In Vivo Detection of Flat Colorectal Neoplasms with CT Colonography

描述（由申请人提供）：虽然结直肠癌是美国男性和女性癌症死亡的第二大原因，但如果早期发现并切除其前驱病变，则在很大程度上可以预防。大多数结直肠癌是由无梗或有梗的息肉样肿瘤发展而来。早期切除此类肿瘤已被观察到可减少结直肠癌的发生。结直肠癌在没有前体息肉样肿瘤的情况下也会发生。最近的研究表明扁平或凹陷的非息肉样病变可能是这种新发癌的来源。直到最近，非息肉样病变被认为在日本以外的地区是罕见的，在最先进的光学结肠镜检查（OC）中报道的相对较多。非息肉样病变的检测是具有挑战性的，因为它们往往高度小于3mm，通常模仿正常的结肠粘膜或增厚的褶皱。然而，当出现非息肉样病变时，其恶性肿瘤的可能性高于息肉样肿瘤。尽管在目前的结肠检查方法中，结肠直肠癌的诊断准确率最高，但仍存在筛查能力不足和患者是否遵守结直肠筛查指南的问题。研究表明，计算机断层结肠镜（CTC）在检测临床上显著大小的息肉样肿瘤方面具有与OC相当的性能。因此，在大规模结直肠检查中，通过CTC进行初级结直肠筛查，然后选择治疗性OC，可以提供足够的筛查能力，并最大限度地提高患者的依从性。然而，初步研究表明，CTC往往会遗漏非息肉样病变。以前，为了最大限度地提高CTC检查的检测准确性和一致性，引入了计算机辅助检测（CAD），即计算机化方案自动检测结直肠病变并向放射科医生指示其位置。然而，大多数CAD方案被设计用于检测息肉样肿瘤，最近的试点研究表明，它们将需要适用于非息肉样病变的检测，以重现已报道的息肉样肿瘤CAD的高检测精度。在本提案中，我们将开发一种用于CTC非息肉样病变检测的CAD方案，以提高放射科医生在检测此类病变时解释的准确性和一致性。可靠、一致的非息肉样病变检测将极大地推进基于ctc的微创结直肠癌人群筛查的临床实施，从而提高患者对结直肠癌筛查指南的依从性，促进结直肠癌的早期预防，最终最大限度地减少结直肠癌的发生。公共卫生相关性：我们将开发一种计算机辅助检测（CAD）方案，用于在计算机断层结肠镜（CTC）中检测非息肉样病变，以提高放射科医生在检测非息肉样病变时解释的准确性和一致性。CAD对放射科医生表现的影响将通过观察研究来评估。我们假设CAD的应用可以显著提高放射科医生对CTC非息肉样病变检测的敏感性。可靠、一致的非息肉样病变检测，将极大地推进基于ctc的微创结直肠肿瘤大规模筛查的临床实施，从而提高患者对结直肠筛查指南的依从性，促进结直肠癌的早期预防，最终最大限度地减少结直肠癌的发生。

DESCRIPTION (provided by applicant): Although colorectal cancer is the second leading cause of cancer deaths for men and women in the United States, it would be largely preventable if its precursor lesions were detected and removed early. Most colorectal cancers develop from sessile or pedunculated polypoid neoplasms. Early removal of such neoplasms has been observed to reduce the occurrence of colorectal carcinoma. Colorectal cancer has been observed to develop also in the absence of precursor polypoid neoplasms. Recent studies have indicated that flat or depressed non-polypoid lesions may be the source of such de novo carcinomas. Until recently, non-polypoid lesions were thought to be rare outside Japan, where they are reported relatively often on state-of-the-art optical colonoscopy (OC) examinations. The detection of non-polypoid lesions is challenging, because they tend to be less than 3 mm in height and often imitate normal colonic mucosa or thickened folds. However, when present, non-polypoid lesions have a higher potential for malignancy than do polypoid neoplasms. Although OC has the highest diagnostic accuracy among current methods for examination of the colon, there are concerns about adequate screening capacity and patient adherence to colorectal screening guidelines. Studies have indicated that computed tomographic colonography (CTC) has performance comparable to that of OC in the detection of polypoid neoplasms of clinically significant size. Therefore, primary colorectal screening by CTC followed by optional therapeutic OC could be used to provide adequate screening capacity and maximize patient compliance in large-scale colorectal examinations. However, pilot studies have indicated that CTC tends to miss non-polypoid lesions. Previously, computer-aided detection (CAD), where a computerized scheme detects colorectal lesions automatically and indicates their locations to radiologists, was introduced to maximize the detection accuracy and consistency of CTC examinations. However, most CAD schemes have been designed to detect polypoid neoplasms, and recent pilot studies have indicated that they will need to be adapted for the detection of non-polypoid lesions to reproduce the high detection accuracy that has been reported for CAD of polypoid neoplasms. In this proposal, we will develop a CAD scheme for the detection of non-polypoid lesions in CTC for increasing the accuracy and consistency of radiologists' interpretation in the detection of such lesions. Reliable and consistent detection of non-polypoid lesions would substantially advance the clinical implementation of minimally invasive CTC-based population screening for colorectal neoplasms, thereby increasing patient adherence to colorectal screening guidelines, promoting early prevention of colorectal cancer, and ultimately minimizing the occurrence of colorectal cancer. PUBLIC HEALTH RELEVANCE: We will develop a computer-aided detection (CAD) scheme for the detection of non-polypoid lesions in computed tomographic colonography (CTC) for increasing the accuracy and consistency of radiologists' interpretation in the detection of non-polypoid lesions. The effect of CAD on radiologists' performance will be assessed by use of an observer study. We hypothesize that the application of CAD can provide significant improvement in radiologists' sensitivity for the detection of non-polypoid lesions in CTC. Reliable and consistent detection of non-polypoid lesions would substantially advance the clinical implementation of minimally invasive CTC-based large-scale screening for colorectal neoplasms, thereby increasing patient adherence to colorectal screening guidelines, promoting early prevention of colorectal cancer, and ultimately minimizing the occurrence of colorectal cancer.