Research For Real-Time Tumor Therapy Evaluation Factor Of Laser Induced Interstitial Thermotherapy

Laser-induced interstitial thermotherapy (LITT) is a new technology for tumor treatment. It causes the tissue necrosis through the interaction of light and heat effects. But during clinical application it cannot achieve real-time efficacy evaluation and control of dosage. The present study mainly makes use of Near Infrared Spectroscopy (NIRS) technique to explore real-time efficacy evaluation during LITT, and provide theoretical evidence for accurate monitoring of clinical surgery.The main work of this study is as follows: 1. Base on principle of biological tissue heat conduction and heat damage, this paper carried on analog simulation research during laser treatment. We developed a dynamic theoretical model of biological tissue (principal focus on optics parameters) and utilized dynamic theoretical model to simulate temperature field distribution of target tissue. The result proved that dynamic characteristics of tissue parameters are highly affected during LITT by comparing the dynamic model analysis with the static model. 2. We can obtain parameters of efficacy evaluation by vitro and vivo experiments with LITT. We have gained near-infrared optics parameters (reduced scattering coefficient:μs', absorption coefficient:μa) and hemoglobin oxygen parameter (hemoglobin oxygen saturation: SO2) through experiments of vitro porcine liver and transplantation of liver tumor in vivo rat subcutaneous. 3. Base on a lot of experimental data analysis, we obtained a reliable parameter (μs',μa) used to real time monitor operation, and established a relationships model between parameters of efficacy evaluation and laser therapeutic parameters (laser power: P and lasting time: t). And we can achieve an ideal evaluation of therapeutic efficacy through mathematical models.The main creativeness of this study is as follows: (1) proposed an real time efficacy evaluation technology based on LITT using Near Infrared Spectroscopy (NIRS) technique; (2) constructed a dynamic theoretical model of biological tissue and simulated the temperature field distribution; (3) established a mathematical models of efficacy evaluation through experiments of vitro porcine liver and transplantation of liver tumor in rat subcutaneous, and initial implemented real time efficacy evaluation using NIRS.