Low CT-derived vertebral attenuation as a prognostic factor in hepatocellular carcinoma patients treated with immune checkpoint inhibitors

Background Computed tomography (CT)-derived vertebral attenuation has been recognized as an indicator of prognosis for patients undergoing tumor removal, liver transplant, or transcatheter arterial chemoembolization (TACE) therapy, but similar research has not been reported in hepatocellular carcinoma (HCC) patients treated with immune checkpoint inhibitors (ICIs). This study aims to explore the prognostic value of CT-derived vertebral attenuation in HCC patients treated with ICIs. Methods This retrospective study included HCC patients who received ICI treatment at Wuhan Union Hospital between July 2020 and March 2024. CT-derived vertebral attenuation was assessed by measuring mean Hounsfield unit (HU) values in the center of the first lumbar vertebra (L1) on non-contrast CT scans. Based on the optimal cutoff value derived from X-tile software, patients were classified into the CT-derived L1 attenuation-low group (≤100 HU) and the CT-derived L1 attenuation-high group (>100 HU). A comparison of the baseline characteristics of the two groups was made, followed by a propensity score matching (PSM) analysis to balance the variables. The objective response rate (ORR) and disease control rate (DCR) were calculated for both groups, and Kaplan-Meier survival curves and Cox regression models were used to analyze overall survival (OS) and progression-free survival (PFS). Results The cohort consisted of 357 patients, divided into the L1 attenuation-low group (n = 112) and the L1 attenuation-high group (n = 245). Among all patients, 30.0% (107/357) achieved complete or partial response. After PSM analysis, both groups contained 91 patients. The L1 attenuation-low group had shorter OS (hazard ratio [HR], 1.73; 95% confidence interval [CI], 1.15–2.60; P = 0.008) and PFS (HR, 1.47; 95% CI, 1.04–2.08; P = 0.030) than the L1 attenuation-high group. Conclusion CT-derived L1 attenuation can stratify survival risk for HCC patients undergoing ICI treatment.