Local treatment of hepatic metastases with low-level direct electric current: Experimental results

Background: Several authors have recently reported encouraging results from low-level direct current therapy in easily accessible malignant tumors. Ho wever, antitumoral effects in colorectal metastases have not been investiga ted experimentally. Methods: Using an animal model with induced hepatic met astases. we analyzed the effectiveness and the tumor growth dynamics after direct current application. Three weeks after induction tumor volumes were estimated with magnetic resonance imaging (MRI). Then direct current (80 C/ cm(3)) was applied in the treatment group by means of one anode in the tumo r center and four cathodes peripherally. In the control group electrodes we re placed without applying current. Tumor growth dynamics was analyzed with MRI after 3 and 5 weeks. After this all animals were killed, and the liver s histologically examined. Results: After 5 weeks MRI showed a 1.6-fold tum or enlargement in the treatment group versus a 2.9-fold enlargement in the control group (Student t test, P = 0.0051). The histopathologic analysis of the treated livers yielded a 21% complete response rate and a 78% partial response rate. No necroses were found in the control group. Conclusions: Th ese results confirm the effectiveness of low-level direct current applicati on as a potential modality for the treatment of hepatic metastases.