1999 Volume 15 Issue 2 Pages 65-70
For deep hyperthermia using an 8 MHz radiofrequency (RF) capacitive heating device, overheating the subcutaneous fatty layer is a major problem. Increasing the cooling ability of the overlay bolus circulating liquid by the external cooling unit was carried out to prevent overheating the subcutaneous fatty layer. Using the external cooling unit, the cooling ability was significantly improved at a depth of 1.5 cm from the surface in the agar phantom experiments. In clinical studies, we increased the RF output by over 50% even in cases of a subcutaneous fatty layer over 2 cm. Increasing the cooling ability of the overlay bolus circulating liquid is considered an effective method for deep hyperthermia.