Combined transarterial iodized oil injection and computed tomography-guided thermal ablation for hepatocellular carcinoma: utility of the iodized oil retention pattern

Abstract

Purpose: To investigate whether the iodized oil (Lipiodol, Guerbet Group, Villepinte, France) retention pattern influences the treatment efficacy of combined transarterial Lipiodol injection (TLI) and thermal ablation in patients with hepatocellular carcinoma (HCC).

Methods: Data of 198 patients (280 HCC lesions), who underwent TLI plus computed tomography (CT)-guided thermal ablation at three separate medical institutions between June 2014 and September 2020, were reviewed and analyzed. The Lipiodol retention pattern was classified as complete or incomplete based on non-enhanced CT at the time of ablation. The primary outcome was local recurrence-free survival (LRFS) for lesions; the secondary outcome was overall survival (OS) for patients. Propensity score matching (PSM) was performed using a caliper width of 0.1 between the two groups. Differences in LRFS and OS between the two groups were compared using the log-rank test.

Results: A total of 133 lesions exhibited a complete Lipiodol retention pattern, while 147 exhibited an incomplete pattern. After PSM analysis of baseline characteristics of the lesions, 121 pairs of lesions were matched. LRFS was significantly longer for lesions exhibiting complete retention than for those exhibiting incomplete retention (P = 0.030). After PSM analysis of patient baseline characteristics, 74 pairs of patients were matched. There was no significant difference in OS between the two groups (P = 0.456).

Conclusion: Lipiodol retention patterns may influence the treatment efficacy of combined TLI and thermal ablation for HCC lesions. However, a survival benefit for the Lipiodol retention pattern among HCC patients was not observed and needs further confirmation.

Keywords: Ablation techniques; Hepatocellular carcinoma; Matched-pair analysis; Survival analysis; Transarterial chemoembolization.

Fig. 1

Flow diagram illustrating selection of the study population

Fig. 2

Schematic example and representative images of the complete and incomplete iodized oil (Lipiodol, Guerbet Group, Villepinte, France) retention patterns. Schematic representation of Lipiodol retention patterns on non-enhanced computed tomography (CT) (A). A 47-year-old male with two hypervascularized hepatocellular carcinoma (HCC) lesions in the right lobe of the liver (B). A homogeneous complete Lipiodol retention pattern after transarterial Lipiodol injection (TLI) is exhibited in two HCC lesions (black arrow), and the outlines of the lesions are well defined (C). A 50-year-old male with a hypervascularized HCC lesion in the right lobe of the liver (D). A heterogeneous incomplete Lipiodol retention pattern (white arrow) after TLI, and the outline of the lesion is poorly defined (E)

Fig. 3

Kaplan–Meier LRFS curves for patients with complete and incomplete iodized oil (Lipiodol, Guerbet Group, Villepinte, France) retention patterns before and after propensity score matching (A) and (B), respectively

Fig. 4

Kaplan–Meier LRFS curves for patients with complete and incomplete iodized oil (Lipiodol, Guerbet Group, Villepinte, France) retention in the subgroups with a time interval between transarterial Lipiodol injection (TLI) and ablation of within 1 month (A) or beyond 1 month (B), a tumor size < 3 cm (C) or > 3 cm (D), a perivascular (E) or non-perivascular (F) location of hepatocellular carcinoma (HCC) lesions, performed transarterial chemoembolization (TACE) (G) or TLI alone (H)

Fig. 5

Kaplan–Meier OS curves for patients with complete and incomplete iodized oil (Lipiodol, Guerbet Group, Villepinte, France) retention before (A) and after (B) propensity score matching