The purpose of this project is to develop adjunctive hyperthermia modalities for cancer treatment through theoretical and experimental studies of the spatial and temporal variation in the temperature field of tissues subjected to radio-frequency electromagnetic radiation. We are currently involved in measuring the patterns of energy deposition produced by a miniannular phased array (MAPA) applicator within various types of extremity phantoms, describing the electromagnetic fields of a MAPA in terms of its design parameters, describing the transient thermal profiles within limbs produced by a MAPA, and describing the systemic temperature and cardiac changes associated with heating various regions of the body. We are also continuing to refine a noninvasive method for measuring temperature in vivo, using magnetic resonance imaging of molecular diffusion.