Fig. 2
From: Status quo and directions in deep head and neck hyperthermia
a Design and (b) clinical prototype of the HYPERcollar3D applicator. Twenty antennas are arranged in three rings to allow more precise longitudinal steering, as compared to the HYPERcollar applicator. In addition, positioning reproducibility and waterbolus shape stability was improved to improve the focusing ability and reproducibility of the applicator, and hence the treatment. Note that still a high power system with twelve channels is used and hence a dedicated antenna selection procedure was developed