中国医学物理学杂志
中國醫學物理學雜誌
중국의학물이학잡지
CHINESE JOURNAL OF MEDICAL PHYSICS
2010年
1期
1573-1577
,共5页
张圈世%李凯%王喜文%华保卫%崔立春%王琦%王宵%黄磊
張圈世%李凱%王喜文%華保衛%崔立春%王琦%王宵%黃磊
장권세%리개%왕희문%화보위%최립춘%왕기%왕소%황뢰
光核反应%PET/CT%剂量验证%生物靶区
光覈反應%PET/CT%劑量驗證%生物靶區
광핵반응%PET/CT%제량험증%생물파구
photonuclcar reaction%PET/CT%high energy X-ray%dose verification
目的:研究MM50加速器高能X射线放疗患者时光核反应产生的正电子发射核在PET/CT的显象技术及显象信息,探讨用该信息对照射的肿瘤靶区准确度和剂量分布进行活体的生物学验证.材料与方法:当用高能光子线照射肿瘤时,其与人体的主要组成元素碳C、氧O、氮N等进行光核反应,在照射区会产生可发射正电子的~(11)C,~(15)O,~(13)N等核素,用正电子发射断层扫描仪PET/CT立即扫描照射后的病人,~(11)C,~(15)O,~(13)N等发射的正电子即可在功能影像或分子生物学影像设备PET/CT上显像.根据显像的位置和强度便可分析推断和验证肿瘤照射的生物学位置和生物学剂量,从而真正意义上实现精确的生物适形放疗和验证.用与人体组成类似的有机玻璃头模实验,按常规放射治疗程序,先在PET/CT进行肿瘤的CT定位,之后用治疗计划系统TPS设计三野照射计划,按计划在MM50加速器上用三组不同能量(10 MV,25 MV,50 MV)和剂量为1 Gy-10 Gy的X射线进行照射.由于碳C、氧O是人体最主要的组成元素,所以我们只研究~(11)C,~(15)O等核素的显像.对~(11)C和~(15)O,PET/CT上分别扫描20 min或2 min～5 min获取正电子核素显像及显像位置、强度分布等信息.MM50是IBA公司医用跑道式电子回旋加速器,束流能量范围10MeV～50MeV,三维治疗计划设计系统是核通公司的3D治疗计划系统TPP 3.2,美国GE公司的Discovery LSⅡ PET/CT,用于肿瘤定位和核医学图像扫描及数据处理.结果:10MVX射线,放疗后不能产生光核反应;25MVX射线可产生光核反应,但需要较大的照射剂量,方能获得有意义的信息.对50MVX射线,2Gy～4Gy的常规放疗剂量即可获得~(11)C,~(15)O的正电子显像图及强度分布等信息,10Gy的剂量即可清楚获得~(15)O和~(11)C的正电子显像图及强度分布等信息.结论:MM50加速器50MVX射线放疗病人时光核反应产生正电子发射核可在PET/CT上显像,显像的位置和强度分布可用来对射线照射肿瘤靶区的准确度和照射剂量进行生物学验证,但要获得定量关系还需做大量工作.
目的:研究MM50加速器高能X射線放療患者時光覈反應產生的正電子髮射覈在PET/CT的顯象技術及顯象信息,探討用該信息對照射的腫瘤靶區準確度和劑量分佈進行活體的生物學驗證.材料與方法:噹用高能光子線照射腫瘤時,其與人體的主要組成元素碳C、氧O、氮N等進行光覈反應,在照射區會產生可髮射正電子的~(11)C,~(15)O,~(13)N等覈素,用正電子髮射斷層掃描儀PET/CT立即掃描照射後的病人,~(11)C,~(15)O,~(13)N等髮射的正電子即可在功能影像或分子生物學影像設備PET/CT上顯像.根據顯像的位置和彊度便可分析推斷和驗證腫瘤照射的生物學位置和生物學劑量,從而真正意義上實現精確的生物適形放療和驗證.用與人體組成類似的有機玻璃頭模實驗,按常規放射治療程序,先在PET/CT進行腫瘤的CT定位,之後用治療計劃繫統TPS設計三野照射計劃,按計劃在MM50加速器上用三組不同能量(10 MV,25 MV,50 MV)和劑量為1 Gy-10 Gy的X射線進行照射.由于碳C、氧O是人體最主要的組成元素,所以我們隻研究~(11)C,~(15)O等覈素的顯像.對~(11)C和~(15)O,PET/CT上分彆掃描20 min或2 min～5 min穫取正電子覈素顯像及顯像位置、彊度分佈等信息.MM50是IBA公司醫用跑道式電子迴鏇加速器,束流能量範圍10MeV～50MeV,三維治療計劃設計繫統是覈通公司的3D治療計劃繫統TPP 3.2,美國GE公司的Discovery LSⅡ PET/CT,用于腫瘤定位和覈醫學圖像掃描及數據處理.結果:10MVX射線,放療後不能產生光覈反應;25MVX射線可產生光覈反應,但需要較大的照射劑量,方能穫得有意義的信息.對50MVX射線,2Gy～4Gy的常規放療劑量即可穫得~(11)C,~(15)O的正電子顯像圖及彊度分佈等信息,10Gy的劑量即可清楚穫得~(15)O和~(11)C的正電子顯像圖及彊度分佈等信息.結論:MM50加速器50MVX射線放療病人時光覈反應產生正電子髮射覈可在PET/CT上顯像,顯像的位置和彊度分佈可用來對射線照射腫瘤靶區的準確度和照射劑量進行生物學驗證,但要穫得定量關繫還需做大量工作.
목적:연구MM50가속기고능X사선방료환자시광핵반응산생적정전자발사핵재PET/CT적현상기술급현상신식,탐토용해신식대조사적종류파구준학도화제량분포진행활체적생물학험증.재료여방법:당용고능광자선조사종류시,기여인체적주요조성원소탄C、양O、담N등진행광핵반응,재조사구회산생가발사정전자적~(11)C,~(15)O,~(13)N등핵소,용정전자발사단층소묘의PET/CT립즉소묘조사후적병인,~(11)C,~(15)O,~(13)N등발사적정전자즉가재공능영상혹분자생물학영상설비PET/CT상현상.근거현상적위치화강도편가분석추단화험증종류조사적생물학위치화생물학제량,종이진정의의상실현정학적생물괄형방료화험증.용여인체조성유사적유궤파리두모실험,안상규방사치료정서,선재PET/CT진행종류적CT정위,지후용치료계화계통TPS설계삼야조사계화,안계화재MM50가속기상용삼조불동능량(10 MV,25 MV,50 MV)화제량위1 Gy-10 Gy적X사선진행조사.유우탄C、양O시인체최주요적조성원소,소이아문지연구~(11)C,~(15)O등핵소적현상.대~(11)C화~(15)O,PET/CT상분별소묘20 min혹2 min～5 min획취정전자핵소현상급현상위치、강도분포등신식.MM50시IBA공사의용포도식전자회선가속기,속류능량범위10MeV～50MeV,삼유치료계화설계계통시핵통공사적3D치료계화계통TPP 3.2,미국GE공사적Discovery LSⅡ PET/CT,용우종류정위화핵의학도상소묘급수거처리.결과:10MVX사선,방료후불능산생광핵반응;25MVX사선가산생광핵반응,단수요교대적조사제량,방능획득유의의적신식.대50MVX사선,2Gy～4Gy적상규방료제량즉가획득~(11)C,~(15)O적정전자현상도급강도분포등신식,10Gy적제량즉가청초획득~(15)O화~(11)C적정전자현상도급강도분포등신식.결론:MM50가속기50MVX사선방료병인시광핵반응산생정전자발사핵가재PET/CT상현상,현상적위치화강도분포가용래대사선조사종류파구적준학도화조사제량진행생물학험증,단요획득정량관계환수주대량공작.
Purpose:The image information and technique of positron emitter nuclei generated by high energy X-ray photonuclear reactions with body tissues from MM50 is studied.It is explored to verify for dose delivery and location monitoring in tumor target after high energy photon radiation therapy with the image information.Materials and Methods:The technique is based on the photonuclear reactio-as in body tissues elemental composition ~(12)C,~(16)O and ~(14)N with high energy X-Ray,energies well above 20 MeV,resulting primarily in ~(11)C and ~(15)O but also ~(13)N.The induced positron activity distributions were scanned off-line in a PET/CT after irradiation.The activity distributions and position may be used to verify for dose delivery and location in tumor target.These radiations are similar to RT in three fields with some different dose delivery from TPS.The phantom began to be scanned off-line in a PET/CT a couple of minutes after irradiation.The scanning time is respectively 20 minutes and(2～5)mniutes for ~(12)C and ~(16)O.The levels of the beam energy are 10MV,25MV,50 MV.The extent of dose is 1.0 Gy～10.0 Gy.Since measured PET images change with time post irradiation,as a result of the different decay tim-es of the radionuclides,the signals from activated ~(12)C,~(16)O within the irradiated volume could be separated from each other.Most informationis obrained from the carbon and oxygen radionuclide's which the most abundant elements are in soft tissue.A brain phantom Rlade oneself was irradiated with high energy X-ray beams from IBA MM50.The 3D radiation treatment planning system,Nucletron-TPP 3.2,was used to calculate the delivered dose distributions.The phantom was directly simulated in the Nucletron-TPP after CT scan.PET/CT is fro-m GE Discovery LS Ⅱ.Resuits:It was confirmed that no activity was detected at 10 Mv X-ray energy,which was far below the energy threshold for photonuclear reactions.Totally 25 MV X-ray beams can produce photonuclear reactions and get to activity distributions images in PET/CT.It need to greater dose in order to good images information.For 50 MV X-ray beams,2 Gy-3 Gy dose,a normal RT dose,can get to activity distributions images.Conclusions:It was concluded that the PET-CT image acquired from the activity of the ~(15)O and ~(11)C positron emitter nuclei might provide the area and dose distribution information of 50 MV X-ray irradiation in a phantom.It can verify the in vivo dose delivery and location in tumor target after high energy X-ray RT.
