正常組織和器官的放射損傷課件

正常組織和器官的放射損傷腫瘤放射治療學(xué)RADIATIONONCOLOG放射生物學(xué)放射與放療學(xué)者讀本中殷蔚笛余子豪徐該胡民RadiobiologyfortheRadiologistB細(xì)胞和組織放射效應(yīng)細(xì)胞殺傷效應(yīng)炎性因子介導(dǎo)效應(yīng)腹部放療后幾小時(shí)內(nèi)發(fā)生的惡心、嘔吐大面積照射后的疲勞顱腦放療數(shù)小時(shí)后發(fā)生的嗜睡輻射誘導(dǎo)的急性炎癥和脈管滲漏所導(dǎo)致的的組織急性水腫和皮膚紅斑損傷反應(yīng)的影響因素細(xì)胞本身的放射敏感性組織、細(xì)胞群動(dòng)力學(xué)細(xì)胞構(gòu)成組織的方式BT定律Bergonie和Tribondeau定律組織如果由低分化細(xì)胞構(gòu)成,且具有更大的增殖能力和更快的分裂能力,則其放射敏感性較強(qiáng)1906年提出早期反應(yīng)和晚期反應(yīng)早期(急性)反應(yīng)early(acute)effectsa/B值高組織更新較快(成熟細(xì)胞的壽命較短)幾天或者幾周內(nèi)皮膚表皮層、腸胃上皮細(xì)胞、造血系統(tǒng)快速修復(fù)、完全修復(fù)、源于干細(xì)胞的迅速增殖晚期反應(yīng)對(duì)分割劑量敏感數(shù)月或數(shù)年肺、腎、心臟、肝、中樞神經(jīng)系統(tǒng)不能修復(fù)或完全修復(fù);源于血管和實(shí)質(zhì)細(xì)胞的損傷繼發(fā)晚期反應(yīng)(consequentiallateeffect)功能性亞單位(FSUs)解剖上符合(腎單位、肝小葉、肺泡)解剖上不具有相應(yīng)結(jié)構(gòu)(皮膚、黏膜、脊根據(jù)器官的功能設(shè)想其結(jié)構(gòu)具有功能亞單位functionalsubunits,FSUsFSUs的排列:鏈?zhǔn)?非鏈?zhǔn)?串聯(lián);并聯(lián);混合)口口口口H16體積和劑量閾值口口耐受劑量tolerancedose:產(chǎn)生臨床可接受并發(fā)癥的劑量525476Dose(Gy)20.1Relationshipbetweendoseandprobabilityofcomplicationsfordifferenttypesofnormaltissues.CurveArelatesanormaltissueinwhichthefunctionalsubunitsarenotarrangedseriallyregardlessofwhetheroneorallsubunitsareexposed(i.e.,regardlessoffieldsize).Italsoappliestoanormaltissueinwhichfunctionalsubunitsarearrangedseriallyifonlyonesubunitisexposed(i.e,,ifthefieldissmall).Notethatthecurveisrelativelyshallow(i.e,,theprobabilityofacomplicationrisesrelativelyslowlywithdose).CurvesBandCrefertoatissuewithseriallyarrangedfunctionalsubunits;thecomplicationcurvegetssteeperandmovestolowerdosesasthetreatmentfieldsizeincreasesForexample,curvesBandC,respectively,relateto4or16functionalsubunitsexposed.(Notethatthepositionofthecurvesinrelationtotheabscissaeisarbitrary,resultingfromtwoassumptions:thatthereisaneffectivedoof4Gyforarvivalcurveforcellsexposedtomultipledosesof2Gy,andthat58Gyin2-Gyfractionssterilizes10%ofthefunctionalsubunits.)(AdaptedfromWithersHR,TaylorJMG,MaciejewskiBTreatmentvolumeandtissuetolerance.IntJRadiatOncolBio