We have introduced a thermal treatment using an endoscope and a thin microwave antenna for treatment of bile duct carcinoma. In the bile duct carcinoma, stent placement is often utilized for palliative treatment of malignant bile duct obstruction due to enlarged tumors or abscesses in general. In addition, we have known that a metallic stent could shield electromagnetic energy. Therefore, in this paper, a new biliary metallic stent compatible with microwave hyperthermia will be introduced. It has several plastic stents in order to generate more effective and extensive heating regions around it. By comparisons of the SARs of the proposed and conventional metallic stent, we confirmed that the proposed biliary stent could generate extensive heating regions in the longitudinal direction up to 60 mm. Therefore, it is highly possible that the developed biliary stent would be useful for microwave hyperthermia for the bile duct carcinoma in situation that it has implanted in a bile duct.

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