TW436814B - A novel method for fabrication of germanium-68 sealed sources - Google Patents

Abstract

This invention deals with a novel method for the fabrication of 68 Ge sealed source, which is commonly used in nuclear medicine applications, to calibrate a positron emission tomography scanning system for activity measurement. The related fabrication process is simply described as follows: the millicuries 68 Ge presented in a high concentration of nitric acid solution is primarily shaken with an appropriate amount of silica gel as an inorganic adsorbent for 20 to 40 minutes. After centrifugation, the supernatant is discarded. Most of the 68 Ge can be adsorbed onto this adsorbent. The adsorbent matrix is further purified washing twice repeatedly with the same acidity of nitric acid in order to remove the silver radionuclide impurities. The 68 Ge adsorbed on this adsorbent is then dried, loaded directly into a specific dimension of stainless steel tube or polyacrylic vessel, and sealed eventually. The results obtained from the quality assurance testing indicate that this fabricated 68 Ge sealed source has the advantages of well-sealed property, good homogeneity of radioactivity distribution, no radioactivity leakage and contamination, high radiation resistance of the adsorbent, and ease of preparation, loading, and handling.

Description

436B1Λ ^ Case E89108488 H a .............-... ....................................... 乂., [I] LC- 5. Description of the invention (]) 1. Field of invention The present invention is a Positron Eniission Tomography Scanner (referred to as PET) activity that can be applied to the correction of nuclear medical diagnostic instruments-Positron Eniission Tomography Scanner (referred to as PET). Method for manufacturing germanium _68 (tisGe) sealed radioactive source of detection system, especially the absorption of the wrong nucleus species-68 isotope gallium-68 (li8Ga) adsorbed on the inorganic adsorbent stone dioxide, which can be released Two special opposite gamma rays, with an energy of 5 n keV, can be used to correct the relevant parameters of the PET scanner detection system and the attenuation change of the activity measurement by virtue of the penetrability of the gamma rays. The accuracy of clinically acquired data and the improvement of clinical application judgment are one of the ideal calibration sources for current nuclear medical diagnostic instruments. ^! | 2. Background of the invention | Germanium_68 (68Ge) has a very long half-life (t1 / 2 = 271d). It can emit low energy and emit i-rays through the decay mechanism of the nuclear capture of the electron capture (Electron capture). 9 _;] keV; K @ 10.3keV), generating daughter nucleus 68Ga (ti / 2: ;; = I 68.3m), at equilibrium, "aGe can produce isoactivity esG &, forming nucleus pair I (Radionucl ide pair) . According to "When Ga decays, the maximum positron radiant energy i βna) is igMeV 'through (1) positron destruction mechanism (pos; [tron a η nih 1 1 a 11 〇η)' releases two horses in opposite directions. Ray with an energy of 5 1 1 ke V (ΐ η tens ί y y 1 7 6%); and through (2) the electron capture mechanism, the gamma rays are released with an energy of 1 Q 7 7 ke V (I ntensity 3. 3%); finally converted to stable isotope "Zn. By ssGa release Gama rays penetrability, I i corrected PET scanner detection system activity measurement related parameters such as: Counting e; ff; j; ciency), amplification factor (.Gain), coincidence time | (Coincidence time), and attenuation correction (Attenuation

Page 7 4368,1 4 ........................ Room—thin .. 89108488 ... ...............................................Ren-- _J_— —0 ............— f-iL _________________ ______________— 5. Description of the invention (2) correction) and so on. Due to the extremely long half-life of b8Ge, this sealed source can be used for more than one year. The basic requirements for the production of sealed radioactive sources are whether the radioactive sources can be stably and uniformly distributed in the medium, easy to load and operate, and there is no concern about the leakage of radioactive materials. Calibration sources traditionally used in PET scanner detection systems, including liquid shots using radionuclide isotopes 6% & (: 13 and iaF-FDG [t1 / 2 = 109.8m; 511keV (194%)) Source, the former can be obtained from the usGe / 68Ga nuclear seed generator (Radionuclide generator) with dilute acid elutriation, the latter must be separated and prepared by cyclotron irradiation of nuclear reaction 180 (p, n) 18F. Because both are liquid, the activity Its high uniformity of distribution is its advantage, but its half-life is too short, it must be prepared routinely, and the liquid radio source packaging operation is easy to cause radioactive leakage pollution, which is extremely inconvenient .: The main production methods in commercial eaGe sealed radio source products There are three species, as comprehensively reported by S. Mir jadeh et al. In `` Radiochemistry of German ium " (J. Radioanal. &Amp; Nu cl. Che in., Article, 2 0 2, 7) in 1996. Published in the article: (1)% e is formulated in a suitable electrolyte solution, electroplated on a nickel metal foil or tube, and subjected to vacuum heating treatment; (2) esGe is formulated in an appropriate solution and adsorbed on an ion exchange resin; (3) esGe solution mixed ceramic material Is then loaded in a stainless steel tube to be sealed. Other studies reported, 68Ge may dilute the cyanide-containing alkaline solution, the nickel alloy plating to esGeCu3 metal foil, for example, a T. A.

Girard et al. In 1983, 'Preparation of Intense S8Ga Positron Sources by Electrodepositio n of B8G eCu3 ^ (Nu.cl. Instrun !, & Method, 205,567) —published by the author; or as formulated by KSGe Gels in dilute hydrochloric acid solution and appropriate composition, made of RS ι ^ ϋ—

4 3 68 1 ά 89108488 ... ........ year ............... g ... ................ S ............ ............. Charm ............ ........................ V. Description of Invention (3)

Tilbury et al., In 1991, " Reusable Gels for Germanium-68 Sources " (Appl. Radiat. I sot., 42, 1111 (19 9 1), Int. J. Radiat. Appl. Instrum. Part A,) — After the mixture of Polyethylene glycol (PEG-1450) and I gelatin (G eiati η) published in the article was stirred well, it was injected into the container to be solidified and sealed. -According to the above related reports, the manufacturing process of the saGe sealed emission source by electroplating is complicated, and the ion-exchange resin is used as the ^ Ge adsorption medium, which has poor radiation resistance; 直接 Ge is directly mixed with the gel and stirred, the advantages The colloid has a low melting point (< 45 ° C). After using the sealed source for a period of time, this colloid can be melted to replenish the appropriate activity B8Ge and then used repeatedly. However, the disadvantage is that the process must be quickly stirred to avoid solidification, and the colloid will stick. The wall caused e8Ge loss. In view of this, a novel manufacturing method of the present invention using the inorganic adsorbent Si02 as a 68Ge adsorption medium was developed. Although some studies have reported on the preparation of eaGe / HSGa nuclear seed generators, many types of inorganic adsorbents are used> including Si 02, Sn02, A 1203, a-Fe203, Ti 02, Zr 02, (OHh, Fe ( 0H) 3, etc., except that SiO ^ adsorbs iiSG e under the condition of high-concentration acidic solution (see the aforementioned literature by S. Mirjadeh et al.), And others adsorb MGe (g or PH 2 ~ 8) in low-concentration acidic solution. The present invention uses S i 〇? As an adsorption medium, which mainly focuses on solid irradiation and non-reactive Ga / Ag alloy materials in the manufacturing process, and is easily soluble in high-concentration acid solution (10 μHNOj), in W-L. Cheng et al. People in April 1999

Bethesda hosted the 10th Modern Trends in Actrvaiion Analysis International Symposium, prearatiori of esGe / 68Ga

Page 9 436814? _ Case No. 891Q 8488 __Year Month Day ____ V. Description of the invention (4)

Generator with a Binary Ga / Ag E1ectrodepos iti 〇ns I as S oiid ΐ arget / y < had previously mentioned that Si 02 under this condition has a large adsorption capacity of 68G e, about 30mg Ge / g Si02, at P. Lievens and others published "Selective Removal of Germanium by Retention on Silica Gel" (Anal. Ch i m. Acta, 7 0, 46 2 (1 9 74) — it is also mentioned in the article, and 37MBq (lmCi) "Ge It is only equivalent to 1.4 x ΐ 0m g G e, and S i Q a has the advantages of high radiation resistance (gi 0 5 Gy), easy loading, and low price. 3. Purpose of the invention: From the above background, The main purpose of the present invention is to make a safe, practical and easy-to-operate sealed radioactive source, to provide a nuclear medicine diagnostic instrument-positron radiation tomography scanner activity detection system for calibration and use, and to improve the instrument: Accuracy and improve the effect of clinical application judgment. | Another object of the present invention is to produce a nuclear medicine diagnostic instrument _ PET scanner detection system calibration sealed radiation source to implement the localization of research and development technology. Used positron isotope ⑽Ga Release Gama rays in two opposite directions have an energy of 5 1 1 keV. The mother nucleus "Ge has a long half-life, can be manufactured in China, and has a useful life of more than one year. Another object of the present invention is to produce a nuclear medicine Diagnostic instrument-PET scanner detection system calibration sealed radiation source to select the best adsorption medium, has a high adsorption capacity for e, radiation resistance, easy loading and low price. According to the drawings, a nuclear Medical diagnostic instrument „PET scanner” s8Ge sealed shot source calibration device for chastity system calibration .. Brief description is as follows:

Page] ι0 4 3 6814 _ Case No. 89108488_year month ^^ _ V. Description of the invention (5) Figure 1 is a schematic diagram of the main structure of the "Ge sealed emitter" of the present invention, which is called a line source (Pin source) ) A, suitable for the correction and application of the PET scanner detection system for human clinical use. 68Ge (abbreviated as 68Ge / Si 〇2) adsorbed on the SiO2 medium 'filled on the head 1 1 has Yin, Yang (inside, outside ) Threads a, b, and the bottom end 12 is sealed in a metal pipe 10 such as a stainless steel pipe, and the inside of the head end 11 is plugged with glass fiber 13. Then, use a stainless steel internal screw 丨 4 to screw into the female thread hole a of the head end 1 1 Internally lock the nozzle 'and then screw the stainless steel outer screw cap 15 to the male thread b of the head end 11 to lock and seal it. In order to meet the specifications of different brands of PET scanners, the 6SGe / Si〇2 packing size will vary The inner diameter of the steel pipe can be 3-4 mra 'The filling length can be 1 1 2-1 58 mm, and the effective activity dosage is 74-5 5 5MBq (2-15mCi) ° Figure 2 shows the produced ssGe line source An example of packaging 'radiation source A is sealed in the wrong container body b for packaging. The thickness of the wrong container depends on the filling activity design and must reach the surface radiation dose rate of $ 2m. Sv / hr, in compliance with atomic energy regulations for the safe transport of radioactive sources. Figure 3 (1), (2), and (3) show examples of packaging called Phantoms, which are 68Ge / Si02 radioactive sources. Filled in acrylic containers of different shapes ci ~ C3 ', then lock the material inlet and outlet with metal or plastic tapping screws 20, and seal it. This sealed shot source generally has a low filling activity (& 74MBq s8Ge), suitable for animals Calibration of the clinical PET scanner detection system. The packaging method only needs to place the prosthesis in a suitable box D and fix it, and the staff can maintain a distance of 5-30 cm to meet the standards of safe transportation regulations. In addition to acrylic, suitable plastic materials such as PP and PE can also be used. The above-mentioned various packaging examples of sources are for reference only. Any packaging method can be used as long as it conforms to the atomic energy regulations for the use of source transportation. Is not limited to the above.

436814 > ^ .............................. 89108488 ............................................. ................ ΐ ...................... .... month ............ a ............. ............................. I .. — ——— V. Description of the Invention (6)! The germanium produced by the present invention The detailed structure of the -68 sealed source is as described above, and the detailed manufacturing method of the germanium-6 8 sealed source according to the present invention is explained in related embodiments as follows:! The manufacturing process of the esGe sealed source is shown in Figure 4 and first In the first step 10, a high degree 6; IGa / Ag alloy is plated on the standard target base. Secondly, in the second step 20, the solid target (S ο I idtarget) is set to the energy and current of the proton beam set by the cyclotron. After being irradiated under the intensity, after being left to cool for about one month, the activity of the target base material (A g, Cu) is reduced to a low level. In a third step 30, the solid target is dissolved in a dissolution tank at room temperature. Dissolve the solution at 10M, and then filter the solution to remove suspended particles in the fourth step 40 to obtain the "Ge initial The product is shown in the fifth step 50 = followed by the adsorption of this ^ Ge 丨 initial product S] 02 (sixth step 60), and then the suction material is washed with; Η N 0 more than once to obtain purified sa G e, as shown in the seventh step 70,! | Then, in the eighth step 骒 80, the purified product can be filled and sealed in a container after being dried (ninth step 90), and finally tested. After quality control (see the tenth step 100), it can be packaged and shipped (110). On the other hand, the syGe generated in the adsorption and cleaning process (ie steps 60 and 70) can be recycled. (Step ί 2 0). | The main operating steps in this process are the steps below the dashed line in Figure 4. Each step includes: 0) 6SGe isotope preparation; (2) aiiGe adsorption purification; (3) filling and sealing; (4 ) Quality control. Example 1: Preparation of germanium-6 8 isotope This experiment was carried out three times, using high-abundance (9U47% Enriched) -ssGa / .Ag alloy electroplating on the standard target base, at the Institute of Nuclear Energy TR3_t > / 15 Medium Cyclotron Proton East Energy 19 MeV and Current Intensity 150-180yA

Page 12 4 3 68 1 4. ......................... ..................... f E 891084.8.8 ........ ................................................Ren. .........................1........................ ....... 1 ..............—— ^ je V. Description of the invention (7) Under irradiation, the net exposure is 5 0 0 0-8 〇 0 0 at A h ° The solid should be cooled for 25 days or more after irradiation. Wait for some short half-life impurities to reduce their activity as much as possible to reduce the radiation exposure of workers. The solid target was placed in a specially designed dissolution tank. It was dissolved in a 10M ΗΝ03 solution at room temperature and filtered to remove suspended particles (mainly undissolved silver, n) 5 ″ usAg) to obtain a 68Ge initial product solution. The effluent was 0.1 ml diluted 1 03 -1 04 times, and the intensity of nuclear species activity was measured with an ORTEC-GEM- 3 0 1 9 5 -P 4 0 9 6 multi-channel pulse height analyzer (MCA). The experimental results are shown in Table 1. It shows that the appropriate amount of Enriched BsG a / Ag solid solids was irradiated with the nuclear reaction MGaCpjrO ^ Ge and dissolved and separated, and the measured s «Ge activity was corrected to the stop irradiation time (E n d. Ofb 〇in bard in ent, JE 0 B), the average yield is about 8.9 ± 1.5 v C i esGe / y Ah / g suGa. In addition to the main nuclear species 6 8 G e / 6 8 G a in the solution of the original S8Ge product, there are also impurities of silver species from 107, mAg (p, pxn) nuclear reactions such as: 05Ag (41.3d), which Ag (8 , 46d), etc., and from the nuclear species impure produced by the nuclear reaction of w7] Ga (p, Xn), (p, pxn) such as MGe (39h), 7UG a (2 1 in) and 72G a (1 4 h). The half-mourning period is short, and it can be completely attenuated after cooling in solid grass for more than one month. The source of the error in the average yield of euGe obtained from the experiment mainly includes the related factors such as the possible influence of the thickness of the electroforged layer, the control of the cyclotron beam energy and current intensity, the dissolution and filtration loss of the solid target, the sampling and dilution operation, and the instrumental analysis.

Page 13 4 3 6 8 1 ά 案 Case No. 89108488 Amendment ... ............................................... ........................................ ........................................ .............,-r,-,,. ,, 5'Invention description (8) Table 1. IE Shoes · Irradiation Conditions and Yield-68 Yield | ϋ It ^ s. Hnnched! Ga content i Radiation amount: 3S, i ^. * I «* 1 '1 1 kg $ 丨 ， Ά 4 丄 present / >il; / r _---- ~-0SGe activity. sGe produced Meng (EOB) MBq (mCi) 丨 (pCi / uAirg i9Ga): 0'2 2 4e ^ h9MeV; pi .1 50liA 5000μ. Λΐ ^ 55 (12.3); 1 0 (cooling 30d) 0. ! 95g I9MsV. P ISO.uA.: 6000uAh 3- ^ 0 (9.2); Q, (cooimg 6〇d) 丨 一 丨 0.391g 19MeV P ^ 180μΑ: SOOOuAh 722 (19.5): (cooling 25d); Preparation: EOB stands for End of Bombardment; 6iGe average house Meng 4 S.9 ± 1.5 μO / μΑη / ε 69Ga Example 2: Adsorption and purification of germanium-6 8 Because (i8Ge initial product solution contains silver nuclear impurities, it must be It was purified and removed. In order to determine the adsorption kinetics of tiSGe on Si 02, this experiment was first configured with four 10ml 10M ΗN03 solutions containing "Ge tracer, respectively with 0.5g SiCM100- 2 0 0 mesh) Put it in a plastic bottle, shake for 5-30 minutes, remove the supernatant after centrifugation, analyze the wGa activity intensity after sampling, and show that e8G e can reach the adsorption equilibrium state within 20 minutes after shaking with Si 02 (Approximately 96%. In order to meet the specifications of different brands of PET scanner systems, the S i 02 used in the B & amp sealed-source production of this experiment weighs 0, 6-0.77 g. Therefore, it has been purified. The process is to take an appropriate amount of "Ge's initial product solution and prepare it in 1 Q M HN03it product of 30 0 κι 1 'and the above amount of adsorption medium in a plastic bottle and shake for 30 minutes.

MM 89108488 ± ^ ——a ______________— Fish Soldier ——_——________________— —_ 5. Description of the invention (9) The second cleaning condition is 10M ΗΝ03, volume 1 5-30 ml, shaking time is 30 minutes. In the process of adsorption and cleaning, the adsorption rate and loss rate of SSG e on the medium can be calculated by mathematical formula (1-A / AJx 100%, where AG represents the total activity of ssGe in the feed solution, and A represents the supernatant 6ttGe after adsorption and cleaning. Total activity. Since B8Ge only releases low-energy X-rays and cannot be measured by MCA, the sample taken out must be left for another day (more than 24 hours). After the generated S8Ga reaches the equilibrium with 6aGe activity, the measurement is performed. The experimental results are summarized in Table 2. It shows that the average adsorption rate of ssGe on the Si 02 medium is (8 1. 6 ± 1.3)%, which is slightly lower than the above result (96%). Due to the proper amount of Ag and Ga in the feed liquid, the influence of trace adsorption competition caused the "Ge adsorption rate to drop slightly. The loss rate of 68Ge in the first cleaning was (4.9 ± 1.3) _%, and the second cleaning of SSG The loss ratio of e is (3.4 ± 0.3)%. The total average recovery of esG e in the adsorption and purification process can be obtained (7 3.2 .2 2.3)%. Figure 5 shows the beginning of 6 8 G e The product solution was analyzed by Gamma Energy analysis before and after purification, and the purity of the final product S8G e / S i 02 nuclear species was greater than 99.9%, other Silver core impurity species in this purification conditions, are almost completely removed.

Page 15 436814 > ............................ ............ noodles .. 89108488 ............. ........................................ ....- f-gg V. Description of the invention (10) Table II. Experiments of the different conditions of Cu-68 in the purification process of dioxin-induced attachment 倏 Companion: Material liquid: 10MHNO3; 30ml Designation agent: Si02 (100 ~ 200mesh): Experiment μ3 is 0 69σ; Experiment 4 is 0.77g. A cleaning bar: 10MHNO :: Experiment 丨 _3 is 3〇m 丨: Experiment * ~-is 15ml when shaking. Time: 30mm

丨 Item times 1 i material liquid application MGe 丨 6SGe suck! 34Ge loss to (%) ί sucking coins in the introduction yh 丨; 6aGe 6iGe total learning 抆 (%) activity (MB q) 丨 quarter (%) | the first cleaning i the second cleaning! 1 330! 80.9 I —1 —1 JJ 3.1 240 74.5 i 0 Ί130! 83.0 | 3.9 98.7 75.9 i -VJ 254 | 79.7:-* 1 /. * R J. / 17-1 68.5 1 4 722; S2.6 | 5.1 3.7 533 T3.S average blowback early (73.2-2_3)% Example 3: The basic considerations for the production of filling and sealing sealed radio sources are that the radio sources can be anchored on the medium 'and have good airtightness. Although the chemical reaction mechanism of 68Ge adsorption on the SiO2 medium is not very clear, but because 68Ge is a tetravalent positive ion in an acidic aqueous solution, S i 〇2 is a transparent amorphous molecule with a layered structure of 0 si-0. 'Study this adsorption behavior may be the electrostatic attraction between the positively charged Ge4 + and the negatively charged oxygen atoms in the Si 02 crystal lattice. The experiment showed that when SSG e / Si was placed in pure water f for 30 minutes, the amount of e that was washed out was extremely small (S 5%). In the filling operation, firstly, put the purified 68Ge / Si02 material in a beaker ’and put it in a dessicator for 4-5 days.

Page 16 4 3 6 8 1/1 Case No. 89108488 Revised

4 3 ^ 6 8 1 4 ............ _ΜΜ—8915.8488 .........羌 ——4 and _ ................. 5. Description of the invention (] .2) _ Lead cover, with movable lifting ring on the periphery to facilitate sealing Source removal and handling. As for the filling and sealing of the esG e prosthesis source production (see Figure 3 for details), the operation method is the same as above. However, the sealing source has a low filling activity and the service life is short. Embodiment 4: Quality Control In order to calibrate the PET scanner activity detection system, the production of esGe sealed emission source must ensure its stability and safety. The related quality control is extremely important. The present invention has produced four G8Ge line radiation sources (filling activity of 1 2 2, 1 4 1, 1, 4 8 and 518 MBq) and three "(^ prosthetic radiation sources (filling activity of g. 1, ι2 5 and 2 5 7 MBq; acrylic instruments provided by the Physics Group of the Nuclear Research Institute), and according to the standard

The quasi-inspection method ANSI Standard N-542, 1977, Appendix AL eak T es ΐ M ethod performs the above-mentioned sealed radio source inspection test and related operations; the operation and experimental results are described as follows: (1) Surface wipe test (W ipe 〇rsmeartest): That is, the surface of the container filled with the shot source is wiped with a damp paper to measure the filter paper activity with an E ber I ine BC-4 counter. The experimental results show that the filter paper activity is the background value C2.0Bq) ', which is much smaller than the regulatory value i85Bq (5nCi), that is, the surface of the container for the sealed radioactive source is free of contamination. (2) Immersion test (丨 test): immerse the entity filled with the injection source for 30 minutes in boiling water or 4 hours in cold water, and take out a sample of the soaking solution in a multi-channel pulse high score analyzer. MCA) measure the activity of the test sample, and the display is also the background value, which is less than the legal value of 1 8 5 B q (5 n C i). (3) Vacuum bubble test (Vacuum bubble test). Place a proper amount of distilled water in it, first extract the air dissolved in water with a vacuum pump, return to the room pressure, and immerse the container filled with the injection source on the water surface.

Page M 4. 3 6 8 1 4 ... fjE 89108488 J a ............... ........................................ ....... V. Description of the invention (13) At least 5 cm, and then pump negative pressure to about 200 Torrs, and let it stand for 2 minutes. Observe that there is no air bubble at the inlet and outlet of the container. The tightness of the sealed source entity is extremely good. (4) Activity distribution uniformity test: a set of collimator designed and manufactured, that is, a Na a (Π) crystal detector is placed in a lead container with a thickness of 5 cni, the middle aperture is 5 in m, and the depth is 5. 5 c πι, coordinated with computer program to control automatic vertical scanning of the source entity fixed on the bracket, the detector is about 6-7 cm away from the source surface, the collimator displacement distance is 0.5 · 1-1 cm, the measurement time is 10 sec . In this test, the loading activity is 5 1 8 MBq (14 mC i) esGe line source and 2 5 7 M Bq (0.6 9 5 mC i) ti8Ge prosthesis source. The test results are shown in Figure 6 below. It shows that the average error of the relative activity distribution of the former is ± 1.5%, and the latter is ± 5. 8%, which is better than the allowable error range (S ± 15%) of the sealed radiation source made by commercial products by related methods. (5) Evaluation of dielectric radiation resistance: According to data reported by D, A. Weber et al. In The Society of Nuclear Medicine i! IMIRD: Radionucl ide Data and Decay Schemes in 1989, the source of S8Ge is The unit absorbed dose is about 1, 9 2 x 1 0G y · g / " C i, h. The weight of Si 02 used for the linear radiation source of the present invention is 0.6 9-0.7 7 g. 518MBq S8Ge is uniformly distributed in SiO; medium as an example, it is estimated that the sealed radiation source will be shaken for one year, and its total absorbed dose is about 3 X 1 04 G y. Since Si 02 is the main component of glass, it has high radiation resistance When the total dose of cobalt-6 0 reaches 105 Gy, it will still not cause deterioration and high stability. In addition, the background radiation value of the s8Ge sealed radiation source can be measured with a portable radiation detector For 5 1 8 and

Page 19 436814 \ f Ε 89108488 ^ ............... β .............. ....... § ................................ ........... H .................................._______ 5. Description of the invention ( 14) 1 48MBq B8Ge line source and three "Ge prosthetic sources (9.1, 1 2.5, 2 5, 7MBq) were measured, and the results are as shown in Table 3. It shows that the two line sources are not The radiation dose rates on the surface of the steel pipe are 35 and 10. 5 m S v / h, and there are still 9.1 and 0.2 5 mS v / h at a distance of 3 G centimeters. In a lead can with a wall thickness of 3.5 cm, the radiation dose rates at the top and the periphery are reduced to 0.4-0.0. 2 4 1 ^ " / 11 and 0.23 ~ 0.0 64 111 $ 7 / [1, showing this line of radiation The source depends on its loading activity and must be placed in a lead can of appropriate shielding thickness in order to meet the standards for safe transportation control of atomic energy regulations (S 2mSv / h). As for the 68Ge prosthesis, its loading activity is low (& 74MBq) Taking the loading amount of 25.7MBq as an example, although the maximum radiation dose rate on the surface is 2.1 mSv / h, the worker's radiation dose is at a distance of 5-30 cm. Can be reduced to 0.4 7-0. 0 3 mSv / h, so depending on the shape of the prosthesis and the filling activity, it can be placed in a special box (with built-in Polytron anti-vibration), and the label can be used to achieve safety. Purpose of transmission

Page 20 436814 f E 89108488 ... ...............years........ ......... § .................... ............... V. Description of the invention (15) Table III. Radiation dose rate of the germanium-68 sealed source entity A. 6SGe. Surface of the source stainless steel tube (mSv / h) Pot surface (mS v / li) | 5 Mutation (cm) 1 Loading activity ”MBq (mCi) Position loading activity, MBq (mCi) 518 (H) 148⑷ 518 (14) 148 (4) j 〇35 10.5 Top 0.4 0.02-1 1 ^! 3 13.5 3.0 '* Li ^^ 4 0.23 0.064 j 30 9.1 0.25 jj

B. 6SGe a body shot carcass 丨 1 ί: 1 loading activity i; _ shot dose transport (mSv / h) MBq (mCi) j 1 0cm! 5cm 丨 30cm 1 1 25.7 (0.695)! 0.084 2.10: 0.47 0.03; 2 ί 9.10 (0.246) ί 2'30; L15; 0.26! 0.016:! 3: 12.5 (0.337) 丨 3.975; 1.34! 0.30: 0.01S The above description is only for describing the embodiment of the present invention, and it is not the present invention. Any limitation, the researcher of the present invention can make various modifications and substitutions to the present invention without departing from the spirit of the present invention. The scope of the invention is defined by the additional patent application scope requirements. 'j „As can be seen from the above description, the present invention adopts a high adsorption capacity and anti-radiation

J | Inorganic adsorbent made of silicon dioxide as the adsorption medium to produce germanium-6 8 seal

Page 2i 436814 j 89108488; ^ J .............. a ... ............... ϋ ————............... ................................................................. (16) The source can provide positron emission The correction and application of the tomography activity detection system will improve the accuracy of the data acquired by the instrument in the clinic and the effect of clinical application judgment, and it will make a significant contribution to nuclear medicine diagnosis in China.

Page 22 436814 Case No. 89108488 a Modification Brief description of the drawing Figure 1 is a cross-sectional view of an embodiment of a germanium ~ 68 line source structure according to the present invention. Figure 2 is a schematic diagram of an example of the physical packaging of a lead can using a germanium-6 8-ray source. Figures 3 (1) ~ (3) are schematic diagrams of three packaging examples of the germanium-6 8 prosthesis source of the present invention. FIG. 4 is a flowchart of manufacturing a germanium-6 8 sealed shot source according to the present invention. Fig. 5 is a graph showing the analysis of the energy spectrum of Sigma before and after the adsorption and purification of germanium-6 8 according to the present invention. Figure 6 is a graph showing the uniformity of the activity distribution of the sealed germanium-6 8 source of the present invention.

Symbol description: A 10 11 12 13 14 15 B Cl, C2, C3 D W-6 8-line radio source Stainless steel tube Head end Bottom glass fiber Inner screw Outer screw cap Lead can Prosthesis source (acrylic container) Box

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Claims (1)

436814 No. 89108488 Amended on the month of day ---------------- Six, please patent patent park 1.-Can be used to calibrate nuclear medical diagnostic instruments-positron radiation tomography scanner activity detection System '(PETS ca η ner) Mistake-6 8 The production method of the sealed radiation source, the main production procedure is to prepare the prepared solution of more than one million baker's (milli Curie grade) germanium-6 8 primary product at a high concentration Nitric acid solution: Adsorbed in the inorganic / adsorption medium under the conditions, washed twice with the same concentration of nitric acid solution, and then dried, then filled in stainless steel pipes or acrylic containers, and sealed. I 2. The manufacturing method of the germanium-6 8 sealed radiation source as described in the first item of the patent application scope, wherein the inorganic adsorption medium for the germanium-6 8 adsorption is silicon dioxide, and the particle size thereof can be 50- 05-0. 0g。 4 0 0 mesh (mesh), the filling weight can be determined according to the container specifications of 0. 05-5. 0g. ^ 3. The method as described in item 1 of the scope of patent application, wherein the adsorption and cleaning conditions of the germanium-6 primary product solution on silica are prepared, and the concentration of nitric acid is 8-1 2 M. And the volume of the cleaning solution can be 10-4 Q in 1, and the supernatant is removed by shaking for 20-40 minutes and centrifugation. 4. The method as described in item 1 of the scope of patent application, wherein the drying process, including b'sGe / Si02 filling material, must be dried in the shade of the dryer for 3-6 days, and then under the infrared lamp (control temperature 3 0 -4 5 ° C) for 6-10 hours to dry out the acid j gas. The method as described in item 1 of the scope of patent application, wherein the inorganic adsorption medium for adsorbing germanium-j 68 is in addition to silicon dioxide, and can be adjusted to the appropriate acidity condition in the germanium-68 primary product 1 1 I solution, Use other non-radiation-resistant I-adsorbents such as Sn02, A 1, α-F e203, Zn'02, T i 02, etc. as the 1 germanium-6-8 adsorption medium ... Page 24 4 3 68 1/1 ......................... ... * E 89108488 ......................................... .......... ± ............. g .............. ......... ΘΘffiE -...................... ..................... 6. Apply for patent dry garden 6 Germanium-6 8-line source for clinical PET scanner detection system, with one end and end: metal with internal and external threads and closed bottom, filled with germanium-6 8 adsorbed on silicon dioxide medium in this tube, ί The glass fiber at the head end of the tube is tightly sealed with internal and external threads of the head end by tapping internal and external screws to double seal to prevent the leakage of radioactive materials. 7. If the germanium-6-8 line radiation source of the 6th item of the patent application, the metal does not record steel pipes, but according to actual needs, the inner diameter is 2-5 mm ^ length is 12 0min, germanium-68 activity Filling capacity can be 7 4-5 5 5 MBq (2-1 5mCi) 8 :. — a germanium-6 8 fake source used in animal clinical PET scanner detection system, the container used can be transparent acrylic , Polyethylene (PE), olefin (PP) and other plastic materials, and can be made according to the actual needs of different shapes, germanium-68 activity filling capacity can be 7.4-74MBq (0,2-2.〇raCi) container materials At the entrance and exit, tapping metal or plastic cymbal screws are used to lock and close the shot tube. The I plug cap lockout tube is 0 0 ~ 〇 body shot polypropylene shape, in: