Comparison of Computed Tomography and Ultrasound-Guided Radiofrequency Ablation for Recurrent Subdiaphragmatic Hepatocellular Carcinoma After Resection

Objective: Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related mortality worldwide. Although surgical resection and liver transplantation are considered curative, recurrence is common, especially after hepatectomy. Radiofrequency ablation (RFA) offers a minimally invasive alternative for treating recurrent HCC. However, its efficacy is influenced by tumor location and imaging guidance. This study aims to compare the outcomes of CT-guided and US-guided RFA in patients with single small recurrent HCCs located in the subdiaphragmatic region after hepatectomy. Methods: In this retrospective single-center study, we included patients who received RFA for recurrent HCC following curative hepatectomy between 2008 and 2020. Patients were categorized into CT-guided or US-guided RFA groups. RFA was performed by experienced interventional radiologists, and follow-up imaging was conducted every 3-6 months to assess recurrence. The primary outcome was recurrence-free survival (RFS), and the secondary outcome was overall survival (OS). Results: In this study, 59 and 32 patients with subdiaphragmatic lesions underwent CT-guided- and US-guided RFA, respectively, for single recurrent HCC. The CT-guided group showed larger tumor size, lower recurrence rates, and significantly better RFS in KaplanMeier analysis compared to the US-guided group (49.5 months vs 35.7 months, p value= 0.042). Multivariate analysis confirmed a superior RFS hazard ratio (HR=0.551) for CT-guided RFA, although the overall survival showed no significant difference. Major complications were absent in both groups. Conclusion: CT-guided RFA provides improved RFS for subdiaphragmatic recurrent HCC, highlighting its potential as a preferred technique for challenging anatomical locations. Further multicenter prospective studies are necessary to validate these findings and assess the long-term survival outcomes.