Abstract
RFA is a treatment modality for cancer that is becoming accepted because of its less-invasiveness and high-curability. Controlling the shape of ablation area increases curative effect. Therefore we propose the mechanism of electrode needle that RF current flow between two secondary electrode needles. We examined the parameters required to obtain a trapezoidal ablation area surrounded by two electrode needles. The result of simulation, it was suggested that the relation of length and thickness of two needles affect ablation. In addition, we performed ablation experiments using agar phantoms. We evaluated the ablation shape of simulation and experiment as three-dimensional cube set. Then, we confirmed that result of simulation and experiments were in agreement.