Predicting prognosis prior to the combination of atezolizumab and bevacizumab on unresectable HCC: Analysis and comparison of tumor heterogeneity at CT and Gd-EOB-DTPA hepatobiliary MR imaging

Since 2007, the combination of atezolizumab and bevacizumab, comprising an immune checkpoint inhibitor and a molecularly targeted agent, has become the first-line treatment for advanced hepatocellular carcinoma (HCC). Predicting prognosis prior to systemic chemotherapy remains a critical concern. This study included 84 advanced HCC patients who underwent enhanced computed tomography (CT) and Gd-EOB-DTPA magnetic resonance imaging (MRI) before the systemic therapy were included. In CT, the 2 radiologists measured mean CT Hounsfield unit (CTHU) value by drawing region of interest at the largest diameter of the tumor on arterial phage. The HU values were categorized into 5 groups: ≤ 0, 0 < HU ≤ 50, 50 < HU ≤ 100, 100 < HU ≤ 150, and HU > 150. The percentage of the entire tumor in each category was calculated. On MRI, hepatobiliary phase imaging features and relative enhancement ratio (RER) were also evaluated by 2 radiologists. Prognostic factors associated with progression-free survival were identified using statistical analysis. RER on HBP MRI correlated with prognosis in systemic chemotherapy. Conversely, other image features on HBP MRI and CT histogram provided consistent treatment effect.