QUALITY ASSURANCE FOR RADIOFREQUENCY REGIONAL HYPERTHERMIA

Today most treatments with regional hyperthermia are applied using rad iofrequency systems with 'focus' steering by amplitude and phase contr ol. This paper deals with quality assurance procedures developed to en sure controlled and safe treatments in such systems. Our results show how the deviations between requested and observed phase and amplitude vary with frequency, and how these deviations depend on both the geome try of the object (phantom) inside the system and the power level appl ied. The results also indicate that the investigated systems' internal quality assurance procedures were inadequate and that additional proc edures should be applied. Since the system parameters depend on patien t and treatment specific conditions it is concluded that there is a ne ed for QA measurements before or during treatment. This paper deals sp ecifically with the commercial BSD-2000 system from BSD Medical Corp. in Salt Lake City, Utah, as installed in Bergen, but the procedure out lined can be applied to other phase and amplitude-controlled RF-RHT sy stems with only minimal adjustments.