The purpose of this study is to see how well electrochemotherapy works at treating people with Stage III pancreatic adenocarcinoma. Electrochemotherapy is a treatment that combines electroporation and chemotherapy administration. Electroporation uses an electric current to produce holes in pancreatic tumor, which causes the tumor cells to die or take up a higher concentration of administered chemotherapy agent. This study will test the safety and look at the effect of electrochemotherapy in the treatment of stage III pancreatic adenocarcinoma. This study will also help to find the safest and most effective amount of electroporation voltage to apply to this type of tumor.