Radionuclides diagnostic applications

The radiation exposure of the patients depends on the activity of the radionuclide, the kind of radiation emitted, the half-life of the radionuclide and its residence time in the body. With respect to radiation exposure, a emitters are not suitable for diagnostic application because of the high energy doses transmitted locally to organs or tissues. 

The lower limit of half-lives of radionuclides for diagnostic application is of the order of minutes. It is detennined by the time needed for synthesis of suitable compounds and for transport in the body to the place of application. On the other hand, half-lives > 1 d are less favourable, because of the longer radiation exposure of the patients and the risk of environmental contamination. 

International Committee For Standardization In Hematology (1988) Panel on diagnostic applications of radionuclides. Recommended method for indium-111 platelet survival studies. J Nucl... 

Radionuclides find applications in many fields. Their major use, however, is in medicine, in both diagnosis and therapy. The production of radionuclides is carried out using nuclear reactors as well as cyclotrons. The reactor produced radionuclides are generally neutron excess nuclides. They mostly decay by P emission. The cyclotron produced radionuclides, on the other hand, are often neutron deficient and decay mainly by EC or emission. They are especially suitable for diagnostic studies. The reactor production of radionuclides is described in Chap. 38 of this Volume this chapter treats radionuclide production with cyclotrons. It is worth pointing out that today more than 300 cyclotrons exist worldwide (cf. Directory of Cyclotrons, lAEA-DCRP/CD, 2004), many of them in hospitals they produce short-lived radionuclides for medical use. Thus, radionuclide production science and technology at cyclotrons has become a very important feature of modern nuclear medicine. 

As Cu has many interesting radionuclides for therapeutic as well as for diagnostic applications (O Tables 45. i and O 45.2), the development of ideal chelators for this metal is of interest. BFCs used for the coupling of Cu-radioisotopes to biomolecules are based on the 14-membered tetraazamacrocycle cyclam 14 (1,4,8,11-tetraazacyclotetradecane) O Fig. 45.17). Two bifunctional versions of cyclam-14, 4-[(l,4,8,ll-tetraazacyclotetradec-l-yl)methyl]-benzoic acid (= CPTA) and [6-(p-bromoacetamido)benzyl]-l,4,8,ll-tetraazacyclotetradecane-l,4,8,ll-tetraacetic acid (= BAT) (O Fig. 45.17), were coupled to monoclonal antibodies and somatostatin analogs (Smith-Jones et al. 1991 Anderson et al. 1995 Wilder et al. 1996). In addition to... 

Administration of radionuclide preparations (radiopharmaceuticals) to patients is widely practiced throughout the world. Many of the diagnostic applications of radionuclides are conducted in vitro and in vivo. Since the in vitro experiments do not give rise to the exposure of patients, only diagnostic in vivo examinations are referred to in this section. 

Metals continue to play an important role in radiopharmaceuticals for diagnostic and therapeutic applications in nuclear medicine. Radiopharmaceuticals are drugs that contain a radionuclide and are used for imaging if the radionuclide is a photon emitter (gamma (7) or positron (/3+)) or for... 

The major driving force for the development of technetium coordination chemistry has undoubtedly been the potential applications in diagnostic nuclear medicine. The primary requirements for a radionuclide to be used in imaging are that the radiation emitted must be of appropriate energy, the decay half-life must lie in a suitable time window, it must be relatively cheap and readily available in the radiopharmacy, and finally it must have highly flexible co-ordination chemistry. 

Coordination compounds have the potential to be used in both diagnostic and therapeutic applications, but only the former have been extensively developed so far. This reflects the differing nature of the two types of application. In diagnosis it is only necessary to detect the location of the radionuclide in the body. Since extremely sensitive devices are available for the detection of ionizing radiation, useful diagnostic information may be obtained with relatively low patient... 

Labelled compounds have found broad application in various fields of science and technology. A great variety of labelled compounds are applied in nuclear medicine. The compounds are produced on a large scale as radiopharmaceuticals in cooperation with nuclear medicine, mainly for diagnostic purposes and sometimes also for therapeutic application. The study of metabolism by means of labelled compounds is of great importance in biology. More details on the application of radionuclides and labelled compounds in medicine and other areas of the life sciences will be given in chapter 19. 

R. E. Weiner, M. L. Thakur, Metallic Radionuclides Applications in Diagnostic and Therapeutic Nuclear Medicine, Radiochim. Acta 70/71, 273 (1995)... 

In general, p - and p" -Particles penetrate deep into the medium however, they do not cause damage to tissues and organs. Radionuclides that decay by p-Particle emissions are used very extensively in nuclear medicine for diagnostic and therapeutic applications. Positron-emitting nuclides are used in nuclear medicine for diagnostic purposes. p+-Emitting radionuclides are under active study for use in radiotherapy. An example... 

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