Development and evaluation of hyperthermia and PET imaging hybrid system for preclinical studies

• Main Author: Παπαδόπουλος, Κώστας
• Other Authors: Καγκάδης, Γεώργιος
• Format: Thesis
• Language: English
• Published: 2017
• Subjects: Magnetic fluid hyperthermia; Superparamagnetic nanoparticles; Cancer therapy; Hyperthermia / PET hybrid system; Simulations; Magnetic fields; Μαγνητική υπερθερμία; Μαγνητικά νανοσωματίδια; Υβριδικά συστήματα; Σύστημα υπερθερμίας / PET; Προσομοιώσεις; Μαγνητικό πεδίο; Μαγνητικό ρευστό; Θεραπεία καρκίνου; 616.994 075 75

The present thesis was elaborated in terms of obtaining the Master of Science degree in the Interdepartmental Post-graduate Program of Medical Physics at University of Patras. The main objective of the conducted research was the development and evaluation of numerical models for the description of the phenomena that participate in Magnetic Fluid Hyperthermia (MFH) anticancer treatment. Three numerical models were developed, including one model for the simulation of the magnetic field, one for the simulation of heat transfer in the magnetic fluid in the presence of an alternating magnetic field (AMF), and one for the simulation of hyperthermia application on a low-grade cerebral glioma with simultaneous monitoring of the thermotherapy, under PET imaging. For the development of the numerical models, the Comsol Multyphysics simulation software, was used. To simulate the magnetic fields the “Magnetic Fields” physics package was exploited, while for the simulation of the magnetic fluid heating process, the “Non-Isothermal Flow” module was used. For the hyperthermia application within the biological system the “Bioheat Transfer” package was used. The calculation of power dissipation due to magnetic nanoparticles (MNPs) in the heat transfer models, was accomplished via implementation of the Rosensweig’s analytical model. To obtain physical and magnetic properties that correspond to a real system and ensure reliability of the simulations’ results, MNPs were fabricated and characterized via a series of experimental processes, including magnetization measurements by SQUID, transmission electron microscopy (TEM), X-Ray diffraction (XRD) and dynamic light scattering (DLS). Subsequently, the magnetic fluid was heated for different configurations of the AMF. Then, the experimental conditions were imported in the numerical models. The correctness of the magnetic field simulations, was inspected via comparison with analytical expressions emanating from the Biot-Savart law, while the simulation results for the heating of the magnetic fluid, were validated via experimental curves. The parameters of the validated analytical hyperthermia model were imported in the biological model in order to obtain reliable results. However, validation of the bioheat transfer model through experimental data was not feasible. Finally, by recruiting the simulations of the biological model in combination with the “Events” mathematical module, the feasibility of an MFH/PET hybrid system was investigated. Further research is required in order to export safer conclusions regarding the feasibility of this venture, however the results of the present study are notably encouraging.