An eccentrically coated asymmetric antenna applicator for intracavitary hyperthermia treatment of cancer

A model based on transmission line theory is used to predict the behavior of an eccentrically coated asymmetric antenna applicator for use in intracavitary hyperthermia. Theoretical results for the heating rate (HR) of the applicators are compared to experimental results. The experimental results were obtained at City of Hope National Medical Center using four different 915-MHz applicators, each with a different antenna size and eccentricity of the coating. A parameter delta is defined, where delta <<1.0 is a thin wire approximation: delta is primarily a function of the eccentricity of the coating, the antenna diameter, and the coating diameter. It is found that when delta or=0.6), the model no longer accurately predicts directivity. Thus, the model that can be used to predict the HR profiles for an eccentrically coated asymmetric antenna only when delta >