Biopsy of Liver Target Lesions under Contrast-Enhanced Ultrasound Guidance - A Multi-Center Study.

PURPOSE:  To retrospectively characterize the prevalence and impact of contrast-enhanced ultrasound (CEUS) as a guidance technique for the biopsy of liver target lesions (LTLs) at six interventional ultrasound centers.

MATERIALS AND METHODS:  The six participating centers retrospectively selected all patients in whom biopsy needles were positioned in LTLs during CEUS. The prevalence of CEUS-guided biopsies at each center between 2005 and 2016, contrast agent consumption, procedure indications, diagnostic yield and complications were assessed. Informed consent was obtained for all patients.

RESULTS:  CEUS-guided biopsy of LTLs was carried out in 103 patients (68 M/35 F, median age: 69 yrs) with 103 liver target lesions (median size: 20 mm) using cutting needles (18 - 20 g) in 94 cases (91.2 %). CEUS-guided biopsy represented 2.6 % (range: 0.8 - 7.7 %) of 3818 biopsies on LTLs carried out at the participating centers. Indications to CEUS-guided biopsy were: a target lesion not visible on non-enhanced US (27.2 %), improvement of conspicuity of the target (33 %), choice of non-necrotic area inside the target (39.8 %). 26 patients (25.2 %) had a previously non-diagnostic cyto-histological exam. The diagnostic accuracy of the technique was 99 %. No major complications followed infusion of contrast agent or biopsy performance.

CONCLUSION:  The indications for CEUS-guided biopsy for LTLs are limited, but CEUS can be useful in challenging clinical scenarios, e. g. poorly visualized or invisible lesions or sampling of non-necrotic areas in the target lesions. There is also a potential advantage in using CEUS to guide repeat biopsies after unsuccessful sampling performed using the standard ultrasound technique.