高能医用直线加速器感生放射性辐射场特点和防护研究

··Astudyoftheprotectionagainstinducedradioactivityfromhigh-energymedicallinearacceleratoranditscharacteristics王志斌，向莹，温涵泳，吕扬阳，刀鸿威WANGZhi-bin，XIANGYing，WENHan-yong，LVYang-yang，DAOHong-wei510507。、、、、。r=0．996P＞0.055min。。、。高能医用加速器;感生放射性;辐射防护Ｒ144A1004－1257201413－1758－03Astudyoftheprotectionagainstinducedradioactivityfromhigh-energymedicallinearacceleratoranditscharacteristicsWANGZhi-binXIANGYingWENHan-yongLVYang-yangDAOHong-weiCenterforDiseaseControlandPreventionThePLAGuangzhouMilitaryＲegionGuangzhouGuangdong510507ChinaAbstractObjectiveTofindspecificmeasuresforprotectionbymonitoringradiationfielddistributionandvariationofinducedra-dioactivityfromhigh-energymedicallinearaccelerator．MethodsThroughsimulatingtheworkingenvironmentofradiotherapytechniciantheinducedradioactivityvariationofhigh-energymedicallinearacceleratorunderdifferentconditionsofenergyradia-tiontypedosebeamfieldareadistanceandtime．ＲesultsTheinducedradioactivitylevelofhigh-energyphotonswasin-creasedwithincreasingdoser=0．996P＞0．05andwasdecreasedwithtimeincreaseandsignificantlyinfirst5minutesde-creasedwithbeamfieldareaincreasing．Theinducedradioactivitywasnotinfluencedbythesquareofdistance．Theinducedradio-activityofhigh-energyelectronsdisappearedrapidlyafteracceleratorshutdown．ConclusionItisnecessarytotakemeasurestoprotectagainsttheinducedradioactivitybyhigh-energyphotonsaftertreatmentonpatientswithaccelerator．Throughshorteningthepositioningtimedelayingenteringreasonablearrangementofhighandlowradiationmachineandeffectiveventilationtheinducedradioactivitycanbeminimized．KeywordsHigh-energymedicallinearacceleratorInducedradioactivityＲadiationprotection。、1。。2。8MeV12MeV。、。βγβγ3-4。。。11．1加速器Varian2300C/D。X15MV600cGy/min20MeV400cGy/min。1200h。1．2监测仪器及性能automess6150AD－b·8571·201473013OccupandHealthJul.2014Vol.30No.13X、γ1～99．99μSv/h23keV～7MeV。。1．3监测时间和内容20136—11γ。1．4监测方法15MVX10cm×10cm200、400、600MU、10min②15MVX600MU、10min③15MVX40cm×40cm600MU、10min④9、12、16、20MeV10cm×10cm10min⑤20MeV10cm×10cm10min。1．5统计学分析SPSS19。22．1automess6150AD－bX、γ0．14～0．20μSv/h。2．2感生放射性与出束剂量的关系300MU/min200、400、600MUr=0.996P＞0.05。1。2．3感生放射性与照射野的关系10cm×10cm、20cm×20cm、30cm×30cm、40cm×40cm30s7．73、8．08、7．71、6．87μSv/h。r=－0．847P＞0.05。2。2．4感生放射性与距离的关系100cm200cm。3。2．5感生放射性与时间的关系、、5min5min1。2．6高能电子线与感生放射性关系9、12、16、20MeV10MeV10MeV30s12、16、20MeV0．10、0．10、0．12μSv/h1min。20MeV10cm×10cm10min30s。115MVXμSv/h10cm×10cmMU30s1min2min3min4min5min6min7min8min9min10min2001．841．711．581．481．331．240．940．820．820．770．664005．234．854．233．963．232．892．412．021．921．761．526007．736．645．555．153．963．503．052．552．292．031．90215MVX600MUμSv/hcm×cm30s1min2min3min4min5min6min7min8min9min10min10×107．736．645．555．153．963．503．052．552．292．031．9020×208．087．166．545．454．593．963．603．032．942．602．3330×307．717．466．145．384．443．783．533．383．082．632．4940×406．876．465．755．164．573．713．443．143．012．582．44315MVX600MUμSv/h40cm×40cm1min2min3min5min8min10min6．465．755．163．713．012．444．153．152．851．801．221．0250cm4．303．563．011．841．150．89100cm4．693．853．021．871．120．88150cm3．883．522．771．670．990．75200cm2．512．211．851．280．770．65·9571·201473013OccupandHealthJul.2014Vol.30No.1313、、、、。Stevenson5-8、、。nγ。。。。2。1min。5min。。5min7～10min。5min10min。30s。、。、、、、、、、、、、9-10。。11-13、、、5min14-16。1．15MVJ．2010295130－131．2．J．2005296297－300．3．J．201126517－19．4BanSNakamuraHSatoT．radioactivityinducedina2．5GeVelectronbeamdumpJ．ＲadiatProtDos200193231－236．5StevensonGＲ．InducedactivityinacceleratorstructuresairandwaterJ．ＲadiatProtDos200196373－380．6YashimaHUwaminoYSugitaHetal．InducedradioactivityinCutargetsproducedbyhigh-energyheavyionsandthecorrespond-ingesti-matedphotondoseratesJ．ＲadiatProtDos2004112195－208．7BanSNakamuraHSatoTetal．Ｒadioactivityinducedina2．5GeVelectronbeamdumpJ．ＲadiatProtDos200193231－236．8StevensonGＲ．Experimentalverificationofparticledistributionsinpro-ton-inducedcascadesJ．AdvSpaceＲes19961795－104．9．J．19931610623－628．10．M．200928．11GB18871－2002．S．12．J．2010812107－108．13．J．2011324107－108．14．J．201126121623－24．15．M．199035．16．M．200645．2013－12－112014－03－05·0671·201473013OccupandHealthJul.2014Vol.30No.13