Whole tumor ablation of locally recurred hepatocellular carcinoma including retained iodized oil after transarterial chemoembolization improves progression-free survival.

OBJECTIVES: To evaluate and compare clinical outcomes of two different radiofrequency ablation (RFA) methods for locally recurred hepatocellular carcinoma (LrHCC) after locoregional treatment.

METHODS: Our institutional review board approved this study with a waiver of informed consent. A total of 313 patients previously treated with transarterial chemoembolization (TACE) (n = 167) and RFA (n = 146) with a single LrHCC ≤ 3 cm was included from five tertiary referral hospitals. RFA was done for LrHCCs using either viable tumor alone ablation (VTA) method (VTA: n = 61 in the TACE group and n = 127 in the RFA group) or whole tumor ablation (WTA) method which includes both viable tumor and retained iodized oil or previously ablated zone (WTA: n = 106 in the TACE group and n = 19 in the RFA group). Local tumor progression (LTP)-free survival as well as progression-free survival (PFS) were estimated using the Kaplan-Meier method, and prognostic factors were evaluated using the Cox proportional hazards regression model.

RESULTS: In 167 patients with LrHCC who underwent TACE, the 5-year LTP-free survival after RFA was significantly higher with the VTA method than with the WTA method (26.9% vs. 87.8%; p < 0.001; hazard ratio (HR) = 8.53 [4.16-17.5]). The estimated 5-year PFS after RFA for LrHCC after TACE using the VTA method was 5.7%, which was significantly lower than that with the WTA method (26.4%) (p = 0.014; HR = 1.62 [1.10-2.38]). However, in 146 patients with LrHCC after initial RFA, there were no significant differences in cumulative incidence of LTP (p = 0.514) or PFS (p = 0.905) after RFA between the two ablation methods.

CONCLUSIONS: For RFA of LrHCC after TACE, the WTA method including both viable tumor and retained iodized oil could significantly lower LTP and improve PFS than VTA.

KEY POINTS: • Whole tumor ablation (WTA) could provide significantly better local tumor control for locally recurred HCC (LrHCC) after TACE than viable tumor alone ablation (VTA). • WTA for LrHCC after TACE could also provide significantly better progression-free survival than VTA. • Regarding LrHCC after RFA, VTA would provide a comparable clinical outcome to WTA.