Irreversible electroporation ablation of end-stage metastatic retroperitoneal lesions: Report on three cases and literature review.

Metastatic retroperitoneal tumors constitute an end-stage disease with poor prognosis that represents a heavy global health burden. The present study aimed to explore the efficacy of irreversible electroporation ablation (IRE) therapy in patients with end-stage retroperitoneal tumors. Between April 2016 and September 2017, three patients with unresectable retroperitoneal malignant tumors were enrolled. Among these cases, ultrasound (US)-guided IRE was palliatively performed for targeting 3 tumors (1 tumor per patient) located around the abdominal aorta. Post-treatment contrast-enhanced US (CEUS) and contrast-enhanced computed tomography (CECT) scans were subsequently performed to evaluate the area adjacent to the ablation zone and determine the prognosis. During the follow-up, the cases experienced a reduction of pain (mean score of 5.8 decreased to 2.2, based on the visual analogue scale), and had an overall survival rate ranging from 2 to 11 months. Case 1 remained alive at the time of submission of this study, but case 2 died within 2 months and case 3 within 11 months due to liver metastases of the primary tumor. At the 3-week follow-up, the CEUS image for case 1 exhibited a contrast defect with a sufficient ablation margin, in accordance with the CECT at 1.5 months following IRE, exhibiting complete tumor necrosis without contrast enhancement. Overall, these results suggest that US-guided percutaneous IRE may be effective in the treatment of end-stage retroperitoneal tumors. However, further studies are required to substantiate the conclusions of the present study. The present clinical trial was registered at clinicaltrials.gov (ID: NCT02822066) on June 20th, 2016.