Experimental low-level direct current therapy in liver metastases: influence of polarity and current dose

Abstract

Several authors recently reported on the successful local treatment of malignant disease with low-level direct current therapy. However, antitumoral effects in colorectal metastases has not been investigated experimentally. The aim of the present study was to assess the effectiveness of this therapy and the influence of polarity and current dose. Colorectal metastases were established in BD IX rats by the injection of colon cancer cells under the liver capsule. After three weeks, the liver tumor volumes were determined by magnetic resonance imaging of the liver. Low-level direct current therapy was applied via five platinum electrodes. Four different applications were used: 60 C/cm(3), anode at the center; 60 C/cm(3), cathode at the center; 80 C/cm(3), anode at the center; and 80 C/cm(3), cathode at the center. In the control group, five electrodes were placed without applying any direct current. All animals were sacrificed on postoperative day 7. Liver metastases were histologically examined for vital tumor cells. Statistical analysis was performed with chi(2)-test. The mean initial tumor diameter before treatment was 3.6 +/- 1.4 mm (volume: 25.2 +/- 9.7 mm(3)). Histological examination of the removed livers revealed significant destruction of the metastases with localized necroses in all treatment groups; 37% had a complete response rate and 63% a partial response rate. There were no significant necroses in the control group (P < 0.0001). The best treatment results were obtained in the group with an anode at the center and a current dose of 80 C/cm(3). Direct current therapy offers a new and safe method for the local treatment of liver metastases. We were able to observe that tumor damage is related to current dose but not to the polarity of the central electrode.

Efficacy of Direct Electrical Current Therapy and Laser-Induced Interstitial Thermotherapy in Local Treatment of Hepatic Colorectal Metastases: An Experimental Model in the Rat

“…Lao et al [35] and Wang [61], who treated 55 and 74 patients with primary liver tumors ranging from 3 to 21 cm in diameter, respectively, achieved a complete tumor destruction in 22% having applied loosely defined doses of 300 to 1500 C. Xin, who treated thousands of patients with different tumor entities, achieved a complete re- sponse rate of 25% in colorectal liver metastases and primary liver tumors by using a volume-related charge of 100 C/cm 3 [36,63]. In the present work, we applied a volume-related dose of 80C/cm 3 , which had proven to be the most effective dose in our previously published pilot study [39]. We believe that the dose of electrical current must not only be related to the tumor size but also to the liver size to find a maximum possible dose while causing minimum damage to adjacent normal liver.…”

“…The electrodes were held firmly in position by a supporting trestle. Next, the electrodes were connected with a current source and low-level direct current was applied at a constant level at 10 mA with 80C/cm 3 tumor as described before [39,42] ( Fig. 2A and B).…”

“…In addition to these experiments, we introduced an experimental model with subcapsularly induced hepatic tumors by injection of a colon cancer cell line. With this experimental set-up we were able to identify optimal treatment modalities and to prove the effectiveness of low level direct current therapy in colorectal liver metastases [39,40]. However, further information on the effectiveness of low level direct current, especially in comparison with a well established palliative treatment method, such as LITT in colorectal liver metastases, is needed before considering widespread clinical application.…”

Prostate Cancer: MR Imaging–guided Galvanotherapy—Technical Development and First Clinical Results

“…The total load applied is dependent on the total volume of the tumor. One hundred coulombs (C) per cubic centimeter have to be applied (22)(23)(24)(25). The voltage range was between 5 and 10 V, while the current values were between 10 and 30 mA.…”

Survival of Chondrocytes in Rabbit Septal Cartilage After Electromechanical Reshaping

“…Mechanical contact between the metal electrode and the wet cartilage specimen initiates a number of oxidation–reduction reactions at the metal–tissue interface 2,5. Application of external voltage to these electrodes may change the intensity or reverse direction of these chemical reactions, depending on voltage strength and polarity 1,29. Regardless of what precise role electrochemical reactions play in producing shape change during EMR, the reactions themselves and their by-products alter the chemical composition of the tissue, possibly creating tissue damage.…”