Development of Magnetic Hyperthermia Coil System for Wide Treatment Temperature Area on Neck and Breast Cancer Models

Magnetic hyperthermia (MH), based on heat generation through the magnetic relaxation mechanisms of magnetic nanoparticles (MNPs) under alternating magnetic fields (AMFs), is a promising cancer treatment technology due to its non-invasiveness compared to other methods such as radiation, microwave irradiation, and chemotherapy. To enhance the therapeutic effect by expanding the area heated to the treatment temperature (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$43~^{\circ }$ </tex-math></inline-formula>C–<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$45~^{\circ }$ </tex-math></inline-formula>C), the spatial distribution of the magnetic field generated by the magnetic coil should be optimized. However, conventional coils, such as solenoid and Helmholtz coils, cannot control field distribution adequately for practical or clinical applications. In this study, we developed and evaluated an MH coil system designed to achieve a wider treatment temperature area in models of neck and breast cancer patients. The Neck coil system demonstrated a magnetic energy uniformity of 99.6% and a treatment temperature area of 77.6%, while the Breast coil system showed a magnetic energy uniformity of 32.2% and a treatment temperature area of 71.4%. We achieved a sixfold increase in the treatment temperature area for the neck and breast model coil systems compared to a conventional solenoid coil. These results suggest that our proposed coil system may enhance the effectiveness of cancer treatment for specific cancer patients.