Cone-Beam CT Hepatic Arteriography-Guided Microwave Ablation of Ultrasound-Occult Liver Lesions.

PURPOSE: To evaluate the technical success and safety of cone-beam computed tomography (CBCT) hepatic arteriography (CBCTHA) guided microwave ablation (MWA) for hepatic lesions invisible on ultrasound. METHODS: In this retrospective study, all consecutive patients with primary or secondary liver malignancies referred for MWA between September 2023 and March 2025, in whom the target lesion was not visible on ultrasound, were included. A catheter was inserted into the common hepatic artery or a segmental branch, and a dual-phase CBCT (DP-CBCT) was performed to visualize the lesion and plan the antenna insertion trajectory. DP-CBCT was repeated to confirm antenna placement and complete ablation. Technical success was defined as successful lesion identification, antenna placement, and visualization of the ablation zone. RESULTS: Thirty-eight patients with 46 nodules were included. Thirty-four (34/46, 74%) nodules were hepatocellular carcinoma and 12 (12/46, 26%) were colorectal cancer metastases. Tumor median size was 11.5 mm (IQR 10.0-13.8). Technical success was achieved in 41/46 lesions (89%). After a median follow-up time of 11.9 months (IQR 6.8-19.8), primary local tumor progression occurred in 2/41 lesions (4.9%). No major complications occurred. CONCLUSION: CBCTHA is a safe and effective procedure for performing MWA of hepatic lesions that are not visible on ultrasound. Key advantages of this technique include increased tumor visualization and ability to assess ablation margins.