A non-contacting scanned hyperthermia system for the treatment of superficial tumours

The authors discuss the use of a scanning system, whereby a spot beam antenna is repeatedly scanned over the area of treatment in a pre-calculated manner. To produce a pattern with a uniform temperature profile a specific power distribution, P(x,y), must be applied. Calculation of this, for the homogeneous case requires an optimisation program based around a thermal model. Given P(x,y) a corresponding velocity profile V(x,y) can be found. Where V(x,y) is the trajectory a particular antenna of constant power must follow to approximate the heating effect of P(x,y). A prototype system employs a computer controlled robot arm to scan a helical antenna. Initial experiments have been made using a thermographic sheet to measure the temperature distributions produced on the surface of a microwave absorber