Comparison of Liquid with Particle Embolics in a Translational Rat Model of Hepatocellular Carcinoma: Histologic and Radiographic Responses

Purpose: To compare the effectiveness of transarterial embolization (TAE) using a liquid embolic (LE) with that of TAE using a particle embolic (PE) based on radiographic and histologic responses in a translational rat model of hepatocellular carcinoma (HCC). Materials and Methods: HCC was induced in Wistar rats using diethylnitrosamine. Tumor response was determined through Response Evaluation Criteria in Solid Tumors applied to T2-weighted magnetic resonance (MR) imaging scans. Tumor necrosis and hypoxia were assessed through hematoxylin and eosin and pimonidazole staining, respectively. Statistical analyses were performed using chi-square tests, Kaplan-Meier estimates, logistic regression, and 1-way analysis of variance, with significance set at P < .05. Results: Twenty-nine rats were randomized to TAE with LE (n = 13), PE (n = 13), or sham (n = 3). LE TAE demonstrated a significantly higher objective response rate (83%) compared with PE TAE (28%; χ² = 11.25; P = .0008). Complete responses were observed in 50% of the LE-treated tumors versus 10% in the PE-treated group. LE TAE prolonged local progression–free survival (hazard ratio, 0.31; P = .032). Histologic analysis of an additional 16 rats randomized to TAE with LE (n = 7), PE (n = 6), or sham (n = 3) showed greater necrosis in LE-treated tumors compared to PE-treated tumors. LE induced a significantly greater reduction in viable tumor tissue (P = .009) and proportionally larger necrotic and necrotic + hypoxic tissue areas compared with PE (P = .003). Conclusions: LE significantly enhanced the therapeutic effectiveness of TAE in a rat model of HCC compared with PE. These results highlight the potential of LEs to improve ischemia and necrosis, thereby offering a promising option for improving the effectiveness of embolization for HCC treatment.