Apparatus and method for producing lutetium-177

Abstract

To provide an apparatus and a method for producing lutetium-177 capable of inhibiting contamination of ytterbium, and producing lutetium-177 with a high recovery rate.SOLUTION: An apparatus and a method for producing lutetium-177 include: an irradiating mechanism of irradiating an ytterbium target with charged particles to generate ytterbium-177 in ytterbium; a dissolution mechanism of dissolving the irradiated ytterbium target irradiated with the charged particles in an agent solution for dissolution to obtain a solution; and a separation recovery mechanism of separating and recovering lutetium-177 and ytterbium from the solution.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to an apparatus and method for producing lutetium-177. [Background technology]

[0002] Radioactive lutetium-177 can be obtained by producing ytterbium with mass number 177 from ytterbium with mass number 176, which then decays to lutetium with mass number 177.

[0003] In order to use the small amount of lutetium-177 generated in ytterbium as a medical radiation source, it is necessary to separate and recover lutetium-177 from ytterbium. Patent Document 1 describes a method of recovering lutetium-177 by distillation after heating, taking advantage of the difference in boiling points between ytterbium and lutetium. In addition to the high processing temperature, this method has the problem of unstable recovery rate due to the separation and recovery of carrier-free lutetium at extremely low concentration.

[0004] In addition, Non-Patent Document 1 describes a method in which lutetium-177 obtained by neutron irradiation of an ytterbium-176 enriched target is separated and recovered by passing the target through a column, taking advantage of the difference in the adsorption characteristics of ytterbium and lutetium on an ion exchange resin, after the target is completely dissolved.

[0005] Furthermore, Non-Patent Document 2 describes a method in which lutetium-177 obtained by neutron irradiation of an ytterbium-176 enriched target is separated and recovered by electrochemical means after the entire target is dissolved, and ytterbium is recovered from the waste solution to regenerate the target. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2023-520878 [Non-patent literature]

[0007] [Non-Patent Document 1] D. McAlister, “A process for the separation of 177Lu from neutron irradiated 176Yb targets”, Radiation and Isotopes, 63(1):23-36 (2005). [Non-Patent Document 2] S. Patra et al., “Electrochemical separation and purification of no-carrier-added 177Lu for radiopharmaceutical preparation from bench to bed”, Chemical Engineering Journal Advances 14 (2023) 100444. Summary of the Invention [Problem to be solved by the invention]

[0008] Ytterbium and lutetium have similar chemical properties, such as the form of dissolved ions, and there is a possibility that ytterbium may be mixed in during the production of lutetium-177. However, ytterbium becomes an impurity when labeled compounds are produced, and from the standpoint of the economics of target reuse of ytterbium, it is a challenge to prevent ytterbium from being mixed in with the separated and recovered lutetium-177.

[0009] The present invention has been made to solve the above problems, and aims to provide an apparatus and method for producing lutetium-177 that can suppress the inclusion of ytterbium and produce lutetium-177 with a high recovery rate. [Means for solving the problem]

[0010] The lutetium-177 manufacturing apparatus according to an embodiment of the present invention is characterized by comprising an irradiation mechanism for irradiating an ytterbium target with charged particles to generate ytterbium-177 in the ytterbium, a dissolution mechanism for dissolving the irradiated ytterbium target with the charged particles using a dissolution chemical to obtain a solution, and a separation and recovery mechanism for separating and recovering lutetium-177 and ytterbium from the solution.

[0011] The method for producing lutetium-177 according to an embodiment of the present invention is characterized by comprising an irradiation step of irradiating an ytterbium target with charged particles to generate ytterbium-177 in ytterbium, a dissolution step of dissolving the irradiated ytterbium target irradiated with the charged particles in a dissolution chemical to obtain a solution, and a separation and recovery step of separating and recovering lutetium-177 and ytterbium from the solution. Effect of the Invention

[0012] According to the embodiments of the present invention, it is possible to provide an apparatus and method for producing lutetium-177 that can suppress contamination with ytterbium and produce lutetium-177 with a high recovery rate. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an apparatus for producing lutetium-177 according to a first embodiment. [Diagram 2] FIG. 2 is a flow chart showing the process flow of the method for producing lutetium-177 according to the first embodiment. [Diagram 3] Graph showing the relationship between relative radioactivity ratio in an ytterbium target and depth from the surface. [Figure 4] FIG. 1 is a diagram showing a schematic configuration of a main part of an apparatus for producing lutetium-177 according to a first embodiment. [Diagram 5] FIG. 1 is a diagram showing a schematic configuration of an apparatus for producing lutetium-177 according to a second embodiment. [Figure 6]FIG. 1 is a diagram showing a schematic configuration of an apparatus for producing lutetium-177 according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an apparatus and method for producing lutetium-177 according to an embodiment will be described with reference to the drawings.

[0015] (First embodiment) FIG. 1 is a diagram showing a schematic configuration of an apparatus for producing lutetium-177 according to the first embodiment, and FIG. 2 is a flow chart showing a process flow for producing lutetium-177 according to the first embodiment.

[0016] As shown in FIG. 1, a lutetium-177 production apparatus 100 according to the first embodiment includes an irradiation unit 10, a target dissolution unit 20, and a separation and recovery unit 30.

[0017] The irradiation unit 10 includes an irradiation mechanism that generates a deuteron (deuterium ion) beam 11, which is a charged particle, and irradiates the deuteron beam 11 onto an ytterbium target 12 housed within the irradiation unit 10 (step 201 in FIG. 2).

[0018] The irradiated ytterbium target 12a is carried into the target dissolving unit 20 from the irradiation unit 10. The target dissolving unit 20 is provided with a dissolving liquid inlet 21 and a dissolving liquid outlet 22, and a liquid contact jig 23 is provided between them. The irradiated ytterbium target 12a carried into the target dissolving unit 20 is held by the liquid contact jig 23, and is dissolved by contact with the dissolving liquid flowing in from the dissolving liquid inlet 21 and flowing out from the dissolving liquid outlet 22 (step 202 in FIG. 2).

[0019] The dissolution liquid flowing out from the dissolution liquid outlet 22 containing the dissolved irradiated ytterbium target 12a is introduced into the separation and recovery unit 30, where lutetium-177 and ytterbium are separated and each is recovered via the separation and recovery liquid outlet 31 (step 203 in FIG. 2). As the separation and recovery unit 30, for example, a chromatography column packed with an ion exchange resin or the like can be used.

[0020] The graph in Figure 3 shows the distribution of ytterbium-177 produced from the target surface when a ytterbium target is irradiated with deuterons (deuterium ions), a charged particle, obtained by activation calculation.

[0021] In the above-mentioned Non-Patent Documents 1 and 2, neutrons, which are electrically neutral particles, are irradiated onto the ytterbium target, so that ytterbium-177 and its decay nuclide, lutetium-177, are uniformly distributed in the ytterbium target. On the other hand, in the first embodiment, deuterons, which are charged particles, are irradiated onto the ytterbium target, so that the generation rate of ytterbium-177 near the surface of the ytterbium target is high. In the example shown in FIG. 3, the generation distribution of ytterbium-177 is high from the surface of the ytterbium target to a depth of about 200 μm, and is approximately zero at about 350 μm.

[0022] In other words, the ratio of lutetium-177 produced by the decay of ytterbium-177 to the raw material ytterbium has a distribution in the target depth direction. Therefore, by controlling the amount of target dissolution in the thickness direction from the target surface in the target dissolution process, it is possible to obtain solutions with different concentration ratios of lutetium and ytterbium.

[0023] When solutions with different concentration ratios of lutetium-177 and ytterbium are separated and collected under the same conditions, such as by passing through a column, the mixing ratio of ytterbium in the lutetium fraction changes. For example, the deeper the target depth of the solution, the greater the amount of ytterbium mixed in relative to lutetium-177 (ytterbium / lutetium-177 concentration ratio).

[0024] Since ytterbium and lutetium have similar chemical properties, the concentration of ytterbium in the separated and recovered material must be limited. Therefore, by dissolving the target at each target depth position and performing separation and recovery according to the ytterbium / lutetium-177 concentration ratio of the solution at each position, it is possible to increase the amount of lutetium recovered while suppressing the amount of ytterbium mixed into the separated and recovered material.

[0025] As described above, since the ratio of lutetium-177 to ytterbium varies in the target depth direction, it is important to obtain a dissolving liquid at each predetermined depth from the target surface. An example of the structure of the liquid contact jig 23 of the target dissolving unit 20 for this purpose is shown in Figure 4. The liquid contact jig 23 shown in Figure 4 is disposed so as to cover the upper part of the irradiated ytterbium target 12a, and forms a flow path 24 for the dissolving liquid that communicates with the dissolving liquid inlet 21 and the dissolving liquid outlet 22.

[0026] In Fig. 4, 12b indicates a lutetium formation region in which lutetium-177 (and ytterbium-177) is formed in the flat irradiated ytterbium target 12a. By flowing a dissolving liquid (such as an acid solution) while pressing a liquid contact jig 23 with a flow path 24 of the dissolving liquid against the irradiated ytterbium target 12a, it is possible to control the amount of dissolution of the target. The flow path 24 is, for example, a cylindrical gap formed in a portion facing the irradiated ytterbium target 12a according to the shape of the lutetium formation region 12b, and the surface of the lutetium formation region 12b of the irradiated ytterbium target 12a facing this portion is structured to come into contact with the dissolving liquid.

[0027] That is, the contact area of ​​the irradiated ytterbium target 12a is limited so that only the portion corresponding to the flow path 24 comes into contact with the dissolving liquid, and only this portion dissolves. Also, since the target is dissolved in the depth direction in sequence from the surface side, dissolving liquids having different ytterbium / lutetium-177 concentration ratios can be collected separately by collecting dissolving liquids in a time series. Also, the amount of target dissolution can be controlled by, for example, adjusting the acid concentration of the dissolving liquid and controlling the target dissolution rate.

[0028] As described above, according to this embodiment, lutetium-177 is generated with a distribution of its abundance ratio in the target depth direction by irradiating the ytterbium target 12 with deuterons, which are charged particles. As a result, by controlling the amount of the target dissolved in the depth direction from the target surface in the target dissolution process, it is possible to obtain a solution with a different ytterbium / lutetium-177 concentration ratio. In addition, by dissolving a part of the target instead of the entire target, the amount of ytterbium in the solution can be reduced. Therefore, it is possible to suppress the contamination of ytterbium, and it is possible to produce lutetium-177 with a high recovery rate, and it is also possible to efficiently recover ytterbium for reuse.

[0029] Second embodiment Next, a second embodiment will be described. Fig. 5 shows a schematic configuration of a lutetium-177 manufacturing apparatus 110 according to the second embodiment. Note that the same reference numerals are used to designate parts corresponding to those of the lutetium-177 manufacturing apparatus 100 according to the first embodiment shown in Fig. 1, and duplicated explanations will be omitted.

[0030] 5, in the manufacturing apparatus 110 for lutetium-177 according to the second embodiment, a radiation measuring instrument 40 is provided in the target dissolution unit 20, which measures and monitors, for example, gamma rays emitted by lutetium-177, and inputs a measurement signal to a control device 41. This makes it possible to monitor the remaining radioactivity of the target or the radioactivity at the outlet of the dissolution liquid, and to grasp the amount of dissolved lutetium-177.

[0031] Since the radioactivity distribution of lutetium-177 in the target can be predicted by determining the irradiation conditions, the dissolution depth of the target can be accurately monitored by monitoring the total amount of dissolved lutetium-177.Based on the monitoring results, for example, by using the control device 41 to control the opening and closing of the valves of the dissolving liquid inlet 21 and the dissolving liquid outlet 22, dissolving liquids with different ytterbium / lutetium-177 concentration ratios can be more reliably obtained.

[0032] Third embodiment Next, a third embodiment will be described. Fig. 6 shows a schematic configuration of a lutetium-177 manufacturing apparatus 120 according to the third embodiment. Note that the same reference numerals are used to designate parts corresponding to those of the lutetium-177 manufacturing apparatus 100 according to the first embodiment shown in Fig. 1, and duplicated explanations will be omitted.

[0033] 6, in the manufacturing apparatus 120 for lutetium-177 according to the third embodiment, a radiation measuring instrument 40 is provided near the separation column of the separation and recovery unit 30, which measures and monitors, for example, gamma rays emitted by lutetium-177, and inputs a measurement signal to a control device 41. This makes it possible to monitor the amount of radioactivity of lutetium-177 during separation or in the separated and recovered liquid, and for example, by controlling the opening and closing of the valve of the dissolving liquid outlet 22 or the separated and recovered liquid outlet 31 based on the amount of lutetium-177 during separation, it becomes possible to increase the amount of lutetium recovered while suppressing the amount of ytterbium contamination.

[0034] As shown in the second embodiment, a radiation measuring device 40 is provided in the target dissolution unit 20, and as shown in the third embodiment, a radiation measuring device 40 is provided near the separation column of the separation and recovery unit 30. By combining these, even more precise control is possible.

[0035] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0036] 10...irradiation unit, 11...deuteron (deuterium ion) beam, 12...ytterbium target, 12a...irradiated ytterbium target, 12b...lutetium formation region, 20...target dissolution unit, 21...dissolution chemical inlet, 22...dissolution chemical outlet, 23...liquid contact jig, 24...flow path, 30...separation and recovery unit, 31...separation and recovery liquid outlet, 40...radiation measuring instrument, 41...control device, 100...lutetium-177 manufacturing apparatus according to the first embodiment, 110...lutetium-177 manufacturing apparatus according to the second embodiment, 120...lutetium-177 manufacturing apparatus according to the third embodiment.

Claims

1. an irradiation mechanism for irradiating an ytterbium target with charged particles to generate ytterbium-177 in the ytterbium; a dissolving mechanism for dissolving the irradiated ytterbium target by a dissolving chemical to obtain a dissolving solution; a separation and recovery mechanism for separating and recovering lutetium-177 and ytterbium from the dissolution solution; An apparatus for producing lutetium-177, comprising:

2. The apparatus for producing lutetium-177 according to claim 1, The dissolution mechanism suppresses the amount of dissolved ytterbium relative to dissolved lutetium-177 by limiting the contact area with the chemical solution and / or controlling the concentration of the chemical solution. An apparatus for producing lutetium-177.

3. The apparatus for producing lutetium-177 according to claim 1 or 2, The processing status of the dissolving mechanism and / or the processing status of the separation and recovery mechanism are monitored by radiation measurement using a radiation measuring device, and control is performed based on the monitoring results. An apparatus for producing lutetium-177.

4. The apparatus for producing lutetium-177 according to claim 1 or 2, The charged particle is a deuteron. An apparatus for producing lutetium-177.

5. The apparatus for producing lutetium-177 according to claim 1 or 2, The dissolution mechanism dissolves a part of the ytterbium target with a dissolution chemical to obtain a dissolution solution. An apparatus for producing lutetium-177.

6. an irradiation step of irradiating an ytterbium target with charged particles to generate ytterbium-177 in the ytterbium; A dissolving step of dissolving the irradiated ytterbium target using a dissolving chemical to obtain a dissolving solution; a separation and recovery step of separating and recovering lutetium-177 and ytterbium from the solution; A method for producing lutetium-177, comprising:

7. A method for producing lutetium-177 according to claim 6, comprising the steps of: In the dissolving step, the amount of dissolved ytterbium relative to the dissolved lutetium-177 is suppressed by limiting the contact area with the chemical solution and / or controlling the concentration of the chemical solution. A method for producing lutetium-177, comprising the steps of:

8. A method for producing lutetium-177 according to claim 6 or 7, comprising the steps of: The processing status of the dissolving step and / or the processing status of the separation and recovery step are monitored by radiation measurement using a radiation measuring device, and control is performed based on the monitoring results. A method for producing lutetium-177, comprising the steps of:

9. A method for producing lutetium-177 according to claim 6 or 7, comprising the steps of: The charged particle is a deuteron. A method for producing lutetium-177, comprising the steps of:

10. A method for producing lutetium-177 according to claim 6 or 7, comprising the steps of: In the dissolving step, a part of the ytterbium target is dissolved by a dissolving chemical to obtain a solution. A method for producing lutetium-177, comprising the steps of:

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