[18F]FDG accumulation in an experimental model of multistage progression of cholangiocarcinoma

• Published in: Hepatology research Vol. 37; no. 2; pp. 127 - 132
• Main Authors: Laverman, Peter, Blokx, Willeke A.M., Te Morsche, René H.M., Frielink, Cathelijne, Boerman, Otto C., Oyen, Wim J.G., Drenth, Joost P.H.
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Asia 01.02.2007
• Subjects: [18F]FDG; autoradiography; carcinogenesis; Cholangiocarcinoma; PET
• ISSN: 1386-6346; 1872-034X
• DOI: 10.1111/j.1872-034X.2007.00016.x

Aim:  The diagnosis of cholangiocarcinoma (CCA) is difficult, and due to the insidious course of the disease, most cases present at a relatively late stage. Positron emission tomography (PET), using [18F]fluoro‐2‐deoxyglucose ([18F]FDG) as a tracer is one the most powerful molecular imaging techniques available. We hypothesized that [18F]FDG accumulates at sites of early CCA development and that FDG‐PET may be of value for the early diagnosis of CCA. Methods:  We added 300 mg/L thioacetamide to the drinking water of rats who went on to develop CCA within 20 weeks. From eight weeks onwards, groups of three rats were injected with [18F]FDG, subsequently the liver was perfused, dissected and subjected to quantitative autoradiography using a phosphor imaging system. The liver sections were stained for histology, and glutathione S‐transferase (GST) enzyme activity was determined. We correlated [18F]FDG uptake with pathological liver changes. Results:  The experiments demonstrate that thioacetamide causes atypical bile ducts and invasive CCA. Rat livers harvested early after the start of administration of thioacetamide contained only cirrhosis and/or atypical bile ducts, but CCA and FDG accumulation were absent. At 20 weeks, all rats had developed CCA and all, except two animals with a very small carcinoma, had strongly elevated focal FDG uptake. Quantitative autoradiography revealed tumor‐to‐normal‐liver ratios as high as 5:4. In all rats with a carcinoma, there was a backdrop of cirrhosis, and interestingly cirrhotic areas did not show elevated FDG accumulation. Conclusion:  [18F]FDG accumulates in CCA, is able to distinguish CCA from liver cirrhosis, but is probably unsuitable to detect very early CCA lesions.