Cyclotron radioisotope production

Molecular [ F]fluorine (P F]F2) is produced in the cyclotron target usually during the irradiation for radioisotope production (see Section 2.4). 

M. S. Livingstone, J. P. Blewett, Particle Accelerators, McGraw-Hill, New York, 1962 M. H. Blewett, The Electrostatic (Van de Graafi) Generator, in Methods of Experimental Physics (Eds. L. C. L. Yuan, C. S. Wu), Vol. 5B, Academic Press, New York, 1963 P. M. Lapostolle, L. Septier, Linear Accelerators, North-Holland, Amsterdam, 1970 A. P. Wolf, W. B. Jones, Cyclotrons for Biomedical Radioisotope Production, Radiochim. Acta 34, 1 (1983)... 

Most of the irradiations for medical radioisotope production at cyclotrons are done using extracted beams. There is more versatility in working with the extracted beam than with the internal beam. Through controlled defocusing and wobbling, it is possible to decrease the... 

Radiolabelled compounds are prepared by introducing artificially produced (nuclear reactor, cyclotron) radioisotopes into the molecules. This can be accomplished by chemical synthesis, biosynthesis and by special procedures (e.g. isotopic exchange, reduction of an unsaturated precursor with tritium gas). As a rule the choice of the preparation method greatly affects the principal characteristics of the radioactive product such as specific activity, type of labelling and purity... 

A glass tube fixed-bed reactor was used as a closed static reactor. The cyclotron produced nC-radioisotope (Ti/2=20.4 min) was used for nC-labeled methanol production by radiochemical process. The nC-labeled methanol (shortly nC-methanol, - 3pmol, -600 MBq) was then introduced into 250 mg of zeolite at ambient temperature by He gas flow. Afterwards, equivalent volume of liquid methyl iodide was injected into nC-methanol to have mixture of methanol and methyl iodide and introduced into catalyst for investigation of methyl iodide influence. After adsorption (2 min), the catalyst was heated up to the required temperature. 

Radioisotope generators provide a desirable alternative to cyclotrons for the production of short lived positron emitters. A fully automated microprocessor controlled generator system for obtaining 76 sec rubidium-82 is described in detail. 

Production of Sr-82. An important consideration in the development of radioisotope generators is the availability, cost, and radionuclidic purity of the long-lived parent. In the case of Sr-82, the 25 day radionuclide is needed in 100-200 mCi amounts in order to provide adequate elution yields of Rb-82 from one loading of Sr-82 every three months. Initially the Sr-82 for the generator was produced at the Lawrence Berkeley Laboratory (LBL) 88-inch cyclotron by the Rb-85 (p,4n) Sr-82 nuclear reaction (12). However, because of the long irradiation time required to produce... 

Experiments performed to date with cyclotrons have used positive ions obtained from carbon dioxide and a gas ion source. This is an advantage in the sense that it permits standard pretreatment practices developed over the last 30 years at decay counting laboratories to be routinely employed up to the point of measurement (29). On the other hand, beam currents using gas ion sources are characteristically significantly less than those from the solid samples currently used with electrostatic type accelerators. In addition, memory effects, which make comparisons of a standard to an unknown difficult, have been reported. The first cyclotrons used for radioisotope measurements had previously been used extensively for nuclear physics experiments and the production of high energy ions. Because of these experiments, some cyclotron systems have apparently been contaminated. For the 88-in. Berkeley cyclotron, the construction of an external ion source was designed to attempt to overcome this problem. Unfortunately, the efficiency of the beam transport system in the external ion source introduced other problems (30). 

For medical purposes, an enormous collection of techniques is accumulated regarding production of short-Kved nuclides mainly by cyclotrons. The technique should undoubtedly be usefiil for appKcation of radioactive tracers to other fields. Such nucKdes include F, and also many nucKdes of metals, halogens, and rare gases. Reactor and cyclotron production of medical radioisotopes is described in Chaps. 38 and 39 of VoL 4, respectively. Basic data for production of short-Kved nucKdes by cyclotron were compfled with substantial references by Qaim (1982). Another review by Waters and Silvester (1982) emphasizes cyclotron-produced nuclides useful for inorganic studies with many references, too. 

Radionuclide production technology at cyclotrons has been well developed, especially for short-lived organic positron emitters, commonly used SPECT radionuclides, and a few therapeutic radioisotopes. In this regard, all components of the technology, i.e., spedal purpose cyclotrons, high current irradiation targets, and automated or remotely controlled chemical processing units can now be purchased. Furthermore, four commonly used cyclotron pro-... 

Most radioisotopes used in nuclear medicine are artificial. They are produced in nuclear reactors (e.g. Sr, Co), cyclotrons (e.g. C, F) or specialized generators such as a molybdenum-technetium generator. The metastable radioisotope ""Tc has a half-life of 6 hours and is important for medical imaging. It is a decay product of Mo - 2.8 days), which is itself man-made, being produced in a nuclear reactor. The radioactive decay of Mo to Tc and the much longer lived Tc is summarized below ... 

In its nuclear medicine business, MDS Nordion remains the world s number one producer of medical isotopes. Radiopharmaceutical producers on five continents use its radioisotopes to make their products. It supplies two-thirds of the reactor-produced isotopes used in the world as well as a wide variety of cyclotron-produced isotopes. Its market leadership continues to be based in its position as the leading supplier of molybdenum-99, the source of technetium 99m, the most important isotope for nuclear medicine. While planning to strengthen its position as the leading supplier of bulk isotopes, MDS Nordion continues to look to the development of its own radiopharmaceutical products as the key to growth in the future. Many of these products help detect medical conditions, but some of the latest ones can aaually treat diseases. MDS Nordion is already selling radiopharmaceuticals for certain types of cancer therapy. 

Van der Merwe, M. J. Chemical Procedures for the Production of Carrier-Free Cyclotron-Produced Radioisotopes. 1971. 50 p. Atomic Energy... 

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