A novel approach to determine the positron emission intensity in the decay of a radionuclide for medical applications: an overview

Abstract With the increasing significance of positron emission tomography in medicine, the need for development of novel positron emitters is increasing. A prerequisite for their use is a precise knowledge of the positron emission intensity in their decay. The literature data are generally based on standardisation of older decay schemes and therefore often lack accuracy. We have developed a new approach of directly measuring the positron emission component through high-resolution γ-ray spectroscopy, beta counting and γγ-coincidence counting, and the electron capture component via high-resolution X-ray spectroscopy. This article provides an overview of the seven radionuclides investigated, namely 45 Ti, 64 Cu, 72 As, 76 Br, 86g Y, 120g I and 124 I. Our results agree with the literature values derived from the extensively investigated decay schemes in recent years, but not with those obtained from poorly characterised older decay schemes. The potentially useful positron emitters that require such studies are briefly outlined.