A Preliminary Propagation Study on Magnetic Scaffolds for Microwave Theranostics

Microwave hyperthermia is a promising therapeutic modality in oncology against deep-seated tumors such as bone cancers. However, antennas and radiating sources fails in providing the therapeutic heat without affecting the healthy tissues. Magnetic nanocomposite biomaterials, called magnetic scaffolds, can be implanted to be used as hyperthermia agents. The possibility of using magneto-dielectric biocompatible implant for performing microwave hyperthermia has been poorly investigated. Furthermore, the possibility of using magnetic scaffolds as microwave-responsive theranostic agents has never been explored. In other words, if and how the change of magnetic properties during the hyperthermia treatment could be detected by using microwave signal has been not investigated so far. In this work, a simplified mono-dimensional electromagnetic propagation model in a multilayer structure by means of the wave-amplitude transmission method has been proposed. The properties of the bolus-matching medium, a suitable set of working frequency for performing the hyperthermia treatment and the monitoring with microwaves has been found. The temperature increase in the tumor and scaffold have been simulated. Then, through the differential analysis of the variation of the transmission coefficient during the treatment it has been preliminarily determined that magnetic scaffolds could be used as microwave theranostic agents.