Simulation of Near Infrared Spectroscopy for Laser Induced Interstitial Thermotherapy on Tumors

Abstract

Laser induced interstitial thermotherapy (LITT) is a useful method for the treatment of tumors. In order to control the treatment of LITT, a new local control technique has been put forward. A functional near infrared spectroscopy (fNIRS) system was used. The temperature of biological tissue is regarded as the most important indicator for treatment of LITT. So, the propagations of near infrared laser in normal tumors and liver tumors were simulated with Monte Carlo method. Based on the distribution of light in normal tumors and liver tumors, the temperature distribution inside tissue under laser irradiation has been retrieved. Furthermore, the influences of laser power and action time on the temperature field were studied. The results show that the normal tumors and liver tumors have different light absorption with laser beam. The difference of temperature distribution in tissues with the same laser power is useful to apply in control the treatment of laser-induced interstitial thermotherapy for liver tumors. It is confirmed that the fNIRS can be a useful local control technology for LITT.