EP1227845A2 - Mixture containing rare earths and use thereof - Google Patents
Mixture containing rare earths and use thereofInfo
- Publication number
- EP1227845A2 EP1227845A2 EP00984964A EP00984964A EP1227845A2 EP 1227845 A2 EP1227845 A2 EP 1227845A2 EP 00984964 A EP00984964 A EP 00984964A EP 00984964 A EP00984964 A EP 00984964A EP 1227845 A2 EP1227845 A2 EP 1227845A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- thulium
- radioactive materials
- radiation
- materials according
- matrix material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000203 mixture Substances 0.000 title claims abstract description 24
- ZIKATJAYWZUJPY-UHFFFAOYSA-N thulium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Tm+3].[Tm+3] ZIKATJAYWZUJPY-UHFFFAOYSA-N 0.000 claims abstract description 81
- 239000011159 matrix material Substances 0.000 claims abstract description 27
- 239000012857 radioactive material Substances 0.000 claims abstract description 25
- 230000005855 radiation Effects 0.000 claims description 46
- 229920003023 plastic Polymers 0.000 claims description 30
- 239000004033 plastic Substances 0.000 claims description 30
- 239000000463 material Substances 0.000 claims description 29
- -1 polyethylene Polymers 0.000 claims description 23
- 230000002285 radioactive effect Effects 0.000 claims description 17
- 229910052775 Thulium Inorganic materials 0.000 claims description 16
- 150000001875 compounds Chemical class 0.000 claims description 14
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 239000004698 Polyethylene Substances 0.000 claims description 12
- 229920000573 polyethylene Polymers 0.000 claims description 12
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- 239000002872 contrast media Substances 0.000 claims description 9
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 9
- FRNOGLGSGLTDKL-UHFFFAOYSA-N thulium atom Chemical compound [Tm] FRNOGLGSGLTDKL-UHFFFAOYSA-N 0.000 claims description 9
- 239000003814 drug Substances 0.000 claims description 8
- 210000003527 eukaryotic cell Anatomy 0.000 claims description 8
- 230000012010 growth Effects 0.000 claims description 8
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 2
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- 150000002910 rare earth metals Chemical class 0.000 description 3
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- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 2
- 241000233866 Fungi Species 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 229920002472 Starch Polymers 0.000 description 2
- 239000000427 antigen Substances 0.000 description 2
- 102000036639 antigens Human genes 0.000 description 2
- 108091007433 antigens Proteins 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- 230000003115 biocidal effect Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
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- 230000004614 tumor growth Effects 0.000 description 2
- DOBUSJIVSSJEDA-UHFFFAOYSA-L 1,3-dioxa-2$l^{6}-thia-4-mercuracyclobutane 2,2-dioxide Chemical compound [Hg+2].[O-]S([O-])(=O)=O DOBUSJIVSSJEDA-UHFFFAOYSA-L 0.000 description 1
- 229910000014 Bismuth subcarbonate Inorganic materials 0.000 description 1
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- 206010061216 Infarction Diseases 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- 206010057267 Periphlebitis Diseases 0.000 description 1
- 229920005372 Plexiglas® Polymers 0.000 description 1
- 206010057430 Retinal injury Diseases 0.000 description 1
- 208000016624 Retinal neoplasm Diseases 0.000 description 1
- 208000007536 Thrombosis Diseases 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 206010000269 abscess Diseases 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
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- 210000000941 bile Anatomy 0.000 description 1
- 210000003445 biliary tract Anatomy 0.000 description 1
- MGLUJXPJRXTKJM-UHFFFAOYSA-L bismuth subcarbonate Chemical compound O=[Bi]OC(=O)O[Bi]=O MGLUJXPJRXTKJM-UHFFFAOYSA-L 0.000 description 1
- 229940036358 bismuth subcarbonate Drugs 0.000 description 1
- 230000036770 blood supply Effects 0.000 description 1
- 239000002639 bone cement Substances 0.000 description 1
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- 210000004347 intestinal mucosa Anatomy 0.000 description 1
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- 210000004185 liver Anatomy 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 210000004324 lymphatic system Anatomy 0.000 description 1
- 230000002912 lymphogenic effect Effects 0.000 description 1
- 238000012961 medicinal therapy Methods 0.000 description 1
- 229910000370 mercury sulfate Inorganic materials 0.000 description 1
- 229910001092 metal group alloy Inorganic materials 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 210000004165 myocardium Anatomy 0.000 description 1
- 235000016709 nutrition Nutrition 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 210000000277 pancreatic duct Anatomy 0.000 description 1
- 208000001297 phlebitis Diseases 0.000 description 1
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- 230000035755 proliferation Effects 0.000 description 1
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K41/00—Medicinal preparations obtained by treating materials with wave energy or particle radiation ; Therapies using these preparations
- A61K41/009—Neutron capture therapy, e.g. using uranium or non-boron material
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P35/00—Antineoplastic agents
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P43/00—Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P9/00—Drugs for disorders of the cardiovascular system
- A61P9/08—Vasodilators for multiple indications
Definitions
- the invention relates to a mixture containing rare earths and their use.
- Radioactive medical devices which, for. B. in the form of stents for bile drainage for tumor-related stenoses.
- metals are used as the radiation source, which, for. B. in the form of a wire spiral directly into body cavities, such as the bile duct are inserted (EP 539 165), or are inside a stent / catheter (EP 801 961).
- the radioactive sources are usually encased to prevent mechanical damage (EP 778 051).
- the mechanical strength of the metallic radiation sources is low as soon as they exceed a certain thickness, so that, for. B. coils of thin wire must be used.
- the internal radiation sources also reduce the free volume of stents / catheters, so that they clog relatively easily.
- the solutions described are also relatively complex and expensive and therefore unsuitable for practical use.
- Patent EP 778 051 describes the processing of metallic thulium into a wire which, after radioactivation, is suitable as a radiation source.
- metallic thulium is an unstable compound that is decomposed by water and body fluids. The metallic thulium must therefore from a coat of z. B. titanium, which protects the core from mechanical and chemical influences.
- a complex process is required to produce the sheathed wire containing thulium. It involves making the core and sheath, pulling the double wire to the desired diameter, cutting to the desired length, and carefully fusing the ends together, in which the core must be completely covered by the sheath. It is also known to coat the stents with an antigen and to bind a radiolabeled antibody to the antigen
- microspheres which consist of radioactive material encased by several layers, as such or contained in a band or wire. To do this, however, it is necessary to produce these microspheres in a complex manner.
- the radioactivity of the neutron-treated material limits the growth of tumor cells or prevents the recurrence of scarred stenosis (inhibition of fibroblast growth).
- radioactivity bound to a suitable matrix material makes it possible to dose the radioactivity on site and to avoid collateral damage, especially when used in medicine.
- Thulium oxide is water-insoluble and well tolerated by the body. Particles of different sizes of this substance are easy to process and can be mixed with different matrix materials (including polyethylene, polyamide, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, silicone and PMMA (highly compressed plexiglass)).
- the matrix material serves to absorb the thulium oxide homogeneously and to enclose it permanently with a suitable external shape.
- the decay product 170 Yb is also a stable isotope, so that no further core decay occurs.
- 170 Tm decays mainly with the emission of P radiation, which is suitable for numerous applications due to its range.
- the low proportion (approximately 2.5% of the total activity) of ⁇ radiation is due to the low intensity of the ⁇ radiation with regard to the danger to healthy tissue which surrounds it and which surrounds the tumor to be irradiated or the target area to be irradiated neglect radiation medical view.
- Another advantage is that the manufactured components and end products can be radioactivated and reused in the same way after the radioactivity has decayed (for example after the storage time has been exceeded). Likewise, recycling of the materials used is possible in order to produce other or the same products after grinding and re-extrusion as well as radioactivation.
- Radioactivation by means of neutron treatment puts the core of Thul ⁇ um-169 in an unstable state and the newly formed isotope Thul ⁇ um-170 decays from this unstable state with a half-life of approx. 4 months (128.6 days) with radiation and radiation. Due to the large core diameter, thulium is particularly suitable for taking up additional neutrons.
- the first ß-fraction (rel. Intensity about 81.6%) has an energy of 986 keV (average energy 323.1 keV)
- the second fraction (rel. Intensity of about 18.3%) has an energy of 883 keV
- the P rays emitted have a range of a few millimeters in the tissue.
- a relatively soft Y radiation (braking radiation, 84 keV) is emitted, which is similar in properties to the X-radiation.
- This " ⁇ radiation has a greater range in the tissue.
- the percentage of thulium oxide added to the matrix material is 0.1 to 25%. If more than 25% of the rare earths were added, the material costs would increase on the one hand and the mechanical properties of the matrix material would change, for example due to increased fracture. If the proportion was less than 0.1%, the necessary irradiation times in the neutron flux would be prolonged too much. If the radiation tents are too long, the radiation becomes too expensive and mechanical damage to the matrix material could occur.
- a thulium content of 4 to 6% by weight based on the matrix material is favorable for these reasons.
- a wide variety of materials are suitable as matrix material, such as.
- plastics such as polyethylene, polyamide, polypropylene, polytetrafluoroethylene, Polyvmylidenfluo ⁇ d, PMMA or silicone, also with reinforcement by fiber materials, glass, polymers, ceramics, metals and their alloys, Teflon, glass fibers, carbon fibers, tooth and bone cement, silicone compounds and organic and bioorganic compounds.
- the matrix material that it can be mixed with the inert compound of the rare earth (as a stable or unstable isotope), while maintaining the required mechanical properties and having the necessary chemical stability, in particular with respect to body fluids.
- heart valves can be made from thulium oxide mixed with carbon fiber-containing plastics, or stents and catheters made from thulium oxide with polyethylene.
- Polyethylene has proven to be advantageous for use in endoprostheses in the area of the biliary tract and pancreatic duct due to its flexibility, durability, resistance to body fluids, inexpensive costs and simple processing options.
- X-ray contrast agents can be added to the neutron-activated radioactive materials in order to be able to determine or correct the position of the endoprostheses produced therefrom by means of X-ray fluoroscopy.
- a contrast medium z.
- Teflon fluorinated matrix
- no additional contrast agent is required for visualization on the MRI.
- a contrast agent content of, for example, is advantageous for good contrast in the X-ray examination.
- B. more than 10 wt .-% based on the matrix material.
- a content of more than 40% leads to an excessive change in the mechanical properties, e.g. B.
- the radioactivatable material consisting of matrix and thulium oxide (and possibly a contrast agent), or end products made from it, can be combined with other radioactivatable, radioactive or non-radioactive materials or components before or after activation.
- the material can be applied to an inert carrier, for example plastics or metals or metal grids.
- the level of radioactivity emitted later can not only be regulated and calculated in advance by the content of thulium oxide, but is also possible by changing the duration and intensity of the neutron radiation.
- the radioactivated material or the radioactivated endoprostheses have a good body contract and serve as a therapeutic agent in humans and animals.
- the P and Y radiation emanating from the end product by radioactivation can in principle limit cell growth, e.g. B. inhibit tumor cells, fibroblasts and bacteria.
- the aim is to first inhibit the cell growth of eukaryotic cells and u. U. to kill resting eukaryotic cells.
- prokaryotic cells such as bacteria and fungi or to prevent further growth
- significantly higher doses than with eukaryotic cells are required. This is for individual applications in the human body, e.g. B. to prevent colonization of the implant surface with prokaryotic organisms, also in combination with other methods such.
- B. a silver coating or antibiotic therapy is important.
- the exponential drop in the applied dose with increasing distance from the stent has an effect on prokaryotic cells, in particular on the implant surface.
- Stents in the form of tubes serve as endoprostheses to keep tubular hollow organs, such as bile ducts or the airways, open.
- Exemplary embodiments
- Polyethylene the formulation of which is approved for the production of bile duct and pancreatic endoprostheses, 5% thulium oxide (Tm 2 0 3 ) in powder form (commercially available or finely ground in a ball mill) and 20% BaS0 4 as a contrast agent.
- Tm 2 0 3 5% thulium oxide
- BaS0 4 20% BaS0 4 as a contrast agent.
- a tube with an inside diameter of 2.5 mm and a wall thickness of 0.25 to 0.5 mm is produced from the melted plastic according to Example 1 by an injection molding machine (extruder). This tube is then processed into an endoprosthesis in the usual dimensions by cutting it to a length of 5 to 10 cm. At both ends of these pieces, parts of a plastic tube with the same diameters are welded on, which was produced without the addition of thulium oxide.
- the end facing the duodenum is free of thulium oxide in a length of 4 cm in order to avoid damage to the intestinal mucosa and other tissues.
- the end facing the liver is also kept free of thulium oxide over a length of 2 cm.
- a chip is lifted at both ends of the blank, which acts like a barb and enables the stent to be anchored in the bile duct.
- the stents are sealed in plastic bags and sterilized with ethylene oxide. They are then activated in a nuclear reactor by irradiation with neutrons. The exit check carried out afterwards measures the spectrum of the emitted radiation and its intensity.
- the neutron-activatable material consisting of matrix and the inert compound of rare earths
- various radioactive or radioactivatable substances with different half-lives, radiation types and energies can be used.
- the combination with other inert compounds of the rare earths with a short half-life would make sense in order to be able to set a high initial dose.
- the neutron-activated, radioactive materials can be used as therapeutic agents in humans and animals. They are suitable as medical devices such as implants, e.g. B. for surgical disciplines, endoprostheses, catheters, stents, for targeted embolization of malignant masses, for external use on the skin, as components of artificial heart valves or as seals in the field of ophthalmology.
- implants e.g. B. for surgical disciplines, endoprostheses, catheters, stents, for targeted embolization of malignant masses, for external use on the skin, as components of artificial heart valves or as seals in the field of ophthalmology.
- Stents or catheters made of radioactive materials are suitable for use in the arterial, venous, pe ⁇ toneal, peridual, cerebral (ventricular drainage) area.
- the material can be applied to an inert carrier, such as. B. on plastics, metals or metal grids.
- the level of radioactivity emitted later can not only be regulated and calculated in advance by the content of the inert compound of the rare earth, but this can also be done by changing the duration and intensity of the neutron radiation.
- the radioactivity achieved - in the area relevant for technical and medical applications - increases proportionally to the irradiation time.
- Radioactivity For the medical and technical application, several activity areas are of interest to which the radioactivity is to be adjusted.
- One goal is to dose the radioactivity so that the growth of eukaryotic cells is prevented.
- the exponential drop in the dose applied has an effect on prokaryotic cells, in particular on the implant surface, and the effect to eukaryotic cells that are not directly in contact.
- neutron irradiation up to a radioactivity of 20,000 PC / cm 2 material surface is useful.
- This effect is particularly useful for components that cannot be exchanged at short notice, but still have to meet aseptic criteria, e.g. B. because they come into contact with organic materials.
- aseptic criteria e.g. B. because they come into contact with organic materials.
- Examples of applications are filter systems, hose systems, collecting containers, etc.
- the materials are suitable for targeted embolization via an arterial access to a tumor or a metastasis, in order to get caught in the capillary area and thus achieve a local growth inhibition.
- the advantage here is that, compared to embolization with non-radioactive substances (eg starch particles), the effect also affects cells that are located in the marginal area of the tumor and other vessels, in addition to the mechanical and nutritional effects of a disturbed blood supply be supplied with. Due to the relatively long half-life of around 4 months for thulium oxide, resting tumor cells, which are significantly less radiation-sensitive than proliferating cells, can also be achieved.
- the use of targeted radio embolization is not only limited to arterial flow areas, but is also possible, for example, on the lymphatic system.
- lymphogenic metastases from a malignant melanoma on one extremity can be treated by injecting radioactive, thulium oxide-containing polyethylene beads.
- the advantage here is that the radioactivity spreads according to the metastasis path and can therefore be applied precisely. As a result, the required radiation doses are considerably lower than with external radiation.
- 5% finely ground thulium oxide is added to the body-compatible polyethylene.
- the thulium oxide enables later radioactivation.
- Upon melting (heating to about 200 C C) remain the finely ground particles are suspended in the mixture and, after cooling of the polymer homogeneously distributed in the mass and firmly enclosed by the plastic.
- the material can also be ground with previous cooling.
- the desired particle size is selected by filtration or sieving processes.
- the particles are then radioactivated by neutron bombardment in a nuclear reactor.
- a hose with z. B an inner diameter of 2.5 mm and a wall thickness of 0.25 mm.
- This The tube is then processed into a double J catheter in the usual dimensions by cutting it to a length of 5 - 10 cm.
- parts of a plastic tube with the same diameter are added, which was produced without the addition of thulium oxide.
- Both ends are brought into a J-shape (e.g. by bending under heat treatment) to hold the catheter in the correct position later.
- the part of the catheter that comes into direct contact with the scarred stenosis or tumor stenosis to be treated is radioactivated. Radioactivity prevents a recurrence of the scarred stenosis (inhibition of fibroblast growth) or limits the growth of tumor cells.
- the stents are melted down in plastic bags and sterilized with ethylene oxide.
- the advantage also lies in the reduction in the number of germs on the surface of the catheter.
- B. fiber-reinforced plastics z. B. carbon fibers
- z. B. carbon fibers a material that are approved for use in heart valves
- the finely ground particles remain suspended in the mixture, homogeneously distributed and can be brought into the desired shape after adding the fiber portion.
- the thulium oxide is homogeneously distributed in the mass and is firmly enclosed by the matrix.
- the workpiece is then radioactivated by neutron bombardment in a nuclear reactor.
- a radioactive heart valve sail With such a radioactive heart valve sail it can be avoided that bacteria get stuck and cause the formation of a septic thrombus. Due to the strong movements of the valve leaflets, thrombi located there tend to migrate to other areas, for example the brain, as emboli, and cause infarctions there. A high surface dose can be achieved through the P radiation of the radioactive material. that prevent germ colonization.
- a mechanical valve flap has no direct contact with the heart muscle tissue, so that due to the short range z. B. at 170 Tm the damage to the heart muscle cells is negligible.
- Such a heart valve sail can be combined with non-radioactive components to form a heart valve.
- Surgical implants such as screws, plates, joints and joint parts, which either consist of plastic with or without fiber reinforcement or of metal alloys or combinations of both materials, are finely ground thulium oxide z.
- B. added with a weight fraction of 0.5 - 10%.
- Combinations of the two materials are e.g. B. in the form of a metal core with surrounding thulium oxide-containing plastic jacket possible.
- plastics are suitable for this.
- B. in particular duroelastic materials and those that have high impact and breaking strength.
- e.g. B. Polyethylene HD compounds and polyarylamide compounds When melting, the finely ground compounds remain suspended and homogeneously distributed in the mixture and are z.
- Radioactive materials there are a variety of possible uses of the radioactive materials in the human eye, since operations due to the spatial proximity of highly differentiated areas such. B. in tumor operations such as reto- and melanoblastomas are often associated with a loss of organ function or impaired vision.
- inflammatory or proliferative processes on the retina and choroid e.g. periphlebitis retinae, Panarterntis nodosa, thrombangitis obliterans, diabetic retopathy
- conventional medicinal therapies and invasive retinabe Treating actions such as cryo- or laser coagulation, which only cause selective scarring, across the board.
- radioactive, thulium oxide-containing (e.g. with a thulium oxide content of 0.1 - 10%) plastic seals e.g. B. polyethylene, transparent silicone polymers or thermoelastic plastics to sew on to the outside of the eye or to be attached inside the retina to stop proliferative processes that can lead to further retinal damage.
- plastic seals e.g. B. polyethylene, transparent silicone polymers or thermoelastic plastics to sew on to the outside of the eye or to be attached inside the retina to stop proliferative processes that can lead to further retinal damage.
- retinal tumors such as retinal oblastomas, which due to their size are too large to avoid surgery to preserve the visual acuity, can be treated preoperatively, postoperatively or as a sole measure.
- the radioactivity can in particular also be used to reach individual mfiltratively growing tumor cells that would otherwise have been removed from treatment.
- Thulium oxide in particular, appears to be particularly suitable here due to the range of its beta radiation of a few millimeters, the half-life that allows longer application to kill even resting cells, and the low proportion of Y radiation, which can cause lens clouding superior to conventional types of radiation.
- the finely ground thulium oxide compound remains suspended and homogeneously distributed in the plastic mixture.
- the mixture is in z. B. brought into the desired shape using injection molding technology and the workpiece subsequently radioactivated by neutron bombardment in a nuclear reactor.
- the radioactive materials are suitable for use in tumors that cannot be used in a surgical procedure due to their position, extent, infiltration or the general condition of the patient.
- tumors of the skin such as basaliomas, melanomas or spinaliomas, but also of the soft parts can be mentioned.
- a radioactive thulium oxide-containing plant pre-operatively, post-operatively or as sole therapy. stucco z.
- Components of technical devices from the medical field which are regularly or potentially contaminated with prokaryiotic organisms and cells, but which are to be kept sterile or low in germs and cannot be subjected to short-term, regular germ reduction, such as.
- Collecting containers, hose systems, filter systems, housings for electronic components, etc. can be made from the variety of the above-mentioned matrix materials such as.
- B. Thulium oxide is added.
- Workpieces made from organic and bio-organic compounds such as cellulose, organic gels, starch, etc.
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Abstract
Description
Seltene Erden enthaltene Mischung und deren VerwendungMixture containing rare earths and their use
Die Erfindung betrifft eine Seltene Erden enthaltene Mischung und deren Verwendung.The invention relates to a mixture containing rare earths and their use.
Es sind radioaktive Medizinprodukte bekannt, die z. B. in Form von Stents zur Gallensaftdrainage bei tumorbedingten Stenosen eingesetzt werden. Bei den bisher bekannten Produkten werden Metalle als Strahlenquelle benutzt, die z. B. in Form einer Drahtspirale direkt in Körperhöhlen, wie den Gallengang eingeführt werden (EP 539 165) , oder sich im Inneren eines Stents/Katheters befinden (EP 801 961) . Zur Verhinderung mechanischer Beschädigungen werden die radioaktiven Quellen gewöhnlich ummantelt (EP 778 051). Dabei ist die mechanische Belastbarkeit der metallischen Strahlenquellen gering sobald sie eine bestimmte Dicke überschreiten, so daß z. B. Spulen aus dünnem Draht verwendet werden müssen. Auch verringern die im Inneren liegenden Strahlenquellen das freie Volumen von Stents/Kathetern, so daß diese relativ leicht verstopfen. Die beschriebenen Lösungen sind zudem relativ aufwendig und teurer und deshalb für die Praxis wenig geeignet .Radioactive medical devices are known which, for. B. in the form of stents for bile drainage for tumor-related stenoses. In the previously known products, metals are used as the radiation source, which, for. B. in the form of a wire spiral directly into body cavities, such as the bile duct are inserted (EP 539 165), or are inside a stent / catheter (EP 801 961). The radioactive sources are usually encased to prevent mechanical damage (EP 778 051). The mechanical strength of the metallic radiation sources is low as soon as they exceed a certain thickness, so that, for. B. coils of thin wire must be used. The internal radiation sources also reduce the free volume of stents / catheters, so that they clog relatively easily. The solutions described are also relatively complex and expensive and therefore unsuitable for practical use.
Patent EP 778 051 beschreibt die Verarbeitung von metallischem Thulium zu einem Draht, der nach Radioaktivierung als Strahlenquelle geeignet ist. Metallisches Thulium ist jedoch eine instabile Verbindung, die durch Wasser und Körperflüssigkeiten zersetzt wird. Das metallische Thulium muß deshalb von einem Mantel aus z. B. Titan umgeben werden, der den Kern vor mechanischen und chemischen Einflüssen schützt. Für die Herstellung des Thulium-haltigen ummantelten Drahtes ist ein aufwendiges Verfahren notwendig. Es umfaßt das Herstellen von Kern und Hülle, das Ziehen des doppelten Drahtes auf den gewünschten Durchmesser, das Schneiden auf die gewünschte Länge und das sorgfältige Verschmelzen der Enden, bei dem der Kern vollständig vom Mantel umhüllt werden muß. Zudem ist bekannt, die Stents mit einem Antigen zu beschichten und einen radiomarkierten Antikörper an das Antigen zu bindenPatent EP 778 051 describes the processing of metallic thulium into a wire which, after radioactivation, is suitable as a radiation source. However, metallic thulium is an unstable compound that is decomposed by water and body fluids. The metallic thulium must therefore from a coat of z. B. titanium, which protects the core from mechanical and chemical influences. A complex process is required to produce the sheathed wire containing thulium. It involves making the core and sheath, pulling the double wire to the desired diameter, cutting to the desired length, and carefully fusing the ends together, in which the core must be completely covered by the sheath. It is also known to coat the stents with an antigen and to bind a radiolabeled antibody to the antigen
(WO 98/43694). Ihre Herstellung ist jedoch aufwendig und teurer, weshalb sie keinen Eingang in die Routine der Klinik gefunden haben.(WO 98/43694). However, their production is complex and expensive, which is why they have not found their way into the routine of the clinic.
In WO 92/03170 wird vorgeschlagen, Mikrokugeln, die aus radioaktivem Material umhüllt von mehreren Schichten bestehen, als solche oder in einem Band oder Draht enthalten einzusetzen. Hierzu ist es edoch erforderlich, diese Mikrokugeln aufwendig herzustellen.In WO 92/03170 it is proposed to use microspheres, which consist of radioactive material encased by several layers, as such or contained in a band or wire. To do this, however, it is necessary to produce these microspheres in a complex manner.
Der in den Patentansprüchen angegebenen Erfindung liegt das Problem zugrunde, einfach herstellbare und gut handhabbare neutro- nenaktivierbare oder neutronenaktivierte, radioaktive Materialien zu finden, die für die verschiedensten Anwendungen einsetzbar und entsprechend anpassbar sind.The problem of the invention specified in the patent claims is to find radioactive materials which are easy to manufacture and easy to handle and which can be used for a wide variety of applications and are correspondingly adaptable.
Dieses Problem wird durch die in den Patentansprüchen angegebenen Merkmale durch neue mittels Neutronen radioaktivierbare Materialien gelost, die mindestens eine Verbindung der Seltenen Erden und/oder Thuliumoxid homogen und fein verteilt in einem Matrixmaterial enthalten.This problem is solved by the features specified in the patent claims by means of new materials which can be radioactivated by means of neutrons and which contain at least one rare earth compound and / or thulium oxide homogeneously and finely distributed in a matrix material.
Durch die Radioaktivität des mit Neutronen behandelten Materials wird das Wachstum von Tumorzellen begrenzt bzw. ein Rezidiv von narbigen Stenose (Hemmung von Fibroblastenwachstum) verhindert.The radioactivity of the neutron-treated material limits the growth of tumor cells or prevents the recurrence of scarred stenosis (inhibition of fibroblast growth).
Der Einsatz von Radioaktivität gebunden an ein geeignetes Matrixmaterial ermöglicht es, die Radioaktivität vor Ort zu dosieren und speziell bei ihrer Anwendung in der Medizin Kollateral- schaden zu vermeiden.The use of radioactivity bound to a suitable matrix material makes it possible to dose the radioactivity on site and to avoid collateral damage, especially when used in medicine.
Die Verwendung einer inerten Verbindung der Seltenen Erden oder des inerten Thuliumoxids gewährleistet, daß es bei Kontakt mit Korperflussigkeiten oder -geweben zu keinen unerwünschten Reaktionen kommt, die eine Veränderung des Materials oder eine ehe- mische Schädigung des Korpers hervorrufen. Thuliumoxid ist wasserunlöslich und gut korpervertraglich. Partikel unterschiedlicher Große dieser Substanz sind einfach zu verarbeiten und mit unterschiedlichen Matrixmaterialien (u. a. Polyethylen, Polyamid, Polypropylen, Polytetrafluorethylen, Polyvinylidenfluo- rid, Silikon und PMMA (hochverdichtetes Plexiglas)) mischbar. Das Matrixmaterial dient dazu, das Thuliumoxid homogen aufzunehmen und bei geeigneter äußerer Formgebung dauerhaft zu umschließen.The use of an inert compound of the rare earths or of the inert thulium oxide ensures that there are no undesirable reactions in contact with body fluids or tissues, which would result in a change in the material or a marriage. cause mixed damage to the body. Thulium oxide is water-insoluble and well tolerated by the body. Particles of different sizes of this substance are easy to process and can be mixed with different matrix materials (including polyethylene, polyamide, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, silicone and PMMA (highly compressed plexiglass)). The matrix material serves to absorb the thulium oxide homogeneously and to enclose it permanently with a suitable external shape.
Bei der Verwendung von Thulium ist von Vorteil, daß es in der Natur nur m Form eines stabilen Isotops vorkommt und damit durch die Radioaktivierung nicht eine unübersichtliche Zahl von radioaktiven Isotopen entsteht. Ferner handelt es sich bei dem Zerfallsprodukt 170Yb ebenfalls um ein stabiles Isotop, so daß kein weiterer Kernzerfall auftritt. Weiterhin zerfallt 170Tm überwiegend unter Abgabe einer P-Strahlung, die aufgrund ihrer Reichweite für zahlreiche Anwendungen geeignet ist. Der geringe Anteil (ca. 2,5 % der Gesamtaktivitat ) von ^-Strahlung ist hinsichtlich der von ihr ausgehenden Gefahr für gesundes Gewebe, das den zu bestrahlenden Tumor bzw. das zu bestrahlende Zielgebiet umgibt, wegen der geringen Intensität der ^-Strahlung aus strahlenmedizimscher Sicht zu vernachlässigen.When using thulium, it is advantageous that it only occurs in nature in the form of a stable isotope and that radioactive activation does not result in an unclear number of radioactive isotopes. Furthermore, the decay product 170 Yb is also a stable isotope, so that no further core decay occurs. Furthermore, 170 Tm decays mainly with the emission of P radiation, which is suitable for numerous applications due to its range. The low proportion (approximately 2.5% of the total activity) of ^ radiation is due to the low intensity of the ^ radiation with regard to the danger to healthy tissue which surrounds it and which surrounds the tumor to be irradiated or the target area to be irradiated neglect radiation medical view.
Von Vorteil ist weiterhin, daß die hergestellten Bauteile und Endprodukte nach Abklingen der Radioaktivität (z. B. nach Überschreiten der Lagerzeit) erneut auf die selbe Art und Weise radioaktiviert und wieder verwendet werden können. Desgleichen ist ein Recycling der verwendeten Materialien möglich, um damit andere oder gleiche Produkte nach Vermählen und Neuextrusion sowie Radioaktivierung herzustellen.Another advantage is that the manufactured components and end products can be radioactivated and reused in the same way after the radioactivity has decayed (for example after the storage time has been exceeded). Likewise, recycling of the materials used is possible in order to produce other or the same products after grinding and re-extrusion as well as radioactivation.
Durch die Radioaktivierung mittels Neutronenbehandlung w rd der Kern des Thulιum-169 in einen instabilen Zustand versetzt und das neu entstandene Isotop Thulιum-170 zerfallt aus diesem instabilen Zustand mit einer Halbwertszeit von ca. 4 Monaten (128,6 Tagen) unter Abgabe von -Strahlung und ^-Strahlung. Aufgrund des hohen Kerndurchmessers eignet sich Thulium besonders, zusatzliche Neutronen aufzunehmen. Die erste ß-Fraktion (rel. Intensität etwa 81,6 %) hat eine Energie von maximal 986 keV (durchschnittliche Energie 323,1 keV) , die zweite Fraktion (rel. Intensität von etwa 18,3 %) eine Energie von maximal 883 keVRadioactivation by means of neutron treatment puts the core of Thulιum-169 in an unstable state and the newly formed isotope Thulιum-170 decays from this unstable state with a half-life of approx. 4 months (128.6 days) with radiation and radiation. Due to the large core diameter, thulium is particularly suitable for taking up additional neutrons. The first ß-fraction (rel. Intensity about 81.6%) has an energy of 986 keV (average energy 323.1 keV), the second fraction (rel. Intensity of about 18.3%) has an energy of 883 keV
(durchschnittliche Energie von 290,5 keV) . Die ausgesandten P- Strahlen haben im Gewebe eine Reichweite von wenigen Millimetern.(average energy of 290.5 keV). The P rays emitted have a range of a few millimeters in the tissue.
Zusätzlich zu der P-Strahlung wird eine relativ weiche Y-Strah- lung (Bremsstrahlung, 84 keV) emittiert, die in ihren Eigenschaften der Röntgenstrahlung ähnelt. Diese "^-Strahlung hat im Gewebe eine größere Reichweite.In addition to the P radiation, a relatively soft Y radiation (braking radiation, 84 keV) is emitted, which is similar in properties to the X-radiation. This " ^ radiation has a greater range in the tissue.
Der Anteil des Thuliumoxids, der dem Matrixmaterial zugesetzt wird, hat einen Prozentsatz von 0,1 bis 25 %. Bei Zusatz von mehr als 25 % der seltenen Erden wurden zum einen die Materialkosten steigen und zum anderen die mechanischen Eigenschaften des Matrixmaterials sich zum Beispiel durch erhöhte Bruchigkeit verandern. Bei einem niedrigeren Anteil als 0,1 % wurden sich die notwendigen Bestrahlungszeiten im Neutronenfluß zu stark verlangern. Durch zu lange Bestrahlungszelten wird aber die Bestrahlung zu teuer und es konnten mechanische Schaden des Matrixmaterials auftreten.The percentage of thulium oxide added to the matrix material is 0.1 to 25%. If more than 25% of the rare earths were added, the material costs would increase on the one hand and the mechanical properties of the matrix material would change, for example due to increased fracture. If the proportion was less than 0.1%, the necessary irradiation times in the neutron flux would be prolonged too much. If the radiation tents are too long, the radiation becomes too expensive and mechanical damage to the matrix material could occur.
Ein Thuliumanteil von 4 bis 6 Gew.-% bezogen auf das Matrixmaterial ist aus diesen Gründen gunstig.A thulium content of 4 to 6% by weight based on the matrix material is favorable for these reasons.
Als Matrixmaterial eigenen sich die unterschiedlichsten Materialien, wie z. B. Kunststoffe wie Polyethylen, Polyamid, Polypropylen, Polytetrafluorethylen, Polyvmylidenfluoπd, PMMA oder Silikon, auch mit Verstärkung durch Faserwerkstoffe, Glas, Polymere, Keramik, Metalle und ihre Legierungen, Teflon, Glasfasern, Kohlefasern, Zahn- und Knochenzement, Silikonverbmdungen sowie organische und bioorganische Verbindungen. Voraussetzung für das Matrixmaterial ist nur, daß es sich mit der inerten Verbindung der Seltenen Erde (als stabiles oder instabiles Isotop) mischen laßt, dabei die geforderten mechanischen Eigenschaften behalt und die notige chemische Stabilität insbesondere gegenüber Korperflussigkeiten aufweist. Durch die Vielzahl der möglichen Matrixmaterialien ist es in den meisten Fallen möglich, auf die bereits für die jeweilige Anwendung, insbesondere medizinische, verwendeten und in ihren Eigenschaften bekannten Materialien zurückzugreifen und diese nur mit einer geeigneten Menge der inerten Verbindung von Seltenen Erden zu vermischen und anschließend zu radioaktivieren. Zum Beispiel können aus Thuliumoxid mit kohlefaserhaltigen Kunststoffen gemischt Herzklappen hergestellt werden oder Stents und Katheter aus Thuliumoxid m t Polyethylen.A wide variety of materials are suitable as matrix material, such as. B. plastics such as polyethylene, polyamide, polypropylene, polytetrafluoroethylene, Polyvmylidenfluoπd, PMMA or silicone, also with reinforcement by fiber materials, glass, polymers, ceramics, metals and their alloys, Teflon, glass fibers, carbon fibers, tooth and bone cement, silicone compounds and organic and bioorganic compounds. requirement it is only for the matrix material that it can be mixed with the inert compound of the rare earth (as a stable or unstable isotope), while maintaining the required mechanical properties and having the necessary chemical stability, in particular with respect to body fluids. Due to the large number of possible matrix materials, it is possible in most cases to fall back on the materials already used for the respective application, in particular medical, and known in their properties, and to mix them only with a suitable amount of the inert compound of rare earths and then to radioactivate. For example, heart valves can be made from thulium oxide mixed with carbon fiber-containing plastics, or stents and catheters made from thulium oxide with polyethylene.
Für die Anwendung bei Endoprothesen im Bereich der Gallenwege und des Pankreasgangs hat sich Polyethylen aufgrund seiner Flexibilität, Haltbarkeit, Resistenz gegenüber Korperflussigkeiten, gunstigen Kosten, und einfachen Verarbeitungsmoglichkeiten als vorteilhaft erwiesen.Polyethylene has proven to be advantageous for use in endoprostheses in the area of the biliary tract and pancreatic duct due to its flexibility, durability, resistance to body fluids, inexpensive costs and simple processing options.
Den neutronenaktivierbaren radioaktiven Materialien können Ront- genkontrastmittel zugesetzt werden, um die Lage daraus hergestellter Endoprothesen mittels Rontgendurchleuchtung bestimmen bzw. korrigieren zu können. Als Kontrastmittel eignen sich z. B. Bariumsulfat , Quecksilbersulfld oder Bismutsubcarbonat . Bei Verwendung von Teflon (fluorierte Matrix) ist zur Sichtbarmachung im MRT kein zusätzliches Kontrastmittel erforderlich. Vorteilhaft für eine gute Kontrastgebung in der Rontgendurchleuchtung ist ein Kontrastmittelgehalt von z. B. mehr als 10 Gew.-% bezogen auf das Matrixmaterial. Ein Gehalt von mehr als 40 % fuhrt zu einer zu starken Veränderung der mechanischen Eigenschaften, z. B. im Hinblick auf Sprodigkeit und Flexibilität, so daß der Kontrastmittelanteil am Endprodukt bei 10 bis 40 % liegen sollte . Das radioaktivierbare Material, bestehend aus Matrix und Thuliumoxid (und ggf. Konstrastmittel), oder daraus hergestellte Endprodukte können vor oder nach der Aktivierung mit weiteren ra- dioaktivierbaren, radioaktiven oder nicht radioaktiven Materialien oder Bauteilen kombiniert werden.X-ray contrast agents can be added to the neutron-activated radioactive materials in order to be able to determine or correct the position of the endoprostheses produced therefrom by means of X-ray fluoroscopy. As a contrast medium z. B. barium sulfate, mercury sulfate or bismuth subcarbonate. When using Teflon (fluorinated matrix), no additional contrast agent is required for visualization on the MRI. A contrast agent content of, for example, is advantageous for good contrast in the X-ray examination. B. more than 10 wt .-% based on the matrix material. A content of more than 40% leads to an excessive change in the mechanical properties, e.g. B. in terms of brittleness and flexibility, so that the contrast agent portion of the end product should be 10 to 40%. The radioactivatable material, consisting of matrix and thulium oxide (and possibly a contrast agent), or end products made from it, can be combined with other radioactivatable, radioactive or non-radioactive materials or components before or after activation.
Je nach beabsichtigtem Effekt können dafür verschiedene Substanzen mit unterschiedlicher Halbwertszeit, Strahlungsart und - energie kombiniert werden. Beispielsweise wäre d e Kombination mit weiteren seltenen Erden mit geringer Halbwertszeit sinnvoll, um eine hohe Initialdosis setzen zu können. Weiterhin ist es möglich, durch verschiedene Verfahren Radioaktivität in den Werkstoff einzubringen, z. B. durch zusätzliche Implantation von 32P in die Oberflache.Depending on the intended effect, different substances with different half-life, radiation type and energy can be combined. For example, the combination with other rare earths with a short half-life would make sense in order to be able to set a high initial dose. It is also possible to introduce radioactivity into the material by various methods, e.g. B. by additional implantation of 32 P in the surface.
Je nach Problemstellung kann es gunstig sein, nur den Teil des Katheters radioaktiv zu halten, der in direktem Kontakt zu der zu behandelnden narbigen Stenose oder Tumorstenose kommt.Depending on the problem, it may be beneficial to keep radioactive only the part of the catheter that comes in direct contact with the scarred stenosis or tumor stenosis to be treated.
Zur Versteifung der Stents oder zum Erreichen bestimmter mechanischer Eigenschaften kann dabei das Material auf einen inerten Trager aufgebracht werden, beispielsweise Kunststoffe oder Metalle bzw. Metallgitter .In order to stiffen the stents or to achieve certain mechanical properties, the material can be applied to an inert carrier, for example plastics or metals or metal grids.
Es ist vorteilhaft, die Aktivierung der Stents durch Neutronen nach medizinisch zugelassener Sterilisation und steriler Verpackung vorzunehmen, weil dadurch weitere Handhabungs- und Produktionschritte mit radioaktiven Materialien vermieden werden können. Die vorhandene bei der Neutronenbestrahlung im Reaktor erzielt ebenfalls eine sterilisierende Wirkung.It is advantageous to carry out the activation of the stents by neutrons after medically approved sterilization and sterile packaging, because in this way further handling and production steps with radioactive materials can be avoided. The existing one neutron radiation in the reactor also has a sterilizing effect.
Die Hohe der spater emittierten Radioaktivität kann nicht nur durch den Gehalt an Thuliumoxid reguliert und voraus berechnet werden, sondern ist auch durch Veränderung von Dauer und Intensität der Neutronenstrahlung möglich. So steigt die erzielte Radioaktivität im für technische und medizinische Anwendungen re- levanten Bereich proportional zur Bestrahlungszelt an. Dies geht auch am Beispiel Thuliumoxid aus der folgenden Naherungsformel zur Berechnung der resultierenden Radioaktivität pro cm Probenlange hervor: A = n σ Φ ln2 t/Tι/ (n = Anzahl der Tm-Atome/cm; σ = 105 barn = 105 x 10"24 cm2; Tl/2 = Halbwertszeit = 128,6 d; Φ = 1,85 x 1012 N / cm3; t = Bestrahlungszelt ) .The level of radioactivity emitted later can not only be regulated and calculated in advance by the content of thulium oxide, but is also possible by changing the duration and intensity of the neutron radiation. The radioactivity achieved increases for technical and medical applications relevant area proportional to the radiation tent. This can also be seen in the example of thulium oxide from the following approximation formula for calculating the resulting radioactivity per cm of sample length: A = n σ Φ ln2 t / Tι / (n = number of Tm atoms / cm; σ = 105 barn = 105 x 10 " 24 cm 2 ; Tl / 2 = half-life = 128.6 d; Φ = 1.85 x 10 12 N / cm 3 ; t = radiation tent).
Das radioaktivierte Material bzw. die radioaktivierten Endoprothesen sind gut korpervertraglich und dienen als therapeutisches Mittel bei Mensch und Tier. Die durch die Radioaktivierung vom Endprodukt ausgehende P- und Y-Strahlung kann prinzipiell das Zellwachstum z. B. von Tumorzellen, Fibroblasten und Bakterien hemmen.The radioactivated material or the radioactivated endoprostheses have a good body contract and serve as a therapeutic agent in humans and animals. The P and Y radiation emanating from the end product by radioactivation can in principle limit cell growth, e.g. B. inhibit tumor cells, fibroblasts and bacteria.
Ziel ist es, zunächst das Zellwachstum eukaryotischer Zellen zu hemmen sowie u. U. auch ruhende eukaryotische Zellen abzutöten. Um außerdem prokaryotische Zellen, wie Bakterien und Pilze, abzutöten bzw. ein weiteres Wachstum zu verhinden sind deutlich höhere Dosen als bei eukaryotischen Zellen erforderlich. Dies ist für einzelne Anwendungen im menschlichen Korper, z. B. um eine Besiedelung der Implantatoberflache mit prokaryotischen Organismen zu verhindern, auch in Kombination mit anderen Verfahren wie z. B. einer Silberbeschichtung oder einer antibiotischen Therapie von Bedeutung. Durch den exponentiellen Abfall der applizierten Dosis bei zunehmenden Abstand vom Stent wird ein Effekt auf prokaryotische Zellen insbesondere auf der Implantatoberflache erzielt.The aim is to first inhibit the cell growth of eukaryotic cells and u. U. to kill resting eukaryotic cells. In order to also kill prokaryotic cells such as bacteria and fungi or to prevent further growth, significantly higher doses than with eukaryotic cells are required. This is for individual applications in the human body, e.g. B. to prevent colonization of the implant surface with prokaryotic organisms, also in combination with other methods such. B. a silver coating or antibiotic therapy is important. The exponential drop in the applied dose with increasing distance from the stent has an effect on prokaryotic cells, in particular on the implant surface.
Stents m Form von Schlauchen dienen als Endoprothesen dazu, röhrenförmige Hohlorgane, wie Gallenwege oder die Luftwege durchgangig zu halten. AusfuhrungsbeispieleStents in the form of tubes serve as endoprostheses to keep tubular hollow organs, such as bile ducts or the airways, open. Exemplary embodiments
Beispiel 1example 1
Herstellung des MaterialsManufacture of the material
Polyethylen, dessen Rezeptur zur Herstellung von Gallengang- und Pankreasgangendoprothesen zugelassen ist, wird 5 % Thuliumoxid (Tm203) in Pulverform (handelsüblich oder in einer Kugelmühle fein vermählen) sowie 20 % BaS04 als Kontrastmittel zugesetzt. Dabei findet eine innige Vermischung statt. Beim Aufschmelzen (Erwarmen auf etwa 200° C) bleiben die feingemahlenen Teilchen in der Mischung suspendiert und sind nach dem Abkühlen des Polymers homogen in der Masse verteilt und vom Kunststoff fest umschlossen.Polyethylene, the formulation of which is approved for the production of bile duct and pancreatic endoprostheses, 5% thulium oxide (Tm 2 0 3 ) in powder form (commercially available or finely ground in a ball mill) and 20% BaS0 4 as a contrast agent. An intimate mixing takes place. When melting (heating to about 200 ° C.), the finely ground particles remain suspended in the mixture and, after the polymer has cooled, are homogeneously distributed in the mass and firmly enclosed by the plastic.
Beispiel 2Example 2
Herstellung eines GallengangstentsProduction of a biliary stent
Aus dem aufgeschmolzenen Kunststoff gemäß Beispiel 1 wird durch eine Spritzgußmaschine (Extruder) ein Schlauch mit einem Innendurchmesser von 2,5 mm und einer Wandstarke von 0,25 bis 0,5 mm hergestellt. Dieser Schlauch wird anschließend zu einer Endo- prothese in den üblichen Abmessungen weiterverarbeitet, indem er auf eine Lange von 5 bis 10 cm geschnitten wird. An beiden Enden dieser Stucke werden Teile eines Kunsto fSchlauches mit den selben Durchmessern angescnweißt , die ohne Zusatz von Thuliumoxid hergestellt wurde. Bei einem insgesamt 14 cm langen Stent ist das dem Duodenum zugewandte Ende in einer Lange von 4 cm Thuliu- moxid-frei, um Schaden an der Darmmukosa und anderen Geweben zu vermeiden. Das der Leber zugewandte Ende ist ebenfalls auf einer Lange von 2 cm Thuliumoxid-frei gehalten. An beiden Enden des Rohlings wird ein Span abgehoben, der wie ein Widerhaken wirkt und die Verankerung des Stents m Gallengang ermöglicht.A tube with an inside diameter of 2.5 mm and a wall thickness of 0.25 to 0.5 mm is produced from the melted plastic according to Example 1 by an injection molding machine (extruder). This tube is then processed into an endoprosthesis in the usual dimensions by cutting it to a length of 5 to 10 cm. At both ends of these pieces, parts of a plastic tube with the same diameters are welded on, which was produced without the addition of thulium oxide. In a 14 cm long stent, the end facing the duodenum is free of thulium oxide in a length of 4 cm in order to avoid damage to the intestinal mucosa and other tissues. The end facing the liver is also kept free of thulium oxide over a length of 2 cm. A chip is lifted at both ends of the blank, which acts like a barb and enables the stent to be anchored in the bile duct.
Die Stents werden in Kunststoffbeutel verschweißt und mit Ethy- lenoxid sterilisiert. Anschließend werden sie m einem Kernreaktor durch Bestrahlung mit Neutronen aktiviert. Die danach durchgeführte Ausgangskontrolle vermisst das Spektrum der ausgesandten Strahlung und deren Intensität. Um eine Aktivität von z. B. 18 'Ci pro cm Schlauchlange bei einem Gewichtsanteil von 4,38 % 169Tm zu erhalten, muß bei einem Neutronenfluß von etwa 2 x 1012 n/cm2/sec über etwa 135 mm bestrahlt werden. Um eine Proliferationshemmung bei Tumorzellen zu erreichen, ist eine Aktivität von 15 -Ci/cm2 in vitro ausreichend.The stents are sealed in plastic bags and sterilized with ethylene oxide. They are then activated in a nuclear reactor by irradiation with neutrons. The exit check carried out afterwards measures the spectrum of the emitted radiation and its intensity. To have an activity of e.g. B. 18 'Ci per cm tube length with a weight fraction of 4.38% 169 Tm, must be irradiated with a neutron flux of about 2 x 10 12 n / cm 2 / sec over about 135 mm. In order to inhibit proliferation in tumor cells, an activity of 15 -Ci / cm 2 in vitro is sufficient.
Beispiel 3Example 3
Um das Zellwachstum z. B. von Tumorzellen oder Fibroblasten im Abstand von 2 bis 3 mm zu einem radioaktiven Thuliumoxid-halti- gen Kunststoffrohrchen mit einem Durchmesser von etwa 3 mm in vitro zu hemmen, sind je nach der Strahlensensibilitat der Zellart ungefähr 6 bis 20 -Ci/cm Rohrchenlange erforderlich. Um ruhende eukaryotische Zellen im selben Versuchsaufbau abzutöten, sind höhere Strahlungsdosen erforderlich. Diese betragen e nach Strahlensensibilitat der Zelle ungefähr 12 bis 50 P-Ci/cm Schlauchlange .To cell growth z. B. to inhibit tumor cells or fibroblasts at a distance of 2 to 3 mm to a radioactive thulium oxide-containing plastic tube with a diameter of about 3 mm in vitro, depending on the radiation sensitivity of the cell type about 6 to 20 -Ci / cm tube length required. In order to kill resting eukaryotic cells in the same experimental setup, higher radiation doses are required. Depending on the radiation sensitivity of the cell, these are approximately 12 to 50 P-Ci / cm tube length.
Das neutronenaktivierbare Material, bestehend aus Matrix und der inerten Verbindung von Seltenen Erden kann vor oder nach der Aktivierung mit weiteren radioaktivierbaren, radioaktiven oder nicht radioaktiven Materialien oder Bauteilen kombiniert werden. Je nach beabsichtigtem Effekt können dafür verschiedene radioaktive oder radioaktivierbare Substanzen mit unterschiedlicher Halbwertszeit, Strahlungsart und -energie eingesetzt werden. Beispielsweise wäre die Kombination mit weiteren inerten Verbindungen der Seltenen Erden mit geringer Halbwertszeit sinnvoll, um eine hohe Initialdosis setzen zu können. Weiterhin ist es möglich, durch verschiedene Verfahren zusätzlich Radioaktivität in den Werkstoff einzubringen, z. B. durch Implantation von 32P in die Oberflache.The neutron-activatable material, consisting of matrix and the inert compound of rare earths, can be combined with other radioactivatable, radioactive or non-radioactive materials or components before or after the activation. Depending on the intended effect, various radioactive or radioactivatable substances with different half-lives, radiation types and energies can be used. For example, the combination with other inert compounds of the rare earths with a short half-life would make sense in order to be able to set a high initial dose. It is also possible to introduce radioactivity into the material by various methods, e.g. B. by implantation of 32 P in the surface.
Die neutronenaktivierten, radioaktiven Materialien sind als therapeutisches Mittel bei Mensch und Tier einsetzbar. Sie eignen sich als Medizinprodukte wie Implantate, z. B. für chirurgisch tatige Disziplinen, Endoprothesen, Katheter, Stents, zur gezielten Embolisation von malignen Raumforderungen, zur äußerlichen Anwendung auf der Haut, als Bestandteile von künstlichen Herzklappen oder als Plomben im Bereich der Augenheilkunde.The neutron-activated, radioactive materials can be used as therapeutic agents in humans and animals. They are suitable as medical devices such as implants, e.g. B. for surgical disciplines, endoprostheses, catheters, stents, for targeted embolization of malignant masses, for external use on the skin, as components of artificial heart valves or as seals in the field of ophthalmology.
Stents oder Katheter aus radioaktiven Materialien eignen sich zur Anwendung im arteriellen, venösen, peπtonealen, peridualen, cerebralen (Ventrikeldrainage) Bereich.Stents or catheters made of radioactive materials are suitable for use in the arterial, venous, peπtoneal, peridual, cerebral (ventricular drainage) area.
Je nach Problemstellung kann es gunstig sein, nur einen Teil eines Schlauchstuckes aus Kunststoff mit Thuliumoxid als radioak- tivierbarer Komponente zu fertigen und diesen mit einem Thulium- freien Schlauch zu verschweißen.Depending on the problem, it can be advantageous to manufacture only a part of a piece of plastic tubing with thulium oxide as a radioactivatable component and to weld it with a thulium-free tube.
Zur Materialeinsparung und/oder zur Verminderung der Y-Strahlen- komponente kann das Material auf einen inerten Trager aufgebracht werden, wie z. B. auf Kunststoffe, Metalle oder Metall- gitter .To save material and / or to reduce the Y-ray component, the material can be applied to an inert carrier, such as. B. on plastics, metals or metal grids.
Von Vorteil ist, daß eine medizinisch zugelassene Sterilisation und die sterile Verpackung der Medizinprodukte vor der Aktivierung durch Neutronen erfolgen kann. Dadurch werden Handhabungsbzw. Produktionschritte mit schon radioaktiven Materialien vermieden.It is advantageous that medically approved sterilization and the sterile packaging of the medical devices can be carried out by neutrons before activation. Thereby handling or Avoid production steps with already radioactive materials.
Die Hohe der spater emittierten Radioaktivität kann nicht nur durch den Gehalt der inerten Verbindung der seltenen Erde reguliert und voraus berechnet werden, sondern dies ist auch durch Veränderung der Dauer und Intensität der Neutronenstrahlung möglich. So steigt die erzielte Radioaktivität - in dem für technische und medizinische Anwendungen relevanten Bereich - proportional zur Bestrahlungszeit an. Dies geht am Beispiel von Thuliumoxid auch aus der folgenden Naherungsformel zur Berechnung der resultierenden Radioaktivität pro cm Probenlange hervor: A = n σ Φ ln2 t / T ι/2, wobei n = Anzahl der Tm-Atome/cm, σ = 105 barn = 105 x 10~24 cm2, T1 2 = Halbwertszeit = 128,6 d, Φ = 1,85 x 1012 N / cm3, t = Bestrahlungszeit.The level of radioactivity emitted later can not only be regulated and calculated in advance by the content of the inert compound of the rare earth, but this can also be done by changing the duration and intensity of the neutron radiation. The radioactivity achieved - in the area relevant for technical and medical applications - increases proportionally to the irradiation time. Using thulium oxide as an example, this can also be seen from the following approximation formula for calculating the resulting radioactivity per cm sample length: A = n σ Φ ln2 t / T ι / 2 , where n = number of Tm atoms / cm, σ = 105 barn = 105 x 10 ~ 24 cm 2 , T 1 2 = half-life = 128.6 d, Φ = 1.85 x 10 12 N / cm 3 , t = irradiation time.
Für die medizinische und technische Anwendung sind mehrere Aktivitätsbereiche von Interesse, auf die die Radioaktivität eingestellt werden soll. Ein Ziel ist es, die Radioaktivität so zu dosieren, daß das Wachstum von eukaryotischen Zellen verhindert wird.For the medical and technical application, several activity areas are of interest to which the radioactivity is to be adjusted. One goal is to dose the radioactivity so that the growth of eukaryotic cells is prevented.
Um das Zellwachstum z. B. von Tumorzellen oder Fibroblasten im Abstand von 2 - 3 mm zu einem radioaktiven Thuliumoxid-haltigen Kunststoffrohrchen mit einem Durchmesser von etwa 3 mm in vitro zu verhindern, sind je nach der Strahlensensibilitat der Zellart ungefähr 6 - 35 P-Ci/cm Schlauchlänge erforderlich. Um ruhende eu- karyotische Zellen im selben Versuchsaufbau abzutöten, sind höhere Strahlungsdosen erforderlich. Diese betragen je nach Strahlensensibilitat der Zelle ungefähr 12 - 80 P-Ci/cm2 Materialoberfläche .To cell growth z. B. to prevent tumor cells or fibroblasts at a distance of 2-3 mm to a radioactive thulium oxide-containing plastic tube with a diameter of about 3 mm in vitro, depending on the radiation sensitivity of the cell type about 6 - 35 P-Ci / cm tube length is required , Higher radiation doses are required to kill resting eukaryotic cells in the same experimental setup. Depending on the radiation sensitivity of the cell, these are approximately 12-80 P-Ci / cm 2 material surface.
Weiterhin kann es Ziel sein, auch prokaryotische Zellen, wie Bakterien und Pilze, abzutöten bzw. ein weiteres Wachstum zu verhindern. Dies ist für einzelne Anwendungen im menschlichen Korper von Bedeutung, z. B. um eine Besiedelung der Implantatoberflache mit prokaryotischen Organismen zu verhindern und deren Folgen, wie septische Embolien, Abszessbildung und Fokusentstehung für weitere Infektionen zu vermeiden, zumal Implantatinfektionen bisher schwer behandelbar sind. Hierfür ist eine Neutronenbestrahlung, bis zu einer Radioaktivität von 500 P-Ci/cm2 Materialoberflache gunstig. Auch die Kombination dieser Materialien mit anderen Verfahren wie einer Silberbeschichtung oder einer antibiotischen Therapie ist möglich.It can also be a goal to kill prokaryotic cells such as bacteria and fungi or to prevent further growth. This is important for individual applications in the human body, e.g. B. to prevent colonization of the implant surface with prokaryotic organisms and to avoid their consequences, such as septic embolisms, abscess formation and focus formation for further infections, especially since implant infections have so far been difficult to treat. Neutron radiation up to a radioactivity of 500 P-Ci / cm 2 material surface is favorable for this. It is also possible to combine these materials with other processes such as a silver coating or antibiotic therapy.
Dabei ist zu beachten, daß durch den exponentiellen Abfall der applizierten Dosis ein Effekt auf prokaryotische Zellen insbesondere auf der Implantatoberfläche erzielt wird und die Wirkung auf nicht direkt anliegende eukaryotische Zellen deutlich geringer ist.It should be noted that the exponential drop in the dose applied has an effect on prokaryotic cells, in particular on the implant surface, and the effect to eukaryotic cells that are not directly in contact.
Auch für die Verhinderung von Keimansiedlungen auf Teilen von medizinischen Anlagen oder Geraten sind diese Materialien von Bedeutung. Für diesen Einsatzzweck ist eine Neutronenbestrahlung, bis zu einer Radioaktivität von 20000 P-C/cm2 Materialoberfläche sinnvoll.These materials are also important for preventing germs from settling on parts of medical systems or devices. For this purpose, neutron irradiation up to a radioactivity of 20,000 PC / cm 2 material surface is useful.
Diese Wirkung ist vor allem bei Bauteilen von Nutzen, die nicht kurzfristig austauschbar sind, dennoch aseptische Kriterien erfüllen müssen, z. B. weil sie in Kontakt mit organischen Materialien kommen. Anwendungsbeispiele sind zum Beispiel Filteranlagen, Schlauchsysteme, Sammelbehalter usw..This effect is particularly useful for components that cannot be exchanged at short notice, but still have to meet aseptic criteria, e.g. B. because they come into contact with organic materials. Examples of applications are filter systems, hose systems, collecting containers, etc.
Weitere AusfuhrungsbeispieleFurther exemplary embodiments
Beispiel 4Example 4
In Form von kleinen Kugelchen aus Kunststoff eignen sich die Materialien zur gezielten Embolisation über einen arteriellen Zugang in einen Tumor oder eine Metastase, um dort im Kapillarge- biet hangen zu bleiben und auf diese Weise eine lokale Wachstumshemmung zu erreichen. Vorteil hierbei ist, daß sich die Wirkung im Vergleich zur Embolisation mit nicht radioaktiven Substanzen (z. B. Starkepartikeln) über die mechanische und nutri- tive Wirkung einer gestörten Blutversorgung hinaus auch auf Zellen auswirkt, die im Randbereich des Tumors sitzen und von anderen Gefäßen mit versorgt werden. Aufgrund der relativ langen Halbwertszeit von etwa 4 Monaten bei Thuliumoxid können auch ruhende Tumorzellen, die wesentlich weniger strahlensensibel als proliferierende Zellen sind, erreicht werden. Damit sinkt die Rezidivquote gegenüber einer punktuellen externen Bestrahlung oder einer Embolisation mit Substanzen kürzerer Halbwertszeit. Es ist eine langfristige Vermeidung eines Lokalrezidives möglich. Die Anwendung der gezielten Radioembolisation ist im Gegensatz zur konventionellen Embolisation jedoch nicht nur auf arterielle Stromgebiete begrenzt, sondern auch zum Beispiel auf dem Lymphweg möglich. So lassen sich lymphogene Metastasen eines malignen Melanoms an einer Extremität durch Injizieren von radioaktiven, Thuliumoxid-haltigen Polyethylenkügelchen behandeln. Vorteil ist hier, daß sich die Radioaktivität entsprechend der Metastasie- rungswege ausbreitet und deshalb zielgenau appliziert werden kann. Dadurch sind die erforderlichen Strahlungsdosen erheblich geringer als bei einer externen Bestrahlung.In the form of small spheres made of plastic, the materials are suitable for targeted embolization via an arterial access to a tumor or a metastasis, in order to get caught in the capillary area and thus achieve a local growth inhibition. The advantage here is that, compared to embolization with non-radioactive substances (eg starch particles), the effect also affects cells that are located in the marginal area of the tumor and other vessels, in addition to the mechanical and nutritional effects of a disturbed blood supply be supplied with. Due to the relatively long half-life of around 4 months for thulium oxide, resting tumor cells, which are significantly less radiation-sensitive than proliferating cells, can also be achieved. This reduces the recurrence rate compared to selective external radiation or embolization with substances with a shorter half-life. Long-term prevention of local recurrence is possible. In contrast to conventional embolization, the use of targeted radio embolization is not only limited to arterial flow areas, but is also possible, for example, on the lymphatic system. For example, lymphogenic metastases from a malignant melanoma on one extremity can be treated by injecting radioactive, thulium oxide-containing polyethylene beads. The advantage here is that the radioactivity spreads according to the metastasis path and can therefore be applied precisely. As a result, the required radiation doses are considerably lower than with external radiation.
Zur Herstellung dieser Partikel wird korpervertraglichem Polyethylen 5 % fein vermahlenes Thuliumoxid zugesetzt. Das Thuliumoxid ermöglicht die spatere Radioaktivierung. Beim Aufschmelzen (Erwarmen auf etwa 200 CC) bleiben die feingemahlenen Teilchen in der Mischung suspendiert und sind nach dem Abkühlen des Polymers homogen in der Masse verteilt und vom Kunststoff fest umschlossen. Aus diesem Material werden kleine Polyethylenpartikel mit einem Durchmesser von z. B. 30 - 100 P-m hergestellt. Das Material kann auch unter vorhergehender Abkühlung vermählen werden. Die gewünschte Partikelgroße wird durch Filtrations- oder Siebevorgange selektiert. Die Partikel werden anschließend durch Neutronenbeschuß in einem Kernreaktor radioaktiviert.To produce these particles, 5% finely ground thulium oxide is added to the body-compatible polyethylene. The thulium oxide enables later radioactivation. Upon melting (heating to about 200 C C) remain the finely ground particles are suspended in the mixture and, after cooling of the polymer homogeneously distributed in the mass and firmly enclosed by the plastic. Small polyethylene particles with a diameter of e.g. B. 30 - 100 .mu.m manufactured. The material can also be ground with previous cooling. The desired particle size is selected by filtration or sieving processes. The particles are then radioactivated by neutron bombardment in a nuclear reactor.
Beispiel 5Example 5
Kunststoffen, deren Rezeptur zur Herstellung von Harnrohren- und Harnleiterkathetern zugelassen ist, wird 5 % in einer Kugelmühle fein vermahlenes Thuliumoxid zugesetzt. Beim Aufschmelzen (Erwärmen auf etwa 200 °C) bleiben die feingemahlenen Teilchen in der Mischung suspendiert und sind nach dem Abkühlen des Polymers homogen in der Masse verteilt und vom Kunststoff fest umschlossen.5% of finely ground thulium oxide is added to plastics whose formulation is approved for the production of urethral and ureter catheters. When melting (heating to about 200 ° C.), the finely ground particles remain suspended in the mixture and, after the polymer has cooled, are homogeneously distributed in the mass and firmly enclosed by the plastic.
Aus dem geschmolzenen Kunststoff wird durch eine Spritzgußmaschine (Extruder) ein Schlauch mit z. B. einem Innendurchmesser von 2,5 mm und einer Wandstärke von 0,25 mm hergestellt. Dieser Schlauch wird anschließend zu einem Doppel-J-Katheter in den üblichen Abmessungen weiterverarbeitet, indem er auf eine Lange von 5 - 10 cm geschnitten wird. An beiden Enden dieser Stucke werden Teile eines KunstoffSchlauches m t den selben Durchmessern angefugt, der ohne Zusatz von Thuliumoxid hergestellt wurde. Beide Enden werden in J-Form (z. B. durch Biegen unter Wärmebehandlung) gebracht, um den Katheter spater in der richtigen Position zu halten. Dabei wird der Teil des Katheters radio- aktiviert, der in direkten Kontakt zu der zu behandelnden narbigen Stenose oder Tumorstenose kommt. Durch die Radioaktivität wird ein Rezidiv der narbigen Stenose (Hemmung von Fibroblasten- wachstum) verhindert bzw. das Wachstum von Tumorzellen begrenzt. Die Stents werden Kunststoffbeutel eingeschmolzen und mit Ethylenoxid sterilisiert.From the molten plastic, a hose with z. B. an inner diameter of 2.5 mm and a wall thickness of 0.25 mm. This The tube is then processed into a double J catheter in the usual dimensions by cutting it to a length of 5 - 10 cm. At both ends of these pieces, parts of a plastic tube with the same diameter are added, which was produced without the addition of thulium oxide. Both ends are brought into a J-shape (e.g. by bending under heat treatment) to hold the catheter in the correct position later. The part of the catheter that comes into direct contact with the scarred stenosis or tumor stenosis to be treated is radioactivated. Radioactivity prevents a recurrence of the scarred stenosis (inhibition of fibroblast growth) or limits the growth of tumor cells. The stents are melted down in plastic bags and sterilized with ethylene oxide.
Der Vorteil liegt zugleich in der Reduktion der Keimbesiedelung auf der Oberflache des Katheders.The advantage also lies in the reduction in the number of germs on the surface of the catheter.
Beispiel 6Example 6
Materialien, z. B. faserverstärkten Kunststoffen (z. B. Kohlefasern) , die zum Einsatz bei Herzklappensegeln zugelassen sind, wird in einer Kugelmühle fem vermahlenes Thuliumoxid z. B. mit einem Gewichtsanteil von 0,5 - 3 % zugesetzt. Beim Aufschmelzen bleiben die feingemahlenen Teilchen in der Mischung suspendiert, homogen verteilt und können nach dem Zufügen des Faseranteils in die gewünschte Form gebracht werden. Das Thuliumoxid ist nach Abkühlen des Polymers homogen in der Masse verteilt und von der Matrix fest umschlossen. Das Werkstuck wird anschließend durch Neutronenbeschuß m einem Kernreaktor radioaktiviert.Materials, e.g. B. fiber-reinforced plastics (z. B. carbon fibers) that are approved for use in heart valves, is ground in a ball mill fem ground thulium oxide z. B. added with a weight proportion of 0.5 - 3%. When melting, the finely ground particles remain suspended in the mixture, homogeneously distributed and can be brought into the desired shape after adding the fiber portion. After the polymer has cooled, the thulium oxide is homogeneously distributed in the mass and is firmly enclosed by the matrix. The workpiece is then radioactivated by neutron bombardment in a nuclear reactor.
Mit einem solchen radioaktiven Herzklappensegel kann vermieden werden, daß sich Bakterien festsetzen und die Ausbildung eines septischen Thrombus verursachen. Aufgrund der starken Bewegungen der Klappensegel neigen insbesondere dort lokalisierte Thromben, als Emboli in andere Gebiete zum Beispiel das Gehirn abzuwandern und dort Infarkte zu verursachen. Durch die P-Strahlung des radioaktiven Materials ist eine hohe Oberflachendosis zu errei- chen, die eine Keimbesiedlung verhindert. Zudem hat ein mechanisches Klappensegel keinen direkten Kontakt zum Herzmuskelgewebe, so daß aufgrund der geringen Reichweite z. B. bei 170Tm die Schädigung der Herzmuskelzellen vernachlassigbar gering ist. Ein solches Herzklappensegel kann mit nichtradioaktiven Bauteilen zu einer Herzklappe kombiniert werden.With such a radioactive heart valve sail it can be avoided that bacteria get stuck and cause the formation of a septic thrombus. Due to the strong movements of the valve leaflets, thrombi located there tend to migrate to other areas, for example the brain, as emboli, and cause infarctions there. A high surface dose can be achieved through the P radiation of the radioactive material. that prevent germ colonization. In addition, a mechanical valve flap has no direct contact with the heart muscle tissue, so that due to the short range z. B. at 170 Tm the damage to the heart muscle cells is negligible. Such a heart valve sail can be combined with non-radioactive components to form a heart valve.
Beispiel 7Example 7
Chirurgischen Implantaten wie Schrauben, Platten, Gelenke und Gelenkteile, die entweder aus Kunststoff mit oder ohne Faserver- starkung oder aus Metallegierungen oder aus Kombinationen beider Werkstoffe bestehen, wird fein vermahlenes Thuliumoxid z. B. mit einem Gewichtsanteil von 0,5 - 10 % zugesetzt. Kombinationen der beiden Werkstoffe sind z. B. in Form eines Metallkernes mit umgebendem Thuliumoxid-haltigen Kunststoffmantel möglich. Als Kunststoffe eignen sich hierfür z. B. insbesondere duroelasti- sche Materialien und solche, die eine hohe Schlag- und Bruchfestigkeit aufweisen. Als Beispiel waren z. B. Polyethylen-HD-Ver- bindungen und Polyarylamid-Verbindungen zu nennen. Beim Aufschmelzen bleiben die feingemahlenen Verbindungen in der Mischung suspendiert und homogen verteilt und werden in Spritz- gußtechnik z. B. um einen Metallkorper im Zentrum gespritzt. Das Werkstuck wird anschließend durch Neutronenbeschuß in einem Kernreaktor radioaktiviert.Surgical implants such as screws, plates, joints and joint parts, which either consist of plastic with or without fiber reinforcement or of metal alloys or combinations of both materials, are finely ground thulium oxide z. B. added with a weight fraction of 0.5 - 10%. Combinations of the two materials are e.g. B. in the form of a metal core with surrounding thulium oxide-containing plastic jacket possible. As plastics are suitable for this. B. in particular duroelastic materials and those that have high impact and breaking strength. As an example, e.g. B. Polyethylene HD compounds and polyarylamide compounds. When melting, the finely ground compounds remain suspended and homogeneously distributed in the mixture and are z. B. sprayed around a metal body in the center. The workpiece is then radioactivated by neutron bombardment in a nuclear reactor.
Beispiel 8Example 8
Vielfaltige Anwendungsmoglichkeiten der radioaktiven Materialien gibt es am menschlichen Auge, da Operationen aufgrund der räumlichen Nachbarschaft hoch differenzierter Gebiete z. B. bei Tumoroperationen wie Ret o- und Melanoblastomen oft mit einem Verlust der Organfunktion oder einer Einschränkung der Sehfahig- keit verbunden sind. Auf der anderen Seite ist es oft nicht möglich, entzündliche oder proliferative Prozesse an der Netz- und Aderhaut (z. B. Periphlebitis retinae, Panarterntis nodosa, Thrombangitis obliterans, diabetische Ret opathie) mit den herkömmlichen medikamentösen Therapien und invasiven Netzhautbe handlungen wie Kryo- oder Laserkoagulation, die ja nur punktu- elle Vernarbungen bewirken, flachendeckend zu behandeln.There are a variety of possible uses of the radioactive materials in the human eye, since operations due to the spatial proximity of highly differentiated areas such. B. in tumor operations such as reto- and melanoblastomas are often associated with a loss of organ function or impaired vision. On the other hand, inflammatory or proliferative processes on the retina and choroid (e.g. periphlebitis retinae, Panarterntis nodosa, thrombangitis obliterans, diabetic retopathy) are often not possible with conventional medicinal therapies and invasive retinabe Treating actions such as cryo- or laser coagulation, which only cause selective scarring, across the board.
Für beide Indikationen ist es möglich, radioaktive, Thuliumoxid- haltige (z. B. mit einem Thuliumoxidanteil von 0,1 - 10 %) Plomben aus Kunststoff, z. B. Polyethylen, transparenten Silikonpolymeren oder auch thermoelastischen Kunststoffen außen an das Auge anzunähen bzw. innen der Netzhaut anliegend zu befestigen, um proliferative Prozesse zu stoppen, die zu weiteren Netzhaut- schadigungen fuhren können. Aber auch Netzhauttumoren wie Retin- oblastome, die sich aufgrund ihrer Große einer Visus-erhaltenden Operation entziehen, können durch solche Plomben praeoperativ, postoperativ oder als alleinige Maßnahme behandelt werden. Durch die Radioakivitat können insbesondere auch einzelne mfiltrativ wachsende Tumorzellen erreicht werden, die sich ansonsten einer Behandlung entziehen wurden. Insbesondere Thuliumoxid erscheint hier aufgrund der Reichweite seiner ß-Strahlung von wenigen Millimetern, der Halbwertszeit, die eine längere Applikation ermöglicht, um auch ruhende Zellen abzutöten, und dem geringen Anteil an Y-Strahlung, die ja eine Linsentrübung hervorrufen kann, besonders geeignet und den herkömmlichen Bestrahlungsarten überlegen. Beim Aufschmelzen bleibt die feingemahlene Thuliumoxidver- b dung in der Kunststoff-Mischung suspendiert und homogen verteilt. Die Mischung wird in z . B. in Spritzgußtechnik in die gewünschte Form gebracht und das Werkstuck anschließend durch Neu- tronenbeschuß in einem Kernreaktor radioaktiviert.For both indications it is possible to use radioactive, thulium oxide-containing (e.g. with a thulium oxide content of 0.1 - 10%) plastic seals, e.g. B. polyethylene, transparent silicone polymers or thermoelastic plastics to sew on to the outside of the eye or to be attached inside the retina to stop proliferative processes that can lead to further retinal damage. However, retinal tumors such as retinal oblastomas, which due to their size are too large to avoid surgery to preserve the visual acuity, can be treated preoperatively, postoperatively or as a sole measure. The radioactivity can in particular also be used to reach individual mfiltratively growing tumor cells that would otherwise have been removed from treatment. Thulium oxide, in particular, appears to be particularly suitable here due to the range of its beta radiation of a few millimeters, the half-life that allows longer application to kill even resting cells, and the low proportion of Y radiation, which can cause lens clouding superior to conventional types of radiation. When melting, the finely ground thulium oxide compound remains suspended and homogeneously distributed in the plastic mixture. The mixture is in z. B. brought into the desired shape using injection molding technology and the workpiece subsequently radioactivated by neutron bombardment in a nuclear reactor.
Beispiel 9Example 9
Die radioaktiven Materialien eignen sich zum Einsatz bei Tumoren, die sich aufgrund ihrer Lage, Ausdehnung, Infiltration oder des Allgemeinzustandes des Patienten einem kurativen operativen Verfahren entziehen. Als Beispiel sind hier Tumoren der Haut, wie Basaliome, Melanome oder Spinaliome, aber auch der Weich- teile zu nennen. Zur Behandlung dieser Tumoren und insbesondere von kleinen makroskopisch nicht sichtbaren Absiedlungen im Randbereich ist es möglich, praeoperativ, postoperativ oder auch als alleinige Therapie ein radioaktives Thuliumoxid-haltiges Werk- stuck z. B. m Form eines Plattchens aus thermoelastischenThe radioactive materials are suitable for use in tumors that cannot be used in a surgical procedure due to their position, extent, infiltration or the general condition of the patient. As an example, tumors of the skin, such as basaliomas, melanomas or spinaliomas, but also of the soft parts can be mentioned. For the treatment of these tumors and in particular small macroscopically invisible settlements in the marginal area, it is possible to use a radioactive thulium oxide-containing plant pre-operatively, post-operatively or as sole therapy. stucco z. B. m shape of a plate made of thermoelastic
Kunststoffen oder Polyethylen als Matrixmaterial bei einem Thuliumgehalt von 0,1 - 10 % aufzunähen bzw. anzubringen. Für unebene anatomische Verhaltnisse lassen sich leicht verformbare, gelartige oder flussige Kunstsstoffpolymere wie z. B. Silikonpo- lymere mit dem selben Thuliumanteil einsetzen. Beim Aufschmelzen bleibt die feingemahlene Thuliumoxidverbmdung m der Kunststoff-Mischung suspendiert und homogen verteilt und wird z. B. in Spritzgußtechnik in die gewünschte Form gebracht. Das Werkstuck wird anschließend durch Neutronenbeschuß in einem Kernreaktor radioaktiviert. Vorteil dieses Verfahrens ist wiederum die geringe Strahlenbelastung des umgebenden Gewebes, die Erfassung vereinzelt liegender Zellen im Randbereich, d e ambulante Be- handlungsmoglichkeit und das Vermeiden verstummelnder chirurgischer Eingriffe.Sew on or attach plastics or polyethylene as matrix material with a thulium content of 0.1 - 10%. For uneven anatomical conditions, easily deformable, gel-like or liquid plastic polymers such as. B. Use silicone polymers with the same amount of thulium. When melting, the finely ground Thuliumoxidverbmdung m suspended in the plastic mixture and homogeneously distributed and z. B. brought into the desired shape by injection molding. The workpiece is then radioactivated by neutron bombardment in a nuclear reactor. The advantages of this procedure are again the low radiation exposure to the surrounding tissue, the detection of isolated cells in the marginal area, the outpatient treatment option and the avoidance of dumbing down surgical interventions.
Beispiel 10Example 10
Bauteile technischer Gerate u. a. aus dem medizintechnischen Bereich, die regelmäßig oder potentiell mit prokaryiotischen Organismen und Zellen kontaminiert werden, die jedoch steril oder keimarm gehalten werden sollen und nicht einer kurzfristigen, regelmäßigen Keimreduktion unterworfen werden können, wie. Sammelbehalter, Schlauchsysteme, Filteranlagen, Gehäuse für elektronische Bauteile usw. können aus der Vielzahl der oben genannten Matrixmaterialien wie z. B. Kunststoffen bestehen, denen eine inerte Verbindung einer seltenen Erde z. B. Thuliumoxid zugesetzt wird. Auch Werkstucke aus organischen und bioorganischen Verbindungen wie Zellulose, organischen Gelen, Starke usw. sind vor Besiedelung und Zersetzung durch Prokaryonten schutzbar, wenn das feingemahlene inerte Thuliumoxid in der Matrix suspendiert und homogen verteilt und anschließend m die gewünschte Form gebracht wird. Das Werkstuck wird anschließend durch Neutronenbeschuß in einem Kernreaktor radioaktiviert. Bei den technischen Werkstucken kann, wenn eine genugende Abschirmung gewährleistet ist, eine deutliche höhere Radioaktivität zum Einsatz kommen als beim Menschen. LiteraturComponents of technical devices from the medical field, among others, which are regularly or potentially contaminated with prokaryiotic organisms and cells, but which are to be kept sterile or low in germs and cannot be subjected to short-term, regular germ reduction, such as. Collecting containers, hose systems, filter systems, housings for electronic components, etc. can be made from the variety of the above-mentioned matrix materials such as. B. plastics exist, which an inert connection of a rare earth z. B. Thulium oxide is added. Workpieces made from organic and bio-organic compounds such as cellulose, organic gels, starch, etc. can also be protected from colonization and decomposition by prokaryotes if the finely ground inert thulium oxide is suspended in the matrix and distributed homogeneously and then brought into the desired shape. The workpiece is then radioactivated by neutron bombardment in a nuclear reactor. In the case of technical workpieces, if adequate shielding is guaranteed, a significantly higher level of radioactivity can be used than in humans. literature
Ayers DC, Evarts CM, Parkinson JR: The prevention of heterotopic ossification in high-risk patients by low-dose radiation therapy after total hip arthroplasty . J Bone Joint Surg 68:1423-30, 1986.Ayers DC, Evarts CM, Parkinson JR: The prevention of heterotopic ossification in high-risk patients by low-dose radiation therapy after total hip arthroplasty. J Bone Joint Surg 68: 1423-30, 1986.
Borok TL, Bray M, Sinclair I: Role of ionizing irradiation for 393 keloids. Int J Radiat Oncol Biol Phys 14:865-70, 1988.Borok TL, Bray M, Sinclair I: Role of ionizing irradiation for 393 keloids. Int J Radiat Oncol Biol Phys 14: 865-70, 1988.
Gross R, Schölmerich P, Gerok W: Lehrbuch der Inneren Medizin. Thieme, 1989.Gross R, Schölmerich P, Gerok W: Textbook of Internal Medicine. Thieme, 1989.
Jung EG: Dermatologie, Hippokrates Verlag, 1991.Jung EG: Dermatologie, Hippokrates Verlag, 1991.
Wallhäuser K H: Praxis der Sterilisation, Desinfektion und Konservierung. 5. Aufläge. Thieme. 1995. Wallhäuser K H: practice of sterilization, disinfection and preservation. 5th editions. Thieme. 1995th
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DE1999153637 DE19953637A1 (en) | 1999-11-09 | 1999-11-09 | Neutron-activated radioactive material comprising rare earth compound, preferably thulium oxide, in matrix, e.g. of polymer, useful in medicine, e.g. for producing restenosis-preventing stents |
DE19953637 | 1999-11-09 | ||
DE19953636 | 1999-11-09 | ||
DE1999153636 DE19953636A1 (en) | 1999-11-09 | 1999-11-09 | Neutron-activated radioactive material comprising rare earth compound, preferably thulium oxide, in matrix, e.g. of polymer, useful in medicine, e.g. for producing restenosis-preventing stents |
PCT/EP2000/010884 WO2001034196A2 (en) | 1999-11-09 | 2000-11-04 | Mixture containing rare earths and use thereof |
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AUPR098300A0 (en) * | 2000-10-25 | 2000-11-16 | Sirtex Medical Limited | Polymer based radionuclide containing microspheres |
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US8842800B2 (en) * | 2007-11-28 | 2014-09-23 | Ge-Hitachi Nuclear Energy Americas Llc | Fuel rod designs using internal spacer element and methods of using the same |
US9362009B2 (en) * | 2007-11-28 | 2016-06-07 | Ge-Hitachi Nuclear Energy Americas Llc | Cross-section reducing isotope system |
US20090135989A1 (en) * | 2007-11-28 | 2009-05-28 | Ge-Hitachi Nuclear Energy Americas Llc | Segmented fuel rod bundle designs using fixed spacer plates |
US20090135990A1 (en) * | 2007-11-28 | 2009-05-28 | Ge-Hitachi Nuclear Energy Americas Llc | Placement of target rods in BWR bundle |
US9202598B2 (en) * | 2007-11-28 | 2015-12-01 | Ge-Hitachi Nuclear Energy Americas Llc | Fail-free fuel bundle assembly |
US8437443B2 (en) * | 2008-02-21 | 2013-05-07 | Ge-Hitachi Nuclear Energy Americas Llc | Apparatuses and methods for production of radioisotopes in nuclear reactor instrumentation tubes |
US8712000B2 (en) * | 2007-12-13 | 2014-04-29 | Global Nuclear Fuel—Americas, LLC | Tranverse in-core probe monitoring and calibration device for nuclear power plants, and method thereof |
US8885791B2 (en) | 2007-12-18 | 2014-11-11 | Ge-Hitachi Nuclear Energy Americas Llc | Fuel rods having irradiation target end pieces |
US8180014B2 (en) | 2007-12-20 | 2012-05-15 | Global Nuclear Fuel-Americas, Llc | Tiered tie plates and fuel bundles using the same |
US7970095B2 (en) * | 2008-04-03 | 2011-06-28 | GE - Hitachi Nuclear Energy Americas LLC | Radioisotope production structures, fuel assemblies having the same, and methods of using the same |
US8050377B2 (en) | 2008-05-01 | 2011-11-01 | Ge-Hitachi Nuclear Energy Americas Llc | Irradiation target retention systems, fuel assemblies having the same, and methods of using the same |
US8270555B2 (en) * | 2008-05-01 | 2012-09-18 | Ge-Hitachi Nuclear Energy Americas Llc | Systems and methods for storage and processing of radioisotopes |
FR2930890B1 (en) * | 2008-05-06 | 2010-12-10 | Univ Claude Bernard Lyon | NOVEL TARGETED RADIOTHERAPY AGENTS OR CURIETHERAPY AGENTS BASED ON RARE EARTH OXIDES OR OXO HYDROXIDES |
US7781637B2 (en) * | 2008-07-30 | 2010-08-24 | Ge-Hitachi Nuclear Energy Americas Llc | Segmented waste rods for handling nuclear waste and methods of using and fabricating the same |
US8699651B2 (en) * | 2009-04-15 | 2014-04-15 | Ge-Hitachi Nuclear Energy Americas Llc | Method and system for simultaneous irradiation and elution capsule |
US9165691B2 (en) * | 2009-04-17 | 2015-10-20 | Ge-Hitachi Nuclear Energy Americas Llc | Burnable poison materials and apparatuses for nuclear reactors and methods of using the same |
US9431138B2 (en) * | 2009-07-10 | 2016-08-30 | Ge-Hitachi Nuclear Energy Americas, Llc | Method of generating specified activities within a target holding device |
US8366088B2 (en) * | 2009-07-10 | 2013-02-05 | Ge-Hitachi Nuclear Energy Americas Llc | Brachytherapy and radiography target holding device |
US8638899B2 (en) * | 2009-07-15 | 2014-01-28 | Ge-Hitachi Nuclear Energy Americas Llc | Methods and apparatuses for producing isotopes in nuclear fuel assembly water rods |
US8488733B2 (en) | 2009-08-25 | 2013-07-16 | Ge-Hitachi Nuclear Energy Americas Llc | Irradiation target retention assemblies for isotope delivery systems |
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- 2000-11-04 JP JP2001536193A patent/JP2003513938A/en active Pending
- 2000-11-04 EP EP00984964A patent/EP1227845A2/en not_active Withdrawn
- 2000-11-04 CA CA002398832A patent/CA2398832A1/en not_active Abandoned
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