FDTD electromagnetic and thermal analysis of interstitial hyperthermic applicators. Finite-difference time-domain.

In this paper, the electromagnetic and thermal behavior of interstitial applicators was analyzed by using the Finite-Difference Time-Domain method. Two configurations were considered: a simple insulated dipole antenna radiating in a layered tissue, and an air cooled applicator radiating in a tissue-equivalent phantom. The proposed approach allows a detailed modeling of the complete structure of the applicator. Furthermore, Specific Absorption Rate and temperature distributions can be determined considering real clinical or experimental conditions. The temperature distribution for the air cooled applicator has been compared with experimental results.

A water-cooled EM applicator radiating in a phantom equivalent tissue--experiments and numerical analysis.

A prototype of a water-cooled electromagnetic applicator for intracavitary hyperthermia has been tested. The temperature distributions produced in a polyacrylamide dissipative medium have been shown using liquid crystals. A complete electromagnetic and heat transfer model can predict the experimental temperatures.

Electromagnetic and thermal models of a water-cooled dipole radiating in a biological tissue.

An insulated, water-cooled dipole, radiating in a biological tissue, is analyzed with a theoretical electromagnetic and thermal model. The SAR and temperature distributions are calculated taking into account the effect of the water flowing inside the applicator. The steady-state temperatures in a dissipative medium, interacting with the dipole, are evaluated for several thicknesses of the external casing, water temperatures and blood perfusions. A correct design of the external casing thickness and a proper choice of the temperature and flow velocity of water allows to control the wall temperature of the applicator within physiological limits. The influence of the blood perfusion on the temperature distribution is investigated.