Association of Liver Tissue Optical Properties and Thermal Damage. Issue 8 (9th January 2020)

• Record Type: Journal Article
• Authors: Nagarajan, Vivek Krishna; Ward, Jerrold M.; Yu, Bing
• Is Part Of: Lasers in surgery and medicine. Volume 52:Issue 8(2020)
• Page Start: 779
• Page End: 787
• Publication Date: 2020-01-09
• Subjects: diffuse reflectance spectroscopy -- thermal ablation -- hepatocellular carcinoma; Lasers in medicine -- Periodicals; Lasers in surgery -- Periodicals; 617
• DOI: 10.1002/lsm.23209
• Languages: English
• ISSNs: 0196-8092

Abstract

Abstract : 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 ( µ a ) and the reduced scattering coefficient ( μ s ′ ) during heating of a porcine liver at 100°C follows a sigmoidal growth curve. Therefore, we concluded that increases in the tissue µ a and μ s ′ during thermocoagulation were correlated with true thermal damage. The goal of this study was to determine if increases in the tissue µ a and μ s ′ during thermocoagulation are correlated with true thermal damage. Study Design/Materials and Methods: In this paper, continuously measured values of µ a and μ s ′ 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). Results: 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). Conclusion: The results indicate that relative changes in µ a and μ s ′ 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.