Association of Liver Tissue Optical Properties and Thermal Damage
Lasers in Surgery and Medicine
Background and Objectives
Complete thermocoagulation of tumors is vital to minimize the risk of local tumor recurrence after a thermal ablation. Histological assessments are not real-time and require experienced pathologists to grade the thermal damage (histopathology) [Correction added on 21 January, 2020 after first online publication: After thermal damage in the preceding sentence, (histopathology) was added]. Real-time assessment of thermal tissue damage during an ablation is necessary to achieve optimal tumor ablation. In our previous studies, we found that continuous monitoring of the wavelength-averaged (435–630 nm) tissue absorption coefficient (µa) and the reduced scattering coefficient () during heating of a porcine liver at 100°C follows a sigmoidal growth curve. Therefore, we concluded that increases in the tissue µa and during thermocoagulation were correlated with true thermal damage. The goal of this study was to determine if increases in the tissue µa and during thermocoagulation are correlated with true thermal damage.
Study Design/Materials and Methods
In this paper, continuously measured values of µa and during heating of the porcine liver tissue were compared with the histology-assessed thermal damage scores at four different temperature points (37°C, 55°C, 65°C, and 75°C).
The damage scores for the tissues in Group 3 (65°C) and Group 4 (75°C) were significantly different from each other and from the other groups. The damage scores were not significantly different between Group 1 (37°C) and Group 2 (55°C).
The results indicate that relative changes in µa and can be used to classify thermal damage (histopathology) scores with an overall accuracy of 72.5% up to 75°C. [Correction added on 21 January, 2020 after first online publication: After thermal damage in the preceding sentence, (histopathology) was added]. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.
Nagarajan, Vivek K.; Ward, Jerrold M.; and Yu, Bing, "Association of Liver Tissue Optical Properties and Thermal Damage" (2020). Biomedical Engineering Faculty Research and Publications. 649.