Thermal Therapy - RF/Microwave Interaction with Biological Tissues - page 180

FIGURE 4.30 Survival rate of combined therapy by radiation and hyperthermia.

Hyperthermia and Combined Effect of Irradiation Ben-Hur [38] reported
that the sensitization effect of irradiation is obtained by combining radiation
and hyperthermia, as shown in Figure 4.30. It was shown that lowering the
equivalent survival rate of cancer cells with irradiation only was compensated
by using hyperthermia: Figure 4.30 shows that there is a large effect and that
the survival rate of cancer cell is greatly reduced even at 42°C when both
hyperthermia and irradiation are used versus the hyperthermia-only therapy.

4.4 METHOD OF THERMOMETRY

Generally, in thermal therapy, temperature-monitoring means different from
the heating means play an important role. Especially in hyperthermia, the tem-
perature at the treatment location must be controlled around 42.5°. Accord-
ingly, accurate thermometry technology is an important problem. Temperature
measurement methods in the intraorganism are generally classified into inva-
sive methods and noninvasive method . As a thermometry method in thermal
therapies such as hyperthermia, the noninvasive method for temperature
measurement without stabbing the sensor into the human body is desirable.
However, presently, technological means measuring temperature accurately
by noninvasive methods have not been established. The following sections
describe practical thermometry methods.

4.4.1 Invasive Thermometry

Measurement by Thermocouple Sensor As a thermometric sensor, the ther-
mocouple has been used widely and generally. This thermometry principle is