Quantification of Dynamic 11C-Phenytoin PET Studies
The overexpression of P-glycoprotein (Pgp) is thought to be an important mechanism of pharmacoresistance in epilepsy. Recently, 11C-phenytoin has been evaluated preclinically as a tracer for Pgp. The aim of the present study was to assess the optimal plasma kinetic model for quantification of 11...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Society of Nuclear Medicine
2015
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| Subjects: | |
| Online Access: | http://eprints.usm.my/37523/ http://eprints.usm.my/37523/1/syahirnuclmedpostprint.pdf |
| Summary: | The overexpression of P-glycoprotein (Pgp) is thought to be an
important mechanism of pharmacoresistance in epilepsy. Recently,
11C-phenytoin has been evaluated preclinically as a tracer for Pgp.
The aim of the present study was to assess the optimal plasma
kinetic model for quantification of 11C-phenytoin studies in humans.
Methods: Dynamic 11C-phenytoin PET scans of 6 healthy volunteers
with arterial sampling were acquired twice on the same day
and analyzed using single- and 2-tissue-compartment models with
and without a blood volume parameter. Global and regional test–
retest (TRT) variability was determined for both plasma to tissue rate
constant (K1) and volume of distribution (VT). Results: According to the
Akaike information criterion, the reversible single-tissue-compartment
model with blood volume parameter was the preferred plasma input
model. Mean TRT variability ranged from 1.5% to 16.9% for K1 and
from 0.5% to 5.8% for VT. Larger volumes of interest showed better
repeatabilities than smaller regions. A 45-min scan provided essentially
the same K1 and VT values as a 60-min scan. Conclusion: A reversible
single-tissue-compartment model with blood volume seems to be a
good candidate model for quantification of dynamic 11C-phenytoin
studies. Scan duration may be reduced to 45 min without notable
loss of accuracy and precision of both K1 and VT, although this still
needs to be confirmed under pathologic conditions. |
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