| Magnetic nanoparticle hyperthermia has attracted growing research interests in malignant tumors treatment due to its simple implementation and few complications. In this approach, magnetic nanoparticles delivered to the tissue induce localized heating when exposed to an alternating magnetic field, leading to irreversible thermal damage to the tumor. Controlling the temperature elevations in such treatment is still an immense challenge in clinical applications. In the first part of this dissertation, we evaluate magnetic nanofluid transport in agarose gel. By adjusting the gel concentration and injection rate, we identify an optimal delivery strategy for achieving a spherically shaped nanoparticle dispersion that allows for a controlled heat distribution. It was shown that the shape and volume of the nanofluid distribution are highly dependent on the injection rate and gel porosity. The measured specific absorption rate (SAR) shows that the nanoparticle distribution is not uniform with a higher concentration close to the injection site.;In the second part of this dissertation, we evaluate the effects of the blood perfusion rate and the nanofluid amount on the heating pattern and temperature elevations in rat muscle tissue during in vivo experiments. Doubling the amount of nanofluid resulted in about 70% increase of the temperature elevation around the injection site and a temperature of 43oC was feasible under the protocol and magnetic field parameters used in the experiment. Using the measured temperature distribution, an inverse heat transfer analysis was performed to evaluate the induced SAR. It showed that the nanoparticles are more concentrated in the vicinity of the injection site when their amount is bigger.;Finally, an optimization algorithm is developed to determine the optimum heating patterns induced by multiple nanoparticle injections in a tumor. The design objective is to elevate the temperatures of at least 90% of the tumor above 43°C, and to ensure that only less than 10% of the normal tissue is heated to temperatures over 43°C. The efficiency and capability of this approach have been demonstrated in two tumors with simple or complicated geometry. The results of this study ought to be coupled with an experimental database to relate the optimized SAR parameters to their appropriate nanoparticle concentration, injection amount, and injection rate. We believe that the developed optimization algorithm can be used as a guideline for physicians to design an optimal treatment plan in magnetic nanoparticle hyperthermia. |
