Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland.
Department of Physics, University College Cork, College Road, Cork, Ireland.
Sci Rep. 2021 Jan 12;11(1):798. doi: 10.1038/s41598-020-79517-2.
Colorectal cancer (CRC) is the third most common type of cancer worldwide and the second most deadly. Recent research efforts have focused on developing non-invasive techniques for CRC detection. In this study, we evaluated the diagnostic capabilities of diffuse reflectance spectroscopy (DRS) for CRC detection by building 6 classification models based on support vector machines (SVMs). Our dataset consists of 2889 diffuse reflectance spectra collected from freshly excised ex vivo tissues of 47 patients over wavelengths ranging from 350 and 1919 nm with source-detector distances of 630-µm and 2500-µm to probe different depths. Quadratic SVMs were used and performance was evaluated using twofold cross-validation on 10 iterations of randomized training and test sets. We achieved (93.5 ± 2.4)% sensitivity, (94.0 ± 1.7)% specificity AUC by probing the superficial colorectal tissue and (96.1 ± 1.8)% sensitivity, (95.7 ± 0.6)% specificity AUC by sampling deeper tissue layers. To the best of our knowledge, this is the first DRS study to investigate the potential of probing deeper tissue layers using larger SDD probes for CRC detection in the luminal wall. The data analysis showed that using a broader spectrum and longer near-infrared wavelengths can improve the diagnostic accuracy of CRC as well as probing deeper tissue layers.
结直肠癌（CRC）是全球第三大常见癌症类型，也是第二大致命癌症。最近的研究工作集中在开发用于 CRC 检测的非侵入性技术上。在这项研究中，我们通过构建基于支持向量机（SVM）的 6 种分类模型，评估了漫反射光谱（DRS）用于 CRC 检测的诊断能力。我们的数据集由 47 名患者的新鲜离体组织中采集的 2889 个漫反射光谱组成，波长范围为 350nm 至 1919nm，源探测器距离为 630μm 和 2500μm，以探测不同深度。我们使用二次 SVM，并通过在 10 次随机训练和测试集迭代上进行的两重交叉验证来评估性能。我们通过探测浅表结直肠组织实现了（93.5±2.4）%的灵敏度、（94.0±1.7）%的特异性 AUC，通过采样更深的组织层实现了（96.1±1.8）%的灵敏度、（95.7±0.6）%的特异性 AUC。据我们所知，这是首次使用更大的 SDD 探头探测更深的组织层来研究在腔壁中使用 DRS 探测 CRC 的潜力的研究。数据分析表明，使用更宽的光谱和更长的近红外波长可以提高 CRC 的诊断准确性以及探测更深的组织层。
