Optimization of tissue temperature field in tumor laser thermal therapy based on step response model and particle...

Laser-induced thermal treatment (LITT) is a minimally invasive method that has shown significant potential for tumor ablation. To achieve maximum treatment results, it is essential to enhance tumor tissue ablation while protecting surrounding healthy tissues from thermal injury. Formulating an efficient thermal therapy regimen is essential for achieving therapeutic success. This paper proposes an optimization scheme for the temperature distribution in biological tissues during LITT, based on step response model and particle swarm optimization algorithm. The proposed scheme addresses the high computational cost associated with optimizing the LITT process using tissue heat transfer mechanism models. First, the step response matrix of the tissue temperature field is determined offline based on the fundamental equations of biological tissue heat transfer during LITT. Subsequently, the step response model for tumor boundary temperature is established using the superposition principle. Furthermore, the particle swarm optimization algorithm is employed to optimize multiple laser heating parameters for continuous and periodic heating processes. Numerical test results show that the proposed method increases LITT process optimization design and assessment efficiency compared to biological tissue heat transfer mechanism models: The error of the optimized final objective function values between the step response model-based method and the bioheat transfer model-based method is less than 1%, and the total computation time for optimization based on the step response model is less than 6% of existing methods. The optimized tumor thermal therapy scheme incorporating a maintenance phase achieves stable therapeutic temperatures, better aligning with actual clinical treatment scenarios.