Single-center nonrandomized clinical trial to assess the safety and efficacy of irreversible electroporation (IRE) ablation of liver tumors in humans: Short to mid-term results

Abstract

Introduction: A single-center nonrandomized clinical trial was performed to assess the safety and efficacy of IRE ablation of liver tumors in humans.

Methods: 38 malignant liver tumors on 30 patients were treated with IRE between September 2011 and September 2014. Treatment was with curative intent, and the diagnoses were colorectal cancer with liver metastases (CRLM) (n = 23), hepatocellular carcinoma (HCC) (n = 8) and other metastasis (n = 7). Patients were selected when surgery, radiofrequency ablation (RFA) or microwave ablation (MWA) was not an option, and when they met inclusion criteria (tumor size < 3 cm, 1-2 tumors). Patients were followed-up at 1 and 6 months with a contrast-enhanced computed tomography (CE-CT), and contrast-enhanced ultrasound (CE-US) at 3 months.

Results: Ablation success was defined as no evidence of residual tumor in the ablated area as confirmed by CE-CT and CE-US. At 3 months ablation success was 78.9%, and 65.8% at 6 months. There was no statistically significant difference between tumor volume (<5 cm³ vs >5 cm³, p = 0.518), and between diagnosis (CRLM vs HCC, p = 0.084) in terms of local recurrence. Complications were classified according to the standardized grading system of Society of Interventional Radiology (SIR). A minor complication occurred in six patients (20%), one patient (3.3%) suffered from a major complication (bile duct dilatation and stricture of the portal vein and bile duct). No mortalities occurred at 30 days.

Conclusions: IRE appears to be a safe treatment modality for a selected group of patients with liver tumors and offers high local tumor control at 3 and 6 months.

Keywords: Colorectal cancer; Interventional ultrasonography; Irreversible electroporation; Liver tumors.