An Updated Numerical Workflow for Predicting Clinical Outcomes of Irreversible Electroporation in Hepatocellular Carcinoma

Background and Objectives: Electroporation ablation is a promising nonsurgical and minimally invasive technique for tumor ablation; however, no monitoring is currently available. In this article, we present recent advances in the numerical workflow toward a peroperative numerical evaluation of clinical irreversible electroporation (IRE) procedures of liver tumors. The objective of this study is to propose an updated numerical workflow for the digital twin of electroporation ablation, to provide relevant information to physicians performing IRE for hepatocellular carcinoma (HCC). Methods: The workflow consists of four main steps: (1) an image registration algorithm to align the contrast-enhanced cone beam computed tomography (CBCT), where the region of interest are visible, with the lower-quality CBCT acquired after needle insertion; (2) extraction of needles position by manual selection directly on the CBCT containing the needles; (3) accurate and efficient numerical computation of the electric field (EF) distribution, using a static linear model and the finite difference method to simulate the EF at the maximum voltage applied between each electrode pair; and (4) numerical assessment of the tumor coverage by the 3D EF. Results: We propose a criterion for electrical heterogeneity of the medium near the electrode thanks to the measurements provided by the Nanoknife IRE device. The full protocol was tested on three representative patients with nodular HCCs &lt;5 cm. The complete numerical workflow, from image registration and needle detection to the computation, requires at most less than 15 min following image acquisitions, making it suitable for clinical use. Interestingly, the number of finite difference computations increases linearly with the number of needles N , despite the number of electrode pairs increasing as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>N</mml:mi> <mml:mo stretchy="true">(</mml:mo> <mml:mi>N</mml:mi> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> <mml:mo stretchy="true">)</mml:mo> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:math> . In addition, the pulse amplitude can be modified without the need for full recomputation, enabling online adjustment of the treatment plan.