Instability of Hyperthermia Temperature for Magnetic Nanoparticles of Low Anisotropy Constant Due to Nonlinear Characteristics.

Magnetic nanoparticles (MNPs) subjected to external alternating magnetic field can induce heat in MNPs due to hysteresis, which is usually employed for tumor hyperthermia. An effective hyperthermia treatment should selectively kill the tumor cells without damaging the ambient healthy tissue. Hence, it is important for hyperthermia to correctly control the alternating magnetic field-induced temperature of MNPs in the tumor. This work develops a thermal model to analyze various forms of temperature-rise with time in magnetic nanoparticles for tumor hyperthermia. Results show that there are horizontal, linear rise, square root, exponential decay and abrupt temperature-rise lines with time in MNPs. The horizontal, linear rise, and square root temperature lines with time are consistent with the available experimental data. It is worthily noted that the form of abrupt temperaturerise with time can result in harm to the normal cells or tissue. If the abrupt temperature-rise does not be controlled and predicted well.