CT虚拟结肠镜课件

CT虚拟结肠镜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%)CENTERSFORDISEASECONTROLANDPREVENTION5结肠腺瘤进展小腺瘤<5mm异常增殖进展性结肠腺瘤>10mm癌10yrs

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。*variesbasedondatasource10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*Afecaloccultbloodtestwithinthepastyear.Note:DatafromparticipatingstatesandtheDistrictofColumbiawereaggregatedtorepresenttheUnitedStates.Source:BehavioralRiskFactorSurveillanceSystemCD-ROM(1996-1997,1999)andPublicUseDataTape(2001,2002,2004),NationalCenterforChronicDiseasePreventionandHealthPromotion,CentersforDiseaseControlandPreventionandPrevention,1999,2000,2002,2003,2005.

12The2008CRCGuidelinesUpdatewasaJointEffortof5OrganizationsAmericanCancerSocietyU.S.Multi-SocietyTaskForceonColorectalCancerAmericanGastroenterologicalAssociationAmericanCollegeofGastroenterologyAmericanSocietyofGastrointestinalEndoscopistsAmericanCollegeofRadiology142008CRCScreeningGuidelinesAverageriskadultsage50andolderTeststhatdetectadenomatouspolypsandcancer

Flexiblesigmoidoscopy(FSIG)every5years*,orColonoscopyevery10years,orDoublecontrastbariumenema(DCBE)every5years*,orCTcolonography(CTC)every5years*Teststhatprimarilydetectcancer

Annualguaiac-basedfecaloccultbloodtest(gFOBT)*withhightestsensitivityforcancer,orAnnualfecalimmunochemicaltest(FIT)*withhightestsensitivityforcancer,orStoolDNAtest(sDNA)*,withhighsensitivityforcancer,intervaluncertain

*Note:Allpositivescreeningtestsshouldbefollowedupwithcolonoscopy15原理16CT虚拟结肠镜(

CTColonography，CTC)17CT虚拟结肠镜(

CTColonography，CTC)CTC图像光学结肠镜18CTColonography3-DviewPolyp2-DviewCourtesyofBethMcFarland,MD20CTCvs.OpticalColonoscopy:SensitivitiesforAllPolyps

PolypSize

>10mm >8mm >6mmCTC 92.2% 92.6% 85.7%Colonoscopy 88.2% 89.5% 90.0% Pickhardtetal,NEJM200321CTC:AdditionalFindingsCTCidentified55polypsnotseenoninitialcolonoscopy21adenomasOne11mmmalignantpolypExtra-colonicfindings5asymptomaticcancersAorticaneurysmsRenalandgallbladdercalculiPickhardtetal,NEJM200323CTColonography:AdditionalEvidenceAnumberofotherstudieshavedemonstratedahighlevelofsensitivityforcancerandlargepolypsFindingsfromtherecentlycompletedmulti-centerACRINtrialreportedlyaresimilartothoseofPickhardtetalSomeresultsfromthistrialhavebeenreportedatmedicalmeetings,buthavenotyetbeenpublishedManuscripthasbeenpreparedandiscurrentlyunderreview24CTColonography:Limitations

Requiresfullbowelprep(whichmostpatientsfindtobethemostunpleasantaspectofcolonoscopy)Colonoscopyisrequiredifabnormalitiesdetected,sometimesnecessitatingasecondbowelprepExtra-colonicfindingscanleadtoadditionaltesting(mayhavebothpositiveandnegativeimplications)Controversyregardingmanagementofsmallpolyps,sensitivityfor“flatpolyps”RadiationexposureSteeplearningcurveforradiologistsLimitedavailabilitytohighqualityexamsinmanypartsofthecountryMostinsurersdonotcurrentlycoverCTCasascreeningmodality26IfteststhatcanpreventCRCarepreferred,whynotrecommendthemalone?GreaterpatientrequirementsforsuccessfulcompletionEndoscopicandradiologicexamsrequireabowelprepandanofficeorfacilityvisitHigherpotentialforpatientinjurythanfecaltestingRisklevelsvarybetweentests,facilities,practitionersPatientpreferenceManyindividualsdon’t