Mapping neuroreceptors with metal-labeled radiopharmaceuticals

Abstract

The growing epidemiological and economic burden of neurological diseases on society is tremendous. A correct and timely diagnosis can help in lowering the burden and improving the life quality of both the diseased person and the caretaker. Imaging of the brain (neuroimaging) using CT, MRI, and nuclear imaging methods can provide anatomical and functional information. Neuroreceptors are central to neurotransmission and neuromodulation in the CNS. imaging of receptors in the brain provides powerful tools for the functional study of the central nervous system (CNS) in normal or diseased states. Presently, PET imaging using non-metallic radiotracers dominates the imaging of neuroreceptors. Metal-based probes for SPECT and PET can be economical and logistically easier to use without compromising the information. This review focuses on the development of metallic radiotracers for (Tc) SPECT and (Ga) PET along with future directions based on the metallic probes developed for other imaging modalities namely MRI.

68Ga‐Labelled Tropane Analogues for the Visualization of the Dopaminergic System

“…In addition, the HBED chelator has two fewer heteroatoms than the DO3A chelator resulting in a lesser amount of hydrogen bridge bonds. In comparison to DO3A, a 100-fold higher lipophilicity could be achieved with the tropane-butyne-HBED (12) and even a 1000fold higher lipophilicity with the tropane-hexadiyne-HBED (13).…”

“…All precursors (8)(9)(10)(11)(12)(13) were labelled with gallium-68 obtained from a 68 Ge/ 68 Ga-generator utilizing the acetone post procession. [31] The free chelators were exposed to 68 GaCl 3 in NaOAc buffer (0.2 M, pH 4.5) at 45°C (for HBED) or 95°C (for DO3A), respectively.…”

“…1 cm [12] . To date, however, there is no DAT tracer labelled with a generator‐produced PET nuclide that has been successfully tested in vivo [13] …”

“…[12] To date, however, there is no DAT tracer labelled with a generator-produced PET nuclide that has been successfully tested in vivo. [13] Gallium-68 is one of the most widely used PET radiometals. Its practical half-life of 68 min and above all its simple and costeffective non-carrier-added (n.c.a.)…”

New Trends and Current Status of Positron-Emission Tomography and Single-Photon-Emission Computerized Tomography Radioligands for Neuronal Serotonin Receptors and Serotonin Transporter

“…[ 99m Tc]-based radioligands for serotonin were reported as early as 1999. A detailed description is presented in the recent review . Our group has also contributed to the development of metal-based radioligands for imaging of 5HT1A.…”