Parameter estimation in high‐intensity focused ultrasound therapy

Abstract

Hyperthermia using High‐Intensity Focused Ultrasound (HIFU) is an acoustic therapy for cancer treatment. This technique consists of an increase in the temperature field of the tumor to achieve coagulative necrosis and immediate cell death. Therefore, for having a successful treatment, the physical problem requires to know several properties due to the high variability from individual to individual, or even for the same individual under different physiological conditions. This article presents a numerical simulation of hyperthermia therapy for cancer treatment using HIFU, as well as the estimation of parameters that influence the physical problem. Two mathematical models were considered to solve the forward problem. The acoustic model based on acoustic pressure performs a frequency‐domain study, and the bioheat transfer model a time‐dependent study. These models were solved using Comsol Multiphysics® software in a 2D‐axisymmetric rectangular domain to determine the temperature field. Parameter estimation was coded in Matlab Mathworks® environment using a Bayesian approach. The Markov Chain Monte Carlo method by the Metropolis–Hastings algorithm was implemented, and the simulated temperature measurements were considered. Results suggest that specific HIFU therapy can be performed for each patient by estimating appropriate parameters for cancer treatment and provides the possibility to define procedures before and during the treatment.

Multifunctional Drug-Loaded Phase-Change Nanoparticles Inhibit the Epithelial-Mesenchymal Transition of Hepatocellular Carcinoma by Affecting the Activity of Activated Hepatic Stellate Cells

“…The subcutaneous ultrasound images of tumor-bearing mice are shown in ( Figure 8 ): When the PPL NPs reached the lesion site and LIFU trigger ADV, the tumor images were enhanced in both B-mode and CEUS-mode, indicating that after LIFU irradiation, The PPL NPs we prepared can phase-transform locally to appear strong echo signals, which can be effectively used for enhanced ultrasound imaging and disease treatment. It is worth noting that the irradiation intensity and irradiation temperature of LIFU used in this study are much lower than those of HIFU, which fully demonstrates the controllability and safety of LIFU [ 38 ].…”