Comparison of Stable and Unstable Ethiodized Oil Emulsions for Transarterial Chemoembolization of Hepatocellular Carcinoma: Results of a Single-Center Double-Blind Prospective Randomized Controlled Trial

Abstract Purpose To compare the stability of stable and unstable water-in-oil emulsions and the efficacy and safety of these emulsions in a single-center, prospective double-blind trial of transarterial chemoembolization for hepatocellular carcinoma (HCC). Materials and Methods A total of 812 patients with inoperable HCC were randomized (stable emulsion, n = 402; unstable emulsion, n = 410). The 2 emulsions were prepared by using the same protocol except that different solvents were used for chemotherapy agents, including epirubicin, lobaplatin, and mitomycin C. The solvent in the stable emulsion arm was contrast medium and distilled water, and the solvent in the unstable emulsion arm was distilled water. The primary endpoint was overall survival (OS), and secondary endpoints were time to progression (TTP), tumor response, adverse events (AEs), and plasma epirubicin concentrations. Results In vitro, stable emulsions did not occur until 1 day, and unstable emulsions, with a lower peak plasma concentration ( P  = .001) in vivo, exhibited rapid separation of the oil and aqueous phases after 10 minutes. Median OS times in the stable and unstable emulsion arms were 17.7 and 19.2 months, respectively ( P  = .81). No differences were found in TTP, tumor response, and AEs except for myelosuppression (anemia, 3.5% vs 7.6%; thrombocytopenia, 11.5% vs 17.7%), which was significantly more severe and frequent in the unstable emulsion arm ( P  = .013). Conclusions Chemoembolization is equally effective with the use of stable and unstable emulsions, but the use of a stable emulsion has the advantage of less myelosuppression and a favorable pharmacokinetic profile.