Department of Biomedical Engineering, Texas A&M University, College Station, USA.
Delft University of Technology, Delft, The Netherlands.
Sci Rep. 2021 Mar 2;11(1):4984. doi: 10.1038/s41598-021-84552-8.
We demonstrate that structured illumination microscopy has the potential to enhance fluorescence lifetime imaging microscopy (FLIM) as an early detection method for oral squamous cell carcinoma. FLIM can be used to monitor or detect changes in the fluorescence lifetime of metabolic cofactors (e.g. NADH and FAD) associated with the onset of carcinogenesis. However, out of focus fluorescence often interferes with this lifetime measurement. Structured illumination fluorescence lifetime imaging (SI-FLIM) addresses this by providing depth-resolved lifetime measurements, and applied to oral mucosa, can localize the collected signal to the epithelium. In this study, the hamster model of oral carcinogenesis was used to evaluate SI-FLIM in premalignant and malignant oral mucosa. Cheek pouches were imaged in vivo and correlated to histopathological diagnoses. The potential of NADH fluorescence signal and lifetime, as measured by widefield FLIM and SI-FLIM, to differentiate dysplasia (pre-malignancy) from normal tissue was evaluated. ROC analysis was carried out with the task of discriminating between normal tissue and mild dysplasia, when changes in fluorescence characteristics are localized to the epithelium only. The results demonstrate that SI-FLIM (AUC = 0.83) is a significantly better (p-value = 0.031) marker for mild dysplasia when compared to widefield FLIM (AUC = 0.63).
我们证明结构光照明显微镜具有增强荧光寿命成像显微镜（FLIM）作为口腔鳞状细胞癌早期检测方法的潜力。FLIM 可用于监测或检测与癌变发生相关的代谢辅因子（例如 NADH 和 FAD）的荧光寿命变化。然而，离焦荧光往往会干扰这种寿命测量。结构光照明显微镜（SI-FLIM）通过提供深度分辨的寿命测量来解决这个问题，并应用于口腔黏膜，可以将收集到的信号定位到上皮。在这项研究中，使用口腔致癌的仓鼠模型来评估 SI-FLIM 在癌前和恶性口腔黏膜中的应用。在体内对脸颊袋进行成像，并与组织病理学诊断相关联。评估了通过宽场 FLIM 和 SI-FLIM 测量的 NADH 荧光信号和寿命，能否区分发育不良（癌前病变）与正常组织。当荧光特征的变化仅局限于上皮时，进行了 ROC 分析，以区分正常组织和轻度发育不良。结果表明，与宽场 FLIM（AUC=0.63）相比，SI-FLIM（AUC=0.83）是轻度发育不良的更好（p 值=0.031）标志物。
