Patient-specific simulation of high-intensity focused ultrasound for head and neck cancer ablation

This study used acoustic and biothermal simulations on reconstructed geometry of a patient with squamous cell carcinoma to investigate the feasibility of using high-intensity focused ultrasound (HIFU) for the thermal ablation of cancerous tumors in the oral cavity. Herein, the effect of HIFU treatment on a patient diagnosed with head and neck cancer was investigated using a commercialized finite-difference time-domain (FDTD) tool. The potential application of spherical and cylindrical transducer geometries with curvature radii ranging from 64 to 100 mm was investigated. The effect of frequency variation (from 0.2 to 1.5 MHz) on the thermal ablation characteristics of a spherical transducer was explored. The study also explored the influence of surrounding tissue structures on transducer motion by placing transducers in different positions. The spherical transducers were found to have focused acoustic energy deposition and their deposited acoustic energy was revealed to increase with frequency. Consequently, a higher ablation volume was realized due to the longer exposure time for the lower frequencies. Interference from bone structures can cause focal shifts or distortions in the deposited acoustic energy. However, no significant secondary hotspot regions were observed. Therefore, the investigated technique has the potential to be used for the successful non-invasive treatment of similar head and neck cancers.