Combination of irreversible and calcium electroporation to overcome heterogeneity-associated incomplete ablation in the pancreas.

Irreversible electroporation (IRE) can be considered as an alternative therapy for pancreatic tumors. However, a previous study revealed that the difference in electrical conductivity between the liver parenchyma and vessels was reported to result in local changes in electric field distribution during IRE, which may contribute to incomplete ablation and tumor recurrence. Therefore, finite element method (FEM) was conducted to examine whether such local changes could also occur in pancreatic tissue. FEM revealed that a similar phenomenon also occurs around the vessels and ducts in pancreatic tissue. To propose combining IRE with calcium electroporation (CaEP) as a potential solution, in vivo experiments using the rat pancreas were performed. The group receiving IRE followed by calcium injection showed a significantly lower percentage of viable cells than the other groups. In conclusion, clinicians should consider that the lowered electric field strength caused by the presence of vessels and ducts can cause unintentional cell survival when IRE is applied to the pancreas. Because the combination of IRE and CaEP reduced unintended cell survival within the treated area in normal pancreatic tissue, further studies using tumor models are needed to determine whether the combination is also applicable for clinical tumor treatment.