A Graphical Method to Compare the in vivo Binding Potential of PET Radioligands in the Absence of a Reference Region: Application to [11C]PBR28 and [18F]PBR111 for TSPO Imaging. Issue 7 (July 2014)

• Record Type: Journal Article
• Authors: Guo, Qi; Owen, David R; Rabiner, Eugenii A; Turkheimer, Federico E; Gunn, Roger N
• Is Part Of: Journal of cerebral blood flow & metabolism. Volume 34:Issue 7(2014)
• Page Start: 1162
• Page End: 1168
• Publication Date: 2014-07
• Subjects: graphical analysis -- PET -- radioligand comparison -- specific binding -- TSPO; Cerebral circulation -- Periodicals; Brain -- Metabolism -- Periodicals; Brain -- Blood-vessels -- Periodicals; Cerebrovascular disease -- Periodicals; 612.824
• DOI: 10.1038/jcbfm.2014.65
• Languages: English
• ISSNs: 0271-678X

Abstract

Positron emission tomography (PET) radioligands for a reversible central nervous system (CNS) demand a high specific to nonspecific signal characterized by the binding potential ( BPND ). The quantification of BPND requires the determination of the nondisplaceable binding usually derived from a reference region devoid of the target of interest. However, for many CNS targets, there is no valid reference region available. In such cases, the total volume of distribution ( V T ) is often used as the outcome measure, which includes both the specific and nonspecific binding signals. Here we present a graphical method that allows for direct comparison of the binding potential of ligands using the regional V T data alone via linear regression. The method was first validated using literature data for five serotonin transporter ligands, for which a reference region exists, and then applied to two second generation 18 kDa translocator protein radioligands, namely [ 11 C]PBR28 and [ 18 F]PBR111. The analysis determined that [ 11 C]PBR28 had a higher BPND than [ 18 F]PBR111.