Three-dimensional modelling and optimisation of thermal fields induced in a human body during hyperthermia

Abstract

In the field of hyperthermia as a cancer therapy, the design of tools to predict as well as to control the thermal fields in biological tissues remains a task of highest importance. In this context, we have developed a three-dimensional numerical model in heterogeneous media in order to compute the rate of volumetric heat generation, produced by means of an electromagnetic irradiation, and the resulting temperature distribution. The electromagnetic power deposition within the tissues is predicted by solving the Maxwell's field equations in the frequency-domain and the thermal process is described by the Pennes' bio-heat transfer equation. All the governing equations have been solved using the boundary element method. Furthermore, our simulation tool has been coupled to an optimisation procedure, whose parameters are the amplitude and phase of each electromagnetic source. The objective is to achieve the highest possible temperature in the tumour without exceeding 42 °C in the surrounding healthy tissues. Simulations based on a three-dimensional heterogeneous model constructed from cross-sectional slices of a person are presented. The studied configurations concern the pelvic region where a tumour is deeply embedded. The efficiency of our optimisation routine in a treatment plan for regional hyperthermia is reported.