Clinical impact of cone beam computed tomography on iterative treatment planning during ultrasound-guided percutaneous ablation of liver malignancies

A standardized cone beam computed tomography (CBCT) protocol may impact optimal ablation probe(s) positioning during ultrasound-guided microwave ablation (MWA). To evaluate this hypothesis, 15 patients underwent ultrasound-guided percutaneous MWA of 15 liver lesions (10 hepatocellular carcinomas, 5 metastasis ranging 11–41 mm) with the ultrasound guidance assisted by a dedicated CBCT protocol. Pre-procedural enhanced CBCT (ceCBCT) was performed after intravenous contrast administration to visualize the lesion and determine the optimal approach using CBCT-based ablation planning software. MW antennas were positioned under ultrasound guidance, and non-enhanced CBCT was performed after deployment and fused with pre-procedural ceCBCT to assess tumor targeting and modify subsequent steps of the procedure. CBCT lesion detection accuracy and number of needle repositioning on the basis of CBCT information were recorded. Clinical success was measured on 1-month follow-up contrast-enhanced CT. The target lesion was detected on ceCBCT in 13 out of 15 patients (87%). The undetected lesions were only visible on diagnostic contrast-enhanced magnetic resonance imaging, which was then fused to the CBCT and fluoroscopy to facilitate targeting. MW antennas were repositioned on the basis of CBCT in 11 lesions (73%). Clinical success was achieved in 14/15 ablations (93%) with a mean follow-up of X months. The only case of local recurrence was expected, as the intent was tumor debulking. CBCT imaging during ultrasound-guided liver ablation is feasible and leads to ablation device repositioning in the majority of cases.