On minimisation of toxicity to skin during capacitive radio-frequency hyperthermia.

Abstract

Common techniques to induce tissue hyperthermia (HT) with radio-frequency (RF) currents are either capacitive or inductive in type (Cheung, 1982; Cosset et al, 1983). An advantage with RF capacitive HT is the possibility of heating deep-seated tissues (Cheung, 1982; U et al, 1984). However, during capacitive heating the higher resistivity of subcutaneous tissues results in excessive heating, which leads to skin and fat burns and induration (Arcangeli et al, 1983; Perez et al, 1983; Hiraoka et al, 1984; Oleson et al, 1984; U et al, 1984). To prevent the direct contact of the electrode with the skin, electrodes are enclosed in bolus bags through which cooled fluids such as saline (Brezovich et al, 1981; Cheung, 1982) or deionised water (Hiraoka et al, 1984; Prionas & Hahn, 1984; U et al, 1984) are circulated. Brezovich et al (1981) have shown that the skin burns during RF capacitive heating could be reduced by using a saline bolus of tissue-equivalent conductivity and Griffiths et al (1984) have reported th...