Electromagnetic phased arrays for regional hyperthermia: optimal frequencyand antenna arrangement

This paper investigates the effects of the three-dimensional arrangement of antennae and frequency on temperature distributions that can be achieved i n regional hyperthermia using an electromagnetic phased array. It compares the results of power-based and temperature-based optimization. Thus, one is able to explain the discrepancies between previous studies favouring more antenna rings on the one hand and more antennae per ring on the other hand. The sensitivity of the results is analysed with respect to changes in ampl itudes and phases, as well as patient position. This analysis can be used f or different purposes. First, it provides additional criteria for selecting the optimal frequency. Secondly, it can be used for specifying the require d phase and amplitude accuracy for a real phased array system. Furthermore, it may serve as a basis for technological developments in order to reduce both types of sensitivities described above.