Dual time-point FDG PET/CT and FDG uptake and related enzymes in lymphadenopathies: preliminary results.
OBJECTIVE
The purpose of this study was to determine the ability of dual time-point (DTP) PET/CT with (18)F-FDG to discriminate between malignant and benign lymphadenopathies. The relationship between DTP FDG uptake and glucose metabolism/hypoxia markers in lymphadenopathies was also assessed.


METHODS
Patients with suspected lymphoma or recently diagnosed treatment-naive lymphoma were prospectively enrolled for DTP FDG PET/CT (scans 60 min and 180 min after FDG administration). FDG-avid nodal lesions were segmented to yield volume and standardized uptake values (SUV), including SUVmax, SUVmean, cSUVmean (with partial volume correction), total lesion glycolysis (TLG) and cTLG (with partial volume correction). Expression of glucose transporter-1 (GLUT-1), hexokinase-II (HK-II), glucose-6-phosphatase (G6Pase) and hypoxia-inducible factor-1alpha (HIF-1alpha) were assessed with immunohistochemistry and enzyme activity was determined for HK and G6Pase.


RESULTS
FDG uptake was assessed in 203 lesions (146 malignant and 57 benign). Besides volume, there were significant increases over time for all parameters, with generally higher levels in the malignant lesions. The retention index (RI) was not able to discriminate between malignant and benign lesions. Volume, SUVmax, TLG and cTLG for both scans were able to discriminate between the two groups statistically, but without complete separation. Glucose metabolism/hypoxia markers were assessed in 15 lesions. TLG and cTLG were correlated with GLUT-1 expression on the 60-min scan. RI-max and RI-mean and SUVmax, SUVmean and cSUVmean on the 60-min scan were significantly correlated with HK-II expression.


CONCLUSIONS
RI was not able to discriminate between malignant and benign lesions, but some of the SUVs were able to discriminate on the 60-min and 180-min scans. Furthermore, FDG uptake was correlated with GLUT-1 and HK-II expression.
Department of Nuclear Medicine, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark. sofie.christlieb@gmail.com.
Sofie Bæk
SB
Christlieb
Department of Nuclear Medicine, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Casper Nørgaard
CN
Strandholdt
Department of Nuclear Medicine, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Birgitte Brinkmann
BB
Olsen
Department of Haematology, Vejle Hospital, Kabbeltoft 25, 7100, Vejle, Denmark.
Karen Juul
KJ
Mylam
Department of Haematology, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Thomas Stauffer
TS
Larsen
Department of Nuclear Medicine, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Anne Lerberg
AL
Nielsen
Department of Ear, Nose and Throat, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Max
M
Rohde
Department of Nuclear Medicine, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Oke
O
Gerke
Department of Pathology, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Karen Ege
KE
Olsen
Department of Pathology, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Michael Boe
MB
Møller
Department of Pathology, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Bjarne Winther
BW
Kristensen
Department of Haematology, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Niels
N
Abildgaard
Hospital of the University of Pennsylvania, 3400 Spruce St., Philadelphia, PA, 19104, USA.
Abass
A
Alavi
Department of Nuclear Medicine, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
Poul Flemming
PF
Høilund-Carlsen
D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D005952:Glucose-6-Phosphatase / Q000378:metabolism*; D006593:Hexokinase / Q000378:metabolism*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008223:Lymphoma / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D047368:Tumor Burden; D055815:Young Adult
D019788:Fluorodeoxyglucose F18; D006593:Hexokinase; D005952:Glucose-6-Phosphatase
Dual time-point FDG PET/CT; Glucose transporter-1; Glucose-6-phosphatase; Hexokinase; Hypoxia-inducible factor-1alpha; Lymphadenopathies