[The physics of heating and temperature measurement]

Among various kinds of phenomena involved in hyperthermic treatment, heating and temperature measurement are essentially simple physical phenomena, which appear complicated due to the complex structure of the body. The key to successful treatment lies in the clinician's knowledge about the essence of these physical phenomena. Heating methods can be classified into low, high and medium frequency electromagnetic field, ultrasound and total body heating. In each case, the heat generation can be estimated by the physical constants of the tissue. The temperature-rise distribution is determined by the heat generation and circulation (and heat conductance, which is negligible in normal tissue). Model calculation is applicable in order to understand the essence of the phenomenon. Temperature measurement methods can be classified into probe, implant, non-invasive and monitoring methods. Each of these has problems and must be selected according to the purpose. The use of phantoms can be done in two ways, which are simulation of the actual situation and the testing of the heating equipment. Computer simulation should also be utilized.