Deep Brain Ultrasound Ablation Thermal Dose Modeling with in Vivo Experimental Validation

Area of Science:

• Neurosurgery
• Biomedical Engineering
• Medical Physics

Background:

• Intracorporeal needle-based therapeutic ultrasound (NBTU) is a minimally invasive technique for thermal ablation of malignant brain tumors.
• The technique uses high-frequency ultrasound to generate localized heating, inducing rapid cell death in cancerous tissues.
• Accurate modeling is crucial for optimizing transducer design and predicting thermal dose delivery.

Purpose of the Study:

• To develop and validate an enhanced finite element method (FEM) simulation for NBTU in brain tumors.
• To improve the evaluation of thermal damage and therapeutic efficacy compared to previous models.
• To assess the accuracy of the FEM simulation against experimental data from magnetic resonance thermal imaging (MRTI).

Main Methods:

• Numerical modeling of the acoustic pressure field generated by piezoelectric transducers.
• Simulation of bioheat transfer to track thermal propagation during treatment.
• Experimental validation using magnetic resonance thermal imaging (MRTI).
• Development of a new FEM simulation with enhanced damage evaluation capabilities.

Main Results:

• MRTI validation demonstrated the feasibility of the initial model, showing consistent thermal propagation.
• The enhanced FEM simulation showed good agreement with experimental results.
• Differences in peak temperature and ablated volume were within acceptable ranges (3.71% and 5.74%, respectively).
• Pearson correlation coefficient (0.7117) and Dice coefficient (0.7021) indicated good accuracy for peak temperature and ablated area.

Conclusions:

• The enhanced FEM simulation provides a more accurate prediction of thermal dose and ablated volume in brain tumors treated with NBTU.
• This advanced modeling approach aids in optimizing NBTU treatment planning and evaluating therapeutic efficacy.
• The simulation's accuracy supports its use for refining NBTU transducer design and treatment protocols.