Radiofrequency ablation for subcardiac hepatocellular carcinoma: therapeutic outcomes and risk factors for technical failure

Objectives: To compare the therapeutic outcomes and safety of radiofrequency (RF) ablation for subcardiac and non-subcardiac hepatocellular carcinoma (HCC) and to evaluate the risk factors for technical failure of the procedure. Methods: This retrospective study was approved by the institutional review board. Between September 2002 and May 2016, 73 patients with subcardiac HCC and the same number of patients with non-subcardiac HCC matched by tumor size were included. Subcardiac HCC was defined as an index tumor that was located ≤ 1 cm from the pericardium in axial or coronal images. Cumulative local tumor progression (LTP) was compared between the two groups using the log-rank test. Prognostic factors for technical failure were assessed using multivariable logistic analysis. Results: Technical success rates between both groups were not significantly different (91.8% in the subcardiac HCC group vs. 95.9% in the non-subcardiac HCC group; p = 0.494). The cumulative LTP rates were 15.4% and 19.1% at 3 and 5 years, respectively, in the subcardiac HCC group, and 10.7% and 15.5% in the non-subcardiac HCC group, without significant difference (p = 0.862). The distance between the index tumor and pericardium (odds ratio [OR], 0.14; p = 0.023) and tumor in segment IV (reference, left lateral sector; OR, 36.53; p = 0.029) were significant factors for technical failure in patients with subcardiac HCC. Conclusions: RF ablation was an effective treatment for subcardiac HCC. However, tumor location should be considered in the planning of treatment to avoid technical failure. Key Points: • RF ablation for subcardiac HCC is technically feasible without major complications. • RF ablation was an effective treatment for subcardiac HCC in terms of LTP. • Risk factors for technical failure were distance of the index tumor from the heart (cutoff value of 0.5 cm) and the location of the tumor (segment IV).