Radioisotopes preparations

The concept of preparing a reference material with property values traceable to SI units is a relatively recent one which has not yet been applied in practice to natural matrix radioisotopic reference materials. This is one of the main reasons why such materials are generally not recommended for calibration purposes. 

The antibody preparations could be administered unaltered or (more commonly) after their conjugation to radioisotopes or toxins. Binding of unaltered monoclonal antibodies to a tumour surface alone should facilitate increased destruction of tumour cells (Figure 13.4). This approach, however, has yielded disappointing results, as the monoclonal antibody preparations used to date have been murine in origin. The Fc region of such mouse antibodies is a very poor activator of human immune function. Technical advances, allowing the production of human/humanized monoclonals (see later) may render this therapeutic approach more attractive in the future. 

Imura and Suzuki36 have prepared labelled organotin compounds from artificial tin isotopes produced in a cyclotron. The carrier-free tin-113 radioisotope was produced by irradiating indium-115 oxide with 40-MeV protons (equation 33). 

Administration of Radioisotopes, Tissue Preparation, and Emulsions Resolution and Quantitative Autoradiography Limitations of EM Autoradiographs Protocols Conclusions References... 

Carrier-free Radioisotopes from Cyclotron Targets. XI. Preparation... 

Radioisotopes from Cyclotron Targets. XVI. Preparation and Isolation of Pd103 from Rhodium. J. chem. Physics 19, 660 (1951)-... 

Carrier-free Radioisotopes from Cyclotron Targets. VI. Preparation and isolation of 10s.108.UIAg from Palladium. J. chem. Physics 18, 391 (1950). 

F]Fluoride is usually prepared from the 0(p,n) F reaction on 0-enriched water [52]. This route is highly attractive because it is a high-yielding reaction, the radioisotope is produced with a high specific radioactivity and all the radioactivity is potentially useful for labelling in contrast to [ F] F2 for which only 50% of the total radioactivity is used. 

Special attention has been paid to Re, since this isotope can readily be obtained from isotope generators which are based on the decay of (physical ti/2 = 69.4 d) in a matrix from which the daughter nuclide Re can readily be separated. This permits continuous availability of the radioisotope at the clinic and allows the preparation of Re-radiopharmaceuticals in a kit procedure as has been established for technetium radiopharmaceuticals. W/ Re generators... 

Radioisotopes are also used in radiation therapy to treat cancer. The goal in radiation therapy is to kill malignant cells, while protecting healthy tissue from radiation effects. Radioisotopes such as yttrium-90, a beta emitter, may be placed directly in the tumor. Alternatively, the diseased tissue may be subjected to beams of gamma radiation. Cobalt-60 used in radiation therapy is prepared by a series of transmutations ... 

Radioactive labels are -emitters selected on the basis of half-lives, the energies emitted, decay products, ease of labeling, availability and expense. Iodine isotopes 121,123, and 124, Indium 111, and Technetium 99 are the labels most widely used. The short half-lives of these labels (hours to days) means that radioimaging reagents are prepared immediately prior to treatment. Radioimaging of diseased tissue also provides useful information on the design of therapies that localize radioisotopes or toxins at tumor sites for therapy. 

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