CT虚拟结肠镜.ppt

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Click to edit Master title style,Click to edit Master text styles,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%),CENTERS FOR DISEASE CONTROL,AND PREVENTION,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,10mm,癌,10 yrs,大多数是增生改变,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 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 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: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 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,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 Gastrointestinal 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 recommended 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,Tests 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(gFOBT)*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,(,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 number 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 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 selected polyp size threshold,Important implications for cost-effectiveness of CTC,Polyp Size Threshold,%Requiring colonoscopy,10mm,7.5,8mm,13.5,6mm,29.7,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 trial 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 to 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,sensitivity 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 not 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 test charges and insurance coverage,26,If tests that can prevent CRC are preferred,why not recommend them alone?,Greater patient requirements for successful completion,Endoscopic and radiologic exams require a bowel prep and an office or facility visit,Higher potential for patient injury than fecal testing,Risk levels vary between tests,facilities,practitioners,Patient preference,Many individuals dont want an invasive test or a test that requires a bowel prep,Some prefer to have screening in the privacy of their home,Some may not have access to the invasive tests due to lack of coverage or local resources,