Local recurrence and complications after percutaneous radiofrequency ablation of hepatocellular carcinoma: a retrospective cohort study focused on tumor location.

We conducted a retrospective cohort study to investigate the predisposing factors for local recurrence and complications after percutaneous radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC). HCC patients (n＝397) consecutively treated with RFA (256 males, 141 females, median age 69 years) were enrolled. In these patients, 1,455 nodules (median size 17mm) were ablated. Predisposing factors for overall recurrence and local recurrence in the context of tumor location and complications were examined. Local recurrence was observed for 113 of the 1,455 nodules. The 1-, 3- and 5-year local recurrence rates were 2.2ｵ, 7.4ｵ and 9.5ｵ, respectively. A multivariate Cox proportional hazard analysis revealed that large tumor size (＞2cm), tumor location (adjacent to the major portal branch or hepatic vein), and small ablated margin (＜3mm) were independent predisposing factors for local recurrence after RFA (HR＝1.70-2.81). Tumor location (adjacent to the major portal branch, hepatic vein, or diaphragm) was also revealed as a risk factor for liver damage due to RFA. HCC adjacent to the major portal vein or hepatic vein was associated with a higher risk for local recurrence and for complications;therefore, special precautions are necessary when applying RFA to HCC near vessels even when the tumors are located at an easy-to-puncture site.