The local efficacy and influencing factors of ultrasound-guided percutaneous radiofrequency ablation in sub-cardiac hepatic tumor: A 7-year experience at a single center.

PURPOSE: To investigate the effectiveness and safety of ultrasound (US)-guided percutaneous radiofrequency ablation (PRFA) for sub-cardiac hepatic tumors and evaluate the factors influencing local tumor progression (LTP).

METHODS: Between January 2016 and January 2023, we included 118 patients (118 lesions) of US-guided RFA for sub-cardiac hepatic tumors (located in S2 or S4a, with a gap between the tumor and the left diaphragm ≤ 10 mm). We retrospectively analyzed patients' electronic medical records and imaging follow-up data to evaluate the success rate, LTP, and complications. We also used univariate and multivariate Cox regression to explore the risk factors for LTP.

RESULTS: The primary technical success rate for treating sub-cardiac hepatic tumors was 113/118 (95.8%). The success rate after the second ablation was 118/118 (100%). A single serious complication was recorded 1/118(0.8%), including acute pericardial tamponade and sudden cardiac arrest. The median follow-up period was 24 months (range, 1.2-72 months), with LTP occurring in 19 lesions (16.1%). Besides, the 1-year, 2-year, and 3-year cumulative rates of LTP were 12.7%, 15.3%, and 16.1%, respectively. Tumor size was an independent risk factor for LTP following ablation of sub-cardiac hepatic tumors (HR 1.06; 95% CI 1.02-1.11; P = 0.008). A larger minimal ablative margin (MAM) was associated with a lower hazard of LTP (HR 0.78; 95% CI 0.65-0.92; Wald P = 0.004; LR P = 0.002). Stratified analysis indicated that lesions ≥ 30 mm in diameter carried a significantly higher risk of LTP (HR 4.35; 95% CI 1.46-12.99; P = 0.009).

CONCLUSIONS: US-guided PRFA for sub-cardiac hepatic tumors is effective and safe, though caution is advised for tumors ≥ 30 mm due to a significantly higher LTP risk.