High-Intensity Focused Ultrasound (Hifu) Energized Nanoparticles-Mediated Enhanced Thermal Ablation of Tumors: Review of Recent Progress and a Proposed Methodology for Distinguishing Heat Sources

Energized metallic nanoparticles (NPs)-mediated enhanced heating is proposed to address the burns and incomplete ablation during high-intensity focused ultrasound sonication. Numerical methods for simulating NPs-enhanced heating have not yet been developed. Therefore, the goal of this research is to develop a computational technique that involves NPs-induced source modeling using remote temperature measurements where focal temperature rises (ΔT) are computed and compared to assess heat sources in tissue phantoms, in the presence and absence of magnetic-NPs (mNPs) at lower (10, 15, and 20 W) input powers. An analytical solution to the transient heat equation for an infinite line source of constant strength, in the form of an exponential integral function is used as an approach to model the mNPs enhanced heating and cavitation-induced heating. The mNPs enhanced heating is found to be 77.55 ± 0.04% of the heat produced for the baseline (no-NPs) case. For higher power (20 W), cavitation-induced heating is found to be 49.73% of the heat produced for the baseline case. In future, combined experiments and computations need to be carried out with an array of thermocouples in tissue phantoms to better characterize the distribution of heat source.