Thin microwave antenna for intracavitary heating of bile duct carcinoma — Experimental evaluations on performances of antenna using a swine

In recent years, various types of medical applications of microwaves have widely been investigated and reported. Among them, microwave thermal therapy is one of the useful applications and is modality for cancer treatment. In this treatment, there are several schemes of microwave heating. The authors have been studying thin coaxial antenna for intracavitary microwave heating aiming at the treatment of bile duct carcinoma. In this treatment, an endoscope is first inserted into the duodenum and a long and flexible coaxial antenna is then inserted into the forceps channel of the endoscope, which is used to insert the tool for surgical treatment. Finally, the antenna is guided to the bile duct through the papilla of Vater, which is located in the duodenum, and is inserted in the bile duct. Up to now, the heating characteristics of the antenna are investigated by numerical simulation, experiment using tissue-equivalent phantom and extracted organs. In this study, the authors have an experience on animal experiment using a swine. In the experiment, temperature rises around the antenna inserted into the bile duct were measured. From the results of this experiment, cooling effect by blood circulation was cleared.