Test–Retest Reproducibility of Binding Parameters in Humans with 11C-LY2795050, an Antagonist PET Radiotracer for the κ Opioid Receptor

Journal of Nuclear Medicine

Michael Kapinos¹  Nabeel Nabulsi¹  Johannes Tauscher¹  David Labaree¹  Richard E. Carson¹  Shu-Fei Lin¹  Ming-Qiang Zheng¹  Shannan Henry¹  Jim Ropchan¹  Yiyun Huang¹  Alexander Neumeister¹  Soheila Najafzadeh¹  Mika Naganawa¹ 

关键词: kappa opioid receptor;    positron emission tomography;    test–retest reproducibility;    brain imaging;   

DOI  :  10.2967/jnumed.114.147975

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

11C-LY2795050 is a new antagonist PET radioligand for the κ opioid receptor (KOR). In this study, we assessed the reproducibility of the binding parameters of 11C-LY2795050 in healthy human subjects. Methods: Sixteen healthy subjects (11 men and 5 women) underwent 2 separate 90-min PET scans with arterial input function and plasma free fraction (fP) measurements. The 2-tissue-compartment model and multilinear analysis-1 were applied to calculate 5 outcome measures in 14 brain regions: distribution volume (VT), VT normalized by fP (VT/fP), and 3 binding potentials (nondisplaceable binding potential, binding potential relative to total plasma concentration, and binding potential relative to free plasma concentration: BPND, BPP, BPF, respectively). Since KOR is distributed ubiquitously throughout the brain, there are no suitable reference regions. We used a fixed fraction of individual cerebellar VT value (VT,CER) as the nondisplaceable VT (VND) (VND = VT,CER/1.17). The relative and absolute test–retest variability and intraclass correlation coefficient were evaluated for the outcome measures of 11C-LY2795050. Results: The test–retest variability of 11C-LY2795050 for VT was no more than 10% in any region and was 12% in the amygdala. For binding potential (BPND and BPP), the test–retest variability was good in regions of moderate and high KOR density (BPND > 0.4) and poor in regions of low density. Correction by fP (VT/fP or BPF) did not improve the test–retest performance. Conclusion: Our results suggest that quantification of 11C-LY2795050 imaging is reproducible and reliable in regions with moderate and high KOR density. Therefore, we conclude that this first antagonist radiotracer is highly useful for PET studies of KOR.

【 授权许可】

Unknown