Pretreatment Positron Emission Tomography with ¹⁸F-Fluorodeoxyglucose May Be a Useful New Predictor of Early Progressive Disease following Atezolizumab plus Bevacizumab in Patients with Unresectable Hepatocellular Carcinoma

Abstract

<b><i>Background and Aims:</i></b> The aim of this study was to identify the utility of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) as a predictor of early progressive disease (e-PD) in patients with hepatocellular carcinoma (HCC) treated with atezolizumab plus bevacizumab (Atezo/Bev). <b><i>Methods:</i></b> Twenty consecutive patients with measurable intrahepatic target nodules who received Atezo/Bev treatment were reviewed. The oncological aggressiveness of tumors estimated by ¹⁸F-FDG-PET/CT was analyzed using the rate of e-PD within 12 weeks and early progression-free survival (e-PFS) and overall survival (OS). Multivariate analysis was used to identify potential confounders for PD during Atezo/Bev therapy. <b><i>Results:</i></b> Using the Response Evaluation Criteria in Solid Tumors version 1.1, a tumor-to-normal liver ratio (TLR) ≥2, indicating higher oncological aggressiveness in HCCs, was associated with lower objective response rates compared with TLR values &#x3c;2 (18% vs. 33%, respectively). Moreover, TLR values ≥2 were significantly associated with higher e-PD rates compared with TLR values &#x3c;2 (64% vs. 11%, respectively) and worse e-PFS (<i>p</i> = 0.021). In multivariate analysis, TLR ≥2 showed marginal significance as a predictor of e-PD (<i>p</i> = 0.053), and utility as a predictor for worse e-PFS (hazard ratio, 7.153; 95% confidence interval, 1.258–40.689; <i>p</i> = 0.027). In contrast, no significant differences in OS with/without e-PD were observed during the treatment course. In this study, 8 patients experienced e-PD and almost 40% of patients experienced acceptable disease control following subsequent lenvatinib treatment. <b><i>Conclusion:</i></b> Pretreatment ¹⁸F-FDG-PET/CT may be a useful new predictor of e-PD and may enable early decision-making based on early treatment changes following Atezo/Bev treatment of HCC.