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-resolution E-field distribution and the CT-resolution tomogram, the CT-resolution SAR distribution is obtained. For a low frequency of 10 MHz this method has been validated sucessfully using CT-resolution SAR computations. It appears that these CT-resolution SAR distributions are completely different from centimetre-resolution SAR distributions, indicating the necessity for high-resolution SAR modelling. Using the presented zooming technique, reliable CT-resolution SAR modelling is now possible with relatively short computation times. So far, the zooming method has only been validated for low frequencies, but clinically relevant frequencies appear to be possible.