1、Advantages of a 3D Cylindrical Water ScannerMax TangMedical PhysicistOutlineTG 106介绍以及数据采集 常见问题3DS 水箱特点v圆筒状箱体设计vAutoSetup 自动摆位功能TG-106This task group was formed to review the physics of commissioning linear accelerators and to provide guidelines and recommendations on proper selection of detector,ph
2、antom,and methods to reduce measurement errors below 1%in beam data acquisition.AAPM Task Group 106“Accelerator beam data commissioning equipment and procedures:Report of the TG-106 of the Therapy Physics Committee of the AAPM,”Med Phys 35(9):4186-4215,Sept 2008.TG-106III.B.Scanning water tankIII.B.
3、1.Positioning and labelingIII.B.2.Scanner movementIII.B.3.OrientationIII.C.Scan mechanism and movementIII.C.1.Array detector weightIII.C.2.Speed and position accuracyIII.C.3.HysteresisIII.C.4.CorrosionIII.E.Data acquisitionIII.E.1.Scanning parameter protocolIII.E.2.SpeedIII.E.3.Delay timeIII.E.4.Sam
4、pling time and signalIII.E.5.Radio frequency noise interference足够大的扫描范围足够大的扫描范围:Diagonal profiles of 40 x40 cm2 with lateral buildup 5cm&over scans.Suggested 75x75 cm2 in transverse size.The half field scan be extended 5 cm past the central axis.相对较小体积的探头相对较小体积的探头:Ion chambers with small volumes are
5、 generally preferred.Ref.detector shall be used for removing the instantaneous fluctuations or drifts in the incident beam output.稳定的扫描结果稳定的扫描结果:The chamber shall scan with the least amount of moving parts;Orient the detector mount so that it provides the highest resolution.Precautions:“Do not scan
6、in the axial direction of the detector.”Adjust the step size to optimize the time and accuracy.TG106 Highlights-Scanner in Accelerator beam data commissioning三维水箱探头的选择三维水箱探头的选择电离室-体积效应半导体-剂量，能量，剂量率响应There are conflicting publications on the use of diode detectors for beam data acquisition,hence,befo
7、re using a diode detector,one should compare it with ion chamber measurements to confirm its correct operation and accuracy in data.-AAPM TG106AAPM TG106AAPM TG106AAPM TG106电离室的体积效应电离室的体积效应 Volumn averaging effect剂量高估剂量高估剂量低估剂量低估剂量准确剂量准确“Detector orientation plays an important role in profiles and p
8、enumbra measurements”TG106AAPM TG 106圆形水箱的优势，扫描方向的一致性圆形水箱的优势，扫描方向的一致性Solution:Cylindrical design with ring drive mechanism方形水箱扫描10 x10的Cross-line和In-line Profile的对比SNC 125cTM SpecificationsThe SNC125c is oblong to provide a sharper penumbra with the same signal.This chamber is designed longer to wor
9、k in the 3D SCANNER with the rotating diameter drive to always keep the chamber in the ideal orientation.its almost like having the signal of a 0.125cc with a penumbra closer to a micro chamber.Chamber ComparisonsIBA CC13内空腔截面内空腔截面SNC 125C内空腔截面内空腔截面Positioning reproducibility with AutoSetupDay 1:An
10、experienced user positioned the tank under the Linac,filled it,used AutoSetup,acquired three profiles,then emptied the tank and put it to the side.The Linac was used clinically for the day.Day 2:A novice user(trained only once,a month before)put the tank back into position under the Linac,filled it,
11、used AutoSetup,and acquired the same three profiles.Results:If you look closely you can see there are 2 profile sets,but the profiles overlap almost perfectly!An experienced user and a novice user get repeatable results with AutoSetup.(Note:no processing was done to these profiles).3DS水箱的物理尺寸水箱的物理尺寸
12、Tank volume large enough to ensure sufficient backscatter thus allowing the system to be used for RTPS commissioning.圆形水箱的优势之一，有效的利用空间。3D-Scanner 166L 65cm（使用（使用offset holder）VS Square Tank 190L 48cm 40 x 40 cm field at SSD 100 and Depths 30,20,10,5,1.53cm无需平移水箱即可以将无需平移水箱即可以将40 x40cm field 的的Profile
13、完整测量完整测量使用使用Off set Hold，3DS最大扫描范围为最大扫描范围为65cm3DS运动方式运动方式3DS是目前唯一能实现是目前唯一能实现AutoSetup自自动摆位功能的三维水箱动摆位功能的三维水箱传统水箱摆位调整流程传统水箱摆位调整流程手动调节水平：通过水平移动探头来调节水箱或移动支架的水平手动调节探头移动方向角度：将使用狭长beam，通过观察探头与beam边界关系来旋转水箱或Collimator。手动将探头调节至水面原点手动或自动调节探头至beam的中心点3D-Scanner自动摆位功能（自动摆位功能（Auto Set-Up）自动调节水箱水平自动调节探头到水箱中心位置 自动
14、寻找并调节水箱中心与Field center 重合自动调节水箱的扫描角度，使扫描方向与Field边界平行或垂直自动将寻找水面并将探头移动至水面作为原点使用电动水平台和水面探测器来实现自动摆位使用电动水平台和水面探测器来实现自动摆位电动水平台与水箱无缝衔接四个步进电机stepper motorsv水平调节点v一个固定支点v两个可调节:5 mmx 和y轴水平移动v移动范围 30 mm水面探测器水面探测器自动调节水平自动调节水平Auto leveling takes three water measurements to determine the leveling required自动调节水平自动
15、调节水平计算机会自动计算出需要水平水箱需要调节的角度计算机会自动计算出需要水平水箱需要调节的角度自动寻找自动寻找Beam Center3DS可以通过扫描数据来确定可以通过扫描数据来确定Beam Center.调节水箱中心调节水箱中心Movement()30 mm确定Beam center之后，计算机会控制电动平台在X，Y轴的方向平移。使水箱中心与Beam center重合自动摆位（自动摆位（Auto Setup）带来的好处）带来的好处Auto Setup 可以将水箱的摆位时间从12个小时缩短至1020分钟。Auto Setup的过程仅仅需要操作人员点击鼠标，以及操作加速器避免人员的因素导致的测
16、量的差异性。自动摆位重复性更高。静电计集成在箱体上。无需连接电离室的延长电缆。减少使用水箱收放电缆的时间减少了延长电缆带来的漏电流引起的噪声3ds 细节设计细节设计水箱箱体仅仅需要两根连接线。水箱箱体仅仅需要两根连接线。数据线接头可以很容易的穿过治疗室数据线接头可以很容易的穿过治疗室到控制室到控制室数据线可以与数据线可以与Sunnuclear其他所有产其他所有产品通用品通用3ds 细节设计细节设计参考探头支架使用金属参考探头支架使用金属软管可以任意形状弯曲软管可以任意形状弯曲3ds 细节设计细节设计3D SCANNER LiftTable 升降台跨越治疗床圆盘避免踩踏引起的水面的波动避免水箱探
17、头运动时引起水箱的整体晃动Measurement with 5 mm/s 3D SCANNERSquare Tank3D MiniLift轻便，可折叠推车易于储藏和运输3DS储水池推车储水池推车快速的抽放水:v装水时间 5 minutesv抽水时间 2 minutes静音设计SNC Dosimetry 软件特点软件特点使用数据库的方式来管理数据 保证数据的完整性 易于归类和整理 易于储存和备份SNC Dosimetry 软件特点软件特点使用Layer的方式类似与PhotoShop记录数据处理步骤，原始数据永远保留。用户可以随时切换会处理之前任意步骤的状态所有TPS接口都开放用户购买3DS可以在任意数目的PC安装SNC DosimetrySNC Dosimetry还支持Sun Nuclear的其他设备包括 1D SCANNER,PC ElectrometerSNC Dosimetry 软件特点软件特点Thank you,Questions?
