(566f) Effect of AEM Probe Configuration On Heating of Magnetic Nano Particles for the Application of Cancer Hyperthermia

Sanapala, K. K., University of Louisville
Hewaparakrama, K., University of Louisville
Kang, K. A., University of Louisville
Rahman, M., University of Louisville

Magnetic nanoparticles, when subjected to alternating electromagnetic (AEM) field, generate heat mainly due to Neel and Brown relaxation. In magnetic particle mediated hyperthermia, the particles accumulated in the tumor are subjected to a non-invasively applied AEM field. For the low heat hyperthermia to be highly effective the temperature of the magnetic particle containing tumor is maintained in the range of 42~45 oC. Iron oxide (Fe 3O 4) nano particles have attracted considerable interest in biomedical application purely because of their biocompatibility. The most important issue in this therapy is applying an appropriate amount of energy to kill tumors of various sizes and at various depths, and to avoid the normal tissue damage, in a non-invasive and user-friendly way. The heat energy generated by the magnetic nano particles is dependent on (1) AEM unit operating parameters (power, time of AEM field application etc.), (2) configuration of the probe, and (3) size of the particles.

In this study, the effectiveness of three configurations of the probe (solenoid, pancake and sandwich) on the heating nano particles was analyzed. The study correlates the heating with the configuration of the probe and concentration of iron oxide particles and size and depth of the tumor. Our study results indicated that the solenoid type probe, which is most commonly used, generates maximum AEM field in the core but was not user-friendly. The probe can also be a pancake type or sandwich configuration with adjusted distance. Pancake probe was better for treating surface tumors but the field doesn't penetrate deep. Sandwich probe(s) provide controlled intensity of magnetic field that can treat deep seated tumors.