Radioactive molybdenum production and radioactive technetium extraction system

Abstract

A system is provided that utilizes radiation emitted by radioactive technetium produced by the radioactive decay of radioactive molybdenum. [Solution] The system comprises a radioactive molybdenum production unit that produces radioactive molybdenum by irradiating a molybdenum solution with neutrons using a small accelerator neutron source, and a radioactive technetium extraction unit that extracts radioactive technetium, a daughter nuclide produced by radioactive decay of the radioactive molybdenum produced in the radioactive molybdenum production unit. The radioactive technetium extraction unit is integrated with the radioactive molybdenum production unit and applies ultrasonic vibrations to rod-shaped activated carbon immersed in the molybdenum solution containing the radioactive molybdenum and the radioactive technetium, thereby selectively adsorbing the radioactive technetium onto the surface of the activated carbon, thereby extracting the radioactive technetium, which has a short half-life, so that it can be used at the point of use.

Description

[Technical Field]

[0001] The present invention relates to a radioactive molybdenum production and radioactive technetium extraction system that utilizes radiation emitted by radioactive technetium produced by the radioactive decay of radioactive molybdenum.

[0002] in particular, 99 Mo / 99m Tc and 101 Mo / 101 CANS (Compact Accelerator Neutron Sources; a device consisting of an electron accelerator, a neutron generator, and a beamline for neutron measurement) is used for the production of Tc. It generates neutron beams and is used for activation reactions, analysis of structural materials, evaluation of metallic materials, etc. [Background technology]

[0003] Technetium (Tc) is a transition element with atomic number 43, located in the 5th period of the 7th group of the periodic table. Among the Tc isotopes, technetium-99m ( 99m Tc) has a short half-life (6 hours) and emits only weak gamma-ray energy (Eγ141 keV) associated with isomer transition (IT: a process in which an excited nucleus (isomer) changes to a more stable state by emitting gamma rays and electrons, which is suitable for imaging diagnosis), and is the parent nuclide. 99 Using radioactive equilibrium with Mo 99m Tc generator ( 99 Mo / 99m It is generated at points of use such as hospitals and nuclear pharmacies as a 2Tc generator and is widely used in nuclear medicine imaging diagnostics, accounting for more than 80% of all radiopharmaceuticals in use, and is currently used in 40 million medical diagnoses per year around the world.

[0004] 99 Mo has traditionally been used in fissile uranium ( 235It has been produced by neutron irradiation of uranium (U) as one of the fission products and then separated. In the case of this uranium production method, it is difficult to deliver it to patient users. 99m The Tc drug was initially separated at the end of uranium irradiation (EOB: End of Bombardment). 99 It is said to have less than 10% of the Mo radioactivity and is produced in an inefficient manner with a lot of waste.

[0005] On the other hand, radioactive molybdenum-101( 101 The daughter nuclide of technetium-101 (Mo) 101 Tc emits both gamma rays (Eγ307 keV) and beta rays (Eβ487 keV), which are energies suitable for diagnosis and treatment, and is therefore expected to be used medically as a new theranostics nuclide that enables both radioactive diagnosis and treatment. (Theranostics is a medical technology that integrates diagnosis and treatment, using radiopharmaceuticals to enable everything from cancer detection to treatment and measurement of treatment effects.) However, 101 Mo and 101 The half-lives of Tc are very short, at 14.6 and 14.0 minutes, respectively, so little research has been done on their production and use.

[0006] Patent Document 1 describes radioactive molybdenum, which is the parent nuclide of technetium. 99 Mo is used as a raw material with natural isotope ratio and neutron irradiation is carried out in a nuclear reactor. 98 Produced by the Mo(n,γ) reaction 99 Mo to its daughter nuclides 99m Tc was analyzed using activated charcoal (AC). 99m Tc-containing Mo( 99 The solution containing Mo was passed through the AC column. 99m Only Tc is selectively adsorbed and collected on AC, and then the non-AC-adsorbed Mo( 99 Mo) is washed out with water, and then an alkaline solution (such as caustic soda NaOH) is used to remove the adsorbed material on activated carbon. 99m Tc is eluted from AC and 99m Trace amounts of non-radioactive Mo contained in the Tc recovery solution, 99Mo, radioactive impurities, and other impurities are removed by passing the liquid through a column packed with aluminum oxide (alumina: AL) placed after the AC column, thereby purifying the liquid. 99m A method and apparatus for recovering Tc is described.

[0007] In Patent Document 2, similar to Patent Document 1, Mo with a natural isotope ratio is used as a raw material and neutrons are irradiated in a nuclear reactor, 98 Produced by the Mo(n,γ) reaction 99 Mo to its daughter nuclides 99m Tc was detected using spherical activated carbon (BAC) as AC. 99m The method for adsorbing and collecting Tc, 99 The method of passing the solution containing Mo through the AC column by either a pressurized flow, where the solution is pushed into the column by a pump, or a reduced-pressure flow, where the solution is sucked in by a pump, was compared. Then, as in the previous section, the non-adsorbed Mo ( 99 After washing out the carbon black (including Mo) with water, an alkaline solution (such as caustic soda NaOH) is used to remove the carbon black adsorbed on the AC. 99m As a method for eluting Tc from AC, we investigated a method of accelerating elution by heating to about 80°C. 99m Trace amounts of Mo contained in the Tc recovery solution, 99 Mo, radioactive impurities, and other impurities are separated in a column packed with aluminum placed after the activated carbon column. 99m Mo contained in the Tc recovery solution, 99 Purified by removing Mo and other impurities 99m A method and apparatus for recovering Tc is described.

[0008] In Patent Document 3, similar to Patent Documents 1 and 2, Mo with a natural isotope ratio is used as a raw material and neutrons are irradiated in a nuclear reactor, 98 Produced by the Mo(n,γ) reaction 99 Mo to its daughter nuclides 99m Tc is calculated using AC. 99m The main methods for recovering Tc are 99The Mo( 99 Mo) solution tank to an external cell equipped with an AC column with low radiation shielding capability. 99 The solution (including Mo) is piped to the AC column installed in the external cell and then circulated back to the internal Mo tank. 99m The structure is such that radiation leakage to the outside is prevented by selectively adsorbing and collecting Tc. After that, the activated carbon non-adsorbable Mo( 99 After washing out the adsorbed carbon black (including Mo) with water, an alkaline solution (such as caustic soda NaOH) is used to remove the carbon black adsorbed by AC. 99m Tc is eluted from the activated carbon, and finally 99m Mo contained in the Tc recovery solution, 99 Mo, radioactive impurities, and other impurities are removed by passing the liquid through a column filled with Al placed after the activated carbon column. 99m A method and apparatus for recovering Tc is described.

[0009] Patent Document 4 describes a conventional method in which a solution is passed through an AC column to remove the molybdenum contained in the Mo solution. 99m By improving the distribution method that completely adsorbs and collects Tc, the specific radioactivity (the strength of radioactivity per unit mass of a substance containing a radioisotope, expressed in units of Bq or Ci, and the radioactivity per 1 g or mg of the element or substance) is low. 99 Mo solution, i.e., high concentration Mo( 99 Mo) is produced in solution 99 Mo daughter nuclides 99m As a method for selectively separating and recovering Tc, instead of using an AC column, a cylindrical metal mesh container containing AC is immersed in a Mo solution, and the Mo solution is stirred and flowed to separate Mo( 99 Mo) solution 99m This method involves adsorbing and collecting Tc onto AC.

[0010] As a result of improving the method to not pass the solution through the conventional AC column, 99mSince Tc can always be adsorbed and collected on the AC column, Mo( 99 This eliminates the need to pass a Mo solution through the reactor, and the traces of Mo contained in the solution are removed. 99m A method and apparatus for easily and efficiently carrying out the steps of capturing, separating, and purifying Tc is described and is the work of the present inventors.

[0011] Research to date has shown that 98 Mo and 100 The neutron capture properties of Mo are similar, and the thermal neutron capture cross section is 98 Mo is 0.130b (burn: a unit of activation cross section, 1b is 10 -24 cm 2 ), 100 Mo is 0.199b and the resonance integral cross section is 98 Mo is 6.70b, 100 The Mo is revealed to be 3.76b.

[0012] Non-Patent Document 1 describes the irradiation of natural isotope molybdenum (Mo) with epithermal / resonance neutrons (neutrons with slightly higher energy than thermal neutrons, in the energy range of approximately 0.5 to 100 eV, and resonance neutrons have slightly higher energy than epithermal neutrons) using a compact accelerator neutron source. 99m Tc and 101 The results of producing Tc are shown. The neutrons have an output of 2 × 10 10 A natural isotope molybdenum (Mo) solution was irradiated using a deuterium-deuterium (DD) neutron generator at 1000 keV / s. 99 Mo and 101 Furthermore, the formation of Mo in the solution was confirmed. 99m Tc and 101 Tc was extracted from the low specific activity (LSA) Mo target solution by activated charcoal (AC). 99m Tc and 101 This shows that it is possible to separate Tc.

[0013] Non-patent document 2 describes a new method for producing and supplying short-lived radioisotopes using an accelerator as follows: 99 Mo / 99m Tc and101 Mo / 101 To investigate the possibility of producing Tc, we are considering using a compact accelerator neutron source. 18 In F-fluorodeoxyglucose (FDG) production 18 O(p,n) 18 The results of irradiating a metallic natural molybdenum target with neutrons generated from a 16.5 MeV cyclotron using the F reaction showed that 98 Mo and 100 Mo (n,γ) reaction 99 Mo and 101 Formation of Mo and its daughter nuclides 99m Tc and 101 The generation of Tc has been confirmed.

[0014] Non-patent document 3 is a review of Tc research. 101 Tc) was identified about 80 years ago, shortly after the discovery of the element Tc itself, but research on it has not progressed much compared to other Tc isotopes. 101 The paper presents known data on the chemical, nuclear, and physical properties of Tc and their applications. 101 It may be important for further development of fundamental and applied nuclear and radiochemistry of Tc, 101 It provides comprehensive research results and paper information on Tc.

[0015] Non-patent document 4 shows a new method for producing and supplying short-lived radioisotopes by neutron irradiation, 99m Tc and 101 The use of the Compact Accelerator Neutron Source (CANS) was carried out to investigate the production of Tc. 18 During F-fluorodeoxyglucose (FDG) production 18 O(p,n) 18 Neutron irradiation is performed using a 16.5 Mev cyclotron to induce the F reaction. 18 Using neutron irradiation during F production, 99 Mo / 99m Tc and101 Mo / 101 It has been reported that simultaneous production of Tc is possible.

[0016] Non-patent document 5 states: 99m Tc is used for imaging (diagnosis) and has chemical properties similar to Tc. 188 For the purpose of therapeutic application of Re, their mixed state 99m Tc / 188 Medical research into theranostics by Re is shown. This is 99m Tc / 101 It has almost the same purpose as theranostics using Tc, and its effectiveness can be interpreted as being demonstrated by medical data, so Figure 5 shows an example of this. 99m Tc and 188 The raw materials for producing Re are Mo and W (tungsten), so they cannot be produced simultaneously. Furthermore, although Tc and Re have similar properties, they are different elements and therefore have different properties, so it is anticipated that their production and use will be difficult. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] Patent No. 5427483 [Patent Document 2] Patent No. 5916082 [Patent Document 3] Patent No. 6355462 [Patent Document 4] Patent No. 7515815 [Non-patent literature]

[0018] [Non-Patent Document 1] Fusion-Based Neutron Generator Production of Tc-99m and Tc-101: A Prospective Approach to Technetium Theranostics; Edward J. Mausolf, Erik V. Johnstone, Natalia Steward, David L. Williams, Eugene Yao Z. Guan, and Charles K. Gary, Pharmaceuticals (Basel). 2021 Sep; 14(9):875

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[0019] In recent years, the number of cancer patients has been increasing rapidly worldwide, and research into effective cancer diagnosis and treatment is being actively conducted. Currently, there are four main cancer treatments: (1) surgery, (2) radiation therapy, (3) chemotherapy (anticancer drugs), and (4) immunotherapy, known as the four major cancer treatments. Recent advances in chemotherapy and radiation therapy have demonstrated that they are just as effective as surgery, depending on the type and stage of cancer. Furthermore, in radiation therapy, active research is being conducted into theranostics (diagnosis and treatment), which not only diagnoses the location and progression of cancer, but also simultaneously diagnoses and treats the disease.

[0020] The inventors specialize in technetium (Tc) research. 99m Tc) has a relatively short half-life (6.0 hours) and emits only weak gamma rays (141 keV) associated with isomeric transitions (IT), which are suitable for diagnostic imaging. 99 Using radioactive equilibrium with Mo (half-life 65.9 hours) 99m Tc generator ( 99 Mo / 99m It has been generated at points of use such as hospitals and nuclear pharmacies using a Tc generator and has been widely used in nuclear medicine imaging diagnosis.

[0021] 99m Tc accounts for over 80% of the radiopharmaceutical use, and is currently used in 40 million medical diagnoses worldwide annually. 99Mo has previously been considered a fissile uranium ( 235 However, as shown in Patent Document 4, the inventors have not used uranium as a raw material, but natural molybdenum as a raw material. 99 Mo / 99m We have succeeded in developing technology to manufacture Tc and supply it to hospitals and other facilities.

[0022] Made from natural molybdenum 99 Mo / 99m We have developed a Tc production technology that will enable both diagnosis and treatment at the same time. 99m Tc and 101 The technical point is the radionuclide used. 101 Mo and 101 Both Tc have very short half-lives (14.6 minutes and 14.0 minutes, respectively), so until now, 101 The technology to recover and purify Tc in a short period of time had not yet been developed.

[0023] At use points such as hospitals close to patients, 99 Mo and 99m At the same time as producing Tc, 101 Mo and 101 If Tc can be produced and used, 99m Tc / 101 Tc will be available for diagnosis and treatment.

[0024] As a result of intensive research, 99 Mo, 101 Mo production method: 98 Mo and 100 Neutron activation of natural isotopes of Mo, including [ 98 Mo+n→ 99 Mo→ 99m Tc (γ-ray emission: diagnostic only)] and [ 100 Mo+n→ 101 Mo→ 101 It was found that a method using Tc (beta and gamma ray emission: capable of diagnosis and treatment) is practical.

[0025] 98 Mo and 100 Natural isotope molybdenum containing Mo or isotopically enriched molybdenum-100( 100 As a method of activating Mo, a compact accelerator neutron source (CANS) is used to collide deuterium atoms (DD) with each other to cause a nuclear fusion reaction, generating neutrons (n) with an energy of 2.45 MeV, and then irradiating the neutron beam with the molybdenum (Mo) isotope. 98 Mo and 100 Natural molybdenum containing Mo or isotopes 100 Irradiation of Mo-enriched molybdenum causes neutron capture reaction 98 Mo+n→ 99 Mo and / or 100 Mo+n→ 101 We need to make sure Mo progresses.

[0026] 99 Mo and 101 Daughter nuclides produced by radioactive decay of Mo 99m Tc and 101 As a method for purifying and recovering Tc, 101 Considering the half-life of Tc (14.0 minutes), the conventional AC method shown in Patent Document 4 99m The Tc recovery and purification method was further improved and purified. 99m Tc / 101 It is necessary to make it possible to recover Tc more efficiently and in a shorter time.

[0027] next, 99 Mo / 99m The important points to note when producing Tc are: 99m After Tc generation 99g Tc (Tc99g: ground state, converts to stable ruthenium (Ru) with a half-life of 211,000 years) 99m It becomes a kind of impurity for Tc, 99m This may have a negative effect on Tc formulation. 99g While avoiding excessive coexistence of Tc, 99g Tc / 99m It will be necessary to devise a way to reduce the Tc ratio or keep it below a certain level.

[0028] Furthermore, the present invention is directed to the use of radioactive technetium-99m ( 99m Tc) and radioactive technetium-101 ( 101 It is possible to produce saline solution containing a mixture of Tc), 99m Tc and 101 It is desirable to have a method that can diagnose or treat while diagnosing using either or both Tc.

[0029] Therefore, the present invention provides: 98 Mo and 100 Natural isotope molybdenum containing Mo or isotopically enriched molybdenum 100( 100 by the neutron capture reaction of Mo 99 Mo and / or 101 Mo, and their radioactive decay produces radioactive daughter nuclides, 99m Tc, 101 The purpose of this invention is to provide a system for theranostics (diagnosis and treatment) using beta and / or gamma rays emitted by Tc. [Means for solving the problem]

[0030] In order to solve the above problems, the radioactive molybdenum production and radioactive technetium extraction system of the present invention comprises a radioactive molybdenum production unit that produces radioactive molybdenum by irradiating a molybdenum solution with neutrons from a small accelerator neutron source, and a radioactive technetium extraction unit that extracts radioactive technetium, which is a daughter nuclide produced by radioactive decay of the radioactive molybdenum produced in the radioactive molybdenum production unit, and is characterized in that the radioactive technetium extraction unit is integrated with the radioactive molybdenum production unit and applies ultrasonic vibrations to rod-shaped activated carbon immersed in the molybdenum solution containing the radioactive molybdenum and the radioactive technetium, thereby selectively adsorbing the radioactive technetium onto the surface of the activated carbon, thereby extracting the radioactive technetium, which has a short half-life, so that it can be used at the point of use.

[0031] In the radioactive molybdenum production and radioactive technetium extraction system, the radioactive molybdenum production unit is a natural isotope of molybdenum. 98 Mo and 100 The molybdenum solution containing Mo is irradiated with neutrons to cause a neutron activation (n, γ) reaction, thereby producing the radioactive molybdenum. 99 Mo and 101 It is characterized by producing Mo.

[0032] In the radioactive molybdenum production and radioactive technetium extraction system, the radioactive technetium extraction unit is 99 Mo and 101 As radioactive technetium produced from Mo, it has a short half-life 99m Tc and 101 It is characterized by extracting Tc.

[0033] In the radioactive molybdenum production and radioactive technetium extraction system, the radioactive technetium extraction unit comprises: 101 Before Tc disappears after its half-life 101 Generated from Mo 101 a means for extracting Tc; 101 After Tc has disappeared after its half-life 99 Generated from Mo 99m and a means for extracting Tc.

[0034] In the radioactive molybdenum production and radioactive technetium extraction system, the radioactive technetium extraction unit is provided with a bypass flow path for passing the molybdenum solution containing the radioactive technetium through a column packed with activated carbon. 99m Long half-life produced from Tc 99g It is characterized by removing Tc.

[0035] The radioactive technetium purification and recovery method of the present invention is a method for purifying and recovering radioactive technetium extracted by the radioactive molybdenum production and radioactive technetium extraction system, and is characterized in that it comprises: causing water to flow down the surface of rod-shaped activated carbon to adsorb the radioactive technetium and wash it; adding an alkaline solution dropwise to the surface of the activated carbon to elute the radioactive technetium; passing the alkaline solution containing the radioactive technetium through a column packed with a strongly acidic cation exchange resin to remove alkaline components; passing the alkaline solution through an alumina column packed with granular, acidic aluminum oxide to capture the radioactive technetium; and passing a pH-neutral physiological saline solution through the alumina column to elute and recover the radioactive technetium.

[0036] The radiation irradiation apparatus of the present invention is characterized in that it utilizes beta rays and gamma rays emitted by the radioactive technetium recovered by the method for purifying and recovering radioactive technetium. [Effects of the Invention]

[0037] According to the present invention, 98 Mo and 100 Natural isotope molybdenum containing Mo or isotopically enriched molybdenum 100( 100 by the neutron capture reaction of Mo 99 Mo and / or 101 Mo, and their radioactive decay produces radioactive daughter nuclides, 99m Tc, 101 It is possible to provide a system for theranostics (diagnosis and treatment) using beta and / or gamma rays emitted by Tc.

[0038] 99m Tc is used in more than 80% of all radiopharmaceuticals and is an extremely valuable medical radioactive material used to diagnose 40 million people a year worldwide. 99m To meet the demand for Tc, the parent nuclide 99 A large amount of Mo needs to be produced every week.

[0039] Until now, the fission method has been used to produce fissile uranium ( 235 It is produced as one of the fission products by neutron irradiation of U 99 The uranium source for irradiation was previously highly enriched uranium ( 235 In the past, uranium was used with an enrichment of 80% or more (HEU), but recently low-enriched uranium (LEU) with an enrichment of 20% or less has been used.

[0040] In the case of the Fission method, which uses uranium as a raw material, the fission reaction of uranium 99 The by-production of fission products (FP) and Pu (plutonium) during the production of Mo was unavoidable. In addition, uranium irradiation reactors are located in several places around the world, such as Europe (Belgium, the Netherlands, Poland, etc.), South Africa, and Australia, and many of these reactors and facilities are aging, which has led to frequent problems and the need for stable operation. 99 Mo manufacturing and 99m The supply of Tc has been difficult for many years (more than 20 years already).

[0041] According to the present invention, natural Mo is used as a raw material for diagnostic purposes. 99 Mo / 99m Because Tc is produced at the point of use, it is a distributed method. 99 There are no problems with supplying Mo or the generation of fission by-products. 99m This will increase opportunities for more efficient use of Tc, enabling full cost recovery (FCR; recovering all costs necessary to carry out the project, including not only direct costs but also indirect costs). 101 Mo / 101 Since Tc production can be carried out at the point of use, it will be possible to establish an efficient, low-cost, safe and secure diagnostic and treatment system that generates almost no radioactive waste.

[0042] As a neutron activation method, any of the nuclear reactors, electron accelerators, cyclotrons, RFQ linacs, and DD neutron generators shown in Figure 4 can be used. 99Mo(t 1 / 2 Neutron activation production method (66 hours) 98 Mo(n,γ) 99 All neutron sources shown in Figure 4 can be used for Mo. 101 Mo(t 1 / 2 In the case of 14.2 minutes, the daughter nuclides produced immediately after irradiation 101 Since it is necessary to quickly purify, recover and utilize Tc, a small neutron source such as a cyclotron or a DD neutron generator, which has excellent operability and cost performance, is suitable for the present invention.

[0043] 99m Tc is an important element that supports nuclear medicine, taking advantage of its property of not emitting beta rays but only gamma rays with an energy suitable for diagnosis, and is used in a wide range of scintigrams of various parts of the human body (bones, kidneys, lungs, thyroid, liver, spleen, etc.) (a test method in which a radioactive pharmaceutical is administered into the body and its distribution is imaged, and the gamma rays emitted by the radioactive pharmaceutical inside the body are detected with a special camera to examine the function and lesions of the target organ or tissue).

[0044] for example, 99m Tc tin colloid, 99m Tc-DMSA, 99m Tc-MAA, 99m Tc-PMT, 99m Tc-HSAD, 99m Tc-GSA, 99m Tc-Tetrofosmin, 99m Tc-MIBI and many other 99m Tc-labeled preparations have been developed and are widely used as radiodiagnostic agents for blood flow measurement, bone imaging, tumor diagnosis, etc. 99m The pharmacokinetics of Tc-labeled preparations administered as radiopharmaceuticals has been fully elucidated and approved by the Ministry of Health, Labour and Welfare. 99m Tc preparations are supplied and used.

[0045] Thus, diagnostic 99m A large number of labeled preparations have been developed and put to practical use, even for Tc preparations alone. 99m Tc and 101It is expected that diagnostic and therapeutic drugs labeled with Tc will be approved by the Pharmaceutical Affairs Bureau and become widely used soon.

[0046] 99m Radioactive iodine-131( 131 I) is 99 Like Mo, uranium fission reaction or 130 It is produced by the Te(n,γ) reaction and is widely used in the treatment of thyroid diseases such as thyroid cancer and Graves' disease. 101 Tc (β 487 keV; γ 307 keV) 131 It emits beta and gamma rays with energies equivalent to those of I (β 606 keV; γ 364 keV). 101 Tc is a potential substitute for radioactive iodine, which relies on nuclear reactors for production. 131 It is expected that its use will expand as a substitute for I.

[0047] Also, 99m Tc / 101 The simultaneous use of Tc may be useful as a dual imaging modality, where the similar chemical properties but different gamma-ray emission characteristics of the two isotopes can be utilized.

[0048] Mo and Tc radioisotopes produced by neutron generators at the point of use, combined with real-time use, will enable even more valuable medical applications. 99m CANS-Mo / to meet the current annual global demand for Tc diagnostics (2025; 40 million people / year, 100,000 people / day) 99m The required number of Tc systems is shown in Figure 6. The neutron irradiation capacity (neutron flux) of the CANS is 2 × 10 12 If natural Mo is used as a raw material at n / s, 205 CANS-Mo / TcQC systems will be required to meet global demand. 101 For diagnosis and treatment using Tc, only 21 units, one-tenth of the total, are required, but due to its short half-life (14 minutes), it must be manufactured at the point of use and medical procedures must be carried out.

[0049] 101 Mo / 101 Since the half-life of Tc is short at 14 minutes, it is desirable to use a compact accelerator neutron source (CANS) that is easy to operate. 18 F(t 1 / 2 The generation of positron-emitting radiation (e.g., 109.7 min) is similar to the use in positron emission tomography (PET; a nuclear medicine test that uses positron-emitting radioactive agents to image internal body functions, and is used to assess cancer and inflammatory lesions, tumor size and location, metastatic status, and treatment efficacy). These uses can be generated locally or on-site, near the patient, for example, using mobile diagnostic imaging devices, which is expected to make significant medical and economic contributions. [Brief explanation of the drawings]

[0050] [Figure 1] These are the results of gamma-ray spectrum measurements after a short-term (15-minute) irradiation of a natural molybdenum solution containing the molybdenum isotopes 98Mo and 100Mo using the Compact Neutron Source (CANS). Due to the short irradiation time, only a small amount of 99Mo was produced, whereas a large amount of 101Mo and its daughter nuclide 101Tc was produced. [Figure 2] The figure shows the gamma ray spectrum measurement results of activated carbon recovered after adding granular activated carbon AC to a Mo solution containing a mixture of 101Mo and its daughter nuclide 101Tc, which were produced by neutron irradiation of a natural molybdenum solution, and stirring the mixture. The results show that 101Tc is adsorbed by AC and completely separated from 101Mo. [Figure 3] (a) shows the results of gamma-ray spectroscopy after a natural molybdenum solution containing the molybdenum isotopes 98Mo and 100Mo was irradiated for a long period (5 hours) using a compact neutron source (CANS). This shows that 99Mo and 101Mo were simultaneously produced by long-term irradiation, and their daughter nuclides, 99mTc and 101Tc, were produced and mixed together. (b) shows the results of gamma-ray spectroscopy of activated carbon collected after 3 hours of stirring in a Mo solution containing a mixture of 99Mo, 101Mo, 99mTc, and 101Tc. This shows that the short-lived 101Tc has disappeared, and that 99mTc has been completely adsorbed and separated by AC. [Figure 4] This shows a comparison of the systems and costs of nuclear reactors, electron accelerators, cyclotrons, RFQ linacs, and DD neutron generators for neutron irradiation. [Figure 5] FIG. 1 shows the effectiveness of diagnosis and treatment using 99mTc / 188Re, and demonstrates the effectiveness of the present invention CANS-99mTc / 101Tc. [Figure 6] The number of CANS-Mo / 99mTc+101Tc systems required to meet the current annual global demand for 99mTc diagnostics (40 million people, 100,000 people per day) is shown. [Figure 7] This is a diagram showing the material flow of the CANS-99mTc / 101Tc system, in which Mo solution is circulated and neutron irradiation is performed to generate 99Mo and 101Mo, followed by milking of 99mTc and 101Tc (a process of separating and extracting short-lived daughter nuclides from long-lived parent nuclides, likened to milking a dairy cow), and the 99gTc / 99mTc ratio is controlled using an AC column. [Figure 8] FIG. 1 is a diagram showing the process of extracting 99mTc and 101Tc from 99Mo and 101Mo according to the present invention, showing that the milking time for 99mTc and 101Tc is 1 to 3 minutes (average of about 2 minutes). [Figure 9] This figure shows the ratio of 99gTc and 99mTc produced in a Mo solution containing 99mTc, which was controlled to a constant value using an AC column. [Figure 10] The CANS-Mo / 99mTc+101Tc system is shown, consisting of a production unit and an extraction unit. [Figure 11] This shows the Tc milking operation of the CANS irradiated natural Mo(n,γ)99mTc / 101Tc generator (rod-shaped activated carbon type). [Figure 12] This is the milking data for natural Mo99Mo(n,γ)99Mo / 99mTc, and shows the gamma ray spectrum data in which high purity 99mTc is recovered in a short time (about 2 minutes). DETAILED DESCRIPTION OF THE INVENTION

[0051] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0052] Mo exists in seven naturally occurring isotopes, namely 92 Mo (presence rate: 14.53%), 94 Mo (9.16%), 95 Mo (15.84%), 96 Mo (16.67%), 97 Mo (9.60%), 98 Mo (24.39%), 100 The isotopes that have Mo (9.82%) and that directly produce radioactive Mo when interacting with neutrons are: 98 Mo and 100 Only Mo. The neutron capture characteristics of both are similar, and in the case of epithermal / resonant neutron irradiation, 98 Mo(n,γ) 99 Mo and 100 Mo(n,γ) 101 The reaction of Mo proceeds, and in the case of fast neutron irradiation, 100 Mo(n,2n) 99 Mo progresses.

[0053] In this invention, epithermal / resonance neutrons from a compact accelerator neutron source (CANS) with a high Mo activation rate are used. 98 Mo and 100 We will use the (n,γ) reaction of Mo.

[0054] A natural Mo solution ( 98 Mo, 100 To efficiently irradiate Mo with neutrons, a Mo solution is circulated around the neutron source while irradiating with neutrons. 99 Mo, 101 Mo and its daughter nuclides produced by radioactive decay. 99m Tc, 101 From the circulating Mo solution containing Tc, Tc( 99m Tc, 101 It is desirable to use a method in which only Tc) is selectively adsorbed and collected using activated carbon, which will be described later, and purified, separated, and recovered.

[0055] As shown in Patent Documents 1 to 4, the practicality of trace amounts of Tc in a Mo solution on activated carbon has been confirmed in terms of selective adsorption, adsorption rate, and the ability to purify and recover the adsorbed Tc. However, the target Tc of the present invention has a very short half-life of 14 minutes. 101 Because it is Tc, it has a half-life of 6 hours. 99m The Tc recovery time (about 10 minutes) shown in the previous patent document 4, which targets Tc, is insufficient. 101 Considering the time for medical treatment with Tc (half-life 14.0 minutes), 101 Assuming that the effectiveness of Tc (half-life 14 minutes) remains at 90% or more, 101 The Tc milking time should be within 1 to 3 minutes. 101 From a practical standpoint, it is desirable to smoothly proceed from Tc-labeled formulation to medical processing (administration to diagnosis and treatment).

[0056] 101 Mo, 101 Tc has a short half-life of 14 minutes, 100 Mo(n,γ) 101 Mo / 101 Tc generation → 101 The process of Tc purification and recovery, followed by utilization (diagnosis and treatment), must be completed in a short time. Instead of the conventional method of packing a column with granular activated carbon (AC) or immersing a cylindrical metal mesh container containing AC, as shown in Patent Document 4, we investigated a method that combines rod-shaped activated carbon and ultrasonic (US) vibration as a rapid Tc purification and recovery method. As shown in Figures 10 and 11, the method involves immersing rod-shaped activated carbon in a molybdenum solution and applying vibrations such as ultrasonic waves to efficiently and selectively adsorb radioactive Tc onto the activated carbon surface. Furthermore, because rod-shaped activated carbon with a small apparent surface area is used, ultrasonic vibrations can be used in subsequent processes to accelerate cleaning and Tc elution.

[0057] Because the apparent surface area of ​​the rod-shaped activated carbon that has adsorbed and captured radioactive Tc is small, the remaining unadsorbed Mo and other adhering materials can be washed away to some extent by running a small amount of water over it. Next, a small amount of alkaline solution (such as sodium hydroxide solution (NaOH)) is dropped onto the surface to elute the Tc adsorbed within the activated carbon pores. The alkaline solution containing the eluted radioactive Tc is then passed through a column packed with strong acid cation exchange resin (IER) to remove the alkaline component (NaOH), while passing the solution through a subsequent column packed with granular aluminum oxide (alumina; AL), where it is adsorbed and captured as HTcO4 (acidic Tc) on the AL column.

[0058] At this stage, radioactive impurities other than Tc are captured by the IER and AL columns or are washed out of the columns. Next, a neutral pH saline solution is passed through the alumina column to extract the purified Tc component (TcO4 - This process is called milking.

[0059] By using rod-shaped activated carbon in combination with ultrasonic treatment, the water washing and elution NaOH solution volume in the Tc milking process can be reduced and the process can be completed in a short time, and the cleaning, purification and Tc recovery process of the Tc-adsorbed AC can be carried out efficiently in about 2 minutes. As a result, the targeted radioactive technetium-99m, -101( 99m Tc, 101 By purifying and recovering Tc in a short time, it can be used for practical medical diagnosis and treatment.

[0060] 99m Tc has a half-life of 6 hours 99g It changes to Tc (Tc-99g; ground state, half-life 211,000 years), 99m Whenever Tc is generated, 99g Tc is also produced. 99m Depending on the Tc-labeled compound (preparation), 99g When there is a lot of Tc, 99m Because it has a negative effect on Tc formulation, 99gTc is sometimes treated as a kind of impurity.

[0061] Molybdenum isotopes 98 Mo and 100 A natural isotope molybdenum solution containing Mo was circulated and irradiated with the Compact Accelerator Neutron Source (CANS) to generate technetium-99m, -101( 99m Tc, 101 Tc) parent nuclide radioactive Mo( 99 Mo, 101 In a system in which Mo is simultaneously generated, 99 With the generation of Mo 99m Tc is generated, and 99g Tc is generated, 99g Tc / 99m To reduce or maintain the ratio of Tc at a constant level, a column packed with granular activated carbon is installed in the molybdenum solution flow path as a bypass, and the flow rate of the Mo solution to the column is controlled to reduce the ratio of Tc( 99m Tc+ 99g Tc) by adsorption and removal, 99m Tc) and accumulates as an impurity. 99g Tc) can be removed at a certain rate. 99g Tc / 99m The Tc ratio can be kept constant and controlled.

[0062] Molybdenum isotopes 98 Mo and 100 The radioactive Mo( 99 Mo, 101 Mo) are produced, and their daughter radioactive technetium-99m, -101( 99m Tc, 101 Radioactive technetium-99m (Tc) produced and recovered from a molybdenum solution 99m Tc) and radioactive technetium-101 ( 101 In a saline solution containing a mixture of technetium-101 (Tc), the beta-ray-emitting radioactive technetium-101 ( 101If Tc) is not required, leave the saline solution for 2 to 3 hours. 101 By attenuating Tc 99m for Tc 101 The proportion of Tc can be reduced to 1 / 500 to 1 / 1000. 99m Tc, 101 Tc mixed) and purified saline solution 99m It will be possible to use it only for Tc diagnosis.

[0063] Natural Mo 101 If you want to generate only Tc, 100 Mo(n,γ) reaction time is short, i.e. 100 By shortening the neutron irradiation time of Mo, 99 While avoiding Mo generation 101 Only Tc can be obtained (see Figures 1 and 2).

[0064] 101 Tc is 101 Mo's radioactive decay time is short, so it can be milked every 11 to 22 minutes. 101 When the amount of Mo produced is large, the effective duration easily exceeds 2 hours, so milking can be performed 5 to 11 times during this time, and it is efficient. 101 Tc therapy is possible. The reason for this is 99 Mo and 99m The half-life ratio of Tc is approximately 11:1, 101 Mo and 101 Because the half-life ratio of Tc is almost 1:1, 101 This is because the production efficiency of Tc is significantly improved.

[0065] In the apparatus shown in Figure 10, natural isotope molybdenum (Mo) solution is irradiated with neutrons while being continuously circulated to the deuterium-deuterium (DD) neutron generator production unit by a circulation pump. 98 Mo(n,γ) 99 Mo and 100 Mo(n,γ) 101 The nuclear reaction of Mo proceeds, and then the daughter nuclides 99m Tc and 101 Tc is generated. 99mTc, 101 The Mo solution containing Tc is poured into the Mo solution bottle of the Tc extraction unit, where a certain amount is stored and then drained.

[0066] The radioactive technetium-99m, -101( 99m Tc, 101 By immersing rod-shaped activated carbon in a stored Mo solution containing Tc and applying ultrasonic vibrations, radioactive technetium ( 99m Tc, 101 Tc) is selectively adsorbed onto the surface of the rod-shaped activated carbon.

[0067] The rod-shaped activated carbon that had adsorbed radioactive technetium was pulled out of the Mo solution, and the non-adsorbed Mo and radioactive niobium ( 94 A small amount of water is passed down the activated carbon rods to wash away impurities such as Nb, etc. Furthermore, 2.0 mL of a 6 M sodium hydroxide (NaOH) solution is passed down the surface to elute the adsorbed Tc. Applying ultrasonic vibrations to these activated carbon rods during washing and alkaline elution is effective.

[0068] Next, the alkaline solution containing radioactive Tc is passed through a column packed with a strong acid cation exchange resin (IER) in an amount that has an acid-base exchange capacity greater than that required to neutralize the alkaline (NaOH) component, thereby removing the alkaline component (NaOH). The resulting effluent containing Tc is then passed (flowed down) through a column packed with granular aluminum oxide (alumina) in the subsequent stage, whereby radioactive Tc is temporarily adsorbed and captured inside the alumina column, and at the same time, radioactive niobium ( * It adsorbs and removes impurities such as trace amounts of radioactive impurities generated by the neutron irradiation reaction of natural Mo, such as Nb, which are not used in pharmaceuticals.

[0069] Then, a pH-neutral saline solution is passed through the alumina column to elute only the radioactive Tc, resulting in the purified, highly purified radioactive technetium-99m, -101( 99m Tc, 101 Tc) can be recovered.

[0070] The present inventors have developed a method for producing β-ray and γ-ray emitting materials as described in Non-Patent Documents 1 to 4. 101 The medical effects of Tc were evaluated for its radiological diagnostic and therapeutic capabilities, and research into its production methods was carried out. 98 Mo and 100 Natural isotopes of molybdenum (Mo), including Mo, are irradiated with epithermal / resonance neutrons using a deuterium-deuterium (DD) neutron generator. 98 Mo(n,γ) reaction and 100 The Mo(n,γ) reaction proceeds, and 99 Mo and 101 Mo is produced and then its daughter nuclides 99m Tc and 101 Tc is generated, and by adding activated carbon (AC) to the solution, the generated 99m Tc and 101 It was demonstrated that Tc could be adsorbed and collected on activated carbon (AC) in an extremely short time, and Tc( 99m Tc and 101 These results are shown in Figures 1 to 3.

[0071] Molybdenum isotopes 98 Mo and 100 Technetium-99m, -101( 99m Tc, 101 Tc) parent nuclide radioactive Mo( 99 Mo, 101 In the point-of-use rapid production system of radioactive Mo and radioactive Tc of the present invention, which simultaneously produces technetium-99m (Mo), a column packed with granular activated carbon is installed in the bypass of the flow path that circulates the Mo solution. By allocating the flow rate to the AC column, the technetium-99m ( 99m Tc) is a long-lived impurity produced and accumulated by technetium-99g ( 99g Tc; ground state, half-life 211,000 years) 99m Tc and 99g Tc is removed by adsorption with AC. 99g Without Tc accumulation 99g Tc / 99m The Tc ratio can be kept below a certain level.

[0072] Molybdenum isotopes 98 Mo and 100 Radioactive Mo( 99 Mo, 101 Mo) and their daughter radioactive technetium-99m, -101( 99m Tc, 101 Radioactive technetium-99m (Tc) recovered from molybdenum solution 99m Tc) and radioactive technetium-101 ( 101 In a saline solution containing a mixture of technetium-101 (Tc), the beta-ray-emitting radioactive technetium-101 ( 101 If Tc) is not required, simply leave the saline solution for 2-3 hours. 99m for Tc 101 The proportion of Tc present can be reduced to 1 / 500 to 1 / 1000.

[0073] This operation will 101 Tc decayed and disappeared 99m Since it is a saline solution containing only Tc, 99m It can also be used for diagnosis using Tc. [Example]

[0074] The configuration of the radioactive molybdenum production and radioactive technetium extraction system of the present invention will be described.

[0075] The radioactive molybdenum production and radioactive technetium extraction system includes a radioactive molybdenum production unit that produces radioactive molybdenum by irradiating a molybdenum solution with neutrons from a small accelerator neutron source, and a radioactive technetium extraction unit that extracts radioactive technetium, a daughter nuclide produced by radioactive decay of the radioactive molybdenum produced in the radioactive molybdenum production unit.

[0076] The radioactive molybdenum production unit is a natural isotope of molybdenum.98 Mo and 100 Molybdenum solution containing Mo is irradiated with neutrons to promote the neutron activation (n, γ) reaction, and is converted into radioactive molybdenum. 99 Mo and 101 The radioactive molybdenum production unit is shielded to prevent radiation from leaking outside.

[0077] The radioactive technetium extraction unit immerses a rod-shaped activated carbon in a molybdenum solution containing radioactive molybdenum and radioactive technetium, and applies ultrasonic vibrations to the activated carbon to selectively adsorb the radioactive technetium onto the surface of the activated carbon. By integrating the radioactive technetium extraction unit with the radioactive molybdenum production unit, radioactive technetium with a short half-life can be extracted so that it can be used at the point of use.

[0078] The radioactive technetium extraction unit is specifically radioactive molybdenum 99 Mo and 101 As radioactive technetium produced from Mo, it has a short half-life 99m Tc and 101 Tc is extracted. The activated carbon is washed and Tc is eluted in a short time by a milking operation. Ultrasound is used to efficiently adsorb Tc onto the surface of the activated carbon. Also, since the surface area of ​​rod-shaped activated carbon is small, any unadsorbed adhering molybdenum and other adhering molybdenum can be washed away by running water down the surface.

[0079] In addition, the radioactive technetium extraction unit 101 Before Tc disappears after its half-life 101 Generated from Mo 101 a means for extracting Tc; 101 After Tc has disappeared after its half-life 99 Generated from Mo 99m It has a means for extracting Tc.

[0080] The former is the generation of short-lived nuclides by short-term neutron irradiation. 101 Mo is generated, 101 The latter is a method of recovering Tc by long-term neutron irradiation.99 Mo and 101 Mo is simultaneously generated, 101 Mo and its daughter nuclides 101 After leaving Tc to decay, 99m This is a method for recovering Tc.

[0081] The molybdenum solution after Tc recovery in the radioactive technetium extraction unit is repeatedly returned to the radioactive molybdenum production unit using a pump or the like, thereby circulating the process through radioactive molybdenum production and the radioactive technetium extraction system.

[0082] Furthermore, the radioactive molybdenum production unit or the radioactive technetium extraction unit is provided with a bypass flow path for passing the molybdenum solution containing radioactive technetium through a column packed with activated carbon. 99m Long half-life produced from Tc 99g Remove Tc.

[0083] Circulating the molybdenum solution 99m As Tc is generated, 99m Generated from Tc 99g Tc also accumulates, 99g Tc 99m Removed at the same time as Tc, 99m By generating Tc, 99g To suppress the proportion of Tc, 99g Tc and 99m The atomic ratio of Tc is controlled.

[0084] The method for purifying and recovering radioactive technetium extracted in the radioactive molybdenum production and radioactive technetium extraction system involves washing the surface of rod-shaped activated carbon to which radioactive technetium has been adsorbed by flowing water down, dropping an alkaline solution onto the surface of the activated carbon to elute the radioactive technetium, passing the alkaline solution containing radioactive technetium through a column packed with a strongly acidic cation exchange resin to remove the alkaline component, passing the solution through an alumina column packed with granular, acidic aluminum oxide to capture the radioactive technetium, and passing a pH-neutral physiological saline solution through the alumina column to elute and recover the radioactive technetium.

[0085] Furthermore, the radiation irradiation device may utilize beta rays and gamma rays emitted by radioactive technetium recovered by the radioactive technetium purification and recovery method. [Example]

[0086] An ammonium heptamolybdate (AHM) solution (concentration 10 mmol / L) was placed in a polypropylene container and irradiated with neutrons for 15 minutes using a neutron generator. The irradiated Mo solution was measured for gamma rays using a high-purity germanium (HPGe) detector. The yield of the neutron generator was 2.2 × 10 10 Although the thermal neutron flux measured by the gold foil activation method was as high as 1.5×10 4 n / cm 2 This yield was determined by Bonner ball measurement (a neutron spectrometer with a thermal neutron detector at the center of a spherical neutron moderator), and it was found that the yield was 160 kV and D + This was consistent with known yields from generators producing currents of approximately 30 mA.

[0087] The irradiation time with this low-intensity neutron flux was only 15 minutes, so as shown in Figure 1, 101 Longer half-life than Mo 99 Mo(t 1 / 2 The amount of radioactive material produced in the 66-hour period was a minute amount of 52±3 Bq (1.3±0.1 nCi), but the amount of radioactive material produced in the short-lived period was 101 Mo(t1 / 2 =14.0 min) and its daughter nuclides 101 Tc(t 1 / 2 =14.0 min), the production of 1.2±0.1 kBq (32.7±3.5 nCi) and 4.6±0.5 kBq (124.1±13.2 nCi) was confirmed, respectively. 99 It was produced in larger amounts than Mo.

[0088] Neutron irradiation 101 In the Mo solution (100 mL), 1.0 g of granular activated carbon (AC) (Shirasagi Activated Carbon, particle size 0.5–2 mmφ, BET specific surface area 1500 m) was added. 2 The AC was placed in a meshed SUS container and submerged in water. The Mo solution was thoroughly stirred, then the AC was pulled out and washed with water before gamma ray measurement. As a result, as shown in Figure 2, 101 Tc was selectively adsorbed onto AC. 101 From AC containing Tc 101 By performing the Tc milking operation, 101 Since it becomes a saline solution containing only Tc, 101 It can be used for diagnosis and treatment using Tc. [Example]

[0089] Next, the neutron source 18 A Mo solution was irradiated with neutrons for a long period of time using a PET cyclotron for F(FDG) production. The neutron irradiation time was 20 times longer than in Example 1, for 5 hours, and the Mo solution after irradiation was similarly measured for gamma rays. The measurement results 2 hours after irradiation are shown in Figures 3(a) and (b).

[0090] As a result, as shown in Figure 3(a), 99 Mo, 99m Tc, 101 The presence of Tc was confirmed, and after leaving it for 2 hours 101 Mo had disappeared, but its daughter nuclide 101 Tc remained. 99 The daily converted amount of Mo produced was approximately 13 kBq / d (3.5 μCi / d), and the same amount of Tc( 99m Tc and 101Tc) was adsorbed and recovered, and the Tc-adsorbed AC was washed with water and then gamma rays were measured 2 hours later.

[0091] As a result, the short half-life 101 Tc has decayed and disappeared 99m Only Tc remained (Fig. 3(b)). 99m From activated carbon with only Tc remaining 99m By performing the Tc milking operation, 101 Tc decayed and disappeared 99m It is a physiological saline solution containing only Tc, 99m It can be used for Tc diagnosis.

[0092] In the case of short-term neutron irradiation (15 minutes), 99 Mo is not produced 101 Only Mo is produced 101 Tc can be recovered and used, while in the case of long-term neutron irradiation (5 hours), 99 Mo and 101 Both Mo and Zn are produced, but in this case they have a short half-life. 101 Mo and 101 Let Tc decay 99m These methods are as follows: 99m Tc and 101 This paper shows the method for the fractional production and utilization of Tc. [Example]

[0093] 101 Tc has a short half-life of 14 minutes. 101 Mo production and purification recovery ( 101 It is necessary to carry out the process from Tc milking to use (diagnosis and treatment) in a short period of time. 101 The combined effect of rod-shaped activated carbon and ultrasound (US) as a rapid Tc milking method was confirmed, as well as the recovery of Tc elution.

[0094] As shown in Figures 10 and 11, the method involves immersing rod-shaped activated carbon (outer diameter 2 mm, effective length 100 mm, surface thickness 1 mm, activated carbon activation treatment surface area 1200 to 1500 m) in a solution containing Mo and Tc.2 / g) and ultrasonic vibrations were applied to selectively adsorb the radioactive Tc in the Mo solution onto the surface of the rod-shaped activated carbon. Furthermore, because AC is rod-shaped with a small apparent surface area, ultrasonic vibrations were also used in the subsequent process to confirm whether the Tc milking operation (AC cleaning treatment and Tc elution) could be shortened.

[0095] This Tc milking device consists of a mechanism for moving rod-shaped activated carbon up and down, a mechanism for applying ultrasonic vibration to it, a mechanism for pouring in cleaning solution (water), adsorbed Tc elution solution (NaOH), and physiological saline (saline) from the outside, a valve mechanism for flowing these solutions along the flow path, a mechanism for passing the solution that has been eluted and recovered through an IER and a column filled with alumina, and finally a mechanism for extracting the target purified Tc ( 99m Tc, 101 It consists of a container for collecting Tc.

[0096] A small amount of water (approximately 2 mL) was poured onto the surface of the rod-shaped activated carbon on which the radioactive Tc was adsorbed, to wash away any remaining adhering Mo, etc. Next, 2.0 mL of 6M (molar) sodium hydroxide (NaOH) was poured down the surface of the rod-shaped activated carbon to elute the adsorbed Tc. The alkaline solution containing the eluted radioactive Tc was then poured into a column packed with a strong acid cation exchange resin (IER, 2 cc), and the alkaline component (NaOH) was removed while the alkaline solution containing Tc was passed through a column packed with 5 cc of granular aluminum oxide (acidic alumina) to produce HTcO. 4 The pertechnetate was adsorbed and collected on an alumina column.

[0097] At this stage, radioactive impurities other than Tc are captured by the IER and alumina column. By passing 10 mL of neutral saline through the alumina column, purified pertechnetate (TcO4 - ) was eluted and recovered. As shown in Figure 12, the recovered Tc component was of high purity (purity > 98%) and did not contain impurities such as other radioactive Nb (niobium).

[0098] By using rod-shaped activated carbon in combination with ultrasonic treatment, it became possible to use a small amount of NaOH solution for washing and elution in the Tc milking process, and the cleaning, purification, and recovery process after Tc-AC adsorption could be efficiently carried out in the targeted short time of about 2 minutes. The material flow for CANS-Tc production and recovery is shown in Figure 7, and the process conditions are shown in Figure 8. [Example]

[0099] 99m Tc has a half-life of 6 hours 99g It changes to Tc (Tc-99g; ground state, half-life 211,000 years), 99m The generation of Tc 99g Tc is accompanied. 99m Depending on the type of Tc preparation 99g When there is a lot of Tc 99m This will have a negative effect on the reactivity and quality of Tc formulations. 99m For Tc 99g Tc can be a kind of impurity, 99g Tc / 99m We investigated ways to reduce and stabilize the Tc ratio.

[0100] Molybdenum isotopes 98 Mo and 100 A natural isotope molybdenum solution containing Mo was circulated and irradiated with the Compact Accelerator Neutron Source (CANS) to generate technetium-99m, -101( 99m Tc, 101 Tc) parent nuclide radioactive Mo( 99 Mo, 101 In a system (Fig. 10) in which HCl is simultaneously generated, 99 Mo is produced 99m Tc is generated, and 99g Tc is produced. If it is present in excess, it becomes an impurity. 99g Tc 99m Ratio to Tc ( 99g Tc / 99mTo maintain the Tc concentration below a certain level, an AC column packed with granular activated carbon was installed in the molybdenum solution flow path as a bypass (Figure 10: bypass AC column; Tc adsorption and capture efficiency: 100%).

[0101] By controlling the flow rate to the AC column at 50% to 80%, technetium-99m( 99m Tc) and accumulates as an impurity with a long half-life. 99g Tc 99m As a ratio to Tc, for example, when the AC column flow rate is 80% as shown in Figure 9, 99g Tc / 99m The Tc ratio can be controlled to about 3.

[0102] This method allows: 99g Tc / 99m By controlling the ratio of Tc, 99g It is possible to reduce the accumulation of Tc.

[0103] According to the present invention, 98 Mo and 100 Natural isotope molybdenum containing Mo or isotopically enriched molybdenum 100( 100 by the neutron capture reaction of Mo 99 Mo and / or 101 Mo, and their radioactive decay produces radioactive daughter nuclides, 99m Tc, 101 It is possible to provide a system for theranostics (diagnosis and treatment) using beta and / or gamma rays emitted by Tc.

[0104] Although the embodiments of the present invention have been described above, the present invention is not limited to these.

Claims

1. a radioactive molybdenum production unit that produces radioactive molybdenum by irradiating a molybdenum solution with neutrons using a small accelerator neutron source; a radioactive technetium extraction unit for extracting radioactive technetium, which is a daughter nuclide produced by radioactive decay of the radioactive molybdenum produced in the radioactive molybdenum production unit; the radioactive technetium extraction unit is integrated with the radioactive molybdenum production unit, and applies ultrasonic vibrations to rod-shaped activated carbon immersed in the molybdenum solution containing the radioactive molybdenum and the radioactive technetium, thereby selectively adsorbing the radioactive technetium onto the surface of the activated carbon, thereby extracting the radioactive technetium having a short half-life so that it can be used at the point of use; A radioactive molybdenum production and radioactive technetium extraction system.

2. The radioactive molybdenum production unit is a natural isotope of molybdenum ９８ Mo and １００ The molybdenum solution containing Mo is irradiated with neutrons to cause a neutron activation (n, γ) reaction, thereby producing the radioactive molybdenum. ９９ Mo and １０１ Generate Mo, 2. The radioactive molybdenum production and radioactive technetium extraction system according to claim 1.

3. The radioactive technetium extraction unit is the radioactive molybdenum ９９ Mo and １０１ As radioactive technetium produced from Mo, it has a short half-life ９９ｍ Tc and １０１ Extracting Tc; 3. The radioactive molybdenum production and radioactive technetium extraction system according to claim 2.

4. The radioactive technetium extraction unit comprises: １０１ Before Tc disappears after its half-life １０１ Generated from Mo １０１ means for extracting Tc; １０１ After Tc has disappeared after its half-life ９９ Generated from Mo ９９ｍ means for extracting Tc; 4. The radioactive molybdenum production and radioactive technetium extraction system according to claim 3.

5. The radioactive technetium extraction unit is provided with a bypass flow path for passing the molybdenum solution containing the radioactive technetium through a column filled with activated carbon. ９９ｍ Long half-life produced from Tc ９９ｇ Remove Tc, 4. The radioactive molybdenum production and radioactive technetium extraction system according to claim 3.

6. A method for purifying and recovering radioactive technetium extracted by the radioactive molybdenum production and radioactive technetium extraction system according to any one of claims 1 to 5, comprising: Washing the surface of the rod-shaped activated carbon onto which the radioactive technetium has been adsorbed by running water down the surface; an alkaline solution is dropped onto the surface of the activated carbon to elute the radioactive technetium; the alkaline solution containing the radioactive technetium is passed through a column packed with a strongly acidic cation exchange resin to remove alkaline components, while passing the solution through an alumina column packed with granular acidic aluminum oxide to capture the radioactive technetium; a pH-neutral physiological saline solution is passed through the alumina column to elute and purify radioactive technetium. A method for purifying and recovering radioactive technetium.

7. Utilizing beta rays and gamma rays emitted by the radioactive technetium recovered by the method for purifying and recovering radioactive technetium according to claim 6. A radiation irradiation device characterized by:

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