第十七章辐射防护及放射治疗原理

第17章辐射防护及放射治疗原理学习要求：•掌握5，6（3）节•泛读5（3）•辐射及其防护-第5节•本人研究•放射治疗–6（3）主要内容电离辐射及辐射剂量1.电离辐射哪些射线？2.吸收剂量（照射量不要求）定义单位3.当量剂量定义单位辐射防护1.ICRP所定三原则：辐射实践正当化-效益≥代价+风险辐射防护最优化-AsLowAsReasonablyAchievable，ALARA个人当量剂量限值–见后2.外照射防护定义；种类防护方法3.内照射防护定义；种类防护方法当量剂量限值有效剂量–书上米有EffectiveDose(E):TTTHWEICRPAnnualPublication103.2007本人研究结果–bodyCTRadiationdose(mGy)Organs/TissuesWTHeadThoraxAbdomenPelvisGonads(Girl)0.080.010.201.593.14Gonads(Boy)0.080.010.030.061.04BoneMarrow0.120.020.252.553.34Colon0.120.040.766.622.90Lung0.120.535.412.460.07Stomach0.120.215.674.280.11Bladder0.040.010.140.974.28Breast0.120.267.890.820.05Liver0.040.135.565.670.41Esophagus0.040.664.160.850.04Thyroid0.042.523.400.160.01Skin0.010.704.403.321.67BoneSurface0.010.133.533.620.75Brain0.0117.910.170.040.01Salivarygland0.0122.330.320.060.01Remainder0.120.133.744.391.30Effectivedose(mSv)-0.73.53.01.3organdose/mSvfemalemalegonad8.808.43colon7.778.36stomach7.407.56lung6.736.78bonemarrow5.986.00breast5.737.33thyroid10.6110.06liver8.458.02esophagus7.637.45bladder6.406.18skin7.046.92organfemalemalebonesurface5.975.99brain7.748.40kidney8.007.90spleen6.927.56adrenal7.957.12uterus/prostate7.337.44pancreas7.237.07smallintestines7.306.45largeintestines7.496.84thymus7.497.17muscle6.386.74Heart7.007.92ED:7.2mSv(females),7.4mSv(males)本人研究结果–CTinPET-CTorgandose/mSvgonad5.00colon4.81stomach4.07lung3.70bonemarrow4.07breast2.52thyroid3.70liver4.07esophagus4.07bladder59.20skin2.96bonesurface4.07(thesameformalesandfemales)organdose/mSvbrain4.07kidney4.07spleen4.07adrenal4.07uterus(female)7.77pancreas4.07smallintestines4.07largeintestines4.07thymus4.07muscle4.07heart4.07effectivedose6.2本人研究结果–PETinPET-CTLARforonepediatricbodyCT:HK0.036%0.155%0.072%0.031%0.053%0.044%0.015%0.034%0.00%0.04%0.08%0.12%0.16%0.20%headCTthoraxCTabdomenCTpelvisCTCTscantypeLARofcancerincidencemalefemale0.0%0.2%0.4%0.6%0.8%20304050607080Exposedage(years)LARofcancerincidenceHongKongFemalesAmericanFemalesHongKongMalesAmericanMalesLARfromwholebodyPET-CT:HKandUS1.原理•肿瘤生长过程，DNA活跃复制，对射线敏感•正常组织不敏感•射线破坏肿瘤细胞DNA以抑制生长2.类型•brachytherapy(sealedsourceRT)•systemicradioisotopetherapy(unsealedsourceRT)•externalbeamradiationtherapy(EBRTorXRT)放射治疗–radiationtherapyBrachytherapy–近距离放疗SystemicradioisotopeRT–全身放射性同位素放疗ExternalbeamRT–外照射放疗1.原理•加速器、同位素等产生射线•直接透过人体照射肿瘤病灶2.类型•射线：X（加速器），γ（钴-60），重离子质子（加速器）•技术：γ刀；3-dimensionalconformalradiationtherapy（三维适形）；IMRT（调强适形）；IGRT（图像导引）•标准配置：TPS，CT（MRI），LINAC不同射线在人体内损失能量情况作业P304:17-6，17-10写两段话，分别描述：SPECT的原理是？PET的原理是？IMRT的原理是？