Quantification of glucose utilization in liver metastases: parametric imaging of FDG uptake with PET.
Positron emission tomography (PET) fluorodeoxyglucose (FDG) studies are useful for identifying foci of increased FDG uptake in liver metastases, because of the high glycolytic rate of malignancies, as well as for monitoring changes in tumor glucose metabolism during treatment. We performed 15 kinetic PET FDG studies in four patients with metastatic liver disease. We produced parametric images of glucose metabolism in terms of the rate constant K (ml/min/g) for net phosphorylation of FDG. Tumor K values, estimated with nonlinear regression, correlated well with K values estimated with Patlak graphical analysis (r = 0.96), validating the assumption of low k4* values in liver metastases and supporting the use of pixel by pixel Patlak plot analysis of the data to generate parametric images. In normal liver, high levels of glucose-6-phosphatase produce much higher values of k4* than in liver metastases. Uncorrected Patlak graphical analysis underestimates K in normal liver, but this further increases the contrast between tumor and liver and facilitates both tumor detection and quantification. The technique is computationally feasible and is well suited for serial evaluations of tumor metabolism during treatment.
Messa
C
C
Department of Radiological Sciences, University of California, Los Angeles School of Medicine 90024-1721.
Choi
Y
Y
Hoh
C K
CK
Jacobs
E L
EL
Glaspy
J A
JA
Rege
S
S
Nitzsche
E
E
Huang
S C
SC
Phelps
M E
ME
Hawkins
R A
RA
D000328:Adult; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000556:secondary*; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000378:metabolism / Q000556:secondary*; D008875:Middle Aged; D013160:Splenic Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000556:secondary*; D014055:Tomography, Emission-Computed
D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D005947:Glucose