Quantifying Functional Liver Volume Loss after CT-guided Percutaneous Thermal Ablation: A COVER-ALL Trial Post Hoc Analysis

Purpose To quantify functional liver volume (FLV) loss relative to minimal ablative margins (MAMs) achieved during percutaneous thermal ablation (TA) of liver tumors in COVER-ALL randomized controlled trial (RCT) participants. Materials and Methods In the COVER-ALL single-center RCT (June 2020 through October 2023), software-based ablation confirmation (AC) (experimental) and visual margin (control) assessment were compared among participants with histology-agnostic liver tumors. In this post hoc analysis, the authors compared CT-derived volumes, MAMs, and changes in laboratory-based hepatic function using Wilcoxon rank sum and Spearman correlation tests. Results Among 100 participants (mean age ± SD, 57.8 years ± 13.2; 61 male; experimental group, n = 74, 98 tumors ablated, median diameter = 1.5 cm; control group, n = 26, 41 tumors ablated, median diameter = 1.3 cm), the experimental and control group baseline median FLVs (1707 cm³ [IQR, 1467-1964 cm³] vs 1722 cm³ [IQR, 1338-1916 cm³]; P = .84) were comparable. The median MAM was larger in the experimental versus the control group (6 mm [IQR, 4.5-7.9 mm] vs 1 mm [IQR, 0-4 mm]; P < .001). The median percentage FLV loss was larger in the experimental versus the control group (2.9% [IQR, 1.8%-4.4%] vs 1.7% [IQR, 1.2%-3.4%]; P = .03). The median postablation FLV was comparable between the experimental and control groups (1643 cm³ [IQR, 1403-1886 cm³] and 1696 cm³ [IQR, 1315-1843 cm³]; P = .87). We observed no association between percentage FLV loss and changes in serum albumin (ρ = -0.153, P = .16) or total bilirubin concentrations (ρ = -0.128, P = .25). Conclusion Liver tumor TA resulted in minimal percentage FLV loss. Software-based AC use increased the MAM at the expense of a negligible increase in percentage FLV loss. Keywords: Ablation Techniques, Segmentation, Liver, Volume Analysis ClinicalTrials.gov: NCT04083378 Supplemental material is available online. © RSNA, 2026.