Urquhart P, DaCosta R, Marcon N
St Michael's Hospital, Toronto, ON, Canada.
Curr Gastroenterol Rep. 2013 Jul;15(7):330. doi: 10.1007/s11894-013-0330-8.
The holy grail of gastrointestinal endoscopy consists of the detection, in vivo characterization, and endoscopic removal of early or premalignant mucosal lesions. While our ability to achieve this goal has improved substantially since the development of the modern video-endoscope, inadequate visual inspection, errors of interpretation, and lesion subtlety all contribute to the continued suboptimal detection and assessment of early neoplasia. A myriad of new technologies has thus emerged that may help resolve these shortcomings; high magnification endoscopes, as well as the techniques of dye-based and virtual chromoendoscopy, are now widely available, while confocal laser endomicroscopy and endocystoscopy, optical coherence tomography, and autofluorescence imaging are generally applicable only in a research setting. Such technologies can be broadly categorized according to whether they potentially afford endoscopists improved detection, or real-time characterization, of mucosal lesions. Enhanced detection of otherwise "invisible" lesions, such as a flat area of intramucosal adenocarcinoma within Barrett's esophagus, carries the potential of an endoscopic cure prior to the development into a more advanced or metastatic disease. The ability to characterize a lesion to achieve an in vivo diagnosis, such as a colonic polyp, potentially affords endoscopists the ability to decide which lesions require removal and which can be safely left behind or discarded without histological assessment. Furthermore targeted biopsies, such as in the surveillance of chronic colitis, may prove to be more accurate and efficacious than the current protocol of random biopsies. An important caveat in the discussion of developing technologies in early cancer detection is the fundamental importance of a health-care system that promotes screening programs to recruit at-risk individuals. The ideal tool to optimize the use of endoscopy in population screening would be a panel of reliable biomarkers (blood, stool, or urine) that could effectively select a high-risk group, thus reducing the indiscriminate use of an expensive technology. The following review summarizes the current endoscopic imaging techniques available, and in development, for the early identification of gastrointestinal neoplasia.
胃肠内镜检查的圣杯包括对早期或癌前黏膜病变进行检测、活体特征描述以及内镜下切除。自从现代视频内镜问世以来，我们实现这一目标的能力有了显著提高，但视觉检查不充分、解读错误以及病变细微等因素，都导致早期肿瘤的检测和评估仍未达到最佳状态。因此，涌现出了大量可能有助于解决这些不足的新技术；高倍放大内镜以及基于染料和虚拟染色内镜技术现已广泛应用，而共聚焦激光内镜显微镜和膀胱内视镜检查、光学相干断层扫描以及自体荧光成像目前通常仅适用于研究环境。这些技术可根据它们是否有可能为内镜医师提供更好的黏膜病变检测或实时特征描述进行大致分类。增强对原本“不可见”病变的检测，比如巴雷特食管内黏膜内腺癌的扁平区域，有可能在疾病发展为更晚期或转移性疾病之前实现内镜治愈。对病变进行特征描述以实现活体诊断的能力，比如对结肠息肉的诊断，有可能使内镜医师能够决定哪些病变需要切除，哪些可以安全地留存或丢弃而无需组织学评估。此外，靶向活检，比如在慢性结肠炎监测中，可能比目前的随机活检方案更准确、更有效。在讨论早期癌症检测技术发展时，一个重要的告诫是促进筛查项目以招募高危个体的医疗保健系统的根本重要性。在人群筛查中优化内镜检查使用的理想工具将是一组可靠的生物标志物（血液、粪便或尿液），它们可以有效筛选出高危人群，从而减少对昂贵技术的滥用。以下综述总结了目前可用于以及正在研发的用于早期识别胃肠道肿瘤的内镜成像技术。
