JP6484091B2 - Inspection method and inspection tool for stop position in applicator of guide wire tip - Google Patents

Description

  The present invention relates to a method for inspecting a position where a guide wire tip brachytherapy source stops in an applicator in a combination of a brachytherapy device used in brachytherapy and an applicator, and an inspection method thereof. The present invention relates to an inspection tool that can be used.

  Brachytherapy is a treatment method in which a small granular radiation source (radiation source) that emits radiation is attached to the tip of the guide wire, temporarily inserted into the lesion in the body of a cancer patient, and irradiated from the body. It is intended to reduce the side effects by reducing the irradiation of normal tissues as much as possible while irradiating cancer tissues with an effective amount of radiation to achieve a high therapeutic effect. (See Patent Documents 1 to 4). Therefore, in brachytherapy, it is extremely important to accurately bring the brachysource into a predetermined position in the body lesion.

  Therefore, an applicator and a brachytherapy device are used in brachytherapy. The applicator is a hollow tube or a hollow needle that is previously placed in the body of the cancer patient before inserting the brachytherapy source into the body. The applicator guides and stops at the brachytherapy source attached to the tip of the guide wire. provide. The hollow tube applicator is used for intracavity irradiation in which the distal end occlusion is previously placed in the patient's lesion cavity, and the hollow needle applicator is used for intra-tissue irradiation that is inserted into the patient's lesion with the distal needle section. used. Intracavitary irradiation is used, for example, in nasopharyngeal cancer, esophageal cancer, bile duct cancer, or uterine cancer, and tissue irradiation is used, for example, in tongue cancer, prostate cancer, or breast cancer. On the other hand, the brachytherapy device is a brachytherapy device attached to the distal end of the guide wire. During treatment, the guide wire outlet and the applicator end opening of the brachytherapy device are connected (optionally with a connecting tube). Used to insert a brachytherapy source into the body. Specifically, the guide wire is remotely operated in accordance with the preset delivery distance of the brachytherapy source, and the brachytherapy source is inserted into the applicator and stopped at a predetermined position. It can be moved between predetermined positions, or the brachytherapy source can be extracted from the applicator and stored after irradiation.

Conventionally, brachytherapy using such an applicator and a brachytherapy device has been performed in the following procedure, for example.
(1) The guide wire outlet of the brachytherapy device and the end opening that is one end of the applicator are connected (possibly via a connecting tube), and the applicator is connected to the tip that is the other end. Insert into the luminal organ of the cancer patient from the occluded side, or insert into the cancer tissue.
(2) X-ray imaging and / or CT imaging are performed with the applicator tip occlusion portion inserted or inserted into a predetermined position in the patient's body, and the position of the applicator and the lesion position are confirmed.
(3) Based on the position data obtained by X-ray imaging and / or CT imaging, using the treatment planning software, the position where the brachytherapy source is stopped in the applicator (stop position) and each The irradiation time (stop time) at the stop position is determined.
(4) According to the determined stopping position, the distance for sending the guide wire tip small wire source from the small wire source insertion device to the stopping position is obtained, and the delivery distance of the guide wire tip small wire source is set to the small wire source insertion device. Set.
(5) According to the set delivery distance, the guide wire tip braid source is advanced into the applicator by remote control and stopped at a predetermined stop position.
(6) After irradiating for a predetermined stop time at the stop position, the guide wire tip wire source is wound and stored in the wire source insertion device.

“Brachytherapy”, [online], Osaka University Graduate School of Radiology, [Retrieved March 17, 2015], Internet <URL: http://www.med.osaka-u.ac. jp / pub / radonc / www / general / brachytherapy.htm> “Brachytherapy”, [online], Osaka University Graduate School of Radiology, [Retrieved March 17, 2015], Internet <URL: http://www.med.osaka-u.ac. jp / pub / radonc / www / microselectron.htm> “What is brachytherapy”, [online], Department of Radiation Therapy, Fukuoka University Hospital, [searched on March 17, 2015], Internet <URL: http://www.med.fukuoka-u.ac.jp /radiolog/radiotherapy/brachy/index.html> “Cervical cancer”, [online], Department of Radiation Therapy, Fukuoka University Hospital, [Search March 17, 2015], Internet <URL: http://www.med.fukuoka-u.ac.jp/radiolog/ radiotherapy / brachy / cervix.html>

  In brachytherapy, using an applicator and a brachytherapy device to accurately stop the guidewire tip brachytherapy at a predetermined stopping position as described above is an extremely simple operation. Occurrence of this has not been assumed, and the necessity of confirming in advance the stop position in the applicator of the guide wire tip brachytherapy source prior to the treatment has not been considered at all.

  However, actually, in July 2014, an example of a medical accident in which radiation was accidentally applied to a place other than the affected part in brachytherapy was reported. Specifically, 100 female patients from 30 to 89 years of age who received brachytherapy such as cervical cancer were irradiated with radiation at a position shifted by about 3 cm from the position that should be irradiated, A report was published that seven people developed skin necrosis (ulcers) and urethral strictures that were thought to be affected. This accident is caused by an error when setting the delivery distance of the guide wire tip small wire source to the small wire source insertion device, and the possibility of the same accident cannot be denied.

  Moreover, the cutting process of the applicator and the connecting tube at the treatment site can cause the same medical accident. As an applicator for brachytherapy, there are a plurality of types of applicators. In particular, in the universal type, setting of the total length including the connecting tube is important. Also, metal applicators etc. have standard lengths for each product, so when setting the distance to send the guide wire tip braid source from the braid source insertion device, use the standard value. The sending distance can be set easily. Moreover, when using a connection tube for the connection of the guide wire exit and applicator end opening of the brachytherapy device, a standard value can be used for the length of the connection tube. However, since the brachytherapy applicator and connecting tube can be easily cut at the treatment site, they may be cut for convenience of treatment. It is difficult to deny the possibility of a serious medical accident.

In this way, although a serious medical accident has actually occurred from a simple mistake and may occur in the future, no preventive measures from the hardware aspect have been proposed yet.
Accordingly, it is an object of the present invention to accurately in advance accurately check the position where the guide wire tip brachytherapy source actually stops in the applicator in each combination of the brachytherapy device used for brachytherapy and the applicator. The object is to provide a simple method and prevent the occurrence of a medical accident due to a setting error in the delivery distance of the guide wire tip small wire source.
In addition, since it is possible to accurately measure the position where the guide wire tip brachytherapy source actually stops in the applicator, it is effective for cancer tissue by controlling the brace source stop position more accurately. It is possible to further improve the effectiveness of the brachytherapy that accurately irradiates the amount of radiation and reduces the radiation to the surrounding normal tissue as much as possible.
Furthermore, this invention is providing the test | inspection tool which can be used for the said test | inspection thru | or confirmation method.

According to the present invention, in the combination of a brachytherapy device insertion apparatus and an applicator used in the brachytherapy, the position of the guidewire tip brachytherapy source of the brachytherapy device insertion apparatus is stopped in the applicator. A way to
(1) Applicator holding means comprising a groove or a hole capable of holding the inspection object applicator and extending from a closed front end part capable of contacting the front end closing part of the inspection object applicator to an opening edge, and the applicator holding An inspection object applicator is inserted into the applicator holding means of the base including at least one metal marker provided along the means so that the distal end closing portion of the inspection object applicator is brought into contact with the closing distal end portion of the applicator holding means Process,
(2) A step of placing radiation-sensitive paper on the surface of the base on which the applicator to be inspected is inserted in the contact step;
(3) A guide wire tip braid source is introduced from the inspection subject brachy source insertion device, with the braid source provided at the tip of the guide wire approaching from the end opening of the applicator applicator toward the innermost tip. A step of exposing the radiation-sensitive paper by stopping the guide wire tip brazing beam source for a predetermined time at a predetermined stop position;
(4) A predetermined stop position of the guide wire tip brachytherapy source in the combination of the inspection target brachytherapy device and the inspection applicator is determined from the brachytherapy image and the metal marker image formed on the radiation sensitive paper. This can be solved by the inspection method including the step of confirming.

  In a preferred embodiment of the method of the present invention, after the exposure process at the predetermined stop position, the brachytherapy source is moved to another brachytherapy source stop position in the treatment plan, and the other stop position is moved over the predetermined time. The method further includes a step of confirming each stop position from the small-line source image and the metal marker image obtained by performing the step of exposing the radiation sensitive paper.

The present invention also provides an inspection tool for inspecting a position where a guide wire tip brachytherapy source of the brachytherapy device insertion device stops in the applicator in a combination of a brachytherapy device used for brachytherapy and an applicator. Because;
An applicator holding means comprising a groove or a hole extending from a closed tip end portion to an opening edge portion capable of holding the test subject applicator and being able to contact the tip closing portion of the test subject applicator; The inspection tool is also characterized by including a base including at least one metal marker provided along the applicator holding means.

  In a preferable aspect of the inspection tool of the present invention, the inspection tool further includes a cover that can cover and fix the radiation-sensitive paper placed on the surface of the base in which the applicator to be inspected is inserted.

According to the present invention, in each combination of an applicator actually used in a brachytherapy and a brachytherapy device, a setting stop position of the guidewire tip brachytherapy source is inspected in advance inside the applicator. Therefore, one of the causes of medical accidents in brachytherapy can be reliably removed.
In addition, according to the present invention, the position where the guide wire tip small wire source stops inside the applicator can be accurately measured, so that the stop position of the small wire source can be controlled more accurately, The effectiveness of radiation therapy can be improved.
Furthermore, the applicator and the connecting tube cutting process appropriately performed in the medical field can be executed with peace of mind.
Moreover, according to the inspection tool by this invention, the inspection method by this invention can be implemented simply.

It is a typical top view of the base included in the inspection tool used by the method of the present invention. It is a disassembled perspective view which shows typically the structure at the time of implementing this invention method using the test | inspection tool containing the base of FIG. FIG. 3 is a schematic exploded sectional view taken along line A-A ′ of FIG. 2. FIG. 4 is a schematic exploded cross-sectional view similar to FIG. 3 showing a configuration when the method of the present invention is carried out using a base of another aspect included in the inspection tool according to the present invention. It is a typical top view of the base of another mode included in the inspection tool by the present invention. It is an X-ray photograph which shows the test result by this invention method.

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a plan view of a base 1 included in an inspection tool 10 used in the method of the present invention, and FIG. 2 shows a hollow needle type applicator 31 using the inspection tool 10 including the base 1 of FIG. FIG. 3 is an exploded perspective view schematically showing a configuration when the method of the present invention is performed, and FIG. 3 is a schematic cross-sectional view taken along line AA ′ of FIG. 1 to 3 and FIGS. 4 and 5 to be described later are schematic diagrams for the purpose of explaining the principle of the present invention, and relative dimensional ratios between parts and parts are not accurate. Not exaggerated.

First, the outline of the procedure of the method of the present invention will be briefly described based on the embodiment shown in FIGS.
The method of the present invention is carried out in a radiation irradiation laboratory. First, the brachytherapy outlet 57 of the brazing source insertion device 5 to be inspected and the end opening 37 of the applicator 3 to be inspected are connected to each other via a connecting tube 55 as necessary. The inspection target applicator 3 is inserted into the applicator holding groove 6 provided on the surface 11 of the base 1, and the distal end blocking portion 35 of the inspection target applicator 3 is brought into contact with the closed distal end portion 61 of the applicator holding groove 6. Next, if necessary, the inspection target applicator 3 is fixed with an applicator cover plate 93 or an adhesive tape (not shown) so that it does not move. Fix the whole. That is, the base 1, the inspection target applicator 3, the applicator cover plate 93, the radiation photosensitive paper 91, and the cover 2 are fixed so as not to move.

  Subsequently, the experimenter goes out of the radiation irradiation laboratory and remotely controls the brachytherapy source 51 attached to the tip of the guide wire 53 from the brachytherapy outlet 57 of the brachytherapy device insertion apparatus 5 to be examined. In some cases, the inspection object applicator 3 is entered from the end opening 37 of the inspection object applicator 3 through the connection tube 55 and stopped at the tip reference position 41 at the tip of the inspection object applicator 3. The approach distance to the tip reference position 41 is calculated from the length of the applicator 3 to be inspected or the total length with the connection tube 55. At this tip reference position 41, the beam source 51 is stationary for a predetermined time, and the radiation sensitive paper 91 is exposed to radiation. Here, when the cover 2 is transparent and the radiation sensitive paper 91 is a chromic film, the images of the brachytherapy source 51 and the metal marker 8 directly formed on the radiation sensitive paper 91 are provided in the radiation irradiation laboratory. Images can be taken with an imaging device, observed with an image display device provided in a separate room, and visually confirmed. Further, it is possible to accurately calculate the relative position between the metal marker 8 and the small beam source 51 by processing the image data acquired by the imaging device.

  Next, when the stop position determined in the treatment plan is different from the tip reference position 41, the guide wire 53 is returned from the tip reference position 41 toward the end opening 37, and is stopped at the predetermined stop position. The radiation sensitive paper 91 is exposed to radiation. When the cover 2 is transparent and the radiation sensitive paper 91 is a chromic film, the image formed on the radiation sensitive paper 91 can be observed and confirmed in a separate room, and the image data acquired by the imaging device is processed. Thus, it is possible to accurately calculate the stationary position of the beam source 51.

  When the radiation photosensitive paper 91 needs to be developed or when the cover 2 is opaque, the small beam source 51 is extracted from the inspection target applicator 3 after the necessary image formation is completed, and the inspection target small beam source. It is stored in the insertion device 5, the radiation sensitive paper 91 is taken out, and it is inspected from the images of the small beam source 51 and the metal marker 8 whether or not it is accurately stopped at the tip reference position and the predetermined stop position of the small beam source 51. be able to.

  Incidentally, the exposure of the metal marker 8 is due to Compton scattering of radiation irradiated from the beam source 51. Note that the operation of connecting the small-beam source outlet 57 of the small-beam source insertion device 5 to be inspected and the end opening 37 of the inspection-target applicator 3 to each other via the coupling tube 55 as necessary is as described above. In addition, it may be performed before inserting the inspection target applicator 3 into the applicator holding groove 6, but before the step of causing the distal braid source 51 of the guide wire 53 to enter the inspection target applicator 3 by remote control. It is sufficient to carry out.

Next, the method of the present invention will be described in more detail while specifically explaining the structure of the inspection tool 10 according to the present invention.
The inspection tool 10 according to the present invention includes a base 1 suitable for inspection of a linear hollow needle type applicator 31, preferably includes a cover 2, and can further include an applicator cover plate 93. A linear hollow needle type applicator 31 that is usually used for brachytherapy is a linear hollow body that extends from a distal end blocking portion 35 that is one end portion to an end opening portion 37 that is the other end portion. Yes, when used for tissue irradiation, it is possible to insert the guide wire tip brachytherapy source 51 into the hollow portion by piercing the patient lesion with the tip needle portion 43.

  The base 1 used in the present invention is used with its back surface placed on a flat plane, and an applicator cover plate 93 is optionally placed on the opposite surface 11 before the radiation sensitive paper 91 is placed. Since it mounts, it is preferable that it is a flat plate which has flat both surfaces. Although the shape of each surface of a front side and a back side is not limited, For example, as shown in FIGS. 1-3, it is preferable that it is a substantially square thru | or a substantially rectangular shape. The base 1 can be made of, for example, various synthetic resins (in particular, a radiation transmissive material such as an acrylic resin).

  The base 1 includes an applicator holding groove 6 and a metal marker 8 provided along the holding groove 6 on a flat surface 11. The applicator holding groove 6 extends from the closed tip 61 to the opening edge 63. That is, the closed tip 61 provides a closed tip 61 that can be in contact with the tip closed portion 35 of the hollow needle applicator 31 to be inspected. Exists. Further, since the opening edge 63 is opened at the edge 13 of the base 1, when the hollow needle type applicator 31 is longer than the applicator holding groove 6, the end opening 37 is formed on the base 1. If the hollow needle type applicator 31 is shorter than the applicator holding groove 6, the end opening 37 is connected in the applicator holding groove 6. The connecting tube 55 can be taken out by communicating with the tube 55. The applicator holding groove 6 is hollow in a state in which the closed tip portion 61 of the applicator holding groove 6 is in contact with the tip closing portion 35 of the hollow needle type applicator 31 until the exposure or exposure process of the radiation photosensitive paper 91 by the small beam source 51 is completed. As long as the needle-type applicator 31 can be held inside, the structure or shape of the inner wall surface is not limited.

  When the inspection target applicator 31 is inserted into the applicator holding groove 6, the depth of the applicator holding groove 6 may slightly protrude from the surface 11 of the base 1 or be almost the same level. preferable. In these cases, for example, the applicator 31 can be easily fixed to the surface 11 of the base 1 by the applicator cover plate 93 or an appropriate fixing means (for example, an adhesive tape). In addition, as an applicator holding means, it is not limited to the groove | channel shown in FIGS. 1-3, As shown in FIG. 4, the base 1 is comprised from the 1st half base 1x and the 2nd half base 1y, Holding hole 64 formed by a combination of a first half groove 64x provided on one surface 11x of the first half base 1x and a second half groove 64y provided on one surface 11y of the second half base 1y. The applicator holding means can also be formed. In the base 1 shown in FIG. 4, the metal marker 8 can be provided on the surface 11x of the first half base 1x and / or the surface 11y of the second half base 1y. When using the base 1 shown in FIG. 4, it is not necessary to use the applicator cover plate 93 or the adhesive tape.

  Furthermore, the base for inspection of the linear hollow needle type applicator shown in FIGS. 1 to 3 is not limited to the groove shown in FIGS. 1 to 3 as an applicator holding means, and an applicator holding hole may be provided. it can. The shape of the inner wall surface of the applicator holding hole is preferably substantially the same as the outer shape of the applicator so that the applicator does not move easily during the method of the present invention. Also in this case, it is not necessary to use the applicator cover plate 93 or the adhesive tape.

  There are only a few types of applicators that are commonly used in brachytherapy for intracavitary irradiation, tissue irradiation, or application cases. In the method of the invention, if an applicator holding groove or holding hole having an inner wall surface shape corresponding to the external shape of a few types of general applicators is created, it can be applied to substantially all commonly used applicators. it can. Further, in the method of the present invention, the tip closing portion 35 of the hollow needle type applicator 31 is in contact with the closing tip portion 61 of the applicator holding groove 6 until the exposure process of the radiation photosensitive paper 91 by the small beam source 51 is completed. The applicator holding groove 6 (or holding hole) need not be firmly fixed so that the inner wall surface shape of the applicator holding groove 6 (or holding hole) completely matches the outer shape of the applicator to be inspected. It is applicable to applicators of various sizes and forms by using an appropriate fixing means for fixing the device. The number of applicator holding grooves 6 (or holding holes) provided on one surface of the base 1 is not limited to five as in the embodiment shown in FIGS. Is possible

  The metal marker 8 can be disposed along the applicator holding groove 6. In the present invention, the metal marker exposes the radiation-sensitive paper by Compton scattering when irradiated with radiation from a small-line source, and forms a metal marker image together with the small-line source image on the radiation-sensitive paper. Therefore, in the present invention, any metal marker is disposed in the vicinity of each applicator holding groove. Here, the vicinity of the position where the metal marker is arranged means that the metal marker exposes the radiation sensitive paper by Compton scattering with respect to the radiation from the brazing source inserted inside the applicator to be inspected, and is a metal marker developed image that can be confirmed. Means the distance that can be formed.

  At least one metal marker 8 is preferably arranged as a reference point metal marker 81 provided at a predetermined distance from the closed tip 61 in the vicinity of the closed tip 61 of the applicator holding groove 6. As the reference point metal marker 81, a pair of metal markers 81x and 81y are provided on both sides of the closed tip 61, and the closed tip 61 is positioned at the midpoint of a straight line connecting the pair of metal markers 81x and 81y. It is preferable to arrange in the above. Further, as shown in FIGS. 1 and 2, a metal marker row 83 in which a plurality of metal markers 8 are arranged in a row can be arranged in parallel with the applicator holding groove 6, for example, at least the applicator holding groove 6. It is preferable that a predetermined fixed interval is provided on one side and arranged in parallel with the applicator holding groove 6, and two metal marker rows 83 x and 83 y parallel to each other on both sides of the applicator holding groove 6 are arranged on the applicator. It is particularly preferable that they are arranged equidistant from the holding grooves 6 and arranged so that the midpoint of the straight line connecting them becomes the passage of the small beam source.

  1 to 3 show an embodiment in which metal marker rows 83x and 83y are arranged on both sides of each applicator holding groove 6, respectively, but one row of metal markers is located between adjacent applicator holding grooves 6 and 6. It is also possible to arrange only the row and use it as a common metal marker row for the applicator holding grooves 6 and 6 on both sides.

  As shown in FIGS. 1 to 3, each metal marker 8 is arranged by being embedded in a hole 18 provided on the surface of the base 1, and is arranged without protruding from the surface of the base 1. About the part which carried out, it is preferable to make the surface of the base 1 into a flat surface. The shape of each metal marker 8 is not specifically limited, For example, it may be not only the columnar shape shown in FIGS. 1-3, but arbitrary shapes (for example, prismatic shape, a spherical body, or an elliptical body). . Moreover, each metal marker 8 is arrange | positioned from arbitrary metals (for example, lead, iron, or brass) by the magnitude | size sufficient to raise | generate Compton scattering.

  A brachytherapy source commonly used in brachytherapy is typically a cylinder having a diameter of about 1 mm and a length of about 3 mm. In order to form an image by causing Compton scattering with radiation irradiated from such a small beam source, the metal marker is located at a distance of about 20 mm or less from the applicator holding means serving as the path of the small beam source in consideration of the range of the scattered radiation. Is preferably provided. In addition, when using a cylindrical wire source having a diameter of about 1 mm and a length of about 3 mm, for example, the size of the circular metal marker should be 1 to 3 mm in diameter and 1 to 2 mm in height. Thus, an image sufficient for confirmation and inspection by the method of the present invention can be formed.

  The distance between the metal markers forming the metal marker row 83 is not particularly limited, and when using a cylindrical braid source having a diameter of about 1 mm and a length of about 3 mm, it is in the range of 5 mm to 20 mm. For example, it is preferable to arrange them at an interval of 10 mm.

  In the method of the present invention, when the base 1 has the applicator holding groove 6 as an applicator holding means, an applicator cover plate 93 can be used as necessary. As shown in FIGS. 1 to 3, the applicator cover plate 93 is a flat plate that fixes the applicator 3 by inserting the applicator 3 into the applicator holding groove 6 and placing the applicator 3 on the applicator holding groove 6. The applicator 3 may be fixed as long as it can maintain the contact state between the distal end closing portion 35 of the applicator 3 and the closed distal end portion 61 of the applicator holding groove 6 when the method of the present invention is performed. It is. Therefore, any fixing means (for example, an adhesive tape) can be used instead of or in addition to the applicator cover plate 93. As the applicator cover plate 93, any known material can be used. Specifically, for example, various synthetic resins can be used, and in particular, a radiation transmitting material such as an acrylic resin is suitable. It should be noted that the applicator cover plate 93 is transparent so that the contact state between the tip closing portion 35 of the applicator 3 and the closing tip portion 61 of the applicator holding groove 6 can be visually confirmed from above the applicator cover plate 93. Preferably there is.

  In the method of the present invention, radiation sensitive paper 91 is used. Specifically, after inserting the applicator 3 to be inspected into the applicator holding groove 6 and fixing the applicator 3 with fixing means (for example, applicator cover plate 93 or adhesive tape) as necessary, radiation is placed on the fixing means. A photosensitive paper 91 is placed. As the radiation sensitive paper 91, any known radiation sensitive paper can be used as long as it can form an image by irradiation with radiation from the small beam source 51 and an image of each metal marker 8 by Compton scattering. As described above, it is preferable to use a chromic film because image formation can be observed directly.

  In the method of the present invention, a flat cover 2 can be placed on the radiation sensitive paper 91 to secure the radiation sensitive paper 91 as necessary. Positioning means can be provided for the purpose of facilitating the operation of placing the cover 2 on the base 1. In the embodiment shown in FIGS. 1 to 3, positioning protrusions 17 are provided at the four corners of the base 1, and positioning protrusion receiving holes 25 that can store the positioning protrusions 17 at the corresponding four corners of the cover 2 can be provided. . Further, it is preferable to provide the connecting means for the cover 2 and the base 1. For example, in the embodiment shown in FIGS. 1 to 3, a pair of screw holes 19 are provided on the surface 11 of the base 1. The through hole 23 is provided at a corresponding position of the cover 2, and both can be connected and fixed with the screw 21. For fixing the radiation sensitive paper 91, any means such as an adhesive tape or a rubber string may be used instead of the cover or in addition to the cover.

  FIG. 5 shows a base 1A suitable for inspection of an intracavity applicator. Since the intraluminal applicator has various shapes of bent end portions, the base 1 </ b> A includes a bent applicator holding groove 7 having a bent portion 77 and a straight portion 79. Except for having a bent portion 77 and a straight portion 79, the bent holding groove 7 has the same structure as the linear applicator holding groove 6 shown in FIGS. Can be used.

  Accordingly, the bending-type holding groove 7 also has a closed distal end portion 71 that comes into contact with the distal end closed portion of the intracavity irradiation applicator to be examined, and is opened at the base edge 13A of the base 1A. Further, a metal marker 8A provided along the holding groove 7 together with the applicator holding groove 7 is provided on the flat surface 11A. Also in the metal marker 8A, it is preferable that a reference point metal marker 82 provided at a predetermined distance from the closed tip 71 is disposed in the vicinity of the closed tip 71 of the front holding groove 7. It is preferable that a pair of metal markers 82x and 82y is provided on the first and second metal markers 82x and 82y so that the closed tip 71 is positioned at the midpoint of a straight line connecting the pair of metal markers 82x and 82y. Further, as shown in FIG. 5, along the bent portion 77, a metal marker row 84 in which a plurality of metal markers 8 </ b> A are arranged in a row can be arranged in parallel with the applicator holding groove 7.

The radiographic image obtained by implementing this invention method using the base and chromic film which have the structure similar to the base 1 shown in FIG. 1 is shown in FIG. A cylindrical iridium radiation source having a diameter of 1 mm and a length of 3 mm was used as the small wire source, and a cylindrical lead having a diameter of 2 mm and a length of 2 mm was used as the metal marker.
An image of three great circles arranged in a line in the center is a small source image, and an image in which four small circles are arranged in a line on each side is an image of a metal marker.
In FIG. 6, the uppermost image of the three large circular images at the center is the irradiation image of the small beam source at the tip reference position, and the lower circular image (center image) below is It is an irradiation image at a position returned by 1 cm from the tip reference position, and a great circle image below it (lowermost image) is an irradiation image at a position returned by 2 cm from the tip reference position. The two small circle images observed on both sides of the great circle image at the tip reference position are images of the reference point metal marker, and the distance between them is 2 cm. In both rows of metal markers, the distance between the reference point metal marker (top 1) and the second metal marker from the top is 0.5 cm, and the distance between the second metal marker and the third metal marker, and The distance between the third metal marker and the fourth metal marker was 1 cm, respectively.

  INDUSTRIAL APPLICABILITY The present invention is used for inspection and confirmation of a stop position of a guide wire tip brachytherapy source in a specific combination of a brachytherapy device and an applicator used for intracavity irradiation and tissue irradiation in brachytherapy. It is possible to prevent erroneous irradiation of the brachytherapy.

1, 1A: base; 1x: first half base; 1y: second half base;
2 ... cover; 3 ... applicator; 5 ... brachytherapy device;
6 ... Applicator holding groove; 7 ... Bending applicator holding groove;
8, 8A ... Metal marker; 10 ... Inspection tool; 11, 11A ... Base surface;
11x: surface of the first half base; 11y: surface of the second half base;
13, 13A ... Base edge; 15 ... Metal marker hole;
17 ... Positioning projection; 18 ... Hole; 19 ... Screw hole; 21 ... Screw;
23 ... through hole; 25 ... positioning projection receiving hole;
31 ... hollow needle type applicator; 35 ... tip closing part; 37 ... end opening part;
41 ... tip reference position; 43 ... tip needle part; 51 ... small wire source;
53 ... Guide wire; 55 ... Connection tube; 57 ... Small wire source outlet;
61, 71 ... closed tip; 63 ... open edge;
64 ... holding hole; 64x ... first half groove; 64y ... second half groove;
77 ... bent portion; 79 ... straight portion;
81, 82 ... reference point metal marker; 83,84 ... metal marker row;
91 ... Radiation sensitive paper; 93 ... Applicator cover plate;

Claims (4)

In a combination of a brachytherapy device used in brachytherapy and an applicator, a method for inspecting a position where a guidewire tip brachytherapy source of the brachytherapy device stops in the applicator,
(1) Applicator holding means comprising a groove or a hole capable of holding the inspection object applicator and extending from a closed front end part capable of contacting the front end closing part of the inspection object applicator to an opening edge, and the applicator holding A test object applicator is inserted into the applicator holding means of the base including at least one metal marker provided on one side or both sides of the applicator along the means, and the distal end closing part of the test object applicator is closed by the closed tip of the applicator holding means A step of contacting the part,
(2) A step of placing radiation-sensitive paper on the surface of the base on which the applicator to be inspected is inserted in the contact step;
(3) A guide wire tip braid source is introduced from the inspection subject brachy source insertion device, with the braid source provided at the tip of the guide wire approaching from the end opening of the applicator applicator toward the innermost tip. A step of exposing the radiation-sensitive paper by stopping the guide wire tip brazing beam source for a predetermined time at a predetermined stop position;
(4) Inserting the inspection target beam source from the beam source image formed on the radiation photosensitive paper and the metal marker image formed on the radiation photosensitive paper by Compton scattering by the radiation irradiated from the beam source The said inspection method including the process of confirming the predetermined stop position of the guide wire tip braid source in the combination of an apparatus and the said applicator to be examined.   After the exposure step at the predetermined stop position, the step of moving the brachytherapy source to another brachytherapy source stop position in the treatment plan and exposing the radiation sensitive paper for a predetermined time at the other stop position is performed. The inspection method according to claim 1, further comprising a step of confirming each stop position from the beam source image and the metal marker image obtained in this way. An inspection tool for inspecting a position where a guide wire tip brachytherapy source of the brachytherapy device insertion device stops in the applicator in a combination of a brachytherapy device used for brachytherapy and an applicator;
An applicator holding means comprising a groove or a hole extending from a closed tip end portion to an opening edge portion capable of holding the test subject applicator and being able to contact the tip closing portion of the test subject applicator; only comprising base including at least one metal marker is provided on one or both sides thereof along the applicator holding means, wherein the metallic marker, by Compton scattering by radiation emitted from the brachytherapy, said base The inspection tool, wherein a metal marker image can be formed on radiation-sensitive paper placed on the surface .   The inspection tool according to claim 3, further comprising a cover capable of covering and fixing the radiation sensitive paper placed on the surface of the base into which the inspection object applicator is inserted.