Production of radioisotopes

Abstract

A method of obtaining, from a target compound, a radioisotope of a target element comprised in the target compound includes irradiating the target compound with high energy photon irradiation (gamma irradiation). Thereby the target element radioisotope is formed. The method is performed such that the target element radioisotope is of different oxidation state than the target element, and is comprised in a target element radioisotope compound that is separable from the target compound by a physical and/or chemical separation method.

Claims

1. A method of producing a radioisotope of a target element (target element radioisotope), the method including: irradiating a target compound, comprising the target element, with gamma radiation, as high energy photon irradiation, in a radiation therapy device, wherein the irradiation is performed upstream of a gamma radiation generation target of the radiation therapy device and wherein the gamma radiation is produced as high energy photon irradiation by irradiating a gamma radiation source element or compound with electron beam radiation of an electron beam that is produced by the radiation therapy device, thereby producing the target element radioisotope, wherein the target element radioisotope is a radioisotope of the target element and is of an oxidation state different than that of the target element and is comprised in a target element radioisotope compound that is different from the target compound and that is separable from the target compound by a physical and/or chemical separation method; and wherein the target compound is in gaseous form and is contained in a target compound chamber defined by a module of the radiation therapy device, which module is located in the path of the electron beam upstream of the gamma radiation generation target of the radiation therapy device, and which module contains, in addition to the target compound, the gamma radiation source element or compound.

2. The method according to claim 1, wherein the target element is selected from alkali metals, alkali-earth metals, transition metals, post-transition metals, metalloids, polyatomic non-metals, diatomic non-metals, lanthanide series elements, and actinide series elements.

3. The method according to claim 1, wherein the target element is selected from one or combinations of two or more of Mo, Rb, Re, Sm, Y, Sr, In, Gd, Ac, Bi, Cu, Au, Pt, Sn, Pd, Rh, Lu, Ra, Th, P, I, Pb, Tl, Sb, Co, Ho, Sc, Tc, Ga, Fe, Zn, Ti, Zr, F, Nd, Pr, Tb.

4. The method according to claim 1, wherein the target compound is selected from one, or combinations of two or more of carbonates, halides, sulphates, oxides, oxalates, hydroxides and nitrates of the target element.

5. The method according to claim 1, wherein the target compound is an elemental form of the target element.

6. The method according to claim 1, wherein the target element radioisotope is selected from one, or combinations of two or more of .sup.99Mo, .sup.82Rb .sup.188Re, .sup.186Re, .sup.153Sm, .sup.166Ho, .sup.90Y, .sup.89Sr, .sup.111In, .sup.153Gd, .sup.225Ac, .sup.212Bi, .sup.213Bi, .sup.211At, .sup.60Cu, .sup.61Cu, .sup.67Cu, .sup.64Cu, .sup.62Cu, .sup.198Au, .sup.199Au, .sup.195mPt, .sup.193mPt, .sup.197Pt, .sup.117mSn, .sup.103Pd, .sup.103mRh, .sup.177Lu, .sup.223Ra, .sup.224Ra, .sup.227Th, .sup.32P, .sup.161Tb, .sup.33P, .sup.203Pb, .sup.201Tl, .sup.119Sb, .sup.58mCo, .sup.161Ho, .sup.44Sc, .sup.99mTc, .sup.67Ga, .sup.68Ga, .sup.59Fe, .sup.63Zn, .sup.52Fe, .sup.45Tl, .sup.191mPt, .sup.89Zr, .sup.18F, .sup.131,125,124,123I, .sup.140Nd/Pr, and .sup.155,156Tb.

7. The method according to claim 1, wherein the target element radioisotope compound is selected from one, or more combinations of two or more of carbonates, halides, sulphates, oxide, oxalates, hydroxides and nitrates of the target element radioisotope.

8. The method according to claim 1, wherein the state of matter of the target element radioisotope compound is different to the state of matter of the target element compound.

9. A method of producing a radioisotope of a target element (target element radioisotope), the method including: irradiating a target compound, comprising the target element, with gamma radiation, as high energy photon irradiation, in a radiation therapy device, wherein the irradiation is performed upstream of a gamma radiation generation target of the radiation therapy device and wherein the gamma radiation is produced as high energy photon irradiation by irradiating a gamma radiation source element or compound with electron beam radiation of an electron beam that is produced by the radiation therapy device, thereby producing the target element radioisotope, wherein the target element radioisotope is a radioisotope of the target element and is of an oxidation state different than that of the target element and is comprised in a target element radioisotope compound that is different from the target compound and that is separable from the target compound by a physical and/or chemical separation method; and wherein the target compound is in gaseous form and is contained in a target compound chamber defined by a module of the radiation therapy device, which module is located in the path of the electron beam upstream of the gamma radiation generation target of the radiation therapy device, and which module contains, in addition to the target compound, the gamma radiation source element or compound, wherein: the target element is molybdenum-100 (.sup.100Mo); the target element is comprised by a target element compound that is molybdenum hexacarbonyl (Mo(CO).sub.6) in gaseous form; the target element radioisotope is molybdenum-99 (.sup.99Mo); and the target element radioisotope compound is molybdenum trioxide (MoO.sub.3) in solid form, and the target element radioisotope compound is thus separable from the target element compound by a physical separation method.

Description

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

(1) THE INVENTION WILL NOW BE DESCRIBED IN MORE DETAIL, with reference to the following drawings in which

(2) FIG. 1 shows, diagrammatically, operative parts of one embodiment of a radiation therapy device assembly in accordance with the invention; and

(3) FIG. 2 shows, diagrammatically, operative parts of another embodiment of a radiation therapy device assembly in accordance with the invention.

(4) Referring to the drawings, and in particular to FIG. 1, reference numeral 10 generally indicates operative parts of one embodiment of a radiation therapy device assembly in accordance with the invention, for performing one embodiment of the method of the invention.

(5) The parts 10 comprise an electron beam generator 12 which emits, in use, an electron beam 14. The parts 10 also comprise a gamma radiation generation target 16 in the form of a gamma radiation source element, e.g. tungsten.

(6) The gamma radiation generation target 16 is provided in the path of the electron beam 14 in use.

(7) The parts 10 also comprise a module 18 in accordance with the invention, which module 18 contains a target compound 19, e.g. Mo(CO).sub.6, in gaseous form, which target compound comprises a target element, e.g. .sup.100Mo, of which a target element radioisotope, e.g. .sup.99Mo, is desired, in the form of a target element radioisotope compound, e.g. MoO.sub.3. The module may comprise a further reactant, e.g. oxygen, to render the target element radioisotope into a particular desired material form that it does not achieve merely due to the high energy photon irradiation of the target compound. As explained above it is possible, however, that the high energy photon irradiation would be sufficient for the target element radioisotope to form as the target element radioisotope compound in a particular desired material form, without the involvement of an additional reactant. To contain the target compound 19, the module 18 defines a target compound chamber in which the target compound can be contained.

(8) It will be appreciated from the drawing that the module 18 is effectively located downstream of the gamma radiation generation target 16, with reference to the direction in which the electron beam 14 is in use emitted.

(9) In use, in performing one embodiment of the method of the invention, the electron beam 14 emitted from the electron beam generator 12 hits the gamma radiation generation target 16, from which gamma radiation 15 is then emitted as a result of irradiation thereof with the electron beam 14. Some of the gamma radiation 15 is directed by a collimator 17 into directed gamma radiation 20. The directed gamma radiation 20, which is conventionally for use in radiation therapy, irradiates the module 18, and therefore also the target compound 19. This converts, through a ,n reaction and the Szilard-Chalmers effect, the target element, e.g. .sup.100Mo, to the target element radioisotope, e.g. .sup.99Mo, which precipitates inside the module 18 in solid form as the target element radioisotope compound, e.g. MoO.sub.3, due to the reaction thereof with the oxygen, thus obtaining isotopes of the target element.

(10) Referring to FIG. 2, reference numeral 10A shows another embodiment of parts of a radiation therapy device according to the invention.

(11) Some of the parts of the radiation therapy device illustrated in FIG. 2 are identical to those of the parts of the radiation therapy device illustrated in FIG. 1, and the same reference numerals are used in respect of such parts in FIG. 2.

(12) Differences between the parts of the radiation therapy device of FIG. 1 and the parts of the radiation therapy device of FIG. 2 include the configuration of the module 18, which is therefore referenced in FIG. 2 by reference numeral 18A, and the location of the module 18A.

(13) With respect to location, the module 18A is located upstream of the gamma radiation generation target 16, and therefore not in the path of the gamma radiation 20. Instead, the module 18A is located in the path of the electron beam 14.

(14) With respect to configuration, the module 18A includes a gamma radiation source element or compound 22. Such gamma radiation source element or compound is therefore provided in the device 10A in addition to the gamma radiation generation target 16. In this regard, the module 18A is configured such that the gamma radiation source element or compound 22 is physically in the presence of, or is at least in irradiating proximity to, the target compound 19.

(15) In use, in performing another embodiment of the method of the invention, the device 10A would conventionally operate in the same manner as the device 10 to produce the directed gamma radiation 20 that is, again, conventionally for use in radiation therapy. In the context of the invention, in contrast to the device 10, however, radioisotopes of the target element of the target compound 19 are not obtained by irradiation of the target compound with the gamma radiation 20, since such (therapeutic) gamma radiation would not be produced by the device 10A in the configuration illustrated in FIG. 2, but with gamma radiation 15A emitted from the gamma radiation source element or compound 22. As in the case of the embodiment 10 illustrated in FIG. 1, this converts, through a ,n reaction and the Szilard-Chalmers effect, the target element, e.g. .sup.100Mo, to the target element radioisotope, e.g. .sup.99Mo, which precipitates inside the module 18 in solid form as the target element radioisotope compound, e.g. MgO.sub.3, due to the reaction thereof with the oxygen, thus obtaining isotopes of the target element.

CONCLUSION

(16) IT IS BELIEVED that the invention as described herein would allow for medical treatment facilities to produce, without major overhaul of equipment or infrastructure, radioisotopes in-house. The advantage of this possibility is clear.