Prospective comparison between real time contrast enhanced and conventional ultrasound guidance in percutaneous biopsies of liver tumors.

AIMS The performance of percutaneous echo-guided biopsy in the hepatic tumoral diagnosis is limited (90% sensitivity) by several factors, among which tumor characteristics (type, size, and location) play an important role. Contrast enhanced ultrasound guided percutaneous biopsy (CEUS-PLB) is a new developed technique aimed at increasing the accuracy of percutaneous biopsies. The objective of our study was to evaluate the feasibility and performance of CEUS as a guiding method in performing liver biopsy (PLB). MATERIAL AND METHODS One hundred and seventy one patients with liver tumors referred to the ultrasound department for LB were prospectively included in the study. PLB was performed with CEUS guidance in 90 patients (46 in patients with and 44 in patients without liver cirrhosis), in the remaining 81 (37 in patients with liver cirrhosis and 44 in patients without) with conventional US guidance. The lesions in the CEUS -PLB group were larger than those in the US-LB group (mean diameter 7.73 cm vs. 6.11 cm, p>0.05). In both groups the lesions were further divided in: a) lesions on cirrhosis; b) poorly visualized tumors; c) large tumors (>6 cm); d) cystic tumors; e) recurrences after ablation; and f) portal vein thrombosis. RESULTS Real time CEUS-PLB was technically successful in 84 of the 86 procedures (97.6% technical success rate). The rate of successful single puncture attempt in CEUS-PLB (43.02%) was higher than in the US-PLB group (23.4%) (p<0.05). The sensitivity of LB was significantly higher in the CEUS-PLB group than in the conventional US-LB group for all lesions (96.5% vs. 81.48%, p<0.05), for lesions on liver cirrhosis (95.2% vs. 75%, p<0.05), for large (> 6 cm) (97.8% vs. 82%, p<0.05), and for poorly visible lesions (100 vs. 66.6%, p=0.029). The patients with inconclusive pathological results after conventional guided LB were then biopsied with CEUS guidance. In all cases the final diagnosis could be established. One major complication occurred in each group (p>0.05). CONCLUSIONS Percutaneous LB performed with CEUS guidance is a feasible and safe technique. It significantly improves the overall sensitivity of the procedure especially in patients with large lesions and in those poorly visualized on conventional ultrasound.