THE USE OF IRREVERSIBLE ELECTROPO-RATION FOR LIVER TUMOR TREATMENT: INITIAL BRAZILIAN EXPERIENCE

The treatment of liver tumors, both primary and metastatic, has shown important advances in recent decades. Minimally invasive treatments for early stage liver tumors have gained increasing acceptance due to the consistent body of evidence available in the medical literature. Recently, a new technique was developed and gained notoriety for the treatment of liver tumors: irreversible electroporation (IRE). Its non-thermal mechanism of action allows ablation of tumors without significant damage to adjacent structures. Considering that only a small fraction of patients with liver tumors present with a curative surgical possibility at diagnosis, the investigation of new therapeutic approaches is essential. The objective of the present study is to evaluate the safety of the use of IRE in the first 10 cases carried out in Brazil. Between March 2021 and March 2022, 10 patients (9 males, 1 female) with a mean age of 59.8 years were treated by the |RE technique (NanoKnife® system; Latham, NY, United States ). Study participants had 11 liver tumors (6 colorectal tumor metastases, 4 hepatocarcinomas, 1 cholangiocarcinoma), had already undergone previous treatment in 60% of cases (6 patients), with chemotherapy. Inclusion criteria were: patients with an IRE indication due to a diagnosis of cancer confirmed, ineligibility for conventional ablation, either because of the central location of the tumor, proximity to a major blood vessel or bile duct (< 0.4 cm). Patients with contraindications to general anesthesia, cardiac pacemakers or uncontrollable coagulopathy were not eligible. Technical success was defined as the achievement of an ablation zone ≥ 10 mm in the tumor periphery, characterized on control CT ou MRI, performed with intravenous contrast, after treatment by IRE. All procedures were performed under general anesthesia. No immediate complications were observed after the procedure. Evaluation by image detected margins greater than 10 mm in the control exams, characterizing technical success in 100% of the cases. Therefore, considering that IRE is presented as a minimally invasive option for the treatment of primary and metastatic liver tumors, the present study indicates safety and efficacy in the immediate post-procedure control. As this is the first nationwide study, our results add to the growing body of evidence available in the medical literature, and help both in the dissemination and acceptance of this promising therapeutic method.