Shycade system used for hyperthermia therapy: Determination of the heating pattern

Our purpose is to determine the power deposition inside biological tissues and to deduce the heating pattern in order to achieve the thermal dosimetry which is of great interest in hyperthermia treatment, The determination of the near field radiative diagram of the applicator is obtained from the resolution of the LAPLACE equation in the steady state (according to the method of discrete finite differences ). Then the temperature distribution in the heated tissue volume is calculated from the resolution of the bidimensional bioheat transfer equation. The inhomogeneous character of the medium can be taken into account, particularly for the blood flow term different in each type of tissue (skin, fat, tumour,...) and also the superficial cooling factor (water bolus). In order to verify theoretical results, experimental measurements were performed on phantom simulating human tissues (polyacrylamid gel).