Comparison of Cone-Beam CT Angiography and Contrast-Enhanced CT Guidance Using Electromagnetic Navigation for Percutaneous Liver Microwave Ablation: A Retrospective Nonrandomized Observational Study.

Purpose: To evaluate whether C-arm cone-beam computed tomography (CT) angiography guidance is noninferior to standard contrast-enhanced CT guidance for hepatic microwave ablation (MWA) using an electromagnetic navigation system (Imactis CT-Navigation System) in tumors not visible on ultrasound (US).

Materials and methods: This retrospective, single-center, nonrandomized study included 79 patients with liver neoplasms treated with MWA between September 2019 and June 2024. Patients were allocated to cone-beam CT angiography (n = 53) or contrast-enhanced CT (n = 26) groups based on modality availability. The primary outcome was technique effectiveness, defined by absence of tumor on imaging immediately postprocedurally, at 1-3 months, and at 4-6 months. Secondary end points included procedural time, effective radiation dose, and 30-day adverse events. Comparisons used t tests, Fisher test, and Mann-Whitney U tests.

Results: Technique effectiveness was comparable between cone-beam CT angiography and contrast-enhanced CT at all time points: immediate (technical success), 100% vs 100% (P = 1.000); 1-3 months, 87% vs 73% (P = .208); and 4-6 months, 81% vs 71% (P = .463). No significant differences were found in radiation dose (37.96 vs 32.36 mSv; P = .276) or adverse event rates (11% vs 11%, P = 1.000). Two deaths occurred in the cone-beam CT angiography group: one due to hospital-acquired pneumonia and the other from colonic perforation, possibly related to inadequate technique selection. Cone-beam CT angiography procedures were significantly longer (98.44 vs 62.03 minutes; P = .0001).

Conclusions: This study suggests that cone-beam CT angiography-guided MWA using electromagnetic navigation offers comparable short-term effectiveness and safety to contrast-enhanced CT guidance, but with longer procedural times. The small nonrandomized cohort is subject to selection bias, and further studies are needed to confirm these findings.