CT虚拟结肠镜PPT参考幻灯片

1、CT虚拟结肠镜,福建医科大学附属协和医院 CT室,2,前 言,在美国是肿瘤发病率中居第三位 2009年有近146970例新发病例 占肿瘤死亡的第二位 2009年全美有49920例死亡 超过100万的美国人患有结肠直肠癌,3,结肠直肠癌,散发 (一般危险因素) (65%85%),家族史(10%30%),遗传性非息肉性结肠直肠癌 (HNPCC) (5%),家族性多发性腺癌(1%),罕见综合征 (0.1%),4,危险度因子- 息肉,分类 异常增生 较小癌变可能 腺瘤样 大约90%结肠直肠癌由腺瘤样息肉发展而来,5,结肠腺瘤进展,小腺瘤 5mm,异常增殖,进展性结肠腺瘤 10mm,癌,10 yrs,大

2、多数是增生改变 通常不会发展为癌症,6,筛查的优势,预防癌症 切除癌前病变（恶性息肉）防止癌症发生 提高生存率 早期检测显著增加长期生存机会,7,筛查的优势,8,结肠直肠癌筛查率,只有40%的结肠直肠癌在早期阶段发现 近一半多一点的超过50岁的美国人有进行近期的结肠直肠癌筛查。,*varies based on data source,9,近年来光学直肠镜检查的普及率 (%)的趋势, 大于50岁的美国人, 1997-2004,*A flexible sigmoidoscopy or colonoscopy within the past five years. Note: Data from

3、participating states and the District of Columbia were aggregated to represent the United States. Source: Behavioral Risk Factor Surveillance System CD-ROM (1996-1997, 1999) and Public Use Data Tape (2001, 2002, 2004), National Center for Chronic Disease Prevention and Health Promotion, Centers for

4、Disease Control and Prevention and Prevention, 1999, 2000, 2002, 2003, 2005.,10,近年来粪便潜血试验的普及率 (%)的趋势, 大于50岁的美国人, 1997-2004,*A fecal occult blood test within the past year. Note: Data from participating states and the District of Columbia were aggregated to represent the United States. Source: Behavi

5、oral Risk Factor Surveillance System CD-ROM (1996-1997, 1999) and Public Use Data Tape (2001, 2002, 2004), National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention and Prevention, 1999, 2000, 2002, 2003, 2005.,11,结肠直肠癌筛查率低:原因 (依照患者的说法),对结肠直肠癌不重视

6、 缺乏对结肠直肠癌筛查好处的了解 害怕, 难为情, 不舒服 没时间 费用高 “我医生从来没跟我提到过!”,12,The 2008 CRC Guidelines Update was a Joint Effort of 5 Organizations,American Cancer Society U. S. Multi-Society Task Force on Colorectal Cancer American Gastroenterological Association American College of Gastroenterology American Society of G

7、astrointestinal Endoscopists American College of Radiology,13,CRC Screening Guidelines: What Else is New?,Two new tests recommended: stool DNA (sDNA) and computerized tomographic colonography (CTC) sometimes referred to as virtual colonoscopy The guidelines: establish a sensitivity threshold for rec

8、ommended tests delineate important quality-related factors for each form of testing continue to emphasize options for testing An overriding goal of this update is to provide a practical guideline for physicians and the public,14,2008 CRC Screening Guidelines,Average risk adults age 50 and older Test

9、s that detect adenomatous polyps and cancer Flexible sigmoidoscopy (FSIG) every 5 years*, or Colonoscopy every 10 years, or Double contrast barium enema (DCBE) every 5 years*, or CT colonography (CTC) every 5 years* Tests that primarily detect cancer Annual guaiac-based fecal occult blood test (gFOB

10、T)* with high test sensitivity for cancer, or Annual fecal immunochemical test (FIT)* with high test sensitivity for cancer, or Stool DNA test (sDNA)*, with high sensitivity for cancer, interval uncertain,*Note: All positive screening tests should be followed up with colonoscopy,15,原 理,16,CT虚拟结肠镜 (

11、CT Colonography，CTC),17,CT虚拟结肠镜 ( CT Colonography，CTC),CTC 图像,光学结肠镜,18,CT Colonography,3-D view,Polyp,2-D view,Courtesy of Beth McFarland, MD,19,CT Colonography: Rationale,Allows detailed evaluation of the entire colon Minimally invasive (rectal tube for air insufflation) No sedation required A numb

12、er of studies have demonstrated a high level of sensitivity for cancer and large polyps,20,CTC vs. Optical Colonoscopy: Sensitivities for All Polyps,Polyp Size 10mm8mm6mm CTC92.2%92.6%85.7% Colonoscopy88.2%89.5%90.0%,Pickhardt et al, NEJM 2003,21,CTC: Additional Findings,CTC identified 55 polyps not

13、 seen on initial colonoscopy 21 adenomas One 11 mm malignant polyp Extra-colonic findings 5 asymptomatic cancers Aortic aneurysms Renal and gall bladder calculi,Pickhardt et al, NEJM 2003,22,CTC: Follow-up colonoscopy,Indication for diagnostic/therapeutic colonoscopy varies markedly based on selecte

14、d polyp size threshold Important implications for cost-effectiveness of CTC,Pickhardt et al, NEJM 2003,23,CT Colonography: Additional Evidence,A number of other studies have demonstrated a high level of sensitivity for cancer and large polyps Findings from the recently completed multi-center ACRIN t

15、rial reportedly are similar to those of Pickhardt et al Some results from this trial have been reported at medical meetings, but have not yet been published Manuscript has been prepared and is currently under review,24,CT Colonography: Limitations,Requires full bowel prep (which most patients find t

16、o be the most unpleasant aspect of colonoscopy) Colonoscopy is required if abnormalities detected, sometimes necessitating a second bowel prep Extra-colonic findings can lead to additional testing (may have both positive and negative implications) Controversy regarding management of small polyps, se

17、nsitivity for “flat polyps” Radiation exposure Steep learning curve for radiologists Limited availability to high quality exams in many parts of the country Most insurers do not currently cover CTC as a screening modality,25,2008 CRC Guidelines continue to emphasize options because:,Evidence does no

18、t yet support any single test as “best” Uncertainty exists about performance of different screening methods with regard to benefits, harms, and costs (especially on programmatic basis) Uptake of screening remains disappointingly low Individuals differ in their preferences for one test or another Primary care physicians differ in their ability to offer, explain, or refer patients to all options equally Access is uneven geographically, and in terms of