Irreversible electroporation of pancreatic adenocarcinoma: a primer for the radiologist

Irreversible electroporation (IRE) is increasingly used for the ablation of unresectable locally advanced pancreatic adenocarcinoma. Unlike other ablation technologies that cannot be safely used around critical vasculature or ducts for risk of thermal damage, IRE uses high-voltage pulses to disrupt cellular membranes. This causes cell death by apoptosis and inflammation. IRE has been deployed by both open and percutaneous approaches. Generator parameters are the same for both approaches, and settings are pancreas specific. Variations in settings, probe placement, and probe exposure can result in thermal damage or reversible electroporation and resultant treatment failure, morbidity, or mortality. When used properly, IRE appears to improve overall survival and local recurrence, but does not influence the rate of distant recurrence. However, studies of both open and percutaneous approaches have been relatively small, non-controlled, and without appropriate comparisons. It is challenging for the radiologist to interpret treatment effects after IRE because of a dearth of guiding literature and pathologic correlates. This primer describes technical aspects, pathology correlates, post-IRE imaging, and outcomes for percutaneous and open approaches.