Refereed journal article or data article (A1)

Test-retest reliability of (11)C-ORM-13070 in PET imaging of α2C-adrenoceptors in vivo in the human brain




List of AuthorsJussi Lehto, Jere R. Virta, Vesa Oikonen, Anne Roivainen, Pauliina Luoto, Eveliina Arponen, Semi Helin, Johanna Hietamäki, Aila Holopainen, Marita Kailajärvi, Juha M. Peltonen, Juha Rouru, Jukka Sallinen, Kirsi Virtanen, Iina Volanen, Mika Scheinin, Juha O. Rinne

Publication year2015

JournalEuropean Journal of Nuclear Medicine and Molecular Imaging

Journal name in sourceEuropean journal of nuclear medicine and molecular imaging

Journal acronymEur J Nucl Med Mol Imaging

Volume number42

Issue number1

Start page120

End page127

Number of pages8

ISSN1619-7089

eISSN1619-7089

DOIhttp://dx.doi.org/10.1007/s00259-014-2899-z


Abstract

PURPOSE\nα2C-Adrenoceptors share inhibitory presynaptic functions with the more abundant α2A-adrenoceptor subtype, but they also have widespread postsynaptic modulatory functions in the brain. Research on the noradrenergic system of the human brain has been hampered by the lack of suitable PET tracers targeted to the α2-adrenoceptor subtypes.\nMETHODS\nPET imaging with the specific α2C-adrenoceptor antagonist tracer [(11)C]ORM-13070 was performed twice in six healthy male subjects to investigate the test-retest reliability of tracer binding.\nRESULTS\nThe bound/free ratio of tracer uptake relative to nonspecific uptake into the cerebellum during the time interval of 5 - 30 min was most prominent in the dorsal striatum: 0.77 in the putamen and 0.58 in the caudate nucleus. Absolute test-retest variability in bound/free ratios of tracer ranged from 4.3 % in the putamen to 29 % in the hippocampus. Variability was also <10 % in the caudate nucleus and thalamus. Intraclass correlation coefficients (ICC) ranged from 0.50 in the hippocampus to 0.89 in the thalamus (ICC >0.70 was also reached in the caudate nucleus, putamen, lateral frontal cortex and parietal cortex). The pattern of [(11)C]ORM-13070 binding, as determined by PET, was in good agreement with receptor density results previously derived from post-mortem autoradiography. PET data analysis results obtained with a compartmental model fit, the simplified reference tissue model and a graphical reference tissue analysis method were convergent with the tissue ratio method.\nCONCLUSION\nThe results of this study support the use of [(11)C]ORM-13070 PET in the quantitative assessment of α2C-adrenoceptors in the human brain in vivo. Reliable assessment of specific tracer binding in the dorsal striatum is possible with the help of reference tissue ratios.



Last updated on 2021-24-06 at 09:12