Labelling with positron emitters of pnicogens and chalcogens

Abstract

The increasing importance of the positron emission tomography (PET) in clinical diagnosis led to the development of a multitude of radiotracers labelled with positron‐emitting radionuclides of groups 15 (pnicogens) and 16 (chalcogens) of the periodic table of elements. The positron emitters of the endogenous occurring elements nitrogen, phosphorus, oxygen, and sulphur are characterized by very short half‐lives compared with the most commonly used PET radionuclides carbon‐11 or fluorine‐18. Therefore, the potential of their synthesis and possible applications in PET is challenging and limited. On the other hand, the nonstandard positron emitters arsenic‐72, arsenic‐74, and selenium‐73 have half‐lives in the range of hours to days and, thus, are of interest for PET studies of processes with long biological half‐lives, but novel methods have to be developed for their application, especially in the no‐carrier‐added state. This review summarizes recent research concerning the positron emitters of pnicogens and chalcogens for radiolabelling applications.

Chemistry for Positron Emission Tomography: Recent Advances in 11C‐, 18F‐, 13N‐, and 15O‐Labeling Reactions

“…Considering the extremely short half‐lives of 15 O ( t 1/2 =2.04 min) and 13 N ( t 1/2 =9.97 min), it is more challenging to perform multistep radiochemical synthesis of complex molecules than with 18 F. An automated inline production of 15 O and 13 N agents is often used to improve the synthesis efficiency and quality, so that repetitive PET studies can be conducted on the same subject within a short study period. To complement previous 13 N and 15 O reviews, we highlight the recent development of major synthons and transformations.…”

Chemie der Positronenemissionstomographie: Aktuelle Fortschritte bei 11C‐, 18F‐, 13N‐ und 15O‐Markierungsreaktionen

“…Oft wird eine automatisierte Inline‐Herstellung von 15 O‐ und 13 N‐Agenzien verwendet, um Effizienz und Qualität der Synthese zu verbessern, sodass repetitive PET‐Untersuchungen am gleichen Probanden innerhalb einer kurzen Untersuchungszeit durchgeführt werden können. Ergänzend zu früheren Übersichtsartikeln über 13 N und 15 O werden hier die jüngsten Entwicklungen zu den wichtigsten Synthonen und Umwandlungen vorgestellt.…”

Pyridine-based Strategy towards Nitrogen Isotope Exchange

“…18 It is also one of the primary sources of nitrogen-13 along with [ 13 N]NO2 -, another valuable 13 N building block used to produce a variety of 13 N-labeled derivatives such as amino acids. 17,19 More complex tracers such as [ 13 N]thalidomide, 20 [ 13 N]dantrolene 21 and [ 13 N]nifedipine and derivatives 22 have also been described in the literature showing the rising interest for 13 N-radiotracers.…”