The application of ¹⁸F-FDG PET/CT imaging for human hepatocellular carcinoma: a narrative review

Primary hepatocellular carcinoma (HCC) poses a significant threat to human health. The mean overall survival (OS) of HCC is approximately 15.8 months whereas the 6-month and 1-year OS rates are only 71.6% and 49.7%, respectively. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) has been widely used for the management of several solid cancers; however, HCC frequently displays low ¹⁸F-FDG uptake; approximately 50% of HCC cases do not take up ¹⁸F-FDG. Therefore, ¹⁸F-FDG PET is not considered very useful for the visualization of HCC and is not currently a recommended standard imaging modality for HCC. Conversely, ¹⁸F-FDG PET/CT has been reported to be clinically important in the management, staging, and prognosis of HCC patients. Currently, reports relating to ¹⁸F-FDG uptake in HCC are unclear and controversial. There is an urgent need to clarify the efficacy of ¹⁸F-FDG PET for the management of HCC.

The PubMed database was searched for all articles on the application of ¹⁸F-FDG PET/CT imaging for human HCC up to December 2021. The following search terms were used: 'Hepatocellular carcinoma', '[18F]FDG PET/CT', 'Hypoxia', '[¹¹C]Choline'.

In this review, we re-evaluate the potential hypoxia-dependent uptake mechanism of ¹⁸F-FDG in HCC and review the usefulness of ¹⁸F-FDG PET/CT for identifying, managing, and investigating the biological properties of HCC.

¹⁸F-FDG PET/CT is very useful for HCC visualization, management, and the evaluation of biological properties. A negative test for ¹⁸F-FDG uptake is not meaningless and may reflect a relatively better outcome. ¹⁸F-FDG-positive lesions indicate a significantly less favorable prognosis.