Distribution patterns of 18F-labelled fluoromethylcholine in normal structures and tumors of the head: a PET/MRI evaluation.
OBJECTIVE
To evaluate the distribution of 18F-labelled fluoromethylcholine (FCho) in normal structures and tumors of the head region using positron emission tomography (PET) and magnetic resonance imaging.


METHODS
We retrospectively reviewed the positron emission tomography, magnetic resonance imaging, and the coregistered images obtained in 17 patients with suspected high-grade gliomas. The accumulation of 18F-FCho in the normal structures and in brain lesions was visually and semiquantitatively assessed. A 4-point grading system was used for the visual analysis. A standardized uptake value (SUV) was used to quantify uptake.


RESULTS
In the normal brain parenchyma, 18F-FCho uptake was faint (SUVmean, 0.15 ± 0.03 (SD)). Uptake was generally moderate in the choroid plexus (SUVmean, 0.82 ± 0.16), cavernous sinus (SUVmean, 0.87 ± 0.19), extraocular eye muscles (SUVmean, 1.10 ± 0.27), masticatory muscles (SUVmean, 0.99 ± 0.22), and bone marrow (SUVmean, 1.06 ± 0.26), whereas uptake was usually moderately intense in the pituitary gland (SUVmean, 1.90 ± 0.21). Uptake was variable in the lacrimal glands and the mucosa of the nasal cavity (for SUVmean of subgroups see text). Intense uptake was observed in the parotid glands (SUVmean, 3.27 ± 0.73). (Moderately) intense 18F-FCho uptake was observed in glioblastomas (range SUVmax, 2.26-6.37) and typical meningiomas (range SUVmax, 3.75-5.81). Uptake was globally faint in grade II and III gliomas (range SUVmax, 0.33-0.78). 18F-FCho uptake was also demonstrated in benign lesions, such as a tumefactive demyelinating brain lesion.


CONCLUSIONS
18F-FCho uptake was faint in the normal brain parenchyma and usually moderate in the choroid plexus, cavernous sinus, extraocular eye muscles, masticatory muscles, and bone marrow. Uptake in the pituitary gland was generally moderately intense, whereas uptake in the lacrimal glands and the mucosa of the nasal cavity was variable. Parotid glands had intense uptake. Also, uptake in glioblastomas and meningiomas was usually (moderately) intense, whereas uptake in grade II and III gliomas was globally faint. However, 18F-FCho uptake was not tumor specific.
Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium.
Koen
K
Mertens
Hamphrey
H
Ham
Karel
K
Deblaere
Jean-Pierre Okito
JP
Kalala
Caroline
C
Van den Broecke
Dominique
D
Slaets
Filip
F
De Vos
Ingeborg
I
Goethals
D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D002794:Choline / Q000031:analogs & derivatives*; D005260:Female; D005462:Fluorine Radioisotopes; D005682:Gadolinium / Q000008:administration & dosage; D006257:Head / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000000981:diagnostic imaging / Q000473:pathology; D049268:Positron-Emission Tomography
D005462:Fluorine Radioisotopes; C516370:fluoromethylcholine; D005682:Gadolinium; D002794:Choline