Transcatheter CT Hepatic Arteriography Guided Percutaneous Microwave Ablation for Treatment of Small Hepatocellular Carcinoma: A Comparative Analysis with Conventional CT-guided Ablation and Radiation Segmentectomy

During percutaneous thermal ablation for hepatocellular carcinoma (HCC), small tumors can be difficult to visualize using conventional non-contrast computed tomography (CT) imaging and ultrasound. Selective hepatic arteriography can enhance their visibility with small volume intra-arterial contrast, enabling real-time tumor localization and immediate post-intervention assessment of ablation zone coverage. This study aims to evaluate safety and efficacy of transcatheter CT hepatic arteriography (Angio-CT) guided percutaneous microwave ablation (MWA) for small HCC and compare with conventional CT guidance and radiation segmentectomy (RS).

Materials and Methods:

A single institutional retrospective review was performed to include HCC < 3cm treated with Angio-CT guided MWA, conventional CT guided MWA, and RS from June 2019 to July 2024. Hepatic arteriography was performed after transarterial catheterization in an Angio-CT hybrid suite, in order to improve target visualization and confirm complete ablation coverage. Conventional CT guided ablation was performed with or without ultrasound. RS was performed using glass microspheres with a target dose of >250Gy to no more than two hepatic segments. Target-lesion radiologic response was evaluated according to modified RECIST criteria on follow-up contrast enhanced CT or magnetic resonance imaging. Target-lesion progression-free survival (PFS) was calculated using the Kaplan-Meier method.

Results:

A total of 32 tumors (mean diameter: 1.50 ± 0.40cm) were treated with Angio-CT guided MWA. No major procedure-related adverse events occurred. Compared to conventional CT guided MWA (n=49), Angio-CT guidance demonstrated a significantly higher 3-month complete response rate (79.6% versus 100%, p=0.006) and prolonged PFS (median survival time: 33 months versus not reached, p=0.0037) with 2-year response rate of 63.1% and 94.7%, respectively. Compared to RS (n=61, 2-year response rate: 82.4%), Angio-CT guided ablation demonstrated similar PFS (median survival time was not reached in either group, p=0.150). No significant difference was observed between tumors treated by Angio-CT guided MWA or ablative dose RS (target dose >400Gy; n=22; median survival time was not reached in either group, p=0.0889).

Conclusion:

Angio-CT MWA for HCC < 3cm resulted in higher initial response and prolonged PFS when compared with conventional CT guidance. Compared to RS, Angio-CT MWA appeared to be associated with higher radiologic response than RS, although not statistically significant.