Radioisotope, selection

Safety. The principal concerns regarding nuclear medical imaging are those associated with the radiopharmaceuticals. Much research has gone into the selection of radiopharmaceuticals exhibiting minimal toxicities, rapid elimination from the body, and short half-life. The radioisotope must be... 

Certain operations require that the workspace be at a lower pressure than surrounding workspaces, e.g., radioisotope laboratories. In these cases, the exhaust flow rate should exceed the supply flow rate, but this excess should he within 10%. The additional resistance resulting from this imbalance should be considered in the design of the exhaust system, specifically in the selection of exhaust fans. 

The earliest studies in this field were conducted largely to benefit from the Szilard-Chalmers effect—namely, the separation of radioactive atoms from the bulk material—in order either to make nuclear chemical study of radioactive nuclides or to effect an enrichment of radioisotopes. In Table II are listed some selected works of this type. 

Tab. 4.7 IAEA radioisotope reference materials selected for upgrade (Fajgelj et al. 1999) Code Matrix Measurands Interest ...

Traceability, however, is such an important concept that it will undoubtedly also be applied in future to radioisotopic reference materials. The IAEA is giving high priority to such work in its own reference material program. Table 4.7 provides details of some existing materials which have been selected for upgrade. 

Dobson, E. L., Gofman, J. W., Jones, H. B., Kelly, L. S. and Walker, L. A. (1949). Studies with colloids containing radioisotopes of yttrium, zirconium, columbium and lanthanum. II. The controlled selective localization of radioisotopes of yttrium, zirconium and columbium in the bone marrow, liver, and spleen, J. Lab. Clin. Med. 34, 305. 

Prominent among the elements that provide a selection of radioisotopes with therapeutically useful radiological properties is rhenium. It is attractive for a variety of reasons ... 

The half-life values of selected radioisotopes are listed in Table 15.3. 

TABLE 15.3. Half-Life Values of Selected Radioisotopes. ... 

Selected entries from Methods in Enzymology [vol, page(s)] Radioisotopic assay of acetylcarnitine and acetyl-CoA, 123, 259 short-chain acylcarnitines identification and quantitation, 123,... 

Much research has gone into raising the sensitivity and selectivity of immunosensors to the desired levels. Several labels have proved to ensure a high sensitivity, yet radioisotopic labels have essentially been avoided. Non-isotopic labels for immunosensors include various enzymes, catalysts, fluorophores, electrochemically active molecules and liposomes. Labelled immunosensors are basically designed so that immunochemical complexation takes place on the surface of the sensor matrix. There are several variants of the procedure used to form an immunocomplex on the matrix. In the final step, however, the label should always be incorporated into the immunocomplex for determination, as shown in Fig. 3.27.B. 

Several clinical trials have evaluated (or continue to evaluate) monoclonal antibodies to which a radioactive tag has been conjugated. These are usually employed as potential anti-cancer agents. The rationale is selective delivery of the radioactivity directly to the tumour site. Most of the radioisotopes being evaluated are /i-emitters these include I and I (iodine), Re and Re (rhenium) and (yttrium). The medium-energy radioactivity these emit is capable of penetrating... 

---