Thermometry in Therapeutic Hyperthermia

The delivery of local and regional therapeutic hyperthermia in clinical practice proves to be a difficult challenge. The objective is to elevate the temperature of malignant tissue to a uniform level in excess of some minimum therapeutic temperature (e.g., 42.0 °C) for a period on the order of 30–60 min. At the same time, normal tissue temperatures should be maintained at subtherapeutic levels. This objective is seldom achieved. The difficulty is associated not so much with excessive heating of normal tissue (normal tissue toxicity is thus far reportedly low) as with achieving a minimum, uniform therapeutic temperature in the target tissue volume. It is known that thermal cytotoxicity is very temperature dependent [1]. In addition, thermal tolerance, the ability of cells to become resistant to elevated temperature, is another phenomenon that is highly dependent on temperature and exposure time and may be therapeutically relevant [1,2].