肺癌放療中的運動管理課件

1、肺癌放療中的運動管理課件ContentcontentSpecial ways for intrafraction movement. Average position. Managment thinkings for intrafraction movement. 4DCT is a good way for respire movement.Lung Tumor is moving when treatment.Lung Tumor is moving when treatment.Radiotherapy is completed after several fractions,and t

2、umor position is not identical with planning position.Position movement can be devided into two sorts:1) interfraction movement2)intrafraction movementRespire movement is a major model of intrafraction movement.Respire movement is a major model of intrafraction movement.Scanning model Model of deali

3、ng with images Spiral and Step.Retrospective and perspective.4DCT is a good way for respire movement.4DCT ConfigurationCT Image of Respiratory CycleCT Image of Respiratory CycleCT Image of Respiratory CycleCT Image of Respiratory CycleCT Image of Respiratory CycleCT Image of Respiratory CycleCT Imag

4、e of Respiratory CycleRetrospective 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 directions12345PTVProblems:. Difficult to generate isodose distributions conforming to the moving target s

5、uch as lung tumor with 3DCRT. Unable to minimize the doses to the surrounding normal tissues. Therefore limiting total dose and dose fraction sizesManagment thinkings for intrafraction movement.1. curving the total movement: Maximum density projectionABcurving the total movementManagment thinkings f

6、or intrafraction movement. 2.curving the part movement: Expand the PTV to cover the part ranges of target motions along all three directions12345PTVON ON ON offoffProblem: How to select ONopportunity and off opportunity?Managment thinkings for intrafraction movement. 2.curving the part movement: 132

7、33 phases4 phasesManagment 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 co

8、ver some phase of target total motion 12345PTVoffON offON 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 hereSpecial ways for intrafraction movement.1. curving t

9、he total movement:Max IPSpecial ways for intrafraction movement.1. curving the total movement:Image Registrationtext i hereSpecial ways for intrafraction movement.1. curving the total movement: Planningtext i hereSpecial ways for intrafraction movement.1. curving the total movement: Advantages1. cur

10、ving the total movement: Defects1)dont observe where tumor is.2)working procedure and equipment are easy1)involve more organs2)increase dose exposed on organ 3)working procedure of registering CT image is multifariousSpecial ways for intrafraction movement.2.curving the part movement:How to know tum

11、or position.External position sensorInternal fiducialSpecial 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

12、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

13、 for intrafraction movement.3.point:equipment.ABC techologyAdvantages of ABC techology 2)Decrease normal lung tissue density, therefore less healthy tissuein path of irradiation1)reduce PTV at the most large. Defects of ABC techology Initial patient set up Detecting patient movement duringtreatment

14、Patient training Patient compliance Repeatability of breath holding Margins added to compensate for all the aboveSpecial 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 pa

15、thway.2)quality assurance and quality control is uncertain.3)algorithm is very complex.1)dont observe where tumor is.Average position1)dont observe where tumor is.2)working procedure and equipment are easy.3) reduce PTV to a certain degree.4)decrease dose exposed on organ.3 phases4 phasesIMRT plan1 parameters：Lung V20=30%，V5=60%， MLD=15Gy100% PTV=8200cGydefect：missingIMRT plan2 parameters:Lung V20=35%，V5=70%， MLD=20Gy100% PTV=6000cGydefect: dose