High-resolution SAR modelling for regional hyperthermia: testing quasistatic zooming at 10 MHz

Present-day regional hyperthermia treatment planning systems are limited to centimetre resolution. To obtain CT-resolution SAR distributions, a method called quasistatic zooming has been developed: using the centimetre-resolu tion (E) over right arrow -field distribution and the CT-resolution tomogra m, the CT-resolution SAR distribution is obtained. For a low frequency of 1 0 MHz this method has been validated sucessfully using CT-resolution SAR co mputations. It appears that these CT-resolution SAR distributions are completely differ ent from centimetre-resolution SAR distributions, indicating the necessity for high-resolution SAR modelling. Using the presented zooming technique, r eliable CT-resolution SAR modelling is now possible with relatively short c omputation times. So far, the zooming method has only been validated for lo w frequencies, but clinically relevant frequencies appear to be possible.