ABSTRACT
To understand the principles of Rf interstitial hyperthermia the authors need to consider first the interaction between an electric field and tissue. When an electric field E is present in the tissue, a drift of the free conduction charges occurs which is superimposed on their random thermal motion. The SAR distribution associated with an array of electrodes in which power is switched sequentially between pairs may be found by summing the distributions for each pair. This approach may also be used to determine SAR for other types of incoherent systems such as those with several power sources, each driving a pair of electrodes simultaneously by operating at a slightly different frequency from the others. Further development of three-dimensional electromagnetic and thermal models of Rf interstitial techniques is needed for treatment planning.
