Fluorocholine (FCH) PET assessment of liver lesions: a pilot study

Purpose: FDG PET has somewhat limited use for assessment of certain liver lesions. It shows variable uptake in hepatocellular carcinoma (HCC) although it may have a role in the assessment of cholangiocarcinoma. FCH is a new tracer which allows assessment of cell membrane turnover rather than glycolytic metabolism as with FDG. The purpose of this study was to assess the potential utility of FCH PET in liver lesions.

Methods: An ethics approved prospective trial was performed to compare FDG PET to FCH PET in patients with liver lesions. Patients with colorectal, lung and melanoma metastases to the liver were not included. Clinicopathological data was obtained as was follow up on enrolled patients. Patients were scanned on a Philips Allegro GSO PET scanner at the WA PET/Cyclotron Service.

Results: : Over a 6 month period 14 subjects (6 male, 8 female) were enrolled in the trial. Mean age 59 yrs (range 26–81). The patients underwent FCH and FDG PET scan for evaluation and therapy monitoring of suspected or known liver lesions (8 hepatocellular carcinoma, 2 focal nodular hyperplasia, 1 cyst adenoma, 1 multiple adenomatosis, 1 cholangiocarcinoma, 1 carcinoid metastases). 1 patient with HCC had an FCH study but did not have an FDG PET study. Of 7 patients with known HCC recurrence, FCH was positive in all whereas FDG was positive in 3/6. Of 1 patient with successful treatment of HCC both FDG and FCH were negative. The cyst adenoma and carcinoid metastases patients were both negative for FDG and FCH. One patient with cholangiocarcinoma was positive on FDG and negative for FCH. The opposite occurred with the two patients with FNH and multiple adenoma..

Conclusion: Our preliminary data reveals that FCH PET appears to have a potential role in the assessment of HCC and appears more accurate than FDG PET in this condition. The uptake seen in benign conditions such as FNH and adenoma needs further review. Similarly further work is required on other conditions such as cholangiocarcinoma.