KR101617773B1 - Method and apparatus for monitoring position of radiation treatment system - Google Patents

Abstract

A method and an apparatus for monitoring the position of a radiation therapy apparatus are disclosed. A method for monitoring a position of a radiation therapy apparatus according to an embodiment of the present invention includes: capturing a first image of a patient with respect to a first axis and a second axis using a first camera during radiation therapy; Capturing a second image of the patient with respect to the second axis and the third axis; Obtaining a third image of the patient photographed using the first camera and a fourth image of the patient photographed using the second camera in a previous radiotherapy; The first image and the third image are compared to calculate a first correlation value between the first image and the third image, and the second image and the fourth image are compared with each other, Calculating a second correlation value between the four images; And determining if the first correlation value and the second correlation value are within a predetermined threshold range and if the first correlation value and the second correlation value are outside the threshold range, Determining that the position is out of the radiation treatment position and controlling irradiation of the treatment beam to be interrupted.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for monitoring a position of a radiation therapy apparatus,

The present invention relates to monitoring of a patient's position in a radiation therapy apparatus, and more particularly, to monitoring the position of a patient so that a treatment beam is irradiated to a region of interest (ROI) And more particularly, to a method and apparatus for monitoring the position of a radiation therapy apparatus.

The present invention was derived from research carried out as part of the global expertise development project (World Class 300 R & D project) of the Ministry of Industry, Trade and Industry and the Korea Industrial Technology Evaluation and Management Service [Task Number: 10040362, Development].

In general, many systems or devices should be used for radiation therapy in hospitals. These systems and devices include Electronic Medical Record (EMR), Order Communication System (OCS), Picture Archiving and Communication System (PACS), Radiation Therapy Planning System Radiation Treatment Planning (RTP), and radiotherapy (e.g., Linear Accelerator (LINAC)).

The prescription delivery system (OCS) is a database (DB) that stores various medical information and patient's medical examination data, and a system that a doctor diagnoses a patient and delivers a prescription to each corresponding medical department through a communication network.

An electronic medical record system (EMR) is a system configured for the purpose of archiving and retrieving electronic medical records.

The medical image storage and delivery system (PACS) includes a computed tomography (CT) device, a magnetic resonance imaging (MRI) device, a positron emission tomography (PET) device, a CT simulator, and a computed radiography Is a system that stores and transmits images captured by at least one medical imaging device to a computer file.

The Radiation Therapy Planning System (RTP) is a system that establishes (builds) a patient's radiotherapy plan programmatically. It establishes a radiotherapy plan, that is, it creates radiotherapy plan information and calculates and reviews radiation dose. Among these images of cancer-causing areas acquired by CT or magnetic resonance imaging (MRI) using such a radiotherapy planning system, a user selects an optimal image or displays a medical image of a patient After digitizing and digitizing the image, it performs basic image processing, sets the reference coordinates of the acquired image, contouring each part, and calculates the direction and dose of the beam according to the size of the onset of cancer .

The basic principles of radiation therapy aim at minimizing secondary tumor development as well as acute and chronic radiation reactions or complications that can occur in normal tissues while enhancing cancer treatment effectiveness. For this purpose, it is necessary to establish an appropriate radiotherapy plan.

A radiotherapy device is a device that actually performs radiation therapy on a patient, in accordance with a radiation treatment plan written by the Radiation Therapy Planning System (RTP).

Tumor treatment methods for radiation oncology have been newly developed and diversified, and therapies and applications for various treatment methods have been newly developed.

In the Radiation Oncology Department, the process of radiotherapy for the patient is as follows. First, a medical image of the patient is obtained through a medical imaging device to obtain information about the patient's tumor. The radiation therapy plan is then established via the Radiation Therapy Planning System (RTP) through the medical image of the patient. Next, based on the radiation treatment plan established through the above-described radiation treatment planning system (RTP), the radiation treatment is performed using the radiation therapy apparatus.

At this time, a radiotherapeutic apparatus has been developed and used such as a linear accelerator (LINAC), a brachytherapy, a cyberknife, a tomotherapy, etc. These radiation therapy apparatuses are appropriately selected according to the condition of a patient, Has been used.

Conventional radiotherapy apparatuses are designed so that when a patient's motion occurs during radiation therapy, the treatment beam is irradiated to a position or region other than the ROI of the radiation therapy, so that the tumor or the like in the region of interest is not treated, And may be adversely affected.

Therefore, it is important to perform radiation therapy while continuously monitoring the patient's movement.

Prior art Korean Patent Publication No. 2008-0039916, which monitors the position or movement of a patient in a conventional radiotherapy apparatus, is directed to a system and method for performing radiotherapy on a moving area of interest, , A breathing pattern determined in the monitoring step, and the like.

However, since the prior art has to set all the treatment plans according to the patient's breathing pattern, it is difficult to change the treatment plan when the patient's breathing pattern is different from the set respiration pattern, ), It is possible that the patient may be irradiated to the other region without applying the therapeutic beam to the region of interest if the movement of the patient occurs while maintaining the same breathing pattern. As a result, the normal region may be exposed to the treatment beam have.

Accordingly, there is a need for a method of automatically controlling the position of a patient so as to monitor the position of the patient and prevent exposure of the normal part to the treatment beam even if the patient's motion occurs.

Korean Patent Laid-Open No. 10-2008-0039916 "A system and method for performing radiation therapy on a moving area of interest" (Published on May 28, 2008)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a position monitoring method for a radiation therapy apparatus capable of controlling a position of a patient such that a treatment beam is irradiated to a region of interest even if a patient's motion occurs during radiation therapy, And an object thereof is to provide such a device.

In addition, the present invention monitors movement of a patient through previous radiotherapy using two fixed cameras and image comparison of a patient's position during a current radiotherapy, thereby controlling the irradiation of the radiation therapy beam, And an object thereof is to provide a position monitoring method and apparatus for a radiation therapy apparatus which can prevent a beam from being exposed to an undesired site.

According to an aspect of the present invention, there is provided a method for monitoring a position of a radiotherapy apparatus, comprising the steps of: capturing a first image of a patient on a first axis and a second axis using a first camera during radiation therapy; And photographing a second image of the patient with respect to the second axis and the third axis using a second camera; Obtaining a third image of the patient photographed using the first camera and a fourth image of the patient photographed using the second camera in a previous radiotherapy; The first image and the third image are compared to calculate a first correlation value between the first image and the third image, and the second image and the fourth image are compared with each other, Calculating a second correlation value between the four images; And determining if the first correlation value and the second correlation value are within a predetermined threshold range and if the first correlation value and the second correlation value are outside the threshold range, Determining that the position is out of the radiation treatment position and controlling irradiation of the treatment beam to be interrupted.

The method according to the present invention comprises the steps of: controlling a diagnostic couch in which the patient lies to place the patient's position in the radiation treatment position; And controlling the treatment beam to be irradiated when the position of the patient is located at the radiation treatment position.

Wherein the acquiring includes acquiring a third deformation image and a fourth deformation image that are transformed through the normalization, segmentation, and edge detection processes of the third image and the fourth image, And the calculating step may include obtaining the first transformed image and the second transformed image that are transformed through the normalization, segmentation, and edge detection processes of the first image and the second image, The first deformation image and the third deformation image are compared to calculate the first correlation value, and the second deformation image and the fourth deformation image are compared to calculate the second correlation value .

The method further includes comparing the first image, the second image, the reference image corresponding to the first image, and the reference image corresponding to the second image, so that the reference image corresponding to at least one of the first camera and the second camera And determining whether or not the position is corrected; And calculating a correction value for an angle and a position of at least one of the first camera and the second camera when correction is required as a result of the determination, The first correlation value and the second correlation value may be calculated by reflecting the correction value.

The apparatus for monitoring a position of a radiotherapy apparatus according to an embodiment of the present invention includes a first camera for capturing an image of a patient on a first axis and a second axis in a diagnostic couch; A second camera for capturing an image of the patient with respect to the second axis and the third axis with respect to the patient; An image acquiring unit acquiring a first image and a second image including the diagnosis needle bed and the patient previously photographed and stored by the first camera and the second camera in previous radiation treatment; A method for receiving a third image and a fourth image photographed by the first camera and the second camera during a current radiation therapy, comparing the first image and the third image, and comparing the first image and the third image, A correlation value calculation unit for calculating a first correlation value and calculating a second correlation value between the second image and the fourth image by comparing the second image and the fourth image; And determining if the first correlation value and the second correlation value are within a predetermined threshold range and if the first correlation value and the second correlation value are outside the threshold range, And a monitoring control unit for determining that the position is deviated from the radiation treatment position and stopping the irradiation of the treatment beam.

According to the present invention, even if a motion of a patient occurs during treatment through image comparison of a reference position of a patient using two fixed cameras and the position of the patient during the current radiation treatment, By controlling the position of the patient so that it can be irradiated to the desired region of interest, it is possible to prevent the normal region from being exposed to the treatment beam even if the patient's motion occurs.

That is, the present invention monitors the position of the patient through the correlation value between the image of the patient's reference position with respect to the radiation treatment and the image of the patient taken during the radiation treatment so that the treatment beam is irradiated onto the region of interest such as the tumor The position of the patient can be controlled.

In addition, the present invention can improve the reliability of the position monitoring of the patient by reflecting the photographing position of the camera using the image of the reference position of the camera, thereby improving the reliability of the radiation treatment.

Specifically, the present invention corrects the angle or position of the camera through image analysis during radiotherapy, and performs positional monitoring of the patient by reflecting the corrected angle or position of the camera, Can be improved.

According to the present invention, even when two cameras having a relatively simple configuration are used, the reference position of the diagnostic needle bed and the position of the marker or ISO center displayed on the body of the patient are detected, A monitoring method of a radiation therapy apparatus capable of monitoring a minute change of a pose as well as a position of a radiation therapy apparatus is provided.

1 is a flowchart illustrating an operation of a method for monitoring a position of a radiation therapy apparatus according to an embodiment of the present invention.
Figure 2 shows a further operational flow diagram of the method according to the invention.
FIG. 3 illustrates another exemplary operational flow diagram for step S140 shown in FIG.
Fig. 4 shows an example of a radiation therapy apparatus for explaining the present invention.
FIG. 5 shows a configuration of a position monitoring apparatus for a radiation therapy apparatus according to an embodiment of the present invention.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the accompanying drawings.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, a method and an apparatus for monitoring the position of a radiation therapy apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5.

The present invention is to monitor the position of a patient during radiotherapy. The correlation value between a camera provided on a diagnostic couch and a camera mounted on a side of the diagnostic couch and a reference image is used By automatically monitoring the movement of the patient, it is intended to increase the reliability of the radiation therapy by preventing the treatment beam from being irradiated to the normal region and automatically controlling the position of the patient to be in a normal position.

1 is a flowchart illustrating an operation of a method for monitoring a position of a radiation therapy apparatus according to an embodiment of the present invention. The position monitoring method of FIG. 1 may be executed through a processor of a computing system capable of monitoring the position or movement of a patient in a radiation therapy apparatus, and may be stored in the form of an instruction loaded into a memory connected to the processor .

The present invention is directed to monitoring during the course of performing radiation therapy with the patient's location in a diagnostic couch positioned prior to the start of radiation therapy in the same position as the patient at the previous radiation treatment. That is, the present invention monitors the movement of the patient in real time in a state where the patient is in the correct position for radiotherapy.

Referring to FIG. 1, a method according to the present invention includes a first camera provided in a radiotherapy apparatus during a radiotherapy, and a patient's first and second axes of a diagnostic needle bed (Hereinafter referred to as "second image") with respect to the second axis and the third axis of the diagnostic needle bed using the second camera (S110, S120).

4, the second camera 420 may be a camera for photographing a patient on the upper part of the diagnostic needle bed 430, and the second camera 420 may be a camera And the first, second, and third axes may be x-axis, y-axis, and z-axis. The first camera and the second camera may be fixed to the gantry 440 of the radiotherapy apparatus, but may be fixed and positioned at a specific position other than the gantry.

The camera in the present invention means a photographing device using a CCD (charge coupled device), a CMOS, or the like.

Accordingly, the first image captured by the first camera may be an image for mainly detecting a change in position of the patient in the x-axis and the y-axis, and the second image captured by the second camera may be an image detected in the y- It may be an image for mainly detecting a change in position.

The first image and the second image in the present invention may be an upper image and a lateral image for monitoring the movement or position change of the patient during the current radiation therapy.

When the first image and the second image are photographed, reference images of the patient previously captured and stored by the first camera and the second camera are obtained at the previous radiation treatment (S130).

At this time, the reference images are the medical images including the patients photographed by the first camera and the second camera in the previous radiation therapy, for example, the initial radiation therapy or the immediately preceding radiation therapy. In the present invention, .

That is, the third image means the x-axis and y-axis images of the patient taken by the first camera during the previous radiation treatment performed with the radiation therapy, and the fourth image is taken by the second camera during the previous radiation treatment And the third and fourth images indicate the position of the patient where the radiation beam is accurately irradiated to the region of interest of the patient.

The third image and the fourth image may be acquired from a separate storage device or system connected to the radiotherapy apparatus, for example, a medical image storage transmission system (PACS), and may be acquired from PACS or the like using patient information . Of course, the method according to the present invention can be performed when a user input for monitoring the position of a patient is received through a user interface by a specialist performing radiotherapy.

When the third and fourth images of the patient's position are acquired in the previous radiotherapy in step S130, a correlation value between the first image and the third image is calculated using the first image corresponding to the third image and the third image, (Hereinafter, referred to as "second correlation value "), and calculates a correlation value between the second image and the fourth image (hereinafter referred to as " second correlation value ") using the second image corresponding to the fourth image and the fourth image, Correlation value ") is calculated (S140, S150).

In this case, in steps S140 and S150, a correlation value between deformed images may be calculated using deformed images generated after a deformation image is generated through a specific process of an image. A process of generating a deformed image will be described with reference to FIG.

Figure 2 shows a further operational flow diagram of the method according to the invention.

As shown in FIG. 2, when the first image and the second image are captured, the first image and the second image are received and normalized with respect to the first image and the second image, and the normalized image The first deformed image and the second deformed image are generated through a segmentation process and an edge detection process (S210 to S240).

The normalization, segmentation, and edge detection processes in FIG. 2 are well known to those skilled in the art, so a detailed description thereof will be omitted.

Of course, the process of FIG. 2 is applied to the third image and the fourth image captured in the previous radiotherapy, and the normalization, segmentation and edge detection of the third and fourth images it is preferable that the deformed third deformed image and the fourth deformed image are generated and stored in advance after edge detection.

The generating of the correlation value in steps S140 and S150 may be performed using the first deformed image, the second deformed image, the third deformed image, and the fourth deformed image generated in FIG. That is, the first correlation value is a correlation value through comparison between the first transformed image and the third transformed image, and the second correlation value is a correlation value obtained by comparing the second transformed image and the fourth transformed image.

)은 아래 <수학식 1>, <수학식 2>와 같이 계산될 수 있다.At this time, the calculated correlation value (

Can be calculated as Equation (1) and Equation (2) below.

[Equation 1]

는 template 영상(t)의 이동거리(u, v)에 대한 상호 상관 관계 팩터(cross-correlation factor)를 의미하고, (x, y)는 기본 영상(f)에 대한 좌표축을 의미하고,

는 기본 영상(f)의 평균값을 의미하고,

는 template 영상(t)의 평균값을 의미하는 것으로, 본 발명에서 f는 제1 변형 영상, 제2 변형 영상을 의미할 수 있고, t는 제3 변형 영상, 제4 변형 영상을 의미할 수 있고,

는 제1 변형 영상, 제2 변형 영상의 평균값을 의미할 수 있고,

는 제3 변형 영상, 제4 변형 영상의 평균값을 의미할 수 있다.here,

(X, y) denotes a coordinate axis for the basic image f, and (x, y) denotes a cross-correlation factor for the movement distance (u, v)

Means an average value of the basic image f,

Refers to an average value of the template image (t). In the present invention, f may denote a first transformed image and a second transformed image, t may denote a third transformed image and a fourth transformed image,

May mean an average value of the first transformed image and the second transformed image,

May mean an average value of the third transformed image and the fourth transformed image.

)이 최대인 지점 (u, v) 지점을 찾는 수식이지만, 본 발명은 영상을 모니터링할 때, 전체 영상을 template 영상으로 지정하고, 전체 영상을 대상으로 모니터링하기 때문에 (u, v)는 (0, 0)이 된다.Equation (1) represents the cross-correlation value

(U, v) is a formula for finding a point (u, v) at which the maximum value (u, v) is maximum. However, since the entire image is designated as a template image, , 0).

The normalization of the entire image in Equation (1) can be expressed as Equation (2) below.

&Quot; (2) &quot;

는 t 영상(제3 변형 영상, 제4 변형 영상)에 대한 f 영상(제1 변형 영상, 제2 변형 영상)의 노말라이즈된 상호 상관 관계(normalized cross correlation) 값을 의미하고, n은 전체 픽셀수를 의미하고, f는 제1 변형 영상, 제2 변형 영상을 의미하고, t는 제3 변형 영상, 제4 변형 영상을 의미하고,

는 제1 변형 영상, 제2 변형 영상의 평균값을 의미하고,

는 제3 변형 영상, 제4 변형 영상의 평균값을 의미하고,

는 f 영상에 대한 표준편차를 의미하고,

는 t 영상에 대한 표준편차를 의미한다.here,

Denotes a normalized cross correlation value of an f image (first deformation image, second deformation image) for a t image (a third deformation image or a fourth deformation image), and n denotes a normalized cross- F denotes a first transformed image and a second transformed image, t denotes a third transformed image and a fourth transformed image,

Means an average value of the first transformed image and the second transformed image,

Means an average value of the third transformed image and the fourth transformed image,

Denotes the standard deviation of the f image,

Is the standard deviation of t image.

Referring again to FIG. 1, when the first correlation value and the second correlation value are calculated by steps S140 and S150, two calculated correlation values (the first correlation value and the second correlation value) It is determined whether or not it is within a threshold range (S160).

That is, step S160 determines whether both correlation values are within a threshold range.

If it is determined that the two correlation values are out of the threshold range as a result of the determination in step S160, it is determined that the patient's motion has occurred to such an extent as to affect the radiation therapy, and the irradiation beam is controlled (S170).

Then, the position of the patient is controlled by moving or rotating the diagnostic needle so that the position of the patient is located at the treatment position for performing the radiotherapy (S180).

At this time, the position control of the patient calculates the first positional change of the patient with respect to the first axis and the second axis using the first image and the third image, and calculates the first position and the second axis using the second and fourth images, And the second positional change of the patient with respect to the third axis, and using the calculated first positional change and the second positional change, the diagnostic needle bed can be controlled to position the patient's position at the treatment position. coach may be used to calculate the number of pixels per unit length in the image to calculate the position change of the patient.

The position change of the patient may include a change in the rotation angle in the x-axis direction, the rotation angle in the y-axis direction, and the rotation angle in the z-axis direction, The second position change may mean a position change in the z-axis, and the position change may include a rotation as well as a movement in the corresponding axial direction.

The position change for controlling the position of the patient is calculated based on the markers or the ISO center of the patient's body and the specific reference position of the pre-checked diagnostic bed, and according to the present invention, It is possible to calculate both the change in the position taken from above and the change in the pose taken by the patient.

Of course, the step S180 calculates the difference between the position and the posture taken by the patient in the previous radiation treatment and the position and posture currently taken, and calculates the ROI of the radiation therapy so that the radiation therapy can achieve the desired purpose in the current state. The position of the patient can be controlled by moving the patient's lying down needle bed so that it is correctly positioned in the path of the radiation.

The patient may have moved parallel to the x- and y-axes on the diagnostic needle during radiotherapy, or may have moved obliquely. Or the patient's posture may be slightly distorted when compared to the posture at the previous radiation treatment. The change of the position of the patient can be detected by comparing the first and third images using a plurality of markers displayed on the body of the patient so that the change of the position of the patient in the xy plane and the rotation on the xy plane can be extracted . In addition, when the patient's pose is supine pose, prone pose, or lateral pose, the patient is more twisted compared to the previous treatment , The difference may be detected.

In addition, when the pixel change between specific reference positions of the diagnostic needle bed is analyzed, the position of the diagnostic needle bed is the same, and it can be confirmed whether the patient's position or posture has changed or in which direction the diagnostic needle itself has moved.

For example, in step S180, a predetermined length of the diagnostic couch in the third image is calculated, for example, the number of pixels for the width or length of the diagnostic needle bed and the number of pixels for the position of the patient, Calculating the number of pixels with respect to the width or length of the couch and the number of pixels with respect to the position of the patient, calculating the positional change of the patient using the calculated number of pixels, By moving or rotating the diagnostic needle in the x-, y-, and z-axis directions, the position of the patient is controlled to be in the same position as the patient position in the previous radiotherapy.

At this time, the position of the patient with respect to the x-axis and y in the diagnosis bed can be calculated based on the end of the diagnosis bed or the number of pixels based on at least one reference pattern or reference mark set in advance on the diagnosis bed It is possible. Of course, the position of the patient in the diagnostic bed may be determined by the number of pixels per unit length between the at least one reference pattern preset on the diagnostic bed and the characteristic points preset on the patient, for example, between the marks displayed on the eyes, nose, Axis position and the y-axis position in the diagnosis needle bed can be calculated using the number of pixels per unit length between the reference pattern and the shape of the patient, the body length, and the interval length of the body part, You can also calculate position and y-axis position.

Of course, if the position of the patient in the diagnostic needle bed is changed, the number of pixels per unit length will be the same, but the number of pixels per unit length may vary if movement occurs in the diagnostic needle bed. Therefore, it is preferable to control the position of the patient in consideration of the above change, and the position change in the image can be corrected or supplemented by reflecting the position change information in the other image when calculating the position change of the patient.

Of course, as a result of the determination in step S160, the fact that the irradiation of the radiation treatment beam is stopped when the two correlation values are out of the threshold range may activate an alarm notifying the specialist.

In addition, the present invention can generate breathing cycle data of the patient by analyzing the real-time image of the patient taken in real time by photographing the patient under radiation therapy using two fixed cameras, As a graph or the like.

At the previous and current radiotherapy treatments, the patient may flex the body, stretch the body, or twist the body further. The plurality of markers displayed on the patient's body may appear to be distorted in addition to appearing to be parallel / rotated / zoomed / reduced between the first image and the third image. In this case, the center of the plurality of markers may be regarded as the center of the ROI and step S190 may be performed based on the position control reference. In the present invention, it is preferable that the first camera and the second camera for capturing the first image and the second image are fixed at specific positions. However, depending on the situation, the first camera or the second camera may have a small angle It can be turned off.

Therefore, when the photographing angle or the position of the first camera and the second camera for photographing the position of the patient are different, it is not possible to accurately monitor the position of the patient, so that the photographing angles or positions of the first camera and the second camera It is preferable that the position of the patient is monitored by judging whether it is the same as the photographing angle or the position of the patient.

This will be described with reference to FIG.

FIG. 3 illustrates another exemplary operational flow diagram for step S140 shown in FIG.

Referring to FIG. 3, the first correlation value calculation step S140 may include analyzing first and second images captured by the first camera and the second camera, analyzing the first and second images, It is determined whether the position and angle of the camera should be corrected (S310, S320).

At this time, whether or not the camera is corrected can be achieved through image processing of the patient's bed with the diagnosis needle included in the first image, and the angle direction and position of the camera can be confirmed through the image processing. Therefore, By comparing the positions, it is possible to judge whether the camera is corrected or not.

That is, in step S320, the camera determines whether a change in angle direction and position has occurred due to an external environment or an internal problem.

If it is determined in step S320 that at least one of the first camera and the second camera needs to be corrected, an angle and a position to be corrected for the camera are calculated (S330).

Here, the correction angle and the correction position are calculated by checking the angle and position of the camera through analysis of the first and second images, and comparing the determined angle direction and position with a predetermined reference angle direction and reference position .

When the correction angle and the correction position are calculated in step S330, a first correlation value for the first image and the third image is calculated by reflecting the calculated correction angle and the correction position (S340).

At this time, the step S340 may generate the first correlation value through the correlation between the first image and the third image after reflecting the calculated correction angle and the corrected position of the camera on the first image, The first correlation value may be generated by reflecting the correction angle and the corrected position of the camera calculated in the calculation.

On the other hand, if it is determined in step S320 that the camera position correction is not required, the first correlation value between the first and third images is calculated using only the first image and the third image, as described above (S350).

Of course, the reflection when calculating the correction and the positional change for such angles and positions of the camera can be applied not only to the first correlation value but also to the second correlation value.

Even in the case of adjusting the angle of the camera, the number of pixels between a plurality of markers in each image and the number of pixels between specific reference positions of the diagnostic needle bed are changed, Or the second camera) can be detected. For example, if it is determined that the angle of the second camera is slightly changed due to a pixel change between a specific reference position of the diagnostic needle bed between the second image and the fourth image captured by the second camera, The derived movement of the position in the z-axis direction needs to be corrected by the angle change of the second camera. At this time, it is determined whether there is a position change in the z-axis direction besides the xy plane by using a change in the number of pixels between specific reference positions appearing between the first image and the third image taken by the first camera, It is possible to verify or supplement the calculation result of the z-axis position movement of the second camera using the information extracted from the image captured by the first camera.

In order to determine whether the angle and position of the camera are corrected according to the situation, a reference image for the optimal position of the patient may be provided. By comparing the reference image with the image captured by the camera, It is possible to determine whether or not the position is corrected, and the correction angle and the correction position may also be calculated.

As described above, the method according to the present invention calculates the correlation value between the image captured using the camera configured on the upper part of the diagnostic needle and the camera configured on the side and the image (reference image) captured in the previous radiotherapy during the radiation treatment, By monitoring the movement of the patient using the calculated correlation value, it is possible to control the position of the patient so that the radiation beam can be irradiated to a desired region of interest even if motion of the patient occurs during treatment, It is possible to prevent the normal part from being exposed to the treatment beam.

In addition, the method according to the present invention corrects the angles and positions of the first camera and the second camera by calculating the correlation values by correcting the changed angles and positions, Which can also improve the reliability of radiation therapy.

FIG. 5 shows a configuration of a position monitoring apparatus for a radiation therapy apparatus according to an embodiment of the present invention.

5, a device 500 according to the present invention includes a first camera 510, a second camera 520, a deformed image generating unit 530, an image obtaining unit 540, a correlation value calculating unit 550 and a monitoring control unit 560. The deformed image generating unit 530, the image obtaining unit 540, the correlation value calculating unit 550 and the monitoring control unit 560 monitor the position or movement of the patient Or a processor of a computing system that is capable of executing the instructions.

The first camera 510 photographs the patient on the first axis and the second axis, that is, the x-axis and the y-axis, with the camera for photographing the patient on the upper part of the diagnosis couch lying on the patient in the radiation therapy .

The second camera 520 is a camera for photographing a patient on the side of a diagnosis couch in which a patient lays down during radiation therapy. The second camera 520 is a camera for capturing the patient on the second axis and the third axis, that is, the y axis and the z axis, The patient's image is taken.

The transformed image generator 530 transforms transformed images obtained through the normalization, segmentation, and edge detection processes of the images captured by the first camera 510 and the second camera 520, (deformation image).

That is, the deformed image generation unit 530 generates the third deformed image and the fourth deformed image through the normalization, segmentation, and edge detection processes for the third image and the fourth image captured in the previous radiation therapy, A first deformed image and a second deformed image are generated through normalization, segmentation, and edge detection processes for the first image and the second image that are photographed.

The image acquisition unit 540 acquires the images captured by the first camera and the second camera, that is, the third image and the fourth image, at the previous radiation therapy.

In this case, the image obtaining unit 540 may obtain the first deformed image and the second deformed image in which the first image and the second image are deformed, and may be a separate storage device or system connected to the radiation treatment apparatus, for example, Images of the patient at the time of previous radiotherapy can be obtained from the medical image storage transmission system (PACS).

The correlation value calculation unit 550 receives the first image and the second image captured by the first camera and the second camera during the current radiation therapy, compares the first image and the third image, 3 images and calculates a second correlation value between the second image and the fourth image by comparing the second image and the fourth image.

At this time, the correlation value calculation unit 550 receives the first transformed image and the second transformed image from the transformed image generation unit 530, compares the first transformed image and the third transformed image, And calculate the second correlation value by comparing the second modified image and the fourth modified image.

That is, the correlation value calculation unit 550 compares the reference image corresponding to the first image, the second image, the first image, and the second image, for example, the third image and the fourth image, Wherein the controller calculates the correction value for at least one of an angle and a position of at least one of the first camera and the second camera when the correction is necessary and reflects the calculated correction value And calculates a first correlation value and a second correlation value.

Further, when calculating the correlation value for determining the motion of the patient, the correlation value calculation unit 550 may calculate the correlation value using at least one of the angle of the first camera and the angle of the second camera through the analysis of the first image and the second image, If the correction is required after determining whether or not the position is corrected, the correction angle and the correction position of the camera are calculated. Then, the calculated correction angle and the correction position are reflected in the calculation of the correlation value, Can be calculated accurately.

The monitoring control unit 560 determines whether the first correlation value and the second correlation value are within a predetermined threshold value range, and when the first correlation value and the second correlation value are out of the threshold range, Is determined to be out of the radiation treatment position and controls the irradiation of the treatment beam to be stopped.

Further, the monitoring control unit 560 controls a diagnosis couch lying on the patient so that the position of the patient is placed at the radiation treatment position, and controls the treatment beam to be irradiated when the position of the patient is positioned at the radiation treatment position.

At this time, the monitoring control unit 560 calculates the first positional change of the patient with respect to the first axis and the second axis using the first image and the third image, and uses the second image and the fourth image to calculate the second The second positional change of the patient with respect to the axis and the third axis is calculated and the diagnosis needle bed can be controlled so that the position of the patient is located at the treatment position using the calculated first positional change and the second positional change, the position change of the patient can be calculated by calculating the number of pixels per unit length in the image using a predetermined length of the coach.

Accordingly, the monitoring control unit 560 calculates the positional change including the degree of movement and rotation of the patient on the x-axis, the y-axis, and the z-axis, By moving or rotating in the axial direction, the position of the patient is controlled to be located at the treatment position.

The method for monitoring the position of a radiation therapy apparatus according to an embodiment of the present invention may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (8)

A first image of a patient with respect to a first axis and a second axis is photographed using a first camera during radiation therapy and a second image of the patient with respect to the second axis and the third axis is photographed using a second camera Photographing;
Obtaining a third image of the patient photographed using the first camera and a fourth image of the patient photographed using the second camera in a previous radiotherapy;
Comparing the first image with the third image, and using the change in the number of pixels between the reference position indicated between the first image and the third image, information on a change and a change in the position of the patient in the third axis direction Calculating a first correlation value between the first image and the third image including the first image and the second image, comparing the second image and the fourth image, and calculating a second correlation value between the second image and the fourth image, Calculating; And
And verifying the second correlation value using information about a change and a shift of the position of the patient in the third axis direction included in the first correlation value, and comparing the first correlation value with the second correlation value Determining that the position of the patient is out of the radiation treatment position if the first correlation value and the second correlation value are out of the threshold range, determining whether the relationship value is within a predetermined threshold range, So as to stop the investigation of
Wherein the position of the radiation therapy apparatus is monitored. The method according to claim 1,
Controlling a diagnostic couch in which the patient is lying to place the patient's position in the radiation treatment position; And
Controlling the treatment beam to be irradiated when the position of the patient is located at the radiation treatment position
Further comprising the steps of: detecting a position of the radiation therapy apparatus; The method according to claim 1,
The obtaining step
A third deformation image and a fourth deformation image obtained through the normalization, segmentation and edge detection processes of the third image and the fourth image are acquired,
The step of calculating
The first transformed image and the second transformed image are obtained through the normalization, segmentation and edge detection processes of the first image and the second image, Calculating the first correlation value by comparing the third modified image and comparing the second modified image and the fourth modified image to calculate the second correlation value, How to monitor. The method according to claim 1,
A second image, and a reference image corresponding to each of the first image and the second image to determine whether or not the angle and position of at least one of the first camera and the second camera are corrected ; And
Calculating a correction value for an angle and a position of at least one of the first camera and the second camera when correction is required as a result of the determination;
Further comprising:
The step of calculating the second correlation value
And calculating the first correlation value and the second correlation value by reflecting the calculated correction value. A first camera for capturing an image of a patient with respect to the first axis and the second axis in a diagnostic couch;
A second camera for capturing an image of the patient with respect to the second axis and the third axis with respect to the patient;
An image acquiring unit acquiring a first image and a second image including the diagnosis needle bed and the patient previously photographed and stored by the first camera and the second camera in previous radiation treatment;
A method of receiving a third image and a fourth image photographed by the first camera and the second camera during a current radiation treatment, comparing the first image and the third image, and comparing the first image and the third image, Calculating a first correlation value between the first image and the third image including information about a change in the position of the patient in the third axis direction and a rotation of the third axis using a change in the number of pixels between the reference positions, A correlation value calculator for comparing the second image and the fourth image to calculate a second correlation value between the second image and the fourth image; And
And verifying the second correlation value using information about a change and a shift of the position of the patient in the third axis direction included in the first correlation value, and comparing the first correlation value with the second correlation value Determining that the position of the patient is out of the radiation treatment position if the first correlation value and the second correlation value are out of the threshold range, determining whether the relationship value is within a predetermined threshold range, A monitoring control unit
Wherein the position of the radiation therapy apparatus is monitored. 6. The method of claim 5,
The monitoring control unit
Wherein the control unit controls the diagnostic couch lying on the patient so that the position of the patient is located at the radiation treatment position and controls the treatment beam to be irradiated when the position of the patient is located at the radiation treatment position A device for monitoring the position of a radiotherapy device. 6. The method of claim 5,
A deformed image generating unit for generating a deformed image deformed through normalization, segmentation, and edge detection processes of an image photographed by the first camera and the second camera;
Lt; / RTI &gt;
The image acquiring unit
Obtaining a first transformed image and a second transformed image in which the first image and the second image are transformed,
The correlation value calculation unit
A third transformed image and a fourth transformed image for the third image and the fourth image are received from the transformed image generation unit, and the first transformed image and the third transformed image are compared with each other, And compares the second deformed image with the fourth deformed image to calculate the second correlation value. 6. The method of claim 5,
The correlation value calculation unit
A second image, and a reference image corresponding to each of the first image and the second image to determine whether or not the angle and position of at least one of the first camera and the second camera are corrected And calculates a correction value for an angle and a position of at least one of the first camera and the second camera when correction is required, and calculates a correction value for at least one of the first camera and the second camera by reflecting the calculated correction value, And calculating a value of the position of the radiation therapy apparatus.

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