Relationship of regional cerebral blood flow and kinetic behaviour of O-(2-(18)F-fluoroethyl)-L-tyrosine uptake in cerebral gliomas.
OBJECTIVE
O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) is an established tracer for brain tumour imaging. (18)F-FET kinetics in gliomas appear to have potential for tumour grading, but the mechanisms remain unclear. The aim of this study was to explore the relationship between regional cerebral blood flow (rCBF) as measured by arterial spin labelling MRI and the kinetic behaviour of (18)F-FET PET in cerebral gliomas.


METHODS
Twenty patients with cerebral gliomas were investigated using arterial spin labelling MRI and dynamic (18)F-FET PET. Time-activity curves (TACs) of (18)F-FET uptake were analysed in 33 different tumour regions. The slopes of TAC during the early (0-5 min; slopeup) and late phases of tracer uptake (17-50 min; slopedown) were fitted using linear regression lines. In addition, TACs of each lesion were assigned to different curve patterns. Furthermore, we calculated tumour-to-brain ratios of (18)F-FET uptake. The relationship between (18)F-FET parameters and rCBF was determined.


RESULTS
(18)F-FET uptake in the early phase (slopeup) showed a significant correlation with rCBF (r=0.4; P=0.02). In contrast, both slopedown and TAC patterns showed no significant correlation with rCBF. Furthermore, a significant correlation was found between rCBF and tumour-to-brain ratio (r=0.53; P=0.002).


CONCLUSIONS
There is a relationship between rCBF and (18)F-FET uptake in cerebral gliomas in the initial uptake phase, but the kinetic behaviour of (18)F-FET uptake in the late phase is not significantly influenced by rCBF. Thus, the differential kinetic pattern of (18)F-FET uptake in high-grade and low-grade gliomas appears to be determined by factors other than rCBF.
aInstitute of Neuroscience and Medicine (INM-4) bJülich-Aachen Research Alliance (JARA), Section JARA-Brain, Forschungszentrum Jülich, Jülich Departments of cNuclear Medicine dPsychiatry and Psychotherapy eNeurology, RWTH Aachen University Hospital, Aachen fDepartment of Neurology, University Hospital Cologne, Cologne, Germany.
Ke
K
Zhang
Karl-Josef
KJ
Langen
Irene
I
Neuner
Gabriele
G
Stoffels
Christian
C
Filss
Norbert
N
Galldiks
Lutz
L
Tellmann
Elena
E
Rota Kops
Heinz H
HH
Coenen
Hans
H
Herzog
Nadim J
NJ
Shah
D000328:Adult; D000368:Aged; D001692:Biological Transport; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
C117289:O-(2-fluoroethyl)tyrosine; D014443:Tyrosine