Percutaneous ablation of obscure hypovascular liver tumours in challenging locations using arterial CT-portography guidance

Purpose: The purpose of this study was to evaluate the feasibility, safety and efficacy of percutaneous ablation (PA) of obscure hypovascular liver tumors in challenging locations using arterial CT-portography (ACP) guidance. Materials and methods: A total of 26 patients with a total of 28 obscure, hypovascular malignant liver tumors were included. There were 18 men and 6 women with a mean age of 58 +/- 14 (SD) years (range: 37-75 years). The tumors had a mean diameter of 14 +/- 10 (SD) mm (range: 7-24 mm) and were intrahepatic cholangiocarcinoma (4/28;14%), liver metastases from colon cancer (18/28; 64%), corticosurrenaloma (3/28; 11%) or liver metastases from breast cancer (3/28; 11%). All tumors were in challenging locations including subcapsular (14/28; 50%), liver dome (9/28; 32%) or perihilar (5/28; 18%) locations. A total of 28 PA (12 radiofrequency ablations, 11 microwave ablations and 5 irreversible electroporations) procedures were performed under ACP guidance. Results: A total of 67 needles [mean: 2.5 +/- 1.5 (SD); range: 1-5] were inserted under ACP guidance, with a 100% technical success rate for PA. Median total effective dose was 26.5 mSv (IQR: 19.1, 32.2 mSv). Two complications were encountered (pneumothorax; one abscess both with full recovery), yielding a complication rate of 7%. No significant change in mean creatinine clearance was observed (80.5 mL/min at baseline and 85.3 mL/min at day 7; P=0.8). Post-treatment evaluation of the ablation zone was overestimated on ACP compared with conventional CT examination in 3/28 tumors (11%). After a median follow-up of 20 months (range: 12-35 months), local tumor progression was observed in 2/28 tumours (7%). Conclusion: ACP guidance is feasible and allows safe and effective PA of obscure hypo-attenuating liver tumors in challenging locations without damaging the renal function and with acceptable radiation exposure. Post-treatment assessment should be performed using conventional CT or MRI to avoid size overestimation of the ablation zone. (C) 2020 Societe francaise de radiologie. Published by Elsevier Masson SAS. All rights reserved.