Power requirements from instrumentation for ultrasound interstitial heating at variable heat sinks location

We discuss the role of discrete heat sinks in ultrasound interstitial heating. We consider an array of four applicators used for the heating. Each of the applicators is surrounded by three microscopic heat sinks. Their distance from the applicators varies from 1.60 to 8.14 mm. We found that the heat sinks that are very close to the applicators modify temperatures very substantially. While the required power needs to be increased by about 20% with the heat sinks at 1.60 mm from the applicator, the increase of about 10 % is needed for heat sinks at 8.14 mm. The latter, however, have more dramatic effects and lead to cold regions if they are located at the periphery of ultrasound penetration.