Wideband Dielectric Characterization of Biological Tissues and Realistic Phantom Preparation at Microwave Frequencies

Oncological hyperthermia is a medical technique whose aim is to heat tumours at 41-43 °C for one hour through the application of an electromagnetic field (EMF). Hyperthermia proved to improve both chemotherapy and radiotherapy. For best hyperthermia performances, the knowledge of the dielectric properties (permittivity and conductivity) of the patient is essential, since these properties represent the response of materials to the applied EMF. This information can be used to optimize the treatment’s results but also to validate the hyperthermia device before the application on the patient. The validation procedure is usually done on phantoms, i.e., mixtures of materials which mimic the dielectric properties of biological tissues. This work presents the realization of a muscle equivalent mixture and the measurement of its dielectric properties with the open-ended probe technique. Results were compared with the dielectric properties of ex-vivo animal muscle samples that were measured with the same procedure.