The First Clinical Experience With Electrochemotherapy Of The Colorectal Liver Metastases

Introduction: A prospective study was designed to evaluate the feasibility, safety and efficacy of intraoperative electrochemotherapy in the treatment of colorectal liver metastases.Patients and Methods: From 2009 through 2012 sixteen patients with colorectal liver metastases were enrolled. Adverse events were recorded, and response to electrochemotherapy evaluated radiologically and histologically. Electrochemotherapy was performed during open surgery, by inserting the electrodes with fixed or variable geometry into and around the tumor to cover the whole tumor area and the margin of normal tissue with a sufficiently intensive electric field according to the individualized treatment plan. Electric pulses, synchronized with the electrocardiogram, were delivered after intravenous administration of bleomycin (15,000 IU/m2).Results: 27 out of 29 metastases in 15 out of 16 patients were evaluable. No serious adverse events related to electrochemotherapy were observed. Radiological evaluation showed 85% complete responses and 15% partial responses with no statistically significant difference between metastases treated with electrodes with variable and fixed geometry. Histological analysis showed significantly less viable tumor tissue (p = 0.001) in metastases treated with ECT.Conclusion: Electrochemotherapy of the colorectal liver metastases proved to be a feasible, safe and efficient treatment modality, regardless of the type of the electrodes used. It was shown to have a specific place in difficult to treat metastases, located in the vicinity of major hepatic vessels, not amenable to surgery or radiofrequency ablation. For a higher success rate it is necessary to improve the accuracy of the technique by introducing electrodes based on a carefully designed treatment plan.