School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
Histopathology Department, Nottingham University Hospitals NHS Trust, Queen's Medical Centre, Nottingham, UK.
J Surg Res. 2023 Aug;288:10-20. doi: 10.1016/j.jss.2023.02.014. Epub 2023 Mar 20.
Identifying colorectal liver metastases (CRLM) during liver resection could assist in achieving clear surgical margins, which is an important prognostic variable for both disease-free and overall survival. The aim of this study was to investigate the effect of auto-fluorescence (AF) and Raman spectroscopy for ex vivo label-free discrimination of CRLMs from normal liver tissue. Secondary aims include exploring options for multimodal AF-Raman integration with respect to diagnosis accuracy and imaging speed on human liver tissue and CRLM.
Liver samples were obtained from patients undergoing liver surgery for CRLM who provided informed consent (15 patients were recruited). AF and Raman spectroscopy was performed on CRLM and normal liver tissue samples and then compared to histology.
AF emission spectra demonstrated that the 671 nm and 775/785 nm excitation wavelengths provided the highest contrast, as normal liver tissue elicited on average around eight-fold higher AF intensity compared to CRLM. The use of the 785 nm wavelength had the advantage of enabling Raman spectroscopy measurements from CRLM regions, allowing discrimination of CRLM from regions of normal liver tissue eliciting unusual low AF intensity, preventing misclassification. Proof-of-concept experiments using small pieces of CRLM samples covered by large normal liver tissue demonstrated the feasibility of a dual-modality AF-Raman for detection of positive margins within few minutes.
AF imaging and Raman spectroscopy can discriminate CRLM from normal liver tissue in an ex vivo setting. These results suggest the potential for developing integrated multimodal AF-Raman imaging techniques for intraoperative assessment of surgical margins.
在肝切除术中识别结直肠肝转移（CRLM）有助于获得清晰的手术切缘，这是无病生存率和总生存率的重要预后变量。本研究旨在探讨自动荧光（AF）和拉曼光谱在离体状态下对 CRLM 与正常肝组织进行无标记区分的效果。次要目标包括探索在人肝组织和 CRLM 上进行多模态 AF-Raman 集成的选择，以提高诊断准确性和成像速度。
从接受 CRLM 肝切除术的患者中获得肝组织样本，这些患者均提供了知情同意书（共招募了 15 名患者）。对 CRLM 和正常肝组织样本进行 AF 和拉曼光谱检测，并与组织学结果进行比较。
AF 发射光谱表明，671nm 和 775/785nm 激发波长提供了最高的对比度，因为正常肝组织的平均 AF 强度比 CRLM 高约 8 倍。使用 785nm 波长的优点是可以对 CRLM 区域进行拉曼光谱测量，从而可以区分 CRLM 与正常肝组织区域，这些区域的 AF 强度异常低，可防止误分类。使用小块 CRLM 样本覆盖大部分正常肝组织的初步实验证明了在几分钟内进行双模态 AF-Raman 检测的可行性。
AF 成像和拉曼光谱可在离体环境中区分 CRLM 与正常肝组织。这些结果表明，有可能开发集成的多模态 AF-Raman 成像技术，用于术中评估手术切缘。
