Cancer diagnosis with Photo dynamic Raman spectroscopy

利用拉曼光谱进行光动力诊断有望成为一种新的癌症诊断方法。自2003年以来，我们开发了胃肠道恶性肿瘤拉曼诊断系统（RDS）。RDS的目标是在内镜或手术过程中进行实时光学诊断。内镜下RDS能够实时评估胃肠道粘膜病理。术中RDS具有实时诊断淋巴结转移或腹膜播散的可能性，使胃肠道肿瘤患者可以接受微创、最合适的手术。我们的RDS探测器具有高灵敏度，可以在1064nm激发的有限范围内降低自身荧光对拉曼信号强度的影响。在此之前，我们报道了RDS的初步研究，其中拉曼光谱用主成分分析（PCA）进行评估。获得了足够的精度。进一步改进RDS，提高临床应用价值。我们检查了内镜活检切除的胃癌标本。结果具有较好的重现性和可靠性。在癌症诊断中，敏感性为72%，特异性为70%，准确性为71%。我们已经确认了测量的稳定性和精确度。我们正在改进RDS以提高准确性。我们将检查手术切除的胃癌标本。我们可以连续测量肿瘤病变到正常组织的频谱。RDS是一种新的胃肠道肿瘤诊断方法。目前的数据强烈表明，RDS仪器和方法的改进提高了癌症诊断的准确性，RDS在内镜或手术中的应用有望实现无需组织学检查的实时癌症检测。

Photodynamic diagnosis (PDD) with Raman spectroscopy is expecting to be a novel modality for cancer diagnosis. Since 2003, we developed Raman Diagnostic System (RDS) for gastrointestinal malignancy. The goal of RDS is real-time optical diagnosis during endoscopy or surgery. Endoscopic RDS enables to be a real-time implementation to assess the mucosal pathology in gastrointestinal tract. Intraoperative RDS has the possibility of real-time diagnosis for lymph node metastasis or peritoneal dissemination, resulting that the patients with gastrointestinal cancer can receive less-invasive and most suitable surgery. Our RDS has a novel detector with high sensitivity in which the influence of autofluorescence on Raman signal intensity could be reduced in a limited range at 1064 nm excitation. Previously, we reported the preliminary study of RDS, in which Raman spectra were assessed with principle component analysis (PCA). The sufficient accuracy was obtained. Next we improved RDS to increase the clinical usefulness. We examined gastric cancer specimens removed by endoscopic biopsy. The results had better reproducibility and reliability without PCA. In the cancer diagnosis, the sensitivity was 72 %, specificity was 70 % and accuracy was 71 %. And we have confirmed stability of measurements and the level of accuracy. We are improving RDS to elevate the accuracy.We are going to exam the gastric cancer specimens removed by operation. We can measure the spectrum of cancer lesion to normal tissue continuously.RDS is a novel diagnostic implementation for the gastrointestinal cancer. The present data strongly suggest that improvement of both instruments and methods of RDS increases the accuracy of cancer diagnosis and the application of RDS to endoscopy or surgery is expected to achieve real-time cancer detection without histological examination.