JPS63206261A - Body motion interlock signal generator for radiation treatment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an interlock system of a radiotherapy device, and in particular to an interlock system that continuously monitors the movement of a patient during treatment and detects the movement of a patient when the movement exceeds a predetermined tolerance. The present invention relates to a body movement interlock generating device that immediately generates an interlock signal and interrupts a beam.

[Prior Art] Conventionally, this type of body movement interlock signal generation device uses an ITV camera, and subtracts a reference image at the start of treatment and a 1-numbered image during treatment to determine the region of interest and deviations set in advance. The permissible state was checked by image loading and operation, and if it was outside the range, a status signal (interlock signal) was to be output.

[Problems to be solved by the invention] 1) The conventional body movement interlock signal generating device mentioned above is O.
Since it is always at the binary level of N and F, it is necessary to know the time course of the deviation and the extent of the deviation within the allowable range, and to take corrective measures either from the patient or by instructions from the treating technician (via intercom). Not matched.

For this reason, there are many cases in which the procedure has to be discontinued due to problems related to the method and suitability of the fixation device or to individual patients.

Furthermore, the allowable range of deviation can only be specified in terms of vertical and horizontal dimensions and by direct dimensions. That is, it is necessary to perform prior calibration based on dark shadow conditions (for each patient and every two parts).

SUMMARY OF THE INVENTION An object of the present invention is to provide a body movement interlock signal generating device that solves the above-mentioned problems.

[Means for Solving the Problems] The present invention provides a body movement interlock for radiation therapy.
A mark sheet for body movement tracking is attached to the radiation irradiation site with a calibration scale and allowable body movement range marked, and the drawing of the mark sheet is carried by an ITV camera and constantly tracked and compared with a reference image, and the difference is measured in actual size. A radiotherapy apparatus-side interface comprising an output means for outputting an output, and a means for generating a body movement interlock signal when an output value of the output means exceeds a body movement permissible range on the mark sheet. It is a lock generator.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is an overall view of a radiation therapy apparatus according to the present invention.

The distal end portion of the radiation therapy device main body 1 is a canted portion,
It is possible to rotate 360° around the patient 3 lying on the treatment table 2. Regardless of the rotational position of the main body 1, the ITV camera 4 is always installed at a position where it can see the body surface including the central axis of irradiation when irradiating from directly above the patient 3, and the ITV camera 4 monitors the patient 3's movements during treatment in advance. Monitoring is performed via the body movement tracking mark sheet 5 attached.

The body movement tracking mark sheet 5 is made of, for example, a transparent adhesive tape, on which a large circle of 1 cm is overlaid and a permissible range of body movement on a plane is illustrated using a marker or the like according to the case. It is.

The body movement measurement control unit 6 converts the video signal centered on the body movement tracking mark sheet h5 observed by the ITV camera into a D/A converter at a constant repetition period, reads it into the image memory, and reads the body movement tracking mark sheet 5 into the image memory. Subtraction is performed on the scale ring part using the reference image before the start of treatment.
The deviation is subtracted from the permissible body movement range specified on the mark sheet 5 or the vertical and horizontal permissible values specified directly from the keyboard, and this difference is output to the body motion output terminal 7. Furthermore, if this result exceeds the allowable range, it is output to the body movement interlock signal output terminal 8.

The patient notification device 9 is an application example of the present invention, and is, for example, a BGM volume control device, and is designed to have a structure in which the sound disappears as the body movement increases, like a radio tuner, as the body movement increases. This makes it possible for the patient 3 to correct his or her body movements in a direction that makes it easier to hear the BGM by following the instructions in advance. The purpose of this patient reporting device 9 is to notify the patient of positional deviation due to body movement by some means, and instructions are given through an intercom under the operator's supervision using a blinking light or computer display processing. It may be.

Further, the printer 10 is an application example of the present invention, and by recording the body movements, it is possible to improve and develop better fixing devices.

FIG. 2 is a block diagram of parts of the present invention.

The ITV camera 11 is the same as the ITV camera 4 shown in FIG. Image memories 1 to 12 have A/D in the front stage.
It includes a converter and receives a clock signal from the control unit 17 to store the video signal from the ITV camera 11 as a digital value in the image memory.

The mark outline extraction unit 13 receives the timing signal from the control unit 17, reads the ITV digital image in the image memory 12, and extracts the mark sheets 1-5 and 2 for body movement tracking shown in FIG.
Two contour coordinate groups are extracted. The body movement measurement unit 14 receives the timing signal from the control unit 17 and extracts the outline coordinates of the body movement tracking marks 1-5 before the start of irradiation extracted by the mark contour extraction unit 13 and those currently being irradiated. This value is output to the body movement star output terminal 14a, and the difference is determined in advance if the difference is within the tolerance range on the plane specified from the mark sheet 5 for traces D or X, YIIII specified from the console 16. Check whether the above value is within the range. Furthermore, if the check result exceeds the specified range, the interlock signal generator 1
5, a body movement interrotter signal is generated to avoid driving the interlock system on the radiotherapy apparatus side, and the signal is output to the same output terminal 15a.

The console 16 controls the body movement control unit 17 (body movement control unit 17 before starting irradiation)
Upon receiving an instruction to start reading the D path mark sheet 5, the mark contour extracting unit 13 leaves the first extracted contour coordinate group of the body movement tracking mark sheet 5 in a buffer for reference from the second time onwards. This value is transferred to the body movement measurement unit 14.

In addition, the threshold value can be input directly using the conventional keyboard.

It is also possible to input values on the Y axis.

[Advantageous Effects of the Invention 1] As explained above, the present invention has the advantage of being able to easily and accurately correspond to any permissible body movement range illustrated on a plane by employing a body movement tracking mark sheet. In addition, since it is possible to output body movement information within the permissible body movement range, body movement can be corrected based on this information, which has the effect of realizing accurate treatment in the shortest possible time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a radiation therapy apparatus according to the present invention, and FIG. 2 is a block diagram of a portion of the present invention. 1...Radiotherapy equipment main body 2...Same as above Treatment table 3...Patient being treated 4.
... r-rv camera 5... body! 111 Tracking mark sheet 6...Body movement measurement control unit 7...Radiotherapy device control console 11.
...ITV camera 12...image memory unit

Claims (1)

[Claims] (1) In body movement interlock during radiation therapy, a mark sheet for body movement tracking is attached to the radiation irradiation site with a calibration scale and allowable body movement range marked, and a reference image is obtained by photographing the drawing of the mark sheet with an ITV camera. and output means for constantly tracking and comparing and outputting the difference in actual size, and means for generating a body movement interlock signal when the output value of the output means exceeds the body movement permissible range on the mark sheet. A body motion interlock generator for radiation therapy, characterized in that: