Published in:
01-11-2008 | Research Article
Dual-Time-Point FDG-PET/CT for the Detection of Hepatic Metastases
Authors:
Albert Dirisamer, Benjamin S. Halpern, Wolfgang Schima, Martin Heinisch, Florian Wolf, Mohsen Beheshti, Franz Dirisamer, Michael Weber, Werner Langsteger
Published in:
Molecular Imaging and Biology
|
Issue 6/2008
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Abstract
Purpose
To prove the sensitivity of dual-time-point imaging with 18F-flourodeoxyglucose-positron emission tomography (18F-FDG-PET) of the liver to evaluate possible changes in the tumor-to-background ratio considering an improved detection rate of liver lesions.
Procedures
Image acquisition for the first whole-body scan started at a mean time point of 69 min (55–110 min). The mean time interval between the injection of 18F-FDG and the second delayed scan was 100 min (85–166 min).
Results
Of 90 proven liver metastases in 34 patients, the first scan detected 53 (59%) liver lesions correctly, whereas in the second, delayed scan 81 (90%) lesions were diagnosed correctly (p<0.001). The mean Standardized uptake values in the first and second delayed scan were 6.59 g/ml versus 8.09 g/ml, respectively (p<0.001). Tumor-to-background ratio of the first and second delayed scan were 2.0 and 2.7, respectively (p = 0.04).
Conclusions
Dual-time-point-imaging of the liver showed a significant increase of tumor-to-background ratio and hypermetabolic lesion diameter. Although, 30% of all verified liver lesions could only be detected in the second delayed scan 10% of all malignant liver lesions were missed with FDG-PET.