Ablation treatment of primary and secondary liver tumors under contrast-enhanced ultrasound guidance in field practice of interventional ultrasound centers. A multicenter study.

The present retrospective study was aimed at characterizing the clinical impact of contrast-enhanced ultrasound (CEUS) as a guidance technique for ablation of primary and secondary liver tumors at six interventional ultrasound centers. 148 patients (103M/45F, median age 74 yrs.) with 151 liver target lesions (median size 15 mm, 86.7% Hepatocellular Carcinomas) in whom CEUS guidance was used for Percutaneous Ethanol Injection (35.2%), Radiofrequency (46.3%) and Microwave (18.5%) were selected during the period 2008-2016. CEUS-guided ablations represented 7.3% (range 2.5%-13.8%) of 2015 ablative sessions performed at the participating centers. Indications to CEUS-guided ablation were: improvement of conspicuity of the target (28.5%), a target lesion undetectable on B-mode ultrasound (29.8%), detection of viable areas in nodules with either incomplete ablation or local tumor progression (41.7%). Overall, complete radiological ablation was obtained in 113/151 tumors (74.8%), with heat-based techniques (RF and MW) achieving higher rate of successful ablation (86.7%) than PEI (51%). Neither deaths nor major complications occurred after ablations. CEUS guidance demonstrates improved visibility and effectiveness in aiding ablation procedures that are otherwise technically difficult using only B-Mode US guidance.