Intra-procedural real-time ultrasound fusion imaging improves the therapeutic effect and safety of liver tumor ablation in difficult cases.

In certain difficult cases involving tumors unclear in B-mode ultrasound or tumors in a high-risk location, image-guided liver tumor thermal ablation was previously contraindicated. The aim of this retrospective study was to investigate the value of intra-procedural ultrasound fusion imaging in improving the therapeutic effect and safety of liver tumor ablation in difficult cases. A total of 502 patients (441 males and 61 females, aged 52 ± 11 years) with 805 liver tumors (16 ± 6 mm; range, 4-29 mm) who underwent thermal ablation with intra-procedural fusion imaging from October 2010 to June 2018 in our hospital were enrolled. Fusion imaging was employed for targeting, puncture guidance and immediate evaluation of the therapeutic response. Contrast-enhanced computed tomography (CT)/magnetic resonance imaging (MRI) was performed one month after ablation and every 3~6 months in the follow-up period. 511 and 294 liver tumors were in classified in the difficult case group and the non-difficult case group, respectively. The technical efficacy rate was 99.4% (800/805), and no difference was found between the two groups (P=0.658). No significant difference in the local tumor progression rate was found between the difficult case group (1 year: 3.2%; 3 years: 7.6%; 5 years: 7.6%) and non-difficult case group (1 year: 2.1%; 3 years: 5.5%; 5 years: 11.6%) (P=0.874). The major complication rate was 1.8% (11/608). Injury to adjacent organs occurred in only 1 patient who sustained a bile duct injury. We conclude that intra-procedural fusion imaging can improve the therapeutic efficacy and safety of thermal ablation in difficult cases and may expand the indications for thermal ablation.