肺癌放疗中的运动管理

Han Bai,Study on Administrating Movement of Lung Tumor for Radiotherapy,Content,Lung Tumor is moving when treatment.,Radiotherapy is completed after several fractions,and tumor position is not identical with planning position.Position movement can be devided into two sorts:1) interfraction movement2)intrafraction movement,Respire movement is a major model of intrafraction movement.,Respire movement is a major model of intrafraction movement.,4DCT is a good way for respire movement.,4DCT Configuration,CT Image of Respiratory Cycle,CT Image of Respiratory Cycle,CT Image of Respiratory Cycle,CT Image of Respiratory Cycle,CT Image of Respiratory Cycle,CT Image of Respiratory Cycle,CT Image of Respiratory Cycle,Retrospective 4DCT,Managment thinkings for intrafraction movement.,1. curving the total movement: Expand the PTV to cover the total ranges of target motions along all three directions,Problems:. Difficult to generate isodose distributions conforming to the moving target such as lung tumor with 3DCRT. Unable to minimize the doses to the surrounding normal tissues. Therefore limiting total dose and dose fraction sizes,Managment thinkings for intrafraction movement.,1. curving the total movement:,Managment thinkings for intrafraction movement.,2.curving the part movement: Expand the PTV to cover the part ranges of target motions along all three directions,Problem: How to select ONopportunity and off opportunity?,Managment thinkings for intrafraction movement.,2.curving the part movement:,Managment thinkings for intrafraction movement.,2.curving the part movement:,How to select ONopportunity and off opportunity?1)Movement velocity of tumor in field and 2)distancebetween important organ and tumor.,Managment thinkings for intrafraction movement.,3.point: the PTV only cover some phase of target total motion,Extend the residence time of tumor at this point.,Managment thinkings for intrafraction movement.,4.real-time tracking:field is just a follower of tumor no matter where the tumor .,text i here,Special ways for intrafraction movement.,1. curving the total movement:Max IP,Special ways for intrafraction movement.,1. curving the total movement:Image Registration,text i here,Special ways for intrafraction movement.,1. curving the total movement: Planning,text i here,Special ways for intrafraction movement.,1. curving the total movement: Advantages,1. curving the total movement: Defects,1)dont observe where tumor is.2)working procedure and equipment are easy,1)involve more organs2)increase dose exposed on organ 3)working procedure of registering CT image is multifarious,Special ways for intrafraction movement.,2.curving the part movement:How to know tumor position.,Special ways for intrafraction movement.,2.curving the part movement:How to treat tumor.,Special ways for intrafraction movement.,2.curving the part movement:Advantages.,2.curving the part movement:Defects.,1) reduce PTV2)decrease dose exposed on organ,1)working procedure and equipment are complex.2)establish and exchange relationship between external mark and tumor in vivo.3)working procedure of registering CT image is multifarious.,Special ways for intrafraction movement.,3.point:How to extend the residence time of tumor at this point.,Special ways for intrafraction movement.,3.point:equipment.,ABC techology,Advantages of ABC techology,2)Decrease normal lung tissue density, therefore less healthy tissuein path of irradiation,1)reduce PTV at the most large.,Defects of ABC techology, Initial patient set up Detecting patient movement duringtreatment Patient training Patient compliance Repeatability of breath holding Margins added to compensate for all the above,Special ways for intrafraction movement.,4.real-time tracking:equipment.,Special ways for intrafraction movement.,4.real-time tracking:Advantages.,4.real-time tracking:Defects.,1)initiative pathway.2)quality assurance and quality control is uncertain.3)algorithm is very c