Biodistribution and radiation dosimetry of the 18 kDa translocator protein (TSPO) radioligand [18F]FEDAA1106: a human whole-body PET study

Abstract

Based on the distribution and dose estimates, the estimated radiation burden of [(18)F]FEDAA1106 is moderately higher than that of [(18)F]fluorodeoxyglucose (FDG). In clinical studies, the administered activity of this radioligand ought to be adjusted in line with regional regulations. This result would be helpful for further clinical TSPO imaging studies.

Translocator protein (18 kDa), a potential molecular imaging biomarker for non-invasively distinguishing non-alcoholic fatty liver disease

“…TSPO levels markedly increase at sites of injury and inflammation in the central nervous system (CNS), making it a useful marker of ''active'' CNS pathology in experimental animals and humans [21]. Radiolabeled imaging probes targeting TSPO have allowed the sensitive detection of various neuropathological conditions by PET [7][8][9][10][11][12]. [ 11 C]PK11195 was the first PET ligand used for clinical imaging of TSPO.…”

“…PET with radiolabeled TSPO probes has allowed non-invasive and reliable investigation of TSPO in neuropathological damages of experimental animals and humans [7][8][9][10][11][12]. Mitochondrial dysfunction plays a key role in the physiopathology of NASH irrespective of the initial cause.…”

Molecular Imaging of Neuroinflammation in Neurodegenerative Dementias: The Role of In Vivo PET Imaging

“…11 C-PK11195 presents, however, some limits, such as highly lipophilic nature, low bioavailability, high non-specific binding and limited capacity to detect small changes in TSPO expression, which led to a recent effort towards the development of second-generation TSPO ligands [41]. These new generation tracers include both carbon-11 and fluorine-18 radioligands, such as 11 C-DPA713 [47], 11 C-DAA1106 [48], 11 C-PBR28 [49,50,51], 11 C-vinpocetine [52], 18 F-DPA714 [53], 18 F-FEPPA [54], 18 F-FEMPA [55] and 18 F-FEDAA1106 [56,57,58,59,60], which have all been tested in a few human studies. Notably, TSPO genotype may considerably influence the second-generation radiotracer binding affinity [59], making genetic testing mandatory.…”

“…Moreover, both 18 F-DPA714 and 11 C-PBR28 uptake correlated with cognitive status and grey matter volume [51,53]. Today, the reported findings from PET with other second-generation tracers (i.e., 18 F-FEPPA, 18 F-FEMPA, 18 F-FEDAA1106 and 11 C-DAA1106) are sparse and contradictory [48,54,55,56,57,58,85]. None of the second-generation tracers at present has sufficient and solid evidence to support their use in human studies.…”

Imaging of neuroinflammation

“…Recently a new promising radioligand with greater affinity for TSPO than PK11195 has been developed. [ 18 F]FEDAA1106 has been proposed for the clinical evaluation of neuroinflammatory diseases and its biodistribution has been recently published [18].…”