激光诱导间质热疗中血流冷却效应的模拟

为研究激光诱导间质热疗过程中血管冷却对于生物组织内温度场和损伤度的影响,建立了包含单根血管的双层模型。由M on te C arlo模拟方法得到组织内的激光能量分布,采用有限差分法求解Pennes生物传热方程和血流换热能量方程得到组织内温度场,通过A rrhen ius速率过程方程得到组织损伤度。利用此模型,比较研究了不同血管情况下组织的温度场和损伤度。模拟结果表明,血管直径及血流速度是影响热疗中血管附近组织温度场和损伤度的重要因素。在模拟的5W功率条件下,当血管直径大于1mm时,如果仍采用与无血管情况下相同的治疗方案将可能导致无法完全杀死肿瘤而使热疗失去疗效。

Simulation of the cooling effect of blood flow in laser-induced interstitial thermotherapy

A two-layer model with a single blood vessel was developed to investigate the cooling effect for blood flow during laser-induced interstitial thermotherapy(LITT).The laser energy distribution was simulated using the Monte Carlo method.The Pennes bio-heat equation and the energy equation for the blood vessel were solved to calculate the temperature distribution.The corresponding thermal damage distribution was determined by the Arrhenius rate process formulation.Different sizes of blood vessels with different velocities were compared.The results show that the blood vessel diameter and the average blood velocity are the crucial factors in the temperature determination and thermal damage distributions near the blood vessel.LITT may not work when the laser power is less than 5 W and the blood vessel diameter is larger than 1 mm if the therapy plan is based on a model without blood vessels.