Preliminary results in unresectable cholangiocarcinoma treated by CT percutaneous irreversible electroporation: feasibility, safety and efficacy

Cholangiocarcinoma (CC) accounts for about 3% of the gastrointestinal and 10-25% of all hepatobiliary malignancies. It arises from the epithelium of the bile duct and it can be classified in intrahaepatic (ICC), perihilar (PCC) and distal (DCC) cholangiocarcinoma, depending on the anatomical location. About 50-60% of the cases are PCC. Early detection is very difficult for the lack of symptoms, and most of the patients are not resectable at the time of diagnosis. IRE is a non-thermal ablation technique that determines cellular apoptosis by electrical impulses without involving extracellular matrix like MW or RF ablation (MWA and RFA). The aim of our study is to demonstrate the safety, feasibility and efficacy of this procedure in the treatment of cholangiocarcinoma according to our experience. From 2015 to 2019, fifteen patients with unre-sectable perhilar and intrahepatic colangiocarcinoma (7 female and 8 male, mean age 69.2) were referred to our department to be enrolled in our prospective study that was approved by local Ethical Committee. Eight lesions were defined iCC and seven of them pCC. Six patients had biliary STENT and four external percutaneous transhepatic biliary drainage (PTBD). The IRE procedure was performed to expert radiologist (G.B.) under CT guidance using the Nanoknife IRE device (Angiodynamics, Queensbury, NY). The data before and after treatment were compared using Wilcoxon Rank Test and the survival outcome was evaluated using Kaplan Meyer Test. All procedures performed under CT guidance have been successfully completed. Treated lesions were located seven perhilar and eight intrahepatic sites and showed a mean volume 66.3 (SD 70.9; IC ranged from 5.57 to 267.20 cm(3)). No major complications were observed. From 30 to 90 days, the mortality rate was around 0%. Progression of the disease in all cases were not observed. Only one patient was reported increase of the Ca19-9 without sign of pancreatitis and bile obstruction. The imaging follow-up showed the local disease control with a decrease of the entire volume of the lesion and a further reduction of the densitometric values. From the comparison between the mean volumes for each group (before and after treatment), the Wilcoxon Rank test demonstrated the statistical significant difference with a p value < 0.01. On the contrary, it is believed that this results encouraging in considering the IRE procedure the safe, feasible and effective method in the treatment of the CC