A major limitation of thermal therapies, however, is the lack of detailed thermal information available to monitor and guide the therapy.13, 14,16,25-29 Temperatures are routinely measured with sparse invasive measurements. e limited number of measurements may produce temperature distributions with less detail than is necessary to assess thermal dosimetry properly.16, 26 With the advent of multi-element heating devices, there is increased need for temperature measurements that could provide detailed feedback about temperature distributions. is information in near real time would considerably improve the ability to deliver consistently eective temperature distributions.30-34

To meet the capability of present and forthcoming heating technologies for hyperthermia, a clinically useful method is needed to measure 3D temperature distributions to within 1°C with spatial resolution within 1 cm3 or better. A noninvasive method for volumetrically determining temperature distribution during treatment would greatly enhance the ability to

uniformly heat tumors at therapeutic levels in patients receiving thermal therapy.35