H. Vilkman et al., Measurement of extrastriatal D-2-like receptor binding with [C-11]FLB 457 - a test-retest analysis, EUR J NUCL, 27(11), 2000, pp. 1666-1673
Citations number
21
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
[C-11]FLB 457 is a radioligand for positron emission tomography (PET) that
possesses high affinity to D-2/D-3 receptors. It has been suggested to be u
seful for quantification of low-density dopamine D-2 receptor populations,
e.g. in cortical and limbic brain areas, We explored the reproducibility of
five methods for measuring extrastriatal D-2-like receptor binding potenti
al with [C-11]FLB 457. Seven healthy male volunteers were examined twice wi
th [C-11]FLB 457 thigh specific radioactivity) on the same day, at least 3
h apart. Four brain areas, frontal cortex, nucleus thalamus, temporal corte
x and cerebellar cortex, were examined. Binding potentials (BPs) were deriv
ed from ii) a target to cerebellum distribution volume ratio, (2/3) two rev
ersible reference tissue compartment models and (4) a transient equilibrium
approach. For comparison, BP values were also calculated with the standard
three-compartment kinetic model that does not assume a receptor-free refer
ence region. The use of the standard three-compartment model did not result
in reproducible BP estimates, The distribution volume (DV) ratio, referenc
e tissue compartment models and the transient equilibrium method all had go
od to excellent intraclass correlation coefficients (ICCs) in the studied b
rain areas ranging from 0.56 to 0.93. Absolute variability was also relativ
ely low, ranging from 5.3% to 10.4%. There were no marked differences in th
e ICC or absolute and relative variability between the four methods based o
n a reference tissue (cerebellum). In addition, we did not observe systemat
ic differences in the BP between the first and the second scan. These data
indicate that the reproducibility of the DV ratio, reference tissue models
and the transient equilibrium method is good or excellent. However, each of
these methods includes assumptions affecting their validity. Thus, the cho
ice of method will be critically dependent on the purpose of the study.