Factors Affecting Temporal Changes in Ablated Liver Volume After Radiofrequency Ablation for Hepatocellular Carcinoma Evaluated by Three-Dimensional Volumetric Computed Tomography

Objectives: To evaluate associations between shrinkage of ablated liver area on computed tomography (CT) over time after radiofrequency ablation (RFA) and clinical parameters related to liver function and fibrosis. Methods: Patients with hepatocellular carcinoma who underwent RFA and follow-up CT were retrospectively reviewed. The ablated area volume (AAV) on CT obtained within 1 week and around 6 months after RFA was measured, and reduction rate of AAV was calculated. The AAV reduction rate was compared among Child-Pugh classification, modified albumin-bilirubin (mALBI) grades, FIB-4 index categories, and lesion locations using generalized estimating equations (GEE). Univariable and multivariable GEE analyses were performed to evaluate associations between the AAV reduction rate and clinical parameters. Results: Fifty-three lesions in 41 patients (median age, 76 [range, 38–88] years, 24 men) were evaluated. The AAV reduction rate was significantly lower in Child-Pugh class B than class A (p < 0.001) and in mALBI grade 2b than grade 1 (p < 0.001) or grade 2a (p = 0.004). Significant differences were also observed among FIB-4 index groups (p < 0.001) and among lesion locations, with lower AAV reduction rates in medial and anterior segments than in lateral (p < 0.001) and posterior (p = 0.017) segments. Univariable GEE analyses showed significant associations between AAV reduction rate and cholinesterase, albumin, total bilirubin (T-Bil), prothrombin time, platelet count, and FIB-4 index (p < 0.05). Multivariable GEE analysis demonstrated that both albumin and T-Bil remained independently associated with AAV reduction rate (p < 0.001). Conclusions: The AAV reduction rate tended to be lower in patients with impaired liver function and advanced liver fibrosis.