Monitoring Laparoscopic Radiofrequency Renal Lesions in Real Time Using Contrast-Enhanced Ultrasonography: An Open-Label, Randomized, Comparative Pilot Trial

Abstract

Radiofrequency ablation (RFA) has been considered as an important therapy for small renal lesions. The main limitation of RFA, however, is the lack of pathologic confirmation of complete tumor eradication. A single center, open label, randomized pilot study was designed to evaluate whether contrast-enhanced ultrasonography (CEUS) with Sonovue, performed in real time could allow us to determine the end point during laparoscopic radiofrequency ablation (LRFA) and the clinical outcome of this method. Ninety-six patients undergoing LRFA were randomly assigned to CEUS or a control group; finally, 38 and 40 patients with a pathologic diagnosis of renal-cell carcinoma completed a 3-month follow-up. CEUS was conducted in real time during the procedure to determine the end point in the CEUS group. The primary outcome was the incomplete ablation rate according to a radiographic image at 3 months after the procedure. The secondary outcome included the local tumor control rate and disease-free survival rate. There were no differences in the incomplete ablation rate and disease-free survival rate between the two groups. Within a median 16-month follow-up period, three incomplete ablations and two local recurrences according to a radiographic image were found in the control group. Meanwhile, there was no incomplete ablation or recurrence but one lung metastasis in the CEUS group. The local tumor control rate was 87.5% (35/40) in the control group vs 100% (38/38) (P=0.073) in the CEUS group. In patients undergoing LRFA, there were no differences in the incomplete ablation rate and local tumor control rate between the CEUS group and the control group in our study despite a nonsignificant trend in favor of CEUS. CEUS may have the potential to provide more effective renal tumor ablation. These novel data support the need for a larger study of CEUS during LRFA surgery.