Decreased brain FDG uptake in patients with extensive non-Hodgkin's lymphoma lesions.
OBJECTIVE
Faint brain [(18)F]fluoro-2-deoxyglucose (FDG) uptake has sporadically been reported in patients with FDG-avid large or diffusely extended tumors. The purpose of this study was to investigate whether there is a correlation between massive tumor uptake and decreased brain uptake on FDG positron emission tomography/computed tomography (PET/CT).


METHODS
Sixty-five patients with histologically confirmed non-Hodgkin's lymphoma who underwent FDG-PET/CT were enrolled. Thirty control subjects were also included to evaluate normal brain FDG uptake. PET/CT examinations were retrospectively reviewed. The volumetric regions of interest were placed over lesions by referring to CT and PET/CT fusion images to measure mean standardized uptake value (SUVavg). The products of SUVavg and tumor volume were calculated as total glycolytic volume (TGV). The maximum SUV (SUVmax) and SUVavg were measured in the cerebrum and cerebellum. The values of TGV and brain FDG uptake were plotted and analyzed with a linear regression method.


RESULTS
In the lymphoma patients, there were statistically significant negative correlations between TGV and brain SUVs.


CONCLUSIONS
Demonstrating a significant negative correlation between TGV and brain uptake validated the phenomenon of decreased brain FDG uptake. Diversion of FDG from the brain to the lymphoma tissue may occur during the FDG accumulation process. Recognition of this phenomenon prevents unnecessary further neurological examinations in such cases.
Hanaoka
Kohei
K
Division of Positron Emission Tomography, Institute of Advanced Clinical Medicine, Kinki University School of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, 589-8511, Japan.
Hosono
Makoto
M
Shimono
Taro
T
Usami
Kimio
K
Komeya
Yoshihiro
Y
Tsuchiya
Norio
N
Yamazoe
Yuzuru
Y
Ishii
Kazunari
K
Tatsumi
Youichi
Y
Sumita
Mitsugu
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
D019788:Fluorodeoxyglucose F18; D005947:Glucose