近红外光谱技术在激光热疗监测中的应用研究

针对激光热疗中生物病变组织光学参数随温度变化的特点,将近红外光谱技术应用于激光诱导肿瘤间质热疗疗效监测,在线检测激光作用后生物病变组织的温度与光学参数的变化趋势,以此来对疗效进行评估。基于监测原理分析,设计实验系统,以肝癌小鼠皮下移植瘤为实验对象,研究不同激光功率和作用时间下,生物病变组织约化散射系数和温度的变化,并利用核磁共振成像技术对移植瘤术前、术后的影像进行对比。实验结果表明:病变组织的约化散射系数在激光热疗过程中呈上升趋势,起始阶段上升较快,达到一定数值后趋于稳定,整体变化趋势与温度变化趋势比较吻合,核磁影像对比也证实了治疗效果。因此,通过近红外光谱技术监测激光热疗中病变组织约化散射系数的变化可有助于指导临床激光热疗。

Research on the Application of Near Infrared Spectroscopy Technology for Monitoring in Laser Thermotherapy

In view of the optical parameters of biological lesions varies with temperature during laser thermotherapy, near infraredspectroscopy technology (NIRST) was used to monitor the efficacy of laser induced interstitial thermotherapy (LITT) with the method oftesting the trend of temperature and optical parameters of biological lesions. Based on the analysis of the monitoring principle, anexperimental system has been designed. The subcutaneous implanted rat liver cancers were used for LITT experiments. Under different laser power and duration of action, the reduced scattering coefficient and temperature of the liver cancer were recorded. Theimages of the liver cancer have been compared with magnetic resonance imaging (MRI). The experimental results show that thereduced scattering coefficients of the diseased tissue has an upward trend during LITT, it increases quickly at beginning and graduallyreached the stable state. The overall trends of reduced scattering coefficients are consistent with the temperature. The therapeuticeffects are confirmed with MRI. Thus, NIRST is help to guide LITT with monitoring the changes of the reduced scattering coefficients.