Sun-Nuclear三维水箱特点.ppt

Advantages of a 3D Cylindrical Water Scanner,Max Tang Medical Physicist,Outline,TG 106介绍以及数据采集 常见问题 3DS 水箱特点 圆筒状箱体设计 AutoSetup 自动摆位功能,TG-106,This task group was formed to review the physics of commissioning linear accelerators and to provide guidelines and recommendations on proper selection of detector, phantom, 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-106,III.B. Scanning water tank III.B.1. Positioning and labeling III.B.2. Scanner movement III.B.3. Orientation III.C. Scan mechanism and movement III.C.1. Array detector weight III.C.2. Speed and position accuracy III.C.3. Hysteresis III.C.4. Corrosion III.E. Data acquisition III.E.1. Scanning parameter protocol III.E.2. Speed III.E.3. Delay time III.E.4. Sampling time and signal III.E.5. Radio frequency noise interference,足够大的扫描范围: Diagonal profiles of 40x40 cm2 with lateral buildup 5cm Orient the detector mount so that it provides the highest resolution. Precautions: “Do not scan 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,电离室 - 体积效应 半导体 - 剂量，能量，剂量率响应 There are conicting publications on the use of diode detectors for beam data acquisition, hence, before using a diode detector, one should compare it with ion chamber measurements to conrm its correct operation and accuracy in data. - AAPM TG106,AAPM TG106,AAPM TG106,AAPM TG106,电离室的体积效应 Volumn averaging effect,剂量高估,剂量低估,剂量准确,“Detector orientation plays an important role in profiles and penumbra measurements” TG106,AAPM TG 106,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10x10的Cross-line和In-line Profile的对比,SNC 125cTM Specifications,The SNC125c is oblong to provide a sharper penumbra with the same signal. This chamber is designed longer to work in the 3D SCANNER with the rotating diameter drive to always keep the chamber in the ideal orientationits almost like having the signal of a 0.125cc with a penumbra closer to a micro chamber.,Chamber Comparisons,IBA CC13内空腔截面,SNC 125C内空腔截面,Positioning reproducibility with AutoSetup,Day 1: An 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, 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,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40x40cm field 的Profile完整测量,使用Off set Hold ，3DS最大扫描范围为65cm,3DS运动方式,3DS是目前唯一能实现AutoSetup自动摆位功能的三维水箱,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（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,电动水平台 与水箱无缝衔接 四个步进电机stepper motors 水平调节点 一个固定支点 两个可调节: 5 mm x 和y轴水平移动 移动范围 30 mm,水面探测器,自动调节水平,Auto leveling takes three water measurements to determine the leveling required,自动调节水平,计算机会自动计算出需要水平水箱需要调节的角度,自动寻找Beam Center,3DS可以通过扫描数据来确定Beam Center.,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（Auto Setup）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,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到控制室 数据线可以与Sunnuclear其他所有产品通用,3ds 细节设计,参考探头支架使用金属 软管可以任意形状弯曲,3ds 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 避免水箱探头运动时引起水箱的整体晃动,Measurement with 5 mm/s,3D SCANNER,Square Tank,3D MiniLift,轻便，可折叠推车 易于储藏和运输,3DS储水池推车,快速的抽放水: 装水时间 5 minutes 抽水时间 2 minutes 静音设计,SNC Dosimetry 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