JP2006242668A - Radiation shielding container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized and light-weight radiation shielding container for a generator. <P>SOLUTION: This radiation shielding container is equipped with a column housing hole for housing therein a column with a radioactive isotope adsorbed thereto, and an inflow-side tube housing hole and an outflow-side tube housing hole for severally housing therein an inflow-side tube and an outflow-side tube extending from the column. The column housing hole is formed to have a shape allowing the column to be closely fit therein. The hole diameters of the inflow-side and outflow-side tube housing holes are formed so as to be slightly larger than the outer diameters of the inflow-side and outflow-side tubes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a radiation shielding container used when a radioisotope is transported and used.

  In recent years, PET (Positron Emission Tomography) using a positron nuclide having a short half-life that emits positrons and decays has been used for cancer diagnosis and the like. In PET, first, a labeled drug in which a physiological metabolite such as glucose is labeled with a positron nuclide is injected into the body, and the labeled drug is absorbed into an organ that consumes a large amount of the physiological metabolite, such as cancer. Then, the positrons emitted from cancer and the like are measured outside the body and image-processed, and combined with other image processing means such as CT, the activity status of the organ consuming physiological metabolites, cancer in the body, etc. It is possible to accurately know the position, size, etc. In addition, since radionuclides with a short half-life are used, the radioactivity disappears in a short time after imaging cancer and the like, and changes in the lesion can be known by imaging again later. In view of the effectiveness of such PET, health insurance has come to be applied to PET, and its diffusion is being promoted.

  By the way, the positron nuclide for PET is generated using a cyclotron. However, the cyclotron is expensive and requires a great deal of cost, knowledge and experience for maintenance and production of radionuclides using it. Furthermore, it is difficult to install in many medical facilities due to the necessity of a large radiation control area.

  Therefore, instead of the cyclotron, a method called a generator, which uses a radioisotope having a relatively long half-life as a generation source of a positron nuclide, is used. As described in Non-Patent Document 1, among radioisotopes (parent nuclides) with a relatively long half-life, they decay to produce short half-life nuclides (daughter nuclides) that can be used for PET. It is the use of what there is to do.

  Specifically, after the parent nuclide generated by the cyclotron is temporarily stored in a radiation shielding container, the radiation shielding container is transported to a medical facility, and the daughter nuclide generated from the parent nuclide is separated and eluted at the medical facility, and then PET. In this method, a labeling drug is synthesized and used for diagnosis. Once the daughter nuclide is eluted, the parent nuclide continues to decay to produce the daughter nuclide, so that the daughter nuclide can be taken out from the same generator many times. For this reason, the parent nuclide is called cow and this method is sometimes called milking.

In the past, ^99m Tc (half-life 6 hours) was generated from ⁹⁹ Mo (half-life 66 hours) and used for SPECT. The nuclide radiation energy used for SPECT is, for example, ^99m Tc is about 0.141 MeV, whereas PET uses a nuclide that emits strong energy annihilation radiation (gamma rays) of about 0.51 MeV. For this reason, there is a need for a radiation shielding container having a higher ability to shield radiation than the conventionally used radiation shielding container for SPECT.

Various types of radiation shielding containers are used for generators. For example, Patent Document 1 discloses a method for reducing the weight of a radiation shielding container by partially separating and removing unnecessary shielding bodies due to attenuation of radioactivity during transportation. Has been.
Nuclear Data News, No. 70 (2001) Use of isotopes in nuclear medicine (36 pages) JP 2000-292591 A (paragraphs 0017 to 0020, FIG. 1)

  However, in the structure of the radiation shielding container shown in Patent Document 1, since there is a space between the column adsorbing the radioactive material and the first layer shielding container body, the first layer shielding container body made of lead There is a problem that when the thickness of lead is increased in order to increase the radiation shielding ability, the weight is significantly increased and it is difficult to obtain a light radiation shielding container.

Since PET nuclides emit strong energy annihilation radiation, lead is required to be approximately 40 times thicker if the radioactivity of the parent nuclide is the same as the widely used ^99m Tc / ⁹⁹ Mo generator for SPECT. (In the case of ⁶² Cu / ⁶² Zn). When a PET nuclide of about 4 GBq is handled, the shielding requires lead having a thickness of about 5 cm.

If a structure having a space between the column that adsorbs the PET nuclide and the shield container is used, for example, the inner diameter of the hole that accommodates the column in the structure shown in FIG. 1 of Patent Document 1 is 20 mm, and ⁶² Zn of about 4 GBq is obtained. When enclosed, the weight of the radiation shielding container exceeds 40 kg. For this reason, it is difficult for an operator to carry a plurality of pieces into a narrow hot cell and smoothly perform manufacturing and dispensing work remotely without radiation exposure. Thus, no radiation shielding container suitable for handling the PET parent nuclide has been known.

  In addition, it is necessary to attach an inflow side tube and an outflow side tube (usually about 3 mm in outer diameter) of the eluate for eluting the daughter nuclide to the column that adsorbs the parent nuclide. Usually, in order to simplify the elution operation of the daughter nuclide in the medical facility, it is stored in a shielding container with a connecting tool such as a three-way stopcock attached to the end of the inflow side tube and the outflow side tube. In general, a large tube accommodation hole is provided in the shielding container so that it can be inserted into the shielding container with a three-way stopcock attached to the end of the tube. Moreover, it was a big factor which increased the weight of a shielding container.

  In view of the above problems, an object of the present invention is to provide a small and lightweight radiation shielding container. Another object of the present invention is to provide a radiation shielding container that can be applied to columns of various shapes.

  The present invention is configured to solve the above problems, and the invention according to claim 1 includes a column accommodation hole for accommodating a column in which an adsorption layer in which a radioisotope is adsorbed is contained, An inflow side tube accommodating hole and an outflow side tube accommodating hole for accommodating an inflow side tube and an outflow side tube extending from the column, respectively, and the column accommodating hole have a shape that allows the column to be fitted without a gap. The radiation shielding container is characterized in that the diameters of the tube receiving holes on the inflow side and the outflow side are slightly larger than the outer diameters of the inflow side and the outflow side tubes, respectively.

  According to the first aspect of the present invention, the column accommodation hole is formed with a shape that allows the column to be fitted without a gap, and the inflow side and outflow side tube accommodation holes are respectively formed on the inflow side and the outflow side of the outer diameter of the tube. Because it is formed slightly larger, the gap (space) between the column and the column accommodation hole and the gap between the inflow side, outflow side tube and the inflow side, outflow side tube accommodation hole can be almost eliminated. Thus, the entire radiation shielding container can be reduced in size and weight.

  For example, there is a spherical column with a radius of 1 cm that adsorbs the parent nuclide, and the required thickness of the shield is 5 cm. If the gap between the column and the shield is 1 cm, the lead shield has a hollow sphere structure with a radius of 7 cm and a hollow portion of 2 cm in the center. On the other hand, if the gap between the column and the shield is zero, the lead shield has a hollow sphere structure with a 6 cm radius and a hollow portion with a radius of 1 cm in the center. Therefore, the weight of the lead shield is reduced from 15.9 kg to 10.2 kg.

Thus, the volume of the shield can be reduced by not creating an extra space, and a weight reduction effect can be produced. In particular, when high density lead is used, the weight can be greatly reduced, and the entire radiation shielding container can be reduced in size and weight.
Also, by making the diameter of the tube receiving hole that accommodates the inflow and outflow tubes slightly larger than that of the tube, the extra space can be reduced and the radiation shielding container as a whole can be reduced in size and weight, and collimated. The efficiency of radiation shielding due to the effect can be improved. In this configuration, the inflow side and outflow side tubes are inserted into the tube receiving holes of the radiation shielding container, and then a connecting tool such as a three-way stopcock is attached to the open end of the tube.

  The invention according to claim 2 is the radiation shielding container according to claim 1, which can be divided into a plurality of parts.

  According to the second aspect of the present invention, the radiation shielding container can be divided into a plurality of blocks including the column accommodation hole and the inflow and outflow side tube accommodation holes. By preparing in advance a block in which side and outflow side tube receiving holes are formed, it is possible to deal with columns having different shapes and inflow and outflow side tubes. Further, by dividing the heavy radiation shielding container into a plurality of blocks, the burden on the operator can be reduced and the work can be facilitated.

  The invention according to claim 3 is the radiation shielding container according to claim 1 or 2, wherein the surface is formed using lead coated with stainless steel.

  According to the third aspect of the present invention, since the lead surface is coated with stainless steel, even when the column, the inflow side, and the outflow side tube are accommodated in the radiation shielding container, they can be in direct contact with harmful lead. In addition, it is possible to prevent lead from being mixed into the radioactive material used as the labeling agent. Lead is a metal that is very easily deformed, but by covering the surface with stainless steel, it is possible to prevent lead from being deformed during handling such as assembling and transporting the radiation shielding container. As a result, the radiation shielding container can be used repeatedly.

  The invention according to claim 4 is characterized in that the inflow side tube accommodation hole and the outflow side tube accommodation hole each have a portion bent obliquely with respect to the axis of the column accommodation hole. It is a radiation shielding container of any one of Claim 1 thru | or 3.

  According to the fourth aspect of the present invention, the tube receiving holes on the inflow side and the outflow side of the radiation shielding container have portions bent obliquely with respect to the axis of the column receiving holes (hereinafter referred to as bent portions). Therefore, radiation that goes straight through the inflow side and outflow side tube housing holes radiated from the radioactive material adsorbed by the adsorption layer built in the column can be shielded by the bent portion. In addition, since the structure is bent obliquely with respect to the axis of the column accommodation hole, there is no fear that the tube will be bent excessively to block the path. Note that the bent portions on the inflow side and the outflow side include not only the case of bending so as to be bent but also the case of bending so as to be bent.

  According to the fifth aspect of the present invention, each of the portions where the inflow side tube accommodation hole and the outflow side tube accommodation hole are connected to the column accommodation hole has a linear portion for collimating the radiation radiated from the column. The radiation shielding container according to any one of claims 1 to 4, further comprising a shielding portion that is formed along the axis and shields only the collimated radiation.

In the generator system, in order to elute daughter nuclides from the column, it is necessary to have a portion for connecting the inflow and outflow side tubes to the column. However, this connecting portion is an “extra space” for the radiation shielding container, and increases the weight of the radiation shielding container.
According to the fifth aspect of the present invention, the radiation is collimated while passing through the straight portion of the tube accommodation hole, so that the range that needs to be shielded is narrowed and the shield thickness is small. Therefore, the volume of the shielding part that shields only the collimated radiation can be reduced, so that the radiation shielding container as a whole can be reduced in size and weight.

  The invention according to claim 6 is the radiation shielding container according to any one of claims 1 to 5, characterized in that the radiation shielding container can be housed in a carrying shielding container housing case.

  According to the invention described in claim 6, the radioactive shielding container can be easily and safely transported by accommodating the radioactive shielding container in the shielding container accommodation case. It is also easy to take out the product from the narrow hot cell.

  As described above in detail, according to the present invention, the inflow side, the outflow side tube and the inflow side, the gap between the outflow side tube accommodation hole and the gap between the column and the column accommodation hole, the column and the tube Since a useless gap in the portion connecting the two can be almost eliminated, a small and lightweight radiation shielding container can be provided, and work efficiency during transportation of the radiation shielding container can be improved. In addition, as a result of the reduction in size and weight, it is possible to perform all work with the radionuclide sealed in a radiation shielding container, even during generator preparation and use, which is extremely effective in reducing radiation exposure for workers. Is.

  A radiation shielding container 1 according to an embodiment of the present invention will be described with reference to the accompanying drawings of FIGS. FIG. 1 is a longitudinal sectional view showing a radiation shielding container 1 according to the present embodiment, and FIG. 2 is an exploded perspective view showing the radiation shielding container 1 according to the present embodiment. FIG. 3 is an exploded perspective view showing the radiation shielding container 1 and the transporting shielding container housing case 110, and FIG. 4 is a perspective view showing a state in which the radiation shielding container 1 is housed in the shielding container housing case 110. FIG. 5 is a cross-sectional view showing a process of assembling the column 80 and the inflow side tube 90 to the first shield 10, and FIG. 6 shows the first shield in which the column 80 and the inflow side tube 90 are assembled. 10 is a cross-sectional view showing a process of assembling 10 in the second shielding body 20. FIG. 7 is a cross-sectional view showing a process of assembling the fourth shield 40 to the second shield 20 in which the column 80, the inflow tube 90, the outflow tube 100, and the first shield 10 are assembled. FIG. 8 is a cross-sectional view showing a process of assembling the third shield 30 to the first shield 10 and the second shield 20.

  As shown in FIGS. 1 and 2, the radiation shielding container 1 is divided into a first shielding body 10, a second shielding body 20, a third shielding body 30, and a fourth shielding body 40, The column accommodation hole 50 is configured by an inflow side tube accommodation hole 60 (hereinafter referred to as a tube accommodation hole 60) and an outflow side tube accommodation hole 70 (hereinafter referred to as a tube accommodation hole 70).

The column accommodation hole 50 accommodates a column 80 that adsorbs a radioactive substance, and the tube accommodation holes 60 and 70 have an inflow side tube 90 (hereinafter referred to as a tube 90) and an outflow side tube 100 (hereinafter referred to as a tube). The tube 90 is accommodated, and a three-way stopcock (not shown) as a connection tool is connected to the tube 90 and the end of the tube 100.
The radioactive substance exists only in the adsorption layer (not shown) inside the column 80, and there is no radioactive substance in the portion other than the adsorption layer inside the column 80, and the tube 90 and the tube 100.

  Unless otherwise specified, the first to fourth shields 10 to 40 are formed of a lead material LD that shields radiation, and the outer surface is covered with a stainless steel ST. Thereby, it can prevent that the column 80 or the tubes 90 and 100 and the lead material LD are in direct contact and mixed into the parent nuclide or the daughter nuclide. Further, by protecting the lead material LD that is easily deformed with the stainless steel material ST, it is possible to prevent the first shielding body 10 to the fourth shielding body 40 from being deformed when the radiation shielding container 1 is assembled.

The first shield 10 is formed in a cylindrical shape having an axis L (hereinafter referred to as axis L) of the column accommodation hole 50 as a central axis, and is a column accommodation hole that is a part of the column accommodation hole 50 that accommodates the column 80. 51 and a first tube accommodation hole 61 that constitutes a part of the tube accommodation hole 60 that accommodates the tube 90 is provided. In the present embodiment, the first tube accommodation hole 61 is formed along the axis L and connected to the column accommodation hole 51, and the first tube accommodation hole 61 says “radiation”. Corresponds to a "collimated straight line".
In addition, an annular flange 13 projects from the outer periphery of the first shield 10 (see FIG. 1) on the third shield 30 side toward the radially outer side.

  The second shielding body 20 includes a flat cylindrical bottom portion 20A and a cylindrical portion 20B integrally formed on the outer peripheral portion of the bottom portion 20A and arranged concentrically with the first shielding body 10. The cylindrical portion 20 </ b> B has the same axis L as the first shield 10. A column accommodation hole 54 that is a part of the column accommodation hole 50 and a third tube accommodation hole 63 that constitutes a part of the tube accommodation hole 70 that accommodates the tube 100 are provided.

In the present embodiment, the third tube accommodation hole 63 is formed along the axis L and connected to the column accommodation hole 54, and the third tube accommodation hole 63 says “radiation”. Corresponds to a "collimated straight line".
The second shield 20 is further provided with a fifth tube accommodation hole 66 that penetrates the cylindrical portion 20 </ b> B and constitutes a part of the tube accommodation hole 70.

  Further, two fitting holes 23 are formed on one end face of the second shield 20 so as to face each other in the radial direction, and the other end face is also provided with two other fitting holes facing each other in the radial direction. 24 is formed. Furthermore, the space surrounded by the bottom portion 20A and the cylindrical portion 20B is a columnar shield housing space S. An annular step portion 25 that positions the second shield 20 relative to the first shield 10 by fitting the annular flange 13 of the first shield 10 to the inner periphery of the open end of the cylindrical portion 20B. Is formed.

  The third shield 30 has a cylindrical shape with the axis L as the central axis, and has the same outer diameter as that of the second shield 20 and a large-diameter column portion 31 whose inside is a hollow space S1, A small-diameter cylindrical part 32 having a first shielding part 33 made of lead material LD and formed coaxially in the cylindrical part 31 is constituted. In addition, the cylindrical part 31 and the cylindrical part 32 are formed using the stainless steel ST.

  The third shield 30 is further provided with a second tube accommodation hole 62 constituting a part of the tube accommodation hole 70 obliquely with respect to the axis L. Further, the columnar portion 31 is provided with a sixth tube accommodation hole portion 67 that constitutes a part of the tube accommodation hole 70 at a position corresponding to the fifth tube accommodation hole portion 66.

  Further, a circular hole 35 is formed on one end surface of the cylindrical portion 32, and fitting recesses 36 and 36 are provided so as to face each other in the radial direction (see FIG. 2). A plurality of fitting protrusions 37 project from the other end face of the cylindrical portion 32 at positions corresponding to the plurality of fitting holes 23 of the second shield 20. , The third shield 30 is positioned with respect to the second shield 20.

  Similar to the third shield 30, the fourth shield 40 has a cylindrical shape with the axis L as the central axis, and has the same outer diameter as the second shield 20, and the inside is a hollow space S 2. A large-diameter cylindrical portion 41 and a small-diameter cylindrical portion 42 having a second shielding portion 43 formed coaxially in the cylindrical portion 41 and made of a lead material LD. In addition, the cylindrical part 41 and the cylindrical part 42 are formed using stainless steel ST.

The fourth shield 40 is further provided with a fourth tube housing hole 65 constituting a part of the tube housing hole 70 obliquely with respect to the axis L. Further, a circular through hole 48 is formed in the cylindrical portion 41 at a position corresponding to the fifth tube housing hole 66.
Further, a plurality of fitting protrusions 45 project from one end face of the cylindrical portion 42 at positions corresponding to the plurality of fitting holes 24 of the second shield 20, and the fitting protrusion 45 and the fitting hole 24. The positioning of the fourth shield 40 with respect to the second shield 20 is performed. Further, a circular hole 46 is formed in the end surface on the other side in the axial direction of the cylindrical portion 42, and a plurality of fitting recesses 47 that are opposed in the radial direction are provided.

Next, the column accommodation hole 50 will be described.
The column accommodation hole 50 according to the present embodiment includes a column accommodation hole 51 and a column accommodation hole 54, and is formed in a shape that allows the column 80 to be fitted without a gap. Here, “no gap” means that the smaller the gap between the column 80 and the column accommodation hole 50 is, the better. The gap is preferably 1 mm or less at the maximum. Further, a structure in which the diameter of a part of the column accommodation hole 50 is made smaller than the outer diameter of the column 80 and the column 80 is press-fitted can be adopted.

In this way, by adopting a structure in which the gap (space) between the column 80 and the column accommodation hole 50 is substantially eliminated, a useless space is eliminated and an increase in the volume of the radiation shielding container 1 is prevented. Overall size and weight can be reduced.
In addition, there is no designation | designated in particular in the column 80, For example, commercially available columns, such as Ceppack (trademark), can be selected and used according to a use.

  Further, since the first shield 10 and the second shield 20 including the column accommodation hole 50 are exchangeable blocks, the first shield 10 and the second shield 10 in which the column accommodation holes 50 having various shapes are formed. By preparing the shield 20, a radiation shielding container that can handle columns having various shapes can be obtained.

Next, the two tube housing holes 60 and 70 and the shielding unit that shields only the collimated radiation will be described.
The tube housing hole 60 of the present embodiment is connected to the column housing hole 51 formed in the first shield 10 and is formed along the axis L with a first tube housing hole 61 and a third And a second tube housing hole 62 formed in an oblique direction with respect to the axis L through the first shielding portion 33 of the shielding body 30. The first tube housing hole 61 and the second tube housing hole 62 are connected on the axis L.

  The tube accommodation hole 70 is connected to the column accommodation hole 54 formed in the second shield 20, and the third tube accommodation hole 63 formed along the axis L and the fourth shield 40. A fourth tube housing hole 65 formed in an oblique direction with respect to the axis L through the second shield 43 and a fifth tube housing hole located on the outer peripheral side of the second shield 20 66 and a sixth tube housing hole 67 formed in the third shield 30 and connected to the fifth tube housing hole 66.

In the present embodiment, the tubes 90 and 100 are inserted into the tube receiving holes 60 and 70, respectively, and then a three-way stopcock is attached to each open end. By doing in this way, the hole diameter of the tube accommodation holes 60 and 70 can be determined on the basis of the tube diameter instead of the projected shape of the three-way cock.
The hole diameters of the tube receiving holes 60 and 70 are slightly larger than the outer diameters of the tubes 90 and 100, respectively. Here, “slightly larger” means that the hole diameter can be inserted into the tubes 90 and 100, and the gap is preferably 1 mm or less. Moreover, the hole diameter of a bending part can be made larger than a linear part so that the tubes 90 and 100 can be penetrated easily.

  In this way, by making the hole diameter of the tube housing holes 60 and 70 for housing the tubes 90 and 100 slightly larger than that of the tube, an extra space is reduced from the radiation shielding container 1 and the radiation shielding container 1 as a whole. Can be reduced in size and weight. The tubes 90 and 100 may be made of a flexible resin. For example, a tube made of polyfluoroethylene can be used.

  Incidentally, as described above, the radioactive substance exists only in the adsorption layer (not shown) inside the column 80. Radiation emitted from the adsorption layer and traveling straight through the first tube accommodation hole 61 and the third tube accommodation hole 63 is a second tube accommodation hole 62 corresponding to a portion bent obliquely with respect to the axis L. Then, it collides with the fourth tube housing hole 65 and is shielded by the lead material LD constituting the third shield and the fourth shield.

  In addition, the radiation from the adsorption layer is collimated when passing through the linear first tube accommodation hole 61 and the third tube accommodation hole 63, and is substantially parallel and greatly reduced in intensity. Accordingly, the area that needs to be shielded from this collimated radiation and the thickness of the shield are reduced. In other words, it is sufficient to provide a small shield on the line connecting the adsorbing layer, the first tube accommodation hole 61, and the third tube accommodation hole 63 (on the axis L in the present embodiment). The weight of the container 1 can be greatly reduced.

  In the present embodiment, the first shielding part 33 and the second shielding part 43 function as a shielding part that shields only the collimated radiation. Thereby, the lead material LD corresponding to the volume corresponding to the hollow space S1 of the third shield 30 and the hollow space S2 of the fourth shield 40 is reduced, and the weight of the radiation shielding container 1 is greatly reduced. Yes. In the present embodiment, the first shielding part 33 and the second shielding part 43 correspond to the lead material LD constituting the third shielding body 30 and the fourth shielding body 40, respectively.

  As described above, the radiation shielding container 1 according to the present embodiment can reduce the weight of the conventional radiation shielding container, for example, about 40 kg to about 20 kg by eliminating an extra space, and can reduce the size of the radiation shielding container. Therefore, the work efficiency of the operator when carrying the radiation shielding container can be increased.

  Next, a shielding container housing case 110 for carrying the radiation shielding container 1 will be described with reference to FIGS. 3 and 4. As shown in FIGS. 3 and 4, the shielding container housing case 110 includes a bottomed cylindrical body 111 and a lid body 112 that covers the open end of the cylindrical body 111. The cylindrical body 111 has a cylindrical portion 113 and a bottom portion 114 formed integrally with the end portion of the cylindrical portion 113. The cylindrical portion 113 is provided with substantially U-shaped notches 113A, 113A,... Extending along the axial direction at substantially equal intervals in the circumferential direction. These notches 113A, 113A,... Are for easily taking the radiation shielding container 1 into and out of the cylindrical body 111.

  Further, a plurality of stoppers 113B are attached to the opening end side of the cylindrical part 113 so as to face each other in the radial direction, and the stoppers 113B are hooked on a hook part 112A attached to the lid body 112, whereby the radiation shielding container 1 is attached. Can be fixed in a state of being accommodated in the cylinder 111. Further, a plurality of columnar protrusions 114A are provided on the bottom 114 of the cylindrical body 111 at positions opposed to each other in the radial direction, and a plurality of columnar protrusions 112B are provided on the inner surface of the lid 112. ing.

  The protrusions 112B and 114A are fitted in the fitting recess 36 of the third shield 30 and the fitting recess 47 (see FIG. 1) of the fourth shield 40, respectively, so that the radiation shielding container 1 is accommodated. This prevents the radiation shielding container 1 from rotating in the shielding container housing case 110 when the shielding container housing case 110 is transported. Thereby, it can prevent that the radiation shielding container 1, a tube, and a three-way cock are damaged during transportation to a medical institution.

  Further, the tube body 112 is provided with two tube insertion holes 112C, and as shown in FIG. 4, the tubes 90 and 100 are pulled out through the tube insertion holes 112C. A handle 112D is fixed to the outer surface of the lid body 112, and this handle 112D serves as a grip portion when the operator pulls out or carries the shielding container housing case 110 from the hot cell through a narrow inlet.

Next, a method for extracting a daughter nuclide (for example, ⁶² Cu), which is another radioisotope, from the parent nuclide (for example, ⁶² Zn) adsorbed on the column 80 accommodated in the radiation shielding container 1 will be described.

  First, an aqueous solution containing a parent nuclide produced by a cyclotron (not shown) and separated and purified is accommodated in the radiation shielding container 1 contained in the shielding container accommodation case 110 remotely in a hot cell shielded with lead. The column 80 is dispensed via the tube 90, the parent nuclide is adsorbed on the adsorption layer (not shown) in the column 80, and the remaining liquid is sent to the waste liquid tank (not shown) through the tube 100. Further, the impurity nuclide remaining in the tube or column is washed with an appropriate solvent, and the radioactivity other than the parent nuclide adsorbed on the column is removed from the tube or column. That is, all the parent nuclides are adsorbed on the column 80, and the tubes 90 and 100 are in a state where no radioactive substance is present. When dispensing is completed, the other device is remotely disconnected from the three-way cock attached to the tips of the tubes 90, 100, and taken out from the hot cell using the handle of the storage case.

  In this state, the shielding container housing case 110 is transported to a medical institution, and the eluate tube (not shown) is connected to the three-way stopcock at the medical institution. Next, by injecting the eluate from the tube 90 toward the column 80, only the daughter nuclide out of the parent nuclide and the daughter nuclide generated in the column is selectively eluted into the eluate, and this daughter nuclide is extracted from the tube 100. It is taken out.

When the parent nuclide adsorbed on the adsorption layer is ⁶² Zn, the half-life is about 9 hours. When the parent nuclide decays, ⁶² Cu, which is a short-lived daughter nuclide, is generated. Since ⁶² Zn continues to decay even after the daughter nuclides are once eluted, the daughter nuclides are also generated, so that the daughter nuclides can be repeatedly extracted from the column 80.

Next, a method for assembling the radiation shielding container 1 will be described with reference to FIGS.
First, as shown in FIG. 5, the tubes 90 and 100 are attached to the column 80, and the column 80 and the tube 90 are fitted into the column accommodation hole 50 and the tube accommodation hole 60, respectively. Then, as shown in FIG. 6, the column 80 and the tube 100 are fitted into the column accommodation hole 50 and the tube accommodation hole 70, respectively.

  Next, as shown in FIG. 7, the tube 100 is inserted into the third tube accommodation hole 63 and the fourth tube accommodation hole 65 of the fourth shield 40, and circular from the hollow space S <b> 2. The fitting protrusions 45 and 45 are fitted into the fitting holes 24 and 24 while being pulled out through the hole 46 (see FIG. 8). Accordingly, the fourth shield 40 is brought into contact with the second shield 20 in a state where the fourth shield 40 is positioned with respect to the second shield 20.

  Then, as shown in FIG. 8, the tube 90 is inserted into the second tube housing hole 62 and pulled out from the hollow space S1 through the circular hole 35, while the fitting protrusion 37 is inserted into the fitting hole 23. (See FIG. 1). Accordingly, the third shield 30 is brought into contact with the first and second shields 20 and 30 in a state where the third shield 30 is positioned with respect to the second shield 20. Finally, the tube 100 drawn out from the circular hole 46 is inserted into the hollow space S2, and the tube 100 is inserted into the fifth tube housing hole 66 and the sixth tube housing hole 67. The tube 100 is pulled out to the outside.

  The radiation shielding container 1 assembled in this way is stored in the shielding container storage case 110. Next, after the tubes 90 and 100 are passed through the tube insertion holes 112C, the lid body 112 is fitted into the projections 112B and 112B in the fitting recesses 36 and 36, and then the stopper 113 and the hook 112A are used. Fix the positioning. Finally, the tip of the tubes 90 and 100 that may be contaminated is cut by about 1 cm, and a joint, a three-way cock, etc. are connected thereto. When the generator is used clinically, it is desirable to perform all the above operations in a clean bench. In this state, the set of the radiation shielding container 1 placed in the shielding container storage case 110 is placed in the hot cell and filled with the radionuclide as described above. After removal from the hot cell, the system is sealed with a sterilized blind stopper or a three-way stopcock, and then shipped in a dedicated transport container.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, in the present embodiment, a cylinder having a cylindrical recess at the center is taken up as the second shield 20, but the outer shape of the second shield 20 is not limited to an angular cylinder, and a radiation source In consideration of the distance from the surface and the thickness required for shielding, it is possible to use a circular arc cylinder. Moreover, although the case where the radiation shielding container 1 is divided into four has been described as an example, the number of the radiation shielding container 1 to be divided or the shape of the radiation shielding container 1 is arbitrary.

  Further, in the present embodiment, the case where the bent portions of the tube receiving holes 60 and 70 are bent in the shape of “<” is shown, but the bent portions can be formed in an arc shape. When the bent portion is formed in an arc shape, the tubes 90 and 100 can be easily inserted into the tube accommodation hole.

It is a longitudinal cross-sectional view which shows the radiation shielding container which concerns on embodiment of this invention. It is a disassembled perspective view which shows the radiation shielding container which concerns on embodiment of this invention. It is a disassembled perspective view which shows the radiation shielding container which concerns on embodiment of this invention, and the shielding container accommodation case for conveyance. It is a perspective view which shows the state which accommodated the radiation shielding container which concerns on embodiment of this invention in the shielding container accommodation case. It is sectional drawing which shows the process of assembling a column and the tube of an inflow side to a 1st shield. It is sectional drawing which shows the process of assembling | attaching the 1st shield with which the column and the tube of the inflow side were assembled | attached in the 2nd shield. It is sectional drawing which shows the process of assembling the 3rd shielding body to the 2nd shielding body in which the column, the inflow side tube, the outflow side tube, and the 1st shielding body were assembled | attached. It is sectional drawing which shows the process of assembling a 3rd shielding body to a 1st shielding body and a 2nd shielding body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radiation shielding container 10 1st shielding body 20 2nd shielding body 30 3rd shielding body 40 4th shielding body 50 Column accommodation hole 60 1st tube accommodation hole 70 2nd tube accommodation hole 80 Column 90 1st 1 tube 100 2nd tube 110 shielding container storage case

Claims (6)

  A column accommodation hole for accommodating a column containing an adsorption layer in which a radioisotope is adsorbed, and an inflow side tube accommodation for accommodating an inflow side tube and an outflow side tube extending from the column, respectively. A hole and an outflow side tube accommodation hole, the column accommodation hole is formed with a shape that allows the column to be fitted without a gap, and the diameters of the inflow side tube accommodation hole and the outflow side tube accommodation hole are as follows: A radiation shielding container characterized in that it is formed slightly larger than the outer diameter of each of the inflow side tube and the outflow side tube.   The radiation shielding container according to claim 1, wherein the radiation shielding container can be divided into a plurality of parts.   The radiation shielding container according to claim 1 or 2, wherein the surface is formed by using lead coated with stainless steel.   The said inflow side tube accommodation hole and the said outflow side tube accommodation hole each have the site | part bent diagonally with respect to the axis line of the said column accommodation hole, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. The radiation shielding container according to Item. Each of the portion where the inflow side tube accommodation hole and the outflow side tube accommodation hole are connected to the column accommodation hole,
A linear portion that collimates the radiation emitted from the column is formed along the axis of the column receiving hole,
The radiation shielding container according to any one of claims 1 to 4, wherein a shielding part that shields only the collimated radiation is provided.   The radiation shielding container according to any one of claims 1 to 5, wherein the radiation shielding container can be accommodated in a transporting shielding container accommodating case.

Images