing the surface shape of the patient can be obtained.
Thus, the surface image 11 of the patient 32 measured by the surface measuring instrument 35 is held by the patient positioning device 10.

The calibration unit 27 replaces the coordinate value of the surface image 11 represented by the coordinate system of the surface measuring instrument 35 with the coordinate value of the coordinate system (XYZ) of the irradiation region 31.
The calibration of the optical camera 35 (35a, 35b) will be described with reference to FIG.
The coordinate values of the surface images 11a and 11b obtained by stereo-photographing the calibration body 38 arranged in the irradiation region 31 with a plurality of optical cameras 35 (35a and 35b) are in a two-dimensional coordinate system (xy) unique to the optical camera. It is represented.

From the two-dimensional coordinate system (xy) of these surface images 11a and 11b, the measurement point 45 of the calibration body whose coordinate value in the coordinate system (XYZ) of the irradiation area is known is identified.
Then, the calibration constant B is set so that the measurement point 45 identified from the two-dimensional coordinate system (xy) is replaced with a known coordinate value of the coordinate system (XYZ).
This calibration constant B is used to calculate a coordinate value to be replaced with the coordinate system (XYZ) of the irradiation area from the coordinate system of the surface measuring instrument 35 in the first calculation unit 13 and the marker coordinate calculation unit 15 described later. Used.

The calibration of the surface measuring instrument 35 includes calibration of internal constants such as a focal length and a lens distortion correction coefficient in addition to the above-described external constants related to the replacement of the coordinate system.
The calibration of the surface measuring instrument 35 may be performed when the positional relationship of the surface measuring instrument 35 changes during system construction, system repair or replacement, and does not need to be performed every time the patient 32 changes.

As the internal constant of the optical camera, known coordinate values (X, Y, Z) of at least six points or more in the coordinate system (XYZ) of the irradiation area are used. For example, when the three-dimensional coordinates of the optical camera are (X ₀ , Y ₀ , Z ₀ ), the two-dimensional coordinates obtained by photographing the measurement point 45 of the calibration body 38 by the optical camera are (x, y), and the three-dimensional coordinates Can be expressed as (x ₀ ', y ₀ ', -f).
However, (x ′, y ′) is a value obtained by converting (x, y) by the scale of the photographed image. An internal constant can be obtained from a collinear conditional expression (FIG. 2) using the coordinates expressed in this way on a straight line by a convergence operation such as a least square method.
Incidentally, a ₁₁ ~a ₃₃ in the formula represents a rotation matrix representing the rotation angle of each axis of the optical camera (the posture of the camera).

Using the obtained internal constants of the optical camera, the relative position and orientation of each camera are obtained. Here, the calibration body 38 is fixedly arranged at a position where it can be photographed by all necessary cameras. Using the two-dimensional coordinates of the measurement point 45 obtained by photographing with all the cameras, the position / orientation of each camera is converged using the collinear conditional expression (FIG. 2).
If there are two cameras, at least three known measurement points 45 on the calibration body 38 are required, and the number of calibration measurement points is appropriately increased depending on the convergence status of the convergence calculation.

A calibration method of a laser scanner (not shown) as the surface measuring device 35 is also used to measure the measurement points 45 whose coordinate values in the coordinate system (XYZ) of the irradiation area are known, as in the case of the optical camera 35 described above. This is performed using a calibration body 38 having the same.
Although the calibration method for replacing the coordinate system of the surface measuring instrument 35 with the coordinate system (XYZ) of the irradiation area by actually measuring the calibration body 38 has been described, other than actually measuring the calibration body 38 in this way. It is also possible to perform calibration to replace the coordinate system from the design specification data.

As shown in FIG. 3, when the treatment site is the head, the right external eye angle, the left external eye angle, and the nose tip can be identified from the surface image 11 of the head as the patient feature points 41. In addition, the nose root portion, the outer ear, and the like can be set as the feature points 41.
The first identification unit 12 (FIG. 1) may automatically identify these feature points 41 included in the surface image 11. In addition, a medical worker may manually set the position of the feature point 41 included in the surface image 11 displayed on the monitor (not shown) by using the operation setting unit 17 by a cursor operation or the like.

The feature points 41 identified from the surface image 11 are represented by the coordinate system of the surface measuring instrument 35.
Therefore, the first calculation unit 13 inputs the coordinate value of the feature point 41 expressed in the coordinate system of the surface measuring instrument 35 and, based on the calibration constant B, in the coordinate system (XYZ) of the irradiation region. An operation for replacing the first feature point coordinates P (P ₁ , P ₂ , P ₃ ) is performed and output.

As shown in FIG. 3, the marker 42 is attached to the surface of the patient 32.
As will be described later, the marker 42 moves the pointer 44 so that the posture of the patient 32 on the bed 33 (the arrangement of the surface image 11) matches the posture determined by the treatment plan (the arrangement of the three-dimensional image 21). It plays a role as a target to be projected onto the upper surface.

When the surface measuring instrument 35 is an optical camera, a colored spherical object or a colored rectangular / circular seal is applied as the marker 42. Thereby, even if the posture of the patient 32 is changed, an effect that has little influence on the way the optical camera is captured can be obtained.
On the other hand, when the surface measuring device 35 is a laser scanner, a spherical object or a rectangular / circular seal made of a reflective material that easily reflects the wavelength of laser light or the like is applied as the marker 42.

  The marker detection unit 14 (FIG. 1) may automatically identify the marker 42 attached to the surface image 11. In addition, the medical staff may manually set the position of the marker 42 included in the surface image 11 projected on the monitor (not shown) by the operation setting unit 17 by a cursor operation or the like.

The marker 42 identified from the surface image 11 is represented by the coordinate system of the surface measuring instrument 35.
Therefore, the marker coordinate calculation unit 15 inputs the coordinate value of the marker 42 expressed in the coordinate system of the surface measuring instrument 35 and, based on the calibration constant B, the marker in the coordinate system (XYZ) of the irradiation region. An operation for replacing the coordinates Q (Q ₁ , Q ₂ , Q ₃ ) is performed and output.

The relative positional relationship (see FIG. 3) between the first feature point coordinates P (P ₁ , P ₂ , P ₃ ) and the marker coordinates Q (Q ₁ , Q ₂ , Q ₃ ) calculated in this way is the irradiation area. It is constant irrespective of the arrangement of the surface image 11 in the coordinate system (XYZ).
Therefore, the first feature point coordinate P and the marker coordinate Q are input to the conversion parameter deriving unit 16 to derive a conversion parameter W for coordinate conversion of the first feature point coordinate P to the marker coordinate Q.
By using this conversion parameter W, the corresponding marker coordinate Q can be obtained from the first feature point coordinate P at an arbitrary position in the coordinate system (XYZ) of the irradiation region.
The conversion parameter W derived in this way can be reused in the subsequent treatment beam irradiation only when the marker 42 is attached to the same position and applied to the same patient 32 in the same system.

As described above, the three-dimensional image 21 is obtained by performing a tertiary treatment on the patient 32 with the same posture as that irradiated with the treatment beam by a medical imaging device (modality) such as an X-ray CT apparatus or an MRI apparatus at the stage of treatment planning. The original image was taken. Similarly, the position information 24 is also determined in advance as information that defines how to position the three-dimensional image 21 in the coordinate system (XYZ) of the irradiation region at the stage of treatment planning. .
The three-dimensional image 21 and the position information 24 are held in the patient positioning device 10 before the patient 32 is fixed to the bed 33.

As shown in FIG. 3, the feature points 43 of the three-dimensional image 21 are identified corresponding to the feature points 41 of the surface image 11 measured by the surface measuring device 35.
The second identification unit 22 (FIG. 1) may automatically identify these feature points 43 included in the three-dimensional image 21. In addition, a medical worker may manually set the position of the feature point 43 included in the three-dimensional image 21 displayed on the monitor (not shown) by the cursor operation or the like using the operation setting unit 17. .

The feature points 43 identified from the three-dimensional image 21 are represented by the coordinate system of the medical image equipment that captured the feature points 43.
Therefore, the second calculation unit 23 inputs the coordinate value of the feature point 43 represented in the coordinate system of this medical image device, and based on the position information 24, the second calculation unit 23 of the irradiation area coordinate system (XYZ). 2. Perform the operation of replacing with the feature point coordinates R (R ₁ , R ₂ , R ₃ ) and output.

From this three-dimensional image 21, the position (target coordinate S) corresponding to the marker 42 detected from the surface image 11 cannot be directly derived. However, the relative positional relationship between the second feature point coordinate R and the target coordinate S is constant in the coordinate system (XYZ) of the irradiation region regardless of the position information 24 that defines the arrangement of the three-dimensional image 21. is there.
Therefore, the second feature point coordinate R and the conversion parameter W are input to the target coordinate conversion unit 25, and the second feature point coordinate R is converted to the target coordinate S.

The projector 36 projects a pointer light beam 44a toward the treatment beam irradiation area 31. The pointer 44 is projected at a point where the light ray 44a is incident on the surface of the patient. That is, the body surface of the patient 32 becomes a screen of the pointer 44 projected by the projector 36.
Such a projector 36 includes an output light source of visible light or laser light, an optical lens for adjusting the projection size and focus of the pointer 44, and employs a general optical projector, a laser marking, or the like. can do.

The pointer 44 may have a circular shape, a cross shape, or the like, and may project a body surface model around the affected area of the patient.
The pointer projection control unit 26 also performs the same calibration as the calibration unit 27 described above, so that the pointer light ray 44a is accurately set to the coordinate value specified in the coordinate system (XYZ) of the irradiation region. Adjustments are made to project.
Further, the calibration of the pointer projection control unit 26 may be performed when the positional relationship of the projector 36 changes during system construction, system repair or replacement, and does not need to be performed every time the patient 32 changes.

The pointer projection control unit 26 controls the pointer beam 44a so as to pass through the target coordinates S (S ₁ , S ₂ , S ₃ ). If the marker 42 is positioned at the target coordinates S, the pointer 44 Is projected onto the marker 42.
When the marker 42 is located away from the target coordinate S, the pointer 44 is projected on the surface of the patient other than the marker 42.

The image output unit 28 displays the real-time surface image 11 of the patient 32 on the monitor 37. The patient 32 lying on the bed 33 fixed to the treatment room 30 can move and align his / her body while observing the surface image 11 displayed on the monitor 37.
In addition, when the medical staff attaches to the bed 33 and aligns the patient 32 who is lying down, since the pointer 44 and the marker 42 can be directly observed, it is not necessary to observe the monitor 37.

The state in which all the pointers 44 are projected in accordance with the corresponding markers 42 indicates that the alignment has been completed. That is, it shows a state in which the posture of the patient (arrangement of the surface image 11) in the coordinate system (XYZ) of the irradiation region and the posture of the patient determined by the treatment plan (arrangement of the three-dimensional image 21) match. Yes.
Therefore, if a command is sent to the irradiation control unit 29 of the beam irradiation unit 34 in this state, the treatment beam is intensively irradiated to the affected area of the patient 32 and the affected cell can be killed.

(Second Embodiment)
As shown in FIG. 4, the patient positioning apparatus 10B according to the second embodiment uses coordinates Q (Q ₁ , Q ₂ , Q ₃ ) of the marker 42 in the coordinate system (XYZ) of the irradiation area. A movement vector calculation unit 51 is further provided for calculating a movement vector T to be moved to the target coordinates S (S ₁ , S ₂ , S ₃ ) (FIG. 3). 4, parts having the same configuration or function as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

Then, the pointer projection control unit 26 projects information (arrows 46 (46 ₁ , 46 ₂ , 46 ₃ )) regarding the direction or size of the movement vector T together with the corresponding pointer 44.
By displaying the arrows 46 (46 ₁ , 46 ₂ , 46 ₃ ) in this way, the direction in which the patient is moved can be visually recognized, and the patient 32 can be positioned efficiently.

The threshold determination unit 52 determines whether the movement vector T is larger or smaller than the threshold. Then, the pointer projection control unit 26 projects information (color information) regarding the determination result together with the corresponding pointer 44.
Thus, by projecting the information regarding the determination result, it can be visually recognized whether or not the projected pointer 44 matches the marker 42, and the patient 32 can be positioned efficiently.

  As other information projected by the pointer projection control unit 26 together with the pointer 44, the marker coordinates Q in the coordinate system (XYZ) of the irradiation region and the magnitude of the movement vector T representing the amount of deviation in patient positioning are used. It may be indicated by a numerical value or a figure having a size corresponding to the amount of deviation (for example, an arrow, a circle, a cross, a rectangle, etc.).

(Third embodiment)
As shown in FIG. 5, the patient positioning apparatus 10 </ b> C according to the third embodiment moves the bed 33 on which the patient 32 is placed based on the movement vector T in the treatment beam irradiation region 31. Is further provided. The bed movement control unit 53 can move the bed 33 at least one of a total of six axes including three translation axes and three rotation axes in the coordinate system (XYZ) of the irradiation region.
5 that have the same configuration or function as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  Thus, by providing the bed movement control unit 53 having an arbitrary configuration, the patient 32 can be fixed to the bed 33 so as not to move, and the patient can be positioned by moving the bed 33.

(Fourth embodiment)
As shown in FIG. 6, the patient positioning apparatus 10D according to the fourth embodiment is provided in a monitoring room 50 that is provided separately from the treatment room 30 that irradiates a patient 32 with a treatment beam and that a medical worker waits. A monitor 37 that displays an image of the patient 32 in real time is arranged.
Further, the monitoring room 50 is provided with a voice transmitter / receiver 54 for voice communication between the patient 32 and the medical staff.
In FIG. 6, parts having the same configuration or function as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.
Thereby, the patient 32 and the medical staff can cooperate and can perform patient positioning efficiently.

Furthermore, the patient positioning device 10D according to the fourth embodiment includes components that realize the following functions, although the functional units are not shown.
In the positioning process, the pointer 44 projected from the projector 36 may enter the patient's eyes. Therefore, in conjunction with the change of the patient's eyelid, the projector 36 has a function of turning off the projection when the eyes are open and turning on the projection when the eyes are closed.
In addition, when the marker 42 is displaced in synchronization with respiration, the projection ON / OFF function of the projector 36 can be linked to respiration.

A patient positioning method and patient positioning program according to the embodiment will be described based on the flowchart of FIG. 6 (see FIGS. 1 and 3 as appropriate).
First, in a treatment planning process, a three-dimensional image 21 of a patient is captured by a medical imaging device such as an X-ray CT apparatus or an MRI apparatus (S11). Then, from this three-dimensional image 21, the affected area such as cancer in the patient is specified (S12).
Then, various characteristics such as the direction and intensity of the treatment beam irradiated to the affected area are determined (S13). Further, position information 24 of the three-dimensional image 21 in the treatment beam irradiation area 31 is determined (S14 planning step END).

Next, in the treatment process using the irradiation beam, the three-dimensional image 21 and the determined position information 24 captured in the treatment planning process are held in the patient positioning apparatus 10 (S15).
And the patient's feature point 43 contained in this three-dimensional image 21 is identified (S16). Further, the second feature point coordinate R in the coordinate system of the irradiation area of the feature point 43 identified from the three-dimensional image 21 is calculated based on the position information 24 (S17). In addition, although the process of step S15 to S17 was implemented in the treatment process here, you may make it implement in advance at the process of a treatment plan, and may acquire a calculation result.

  Next, the patient 32 is placed on the treatment beam irradiation area 31 after the marker 42 is pasted on the body surface (S18). And the surface image 11 which shows the surface shape of the patient 32 is measured by the surface measuring device 35 (S19). Further, a patient feature point 41 included in the surface image 11 is identified (S20). And the 1st feature point coordinate P in the coordinate system (XYZ) of the irradiation area | region of the feature point 41 identified from the surface image 11 is calculated (S21).

  Next, the marker 42 attached to the patient 32 is detected from the surface image 11 (S22). And the marker coordinate Q in the coordinate system (XYZ) of the irradiation area | region of the detected marker 42 is calculated (S23). Further, a conversion parameter W for converting the first feature point coordinate P to the marker coordinate Q is derived (S24).

Next, the second feature point coordinate R is converted to the target coordinate S by the conversion parameter W (S25). Then, the projector 36 is controlled to project the pointer 44 toward the target coordinate S (S26). At this time, if the projected pointer 44 does not match the marker 42 (No in S27), the posture of the patient 32 is adjusted so that the pointer 44 matches the marker 42 (S27 Yes).
As a result, the patient 32 arranged in the treatment beam irradiation region 31 is accurately positioned, and the treatment beam is emitted (S29 END).

  According to the patient positioning apparatus of at least one embodiment described above, the patient's position in the treatment beam irradiation region is adjusted by adjusting the posture of the patient so that the pointer projected from the projector matches the marker attached to the patient. Positioning can be performed accurately in a short time.

Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.
Further, the components of the patient positioning device can be realized by a processor of a computer, and can be operated by a patient positioning program.

  The patient positioning device described above includes a control device in which a processor such as a dedicated chip, FPGA (Field Programmable Gate Array), GPU (Graphics Processing Unit), or CPU (Central Processing Unit) is highly integrated, and ROM ( Storage devices such as Read Only Memory (RAM) and Random Access Memory (RAM), external storage devices such as HDD (Hard Disk Drive) and SSD (Solid State Drive), display devices such as a display, and inputs such as a mouse and a keyboard The apparatus and the communication I / F are provided, and can be realized by a hardware configuration using a normal computer.

  A program executed by the patient positioning apparatus is provided by being previously incorporated in a ROM or the like. Alternatively, this program is stored in a computer-readable storage medium such as a CD-ROM, CD-R, memory card, DVD, or flexible disk (FD) as an installable or executable file. You may make it do.

  10 (10A, 10B, 10C, 10D) ... Patient positioning device, 11 (11a, 11b) ... Surface image, 12 ... First identification unit, 13 ... First calculation unit, 14 ... Marker detection unit, 15 ... Marker coordinates Calculation unit, 16 ... Conversion parameter derivation unit, 17 ... Operation setting unit, 20 ... Pre-processing unit, 21 ... Three-dimensional image, 22 ... Second identification unit, 23 ... Second calculation unit, 24 ... Position information, 25 ... Target Coordinate conversion unit, 26 ... pointer projection control unit, 27 ... calibration unit, 28 ... image output unit, 29 ... treatment beam irradiation control unit, 30 ... treatment room, 31 ... treatment beam irradiation region, 32 ... patient, 33 ... bed , 34 ... Beam irradiation unit, 35 (35a, 35b) ... Surface measuring device (optical camera), 36 ... Projector, 37 ... Monitor, 38 ... Calibrator, 41 ... Patient feature point included in surface image, 42 ... Marker 43 ... Included in 3D image 44. Pointer, 44a ... Pointer beam, 45 ... Measurement point, 46 ... Arrow, 50 ... Monitoring room, 51 ... Movement vector calculation unit, 52 ... Threshold determination unit, 53 ... Bed movement control unit, 54: Audio transceiver.

Claims (11)

A first holding unit that holds a surface image obtained by measuring the surface shape of a patient disposed in the irradiation region of the treatment beam;
A first identification unit for identifying a feature point of the patient included in the surface image;
A first calculation unit that calculates first feature point coordinates in the coordinate system of the irradiation region of the feature points identified from the surface image;
A detection unit for detecting a marker attached to the patient from the surface image;
A marker coordinate calculation unit for calculating marker coordinates in a coordinate system of the irradiation area of the marker detected from the surface image;
A conversion parameter deriving unit for deriving a conversion parameter for converting the first feature point coordinates to the marker coordinates;
A second feature in the coordinate system of the irradiation region of the feature point of the patient calculated based on a three-dimensional image obtained by three-dimensionally imaging the patient and position information of the three-dimensional image positioned in the coordinate system of the irradiation region An acquisition unit for acquiring point coordinates;
A conversion unit that converts the second feature point coordinates into target coordinates according to the conversion parameters;
And a controller for controlling a pointer projected onto the target coordinates. The patient positioning device according to claim 1, wherein:
A second holding unit for holding a three-dimensional image obtained by three-dimensionally imaging the patient;
A second identification unit for identifying a feature point of the patient included in the three-dimensional image;
A third holding unit for holding position information of the three-dimensional image to be positioned in the coordinate system of the irradiation region;
A preprocessing unit having a second calculation unit that calculates a second feature point coordinate of the feature point identified from the three-dimensional image in the coordinate system of the irradiation region based on the position information is replaced with the acquisition unit. A patient positioning apparatus, comprising: The patient positioning apparatus according to claim 1 or 2,
An apparatus for positioning a patient, further comprising: an image output unit for displaying the surface image so that the patient or medical staff can observe in real time. The patient positioning apparatus according to any one of claims 1 to 3,
A patient positioning apparatus, further comprising: a movement vector calculation unit that calculates a movement vector for moving the marker coordinates to the target coordinates in the coordinate system of the irradiation region. The patient positioning device according to claim 4.
The said control part projects the information regarding the direction or magnitude | size of the said movement vector with the said corresponding pointer, The patient positioning device characterized by the above-mentioned. The patient positioning device according to claim 4 or 5,
A patient positioning apparatus, further comprising a threshold value determination unit that determines whether the movement vector is larger or smaller than a threshold value, and wherein the control unit projects information on the determination result together with the corresponding pointer. The patient positioning apparatus according to any one of claims 4 to 6,
A patient positioning apparatus, further comprising a bed movement control unit configured to move a bed on which the patient is placed in the irradiation region based on the movement vector. The patient positioning apparatus according to any one of claims 1 to 7,
The patient positioning apparatus according to claim 1, wherein the surface image is acquired by taking a stereo image with a plurality of optical cameras, or acquired by laser scanning the surface of the patient with a laser scanner. The patient positioning apparatus according to any one of claims 1 to 8,
A surface image obtained by measuring the surface shape of the calibration body arranged in the irradiation area is held, and the measurement point of the calibration body having a known coordinate value in the coordinate system of the irradiation area is identified from the surface image, and this identification is performed. And a calibration unit that sets a calibration constant of an arithmetic expression executed by the first calculation unit and the marker coordinate calculation unit so that the measured point takes a known coordinate value of the coordinate system. Patient positioning device. A first holding unit holding a surface image obtained by measuring a surface shape of a patient disposed in a treatment beam irradiation region;
A first identifying unit for identifying a feature point of the patient included in the surface image;
A first computing unit computing first feature point coordinates in a coordinate system of the irradiation area of the feature points identified from the surface image;
Detecting a marker attached to the patient from the surface image;
A marker coordinate calculation unit calculating marker coordinates in a coordinate system of the irradiation area of the marker detected from the surface image;
A conversion parameter deriving unit deriving a conversion parameter for coordinate conversion of the first feature point coordinates to the marker coordinates;
The coordinate system of the irradiation region of the feature point of the patient calculated by the acquisition unit based on the three-dimensional image obtained by three-dimensionally imaging the patient and the positional information of the three-dimensional image positioned in the coordinate system of the irradiation region Obtaining a second feature point coordinate at;
A conversion unit converting the second feature point coordinates into target coordinates according to the conversion parameters;
Controller, operation method of patient positioning device which comprises the steps of: controlling the pointer to be projected onto the target coordinates. On the computer,
Holding a surface image measuring the surface shape of the patient placed in the irradiation region of the treatment beam;
Identifying the patient feature points included in the surface image;
Calculating a first feature point coordinate in a coordinate system of the irradiation area of the feature point identified from the surface image;
Detecting a marker attached to the patient from the surface image;
Calculating marker coordinates in a coordinate system of the irradiation area of the marker detected from the surface image;
Deriving transformation parameters for transforming the first feature point coordinates to the marker coordinates;
A second feature in the coordinate system of the irradiation region of the feature point of the patient calculated based on a three-dimensional image obtained by three-dimensionally imaging the patient and position information of the three-dimensional image positioned in the coordinate system of the irradiation region Obtaining point coordinates;
Converting the second feature point coordinates into target coordinates according to the conversion parameters;
A step of controlling a pointer projected onto the target coordinates is executed.

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