etermination of the optical properties of turbid media sing relative interstitial radiance measurements: onte Carlo study, experimental validation, nd sensitivity analysis

. Alex Vitkin niversity of Toronto and Ontario Cancer Institute epartment of Medical Biophysics, Biophysics and Radiation Oncology oronto M5G 2M9, Canada Abstract. Interstitial quantification of the optical properties of tissue is important in biomedicine for both treatment planning of minimally invasive laser therapies and optical spectroscopic characterization of tissues, for example, prostate cancer. In a previous study, we analyzed a method first demonstrated by Dickey et al., Phys. Med. Biol. 46, 2359 2001 to utilize relative interstitial steady-state radiance measurements for recovering the optical properties of turbid media. The uniqueness of point radiance measurements were demonstrated in a forward sense, and strategies were suggested for improving performance under noisy experimental conditions. In this work, we test our previous conclusions by fitting the P3 approximation for radiance to Monte Carlo predictions and experimental data in tissue-simulating phantoms. Fits are performed at: 1. a single sensor position 0.5 or 1 cm , 2. two sensor positions 0.5 and 1 cm , and 3. a single sensor position 0.5 or 1 cm with input knowledge of the sample’s effective attenuation coefficient. The results demonstrate that single sensor radiance measurements can be used to retrieve optical properties to within 20%, provided the transport albedo is greater than 0.9. Furthermore, compared to the single sensor fits, employing radiance data at two sensor positions did not significantly improve the accuracy of recovered optical properties. However, with knowledge of the effective attenuation coefficient of the medium, optical properties can be retrieved experimentally to within 10% for an albedo greater or equal to 0.5. © 2007 Society of Photo-Optical Instrumentation Engineers. DOI: 10.1117/1.2821406