MRI评估低位直肠癌及MR肿瘤消退分级 ppt

MRI评估低位直肠癌及MR肿瘤消退分级低位直肠癌测量SagittalT2WIshowdistancefromtheanalvergeinandrectaltumorsLowrectal<5cm;Midrectal5–10cm;Upperrectal>10cmSimilarmeasurementtosigmoidoscopyDistanceUpperMiddleLower解剖Attheanorectaljunction,themuscularispropriachanges:Thecircularlayerthickensandbecomestheinternalsphincter(IS)Externalsphincter(ES)complexiscomposedofthecontinuationoftheinferiorportionofthelevatoranimuscle(L)andthepuborectalismuscle(PBR)Radiology:Volume268:Number2—August2013TStagingT1confinedtothemucosaandsubmucosaT2tumorsinvadethemuscularispropriaT3lesionsextendbeyondRadiographics:390March-April2012MR扫描技术非常重要MoststagingfailuresoccurinthedifferentiationbetweenT2andT3lesionsTheuseofthickersectionsandlowerresolutiontechniquesDesmoplasticreactioncomparedwithtumorTechniqueisimportantrectalcontrastmaterialTheuseofrectalcontrastmaterialiscontroversialMayalterthedistancebetweenthetumorandthemesorectalfasciaDonotariseifanappropriateamount(60–100mL)ofwarmUSgelisusedvaluable:withpolypoidtumors(eg,villousadenomas),smallrectaltumors(<3cm),orahistoryofpriortherapy(eg,partialresectionorradiationtherapy).低位直肠影像技术LowrectaltumorsareassociatedwithhigherratesofpositiveCRMhigherlocalrecurrencerates,andpoorersurvivalThisislargelyduetoanatomicconsiderations：themesorectalenvelopetapersdownward直肠系膜逐渐变细TME手术是否安全耻骨直肠肌是否侵犯？Black：TMEGreen：withintersphinctericresectionDashed：conventionalAPRGray：extralevatorAPRTME手术是否安全CRMClearCRMSuspiciouslymphnodeAbuttingthemesorectalfasciaExtramuralVascularInvasionEMVITME不安全——术前放化疗及APRmainindicationsforCRTbeforesurgeryinrectalcancer：放化疗后重新评估CRTMRimagingtumorregressiongrade(mrTRG)MR肿瘤消退分级——评估预后mrTRGAugust15,2014|OncologyJournalJournalKaplan-MeieranalysisofsurvivalJClinOncol201129:3753-3760：MERCURYExperience结论多个临床试验研究表明：mrTRG1-2与病理完全缓解相比有相同的无病生存期及总生存期，较病理完全缓解更常见手术