18F-Fluorocholine PET/CT as an Imaging Biomarker in Patients With Hepatocellular Carcinoma Receiving Atezolizumab Plus Bevacizumab

Background/Aim: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and treatment outcomes for advanced disease remain suboptimal. Immunotherapy, particularly atezolizumab plus bevacizumab, has shown promise in improving survival. This study aimed to evaluate the prognostic value of 18F-fluorocholine positron emission tomography/computed tomography (FCH PET/CT) in patients with unresectable HCC undergoing this combination therapy. Patients and Methods: This prospective study included 29 patients with unresectable HCC treated with atezolizumab plus bevacizumab. All participants underwent FCH PET/CT prior to treatment. The tumor-to-liver ratio (TLR) of FCH uptake was calculated and analyzed as a potential prognostic biomarker. Progression-free survival (PFS) was assessed using Kaplan-Meier analysis, and Cox proportional hazards models evaluated associations between TLR and clinical outcomes. Results: Patients with higher TLR values of FCH uptake (cutoff: 1.36) demonstrated significantly shorter PFS compared to those with lower TLR values (hazard ratio=4.29, p=0.032). Other clinical variables, including age, sex, tumor size, and viral hepatitis status, were not significantly associated with PFS. Conclusion: TLR of FCH uptake is a valuable non-invasive biomarker for predicting PFS in unresectable HCC patients treated with immunotherapy.