JP2008104790A - Radiotherapy apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the treatment accuracy and to suppress the radiation dosage of a patient in a radiotherapy apparatus. <P>SOLUTION: This radiotherapy apparatus 10 is provided with: an irradiation nozzle 12 for irradiating the therapeutic radiation; a treatment table 14 mounting a patient 13 and positioning an affected part of the patient 13 in an irradiation position of the therapeutic radiation 15 irradiated from the irradiation nozzle 12; an image pickup device 18 irradiating diagnosis radiation and capturing an image around the affected part; a television camera 22 for capturing the body surface of the patient; an image processor creating a composite fluoroscopic image around the affected part including the affected part in time series using a fluoroscopic image captured by the image pickup device 18 and camera images captured by the television camera 22 in time series; and a display for displaying the composite fluoroscopic image created by the image processor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a radiotherapy apparatus, and is particularly suitable for a radiotherapy apparatus including an image acquisition apparatus that irradiates diagnostic radiation and captures a fluoroscopic image around an affected area.

  Radiation therapy is a treatment that kills a tumor by irradiating it with a therapeutic radiation on a tumor (affected area) such as cancer. In order not to destroy normal cells around the tumor, the therapeutic radiation is irradiated to the tumor with high accuracy. It is required to do.

  Therefore, when irradiating therapeutic radiation, the image acquisition apparatus irradiates diagnostic radiation and images the affected area, and based on the fluoroscopic image, the irradiation position of the therapeutic radiation matches the affected area position. The positioning is performed by moving the treatment table (prior art 1).

  Further, as described in Japanese Patent Application Laid-Open No. 6-246015 (Patent Document 1), the movement of the treatment table is remotely controlled based on a marker on the patient's body surface photographed by a television camera, and the position of the affected area is determined. A medical radiation irradiation apparatus that corrects the difference in irradiation position is known (prior art 2).

Japanese Patent Laid-Open No. 6-246015

  In the prior art 1, there are a method of photographing diagnostic images around a diseased part by irradiating diagnostic radiation with a photographing device, and a method of photographing the fluoroscopic images as real-time images (continuously photographed images). When positioning based on the former still image, the irradiation position will shift if the affected area moves from the time of shooting until the irradiation of therapeutic radiation, and the therapeutic radiation will be irradiated to the tumor with high accuracy. There was a problem that it was not possible. On the other hand, in the case of positioning based on the latter real-time image, there is a problem that the radiation exposure amount of the patient increases because the diagnostic radiation is continuously applied during the positioning operation.

  On the other hand, according to the above prior art 2 (Patent Document 1), positioning can be performed while confirming the movement of the marker provided on the patient's body surface with a television camera, but it is not confirmed with a fluoroscopic image. There was a problem that radiation could not be irradiated with high accuracy. If the movement of the body surface and the movement of the affected area do not match, an error further occurs by the difference between the movement of the body surface and the movement of the affected area.

  The objective of this invention is providing the radiotherapy apparatus which can suppress a patient's radiation exposure amount while improving a treatment precision.

In order to achieve the above-described object, the present invention provides an irradiation nozzle for irradiating therapeutic radiation, and a treatment table for positioning the affected area of the patient at the irradiation position of the therapeutic radiation irradiated from the irradiation nozzle. An image acquisition device that irradiates diagnostic radiation and images the periphery of the affected area;
Using a television camera that captures the body surface of the patient, a fluoroscopic image captured by the image acquisition device, and a camera image captured over time by the television camera, a combined fluoroscopic image around the affected area including the affected area is obtained. The radiation therapy apparatus includes an image processing apparatus created over time, and a display that displays a composite fluoroscopic image created by the image processing apparatus.

A more preferable specific configuration example of the present invention is as follows.
(1) Control for controlling at least one of the irradiation nozzle and the treatment table so that an irradiation position of the therapeutic radiation and a position of the affected part coincide with each other based on a composite fluoroscopic image created by the image processing apparatus Having equipment.
(2) The image acquisition device can take a fluoroscopic image including a body surface marker for specifying the position of the affected part, and the television camera can take a camera image including the body surface marker over time. The image processing device creates a synthetic fluoroscopic image around the affected area including the affected area over time based on the body surface marker of the fluoroscopic image and the body surface marker of the camera image.
(3) The image processing apparatus calculates a relative position between the irradiation position of the therapeutic radiation and the position of the affected part using the synthetic fluoroscopic image, and the control apparatus calculates the irradiation nozzle so that the relative positions coincide with each other. And controlling at least one of the treatment tables.
(4) The image processing device calculates a relative position between the irradiation position of the therapeutic radiation and the position of the affected part using the synthetic fluoroscopic image, and the control device has a case where the relative position exceeds a predetermined value. And control not to allow the irradiation of therapeutic radiation from the irradiation nozzle.
(5) The image processing apparatus calculates a relative position between the irradiation position of the therapeutic radiation and the position of the affected part using a synthetic fluoroscopic image, and the control apparatus determines that the relative position exceeds a predetermined value. Control to display that effect on the display.
(6) The television camera includes moving means for photographing the patient from different directions.
(7) Two or more image acquisition devices and two television cameras are provided.
(8) While the patient breathes several times, the image acquisition device irradiates diagnostic radiation to photograph the periphery of the affected area with a body surface marker over time, and the image processing device uses the image acquisition device. Using a fluoroscopic image taken over time and a camera image taken over time by the television camera, a synthetic fluoroscopic image around the affected area including the affected area is created over time, and the amount of movement of the affected area and the Calculate the difference in the movement amount of the body surface marker or the movement amount of each.

  According to the radiotherapy apparatus of the present invention, the treatment accuracy can be improved and the radiation exposure dose of the patient can be suppressed.

Hereinafter, the radiation therapy apparatus of several embodiment of this invention is demonstrated using figures. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent.
(First embodiment)
A proton beam therapy apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram of the proton beam therapy apparatus according to the first embodiment of the present invention, and FIG. 2 is a block diagram of the proton beam therapy apparatus of FIG. 1 shown together with the data flow.

  The proton beam therapy apparatus 10 of this embodiment includes a rotating gantry 11, an irradiation nozzle 12, a treatment table 14, image acquisition apparatuses 18, 21, TV cameras 22, 25, an image processing apparatus 30, and a control apparatus 31. And a display 32. A body surface marker 23 is applied to the body surface of the patient 13 in order to specify the position of the affected part of the patient 13. Note that reference numerals 33, 34, 35, 36, 37, 38, 39, and 40 in FIG. 2 indicate signal / data transmission paths between the components.

  The rotating gantry 11 is formed in an annular shape so that the movable table 14 can enter, and is arranged so as to be rotatable in the rotation direction 24 with respect to the installation surface of the proton beam therapy apparatus 10.

  The irradiation nozzle 12 is attached to the inside of the rotating gantry 11 and irradiates a treatment proton beam 15 to an affected area of a patient 13 placed on a treatment table 14. Since the irradiation nozzle 12 can be rotated around the patient 13 by the rotating gantry 11, the proton beam 15 can be irradiated from the entire circumference of the patient 13.

  The treatment table 14 is movably installed so that the affected part of the patient 13 can be positioned at the irradiation position of the therapeutic radiation 15 irradiated from the irradiation nozzle 12 with the patient 13 placed thereon.

  The image acquisition devices 18 and 21 irradiate diagnostic radiation and image the periphery of the affected part of the patient 13 including the body surface marker 23, and are configured by a plurality (two in the illustrated example) of image acquisition devices. . Each of the image acquisition devices 18 and 21 includes a diagnostic radiation source 16 and 19 and an image receiving device 17 and 20.

  The TV cameras 22 and 25 have a CCD image pickup device and take an image of the body surface of the patient 13 including the body surface marker 23, and are composed of a plurality (two in the illustrated example) of TV cameras. By providing a plurality of image acquisition devices 18 and 21 and television cameras 22 and 25, the patient 13 can be photographed from different directions, so that the position of the affected part and the body surface marker 23 can be calculated with high accuracy.

  The image processing apparatus 30 includes a microcomputer, and uses fluoroscopic images 50 and 51 photographed by the image acquisition apparatuses 18 and 21 and camera images 52 and 53 photographed over time by the television cameras 22 and 25, A synthetic fluoroscopic image 55 around the affected area including 13 affected areas is created over time. At this time, the image processing apparatus 30 creates a composite fluoroscopic image 55 around the affected area including the affected area over time based on the body surface marker of the fluoroscopic images 50 and 51 and the body surface marker of the camera images 52 and 53. . This synthesized perspective image 55 is output to the control device 31 and the display 32. The synthesized perspective image 55 is an image in which the perspective images 50 and 51 are associated with the camera images 52 and 53. Further, the image processing device 30 calculates a relative position between the irradiation position of the proton beam 15 and the position of the affected part using the synthetic fluoroscopic image 55 and outputs the calculated relative position to the control device 31.

  The control device 31 controls the irradiation nozzle 12 and the treatment table 14 so that the irradiation position of the proton beam 15 and the position of the affected part of the patient 13 coincide with each other based on the composite fluoroscopic image 55 created by the image processing device 30. In addition, when the relative position between the irradiation position of the therapeutic radiation 15 output from the image processing apparatus 30 and the affected part of the patient 13 exceeds a predetermined value, the control device 31 displays that fact on the display 32. And the irradiation nozzle 12 is controlled not to allow irradiation of the proton beam 15.

  The display 32 displays the composite fluoroscopic image 55 created by the image processing device 30 on the display screen.

  The operation and function of the proton beam therapy apparatus 10 will be described below.

  The patient 13 is fixed on the treatment table 14, and the affected part is roughly positioned at the irradiation position of the proton beam 15 while moving the treatment table 14 so as to follow the treatment plan determined by the diagnosis before treatment. This rough positioning is performed with reference to a laser irradiated to the body surface of the patient 13 with a laser pointer (not shown) and a mark previously attached to the body surface of the patient 13.

  When the rough positioning is completed, the image acquisition devices 18 and 21 irradiate diagnostic radiation to image the affected area of the patient 13 including the body surface marker 23, and send this image data to the image processing device 30. The captured images are referred to as fluoroscopic images 50 and 51. Simultaneously with the imaging of the image acquisition devices 18 and 21, imaging by the television cameras 22 and 25 is started. The television cameras 22 and 25 continuously photograph the periphery of the body surface marker 23 of the patient 13 in real time. Send to processing device 30. The captured images are referred to as camera images 52 and 53. Note that continuous shooting in real time by the television cameras 22 and 25 may be replaced with time-lapse shooting in which shooting is performed at a predetermined interval.

  Upon receiving the fluoroscopic images 50 and 51, the image processing apparatus 30 outputs the composite fluoroscopic image 55 to the display 32. Then, the display 32 displays the synthesized perspective image 55 output from the image processing device 30 on the display screen.

  Further, upon receiving the fluoroscopic images 50 and 51 and the camera images 52 and 53, the image processing apparatus 30 extracts the position of the affected part and the position of the body surface marker 23 from the fluoroscopic images 50 and 51, and from the camera images 52 and 53. The position of the body surface marker 23 is extracted, the body surface marker 23 of each image is associated, and the position of the affected part and the position of the body surface marker 23 are calculated. At this time, the fluoroscopic images 50 and 51, the camera images 52 and 53, and the combined fluoroscopic image 55 are used as reference images for subsequent image processing, and the position of the affected part and the position of the body surface marker 23 are set as reference positions.

  Next, the image processing apparatus 30 extracts the position of the body surface marker 23 from the TV images 52 and 53 that are continuously sent in real time thereafter, and compares the extracted position with the reference position of the body surface marker 23 previously captured. Thus, the movement amount of the affected part or the body surface marker 23 is calculated. The image processing apparatus 30 converts the amount of movement into the amount of movement of the fluoroscopic images 50 and 51, and moves the fluoroscopic images 50 and 51 up and down, left and right, or rotates the corresponding amount to realize the synthesized fluoroscopic image 55. Created continuously in time and output to the display 32. This conversion into the amount of movement is performed using the positional relationship between the television cameras 22 and 25 and the image acquisition devices 18 and 21, the shooting direction, and the like.

  The display 32 continuously displays the composite fluoroscopic image 53 output from the image processing device 30 on the display screen in real time. When the calculation load on the image processing apparatus 30 is large, the composite fluoroscopic image 55 may be created over time at predetermined intervals and displayed on the display 32.

  For the image data (the fluoroscopic images 50, 51 and the camera images 52, 53) used to create the composite fluoroscopic image 55, for example, when the affected part has a body surface marker 23 on the chest of the patient 13 around the chest, The chest moves as the patient 13 breathes. Therefore, during the respiration of several times, the moving image data is acquired by any of the image acquisition devices 18 and 21 and the TV cameras 22 and 25, and the body surface marker 23 and the affected part due to respiration, and if necessary, the bones and organs, etc. A change in the relative positional relationship is calculated, and the difference in the amount of movement between the affected area and the body surface marker 23 is reflected in the synthesized fluoroscopic image 55. When the movement of the affected part and the body surface marker 23 is different, it is not possible to create an accurate synthesized fluoroscopic image 55 simply by moving the fluoroscopic images 50 and 51 up and down, left and right, or rotating them. The perspective images 50 and 51 may be enlarged or reduced, or interpolation calculation or the like may be used.

  The image data (the fluoroscopic images 50 and 51) used for creating the synthetic fluoroscopic image 55 is preferably moving image data in order to accurately reflect the position of the affected part on the synthetic fluoroscopic image 55. It is better to use still image data to reduce the amount of exposure. In the present embodiment, moving image data is used when the motion of the affected area and the body surface marker 23 are different, and still image data is used in other cases, and the patient is irradiated with the proton beam 15 with high accuracy, Consideration is given to both reducing the exposure of diagnostic radiation.

  The body surface marker 23 may be three or more in order to calculate the position of the affected part with high accuracy, and the material is common to the image acquisition devices 18 and 21 and the television cameras 22 and 25 using a radiation translucent material or the like. It is good to be able to use it. When this is difficult and the body surface markers 23 are different between the image acquisition devices 18 and 21 and the television cameras 22 and 25, it is necessary to clarify the relative positions of the respective markers when creating the composite perspective image 55. Can be calculated.

  Next, the surgeon manually moves the treatment table 14 based on the synthetic fluoroscopic image 55 displayed on the display 32 and positions the affected part at the irradiation position of the proton beam 15 with high accuracy. During this time, the television cameras 22 and 25 always photograph the patient 13 and continue to send image data to the image processing device 30. The image processing device 30 creates a composite perspective image 55 from the sent image data as needed, The latest synthesized fluoroscopic image 55 is displayed on the display 32.

  The display 32 displays the synthetic fluoroscopic image 55, the irradiation position of the proton beam 15 calculated from the treatment plan, the relative position of each device, the relative position (error) between the affected part position and the irradiation position of the proton beam 15, and the like. Then, since the operator can confirm the positioning status, it is easy to understand and the treatment accuracy can be improved.

  The relative position (error) between the affected part position calculated from the composite fluoroscopic image 55 and the irradiation position of the proton beam 15 is always monitored by the control device 31. If the error exceeds a predetermined value, the proton beam 15 If the irradiation is not permitted, or is displayed on the display 32 to inform the operator, the safety of the treatment is improved.

  In this embodiment, high-accuracy positioning can be switched between manual and automatic. The automatic high-accuracy positioning is based on the difference (error) between the position of the affected area calculated from the composite fluoroscopic image 55 and the irradiation position of the proton beam 15, and the amount of movement of the treatment table 14 and the rotating gantry 11 for correcting the error. Is calculated by the control device 31, and the error is corrected by moving the treatment table 14 and the rotating gantry 11.

In the present embodiment, the movement of the patient 13 is calculated from the camera images of the television cameras 22 and 25 that are always photographing the patient 13, and the movement of the patient 13 is reflected in the perspective images 50 and 51 of the image acquisition devices 18 and 21. Therefore, the positioning accuracy of the affected part with respect to the irradiation position of the proton beam 15 can be improved, and the treatment accuracy can be improved. Moreover, since it is only necessary to irradiate diagnostic radiation for a short time before high-accuracy positioning, the radiation exposure dose of the patient 13 can be suppressed.
(Second Embodiment)
Next, the radiation therapy apparatus of 2nd Embodiment of this invention is demonstrated using FIG. FIG. 3 is a block diagram of a radiation therapy apparatus according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in the points described below, and the other points are basically the same as those in the first embodiment, and thus redundant description is omitted.

  The second embodiment is an example in which one television camera 60 is provided and the television camera 60 is attached to the moving mechanism 65. The moving mechanism 65 includes, for example, a guide rail 61 and a drive mechanism 62, and can move the TV camera 60 along the guide rail 61 by a command signal from a control device (not shown). Therefore, if an image is taken first at the TV camera position 63 and then at the TV camera position 64, images from different directions can be obtained as in the first embodiment. The position can be calculated.

  However, since the TV camera 60 moves to change the shooting direction when acquiring the reference image, it is not possible to capture and shoot all images simultaneously. Therefore, the second embodiment is effective when the affected part or the body surface marker 23 does not move so much due to breathing or the like.

The configuration in which the moving mechanism 65 is provided in the television camera 60 may be used when there are two television cameras 22 and 25 as in the first embodiment. Depending on the irradiation direction of the proton beam 15, there may be a case where the rotating gantry 11, the treatment table 14, the image acquisition devices 18, 21 interfere with the television cameras 22, 25, or the television cameras 22, 25 cannot capture a marker. In such a case, it is preferable to change the shooting direction of the television cameras 22 and 25 by the moving mechanism 65.
(Other embodiments)
The present invention is not limited to a proton beam treatment apparatus, but can be applied to an apparatus using a particle beam such as a carbon beam in addition to an X-ray or an electron beam.

It is a block diagram of the proton beam therapy apparatus of 1st Embodiment of this invention. It is a block diagram of the proton beam therapy apparatus of FIG. It is a block diagram of the radiotherapy apparatus of 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Proton beam treatment apparatus, 11 ... Rotary gantry, 12 ... Irradiation nozzle, 13 ... Patient, 14 ... Treatment table, 15 ... Proton beam, 16, 19 ... Radiation source for diagnosis, 17, 20 ... Image receiving device, 18, 21 ... Image acquisition device, 22, 25, 60 ... TV camera, 23 ... Marker, 24 ... Rotation direction, 30 ... Image processing device, 31 ... Control device, 32 ... Display, 33, 34, 35, 36, 37, 38, 39, 40 ... signal / data transmission path, 50, 51 ... perspective image, 52, 53 ... camera image, 55 ... synthetic perspective image, 61 ... guide rail, 62 ... drive mechanism, 63, 64 ... stop position of TV camera, 65: Movement mechanism.

Claims (9)

An irradiation nozzle for irradiating therapeutic radiation;
A treatment table for positioning the affected area of the patient at the irradiation position of the therapeutic radiation irradiated from the irradiation nozzle with the patient on;
An image acquisition device that radiates diagnostic radiation and images the periphery of the affected area;
A television camera for photographing the patient's body surface;
An image processing device that creates a synthetic fluoroscopic image around the affected part including the affected part over time using a fluoroscopic image taken by the image acquiring apparatus and a camera image taken over time by the television camera;
A radiotherapy apparatus comprising: a display that displays a composite fluoroscopic image created by the image processing apparatus.   2. The control unit according to claim 1, wherein at least one of the irradiation nozzle and the treatment table is controlled so that an irradiation position of the therapeutic radiation and a position of the affected area coincide with each other based on a composite fluoroscopic image created by the image processing apparatus. The radiotherapy apparatus provided with the control apparatus which performs.   3. The image acquisition device according to claim 1, wherein the image acquisition device can capture a fluoroscopic image including a body surface marker for specifying a position of the affected part, and the television camera captures a camera image including the body surface marker over time. The image processing apparatus is capable of photographing, and based on the body surface marker of the fluoroscopic image and the body surface marker of the camera image, creates a synthetic fluoroscopic image around the affected area including the affected area over time. Radiation therapy device characterized.   The image processing apparatus according to claim 2, wherein the image processing apparatus calculates a relative position between the irradiation position of the therapeutic radiation and the position of the affected part using the synthetic fluoroscopic image, and the control apparatus is configured to match the relative position. A radiotherapy apparatus that controls at least one of an irradiation nozzle and the treatment table.   3. The image processing apparatus according to claim 2, wherein the image processing apparatus calculates a relative position between the irradiation position of the therapeutic radiation and the position of the affected part using the synthetic fluoroscopic image, and the control apparatus determines that the relative position exceeds a predetermined value. And a radiation therapy apparatus for controlling so that irradiation of therapeutic radiation from the irradiation nozzle is not permitted.   3. The image processing apparatus according to claim 2, wherein the image processing apparatus calculates a relative position between the irradiation position of the therapeutic radiation and the position of the affected part using a synthetic fluoroscopic image, and the control apparatus exceeds the predetermined value. In some cases, the radiotherapy apparatus is controlled to display the fact on the display.   7. The radiotherapy apparatus according to claim 1, wherein the television camera includes moving means for photographing the patient from different directions.   The radiotherapy apparatus according to claim 1, wherein two or more of the image acquisition device and the television camera are provided.   9. The image processing apparatus according to claim 1, wherein the image acquisition device irradiates diagnostic radiation while the patient breathes several times to photograph the periphery of the affected area together with a body surface marker over time, and the image processing device. Is to create a synthetic fluoroscopic image around the affected part including the affected part over time using a fluoroscopic image taken with the image acquisition device and a camera image taken with the television camera over time, A radiotherapy apparatus characterized by calculating a difference between a movement amount of the affected part and a movement amount of the body surface marker or each movement amount.

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