Tomotherapy Tomo는 tomotherapy사가 개발하였고 현재는 accuray사가 인수하여 운영하고있다. 08806018 이세림 09806035 이재성
CONTENTS · History · Organization · Principle of operation · Features and benefits · Course of treatment · limitations
HISTORY TomoTherapy evolved from CT scanners CO 60 1955 1972 Clinac 4 1988 EPID MLC 1995 Serial tomotherapy (1st commercial IMRT) 2001 IMRT 2003 CT Guided IG-IMRT (TomoTherapy) 2008 RapidArc IMAT Radiotherapy History – C-Arm Gantries 1992 3D Treatment 1996 1968 (commercialized versions) 1983 MRI Helical CT Helical Multi slice CT 2002 PET/CT use common In RT Imaging History – Ring Gantries 2005 CBCT Commercial Availability Helical TomoTherapy C-Arms invented for diagnostic X-Rays Early 1900s TomoTherapy evolved from CT scanners TomoTherapy is the new paradigm in IG-IMRT. Adaptive Planning DGRT Dose Verification 2007 StatRT Throughput and Reliability Enhancements
Organization ·
Organization
ORGANIZATION Tomo Linac Detector · 기존 Linac과 구조는 동일 · 3.5MV(Image), 6MV Detector · A-Se
ORGANIZATION
ORGANIZATION MLC(Multileaf Collimator) · 동영상 · 종양의 다양한 모양과 크기에 맞춰 정상장기를 차폐 · 여러 개의 Bar모양의 차폐체(Stepping motor를 이용하여 구동) · 64(6.25mm)개 · 주로 W이나 WHA · 동영상 텅스텐 사용이유 납보다 밀도 두 배 높아서 차폐율이 높다. 속도는 250cm/s(보통 Linac의 MLC는 2cm/s) http://discovery.wisc.edu/home/town-center/programs--events/recurring-conferences/open-source-medical-devices/bmmlc-design-2/bmmlc-design-2.cmsx
ORGANIZATION Magnetron · 고주파를 발생시키는 장치 · 구조가 간단하여 소형 장치에 이용 · 조작이 용이하며, 가격이 저렴 · 수명이 짧다 · 출력의 안정성이 나쁘다
ORGANIZATION Gun board Pulse forming network · Linac의 filament에 전압을 공급 · Linac에 고전압(6MV)을 공급 Pulse forming network · 이중 고전압전류를 조절하는 회로
ORGANIZATION Modulator Beam stop · Magnetron에 고전압 공급 · Cathode에 Heater(Fliament) 전압을 공급 Beam stop · 1차 차단 · 차폐 벽 두께 줄임
What is tomotherapy · Dedicated equipment for IMRT · Tumors confined to the high-dose radiation therapy may be possible · Treatment can be performed at the same time(if you need to) ·Currently, IGRT is to implement
Tomo Therapy
Principle of operation · 동영상
Principle of operation
Principle of operation 6 MV Linac Electron beam Target Whole treatment head rotates around y -axis, with an SAD of 85 cm x z y Binary multileaf collimator y-jaws Photons A short 6 MV linac is collimated by jaws and a binary multileaf collimator. The treatment head rotates on a gantry in the x/z plane while a patient is continuously translated through the bore of the machine in the y-direction – the therapy analogue of spiral CT
Features and benefits · 동영상
Course of treatment
What is IMRT · An advanced mode of high-precision radiotherapy that uses computer-controlled linear accelerators to deliver precise radiation doses to a malignant tumor or specific areas within the tumor · Currently, most extensively to treat cancers of the prostate, head and neck, and central nervous system
IMRT
3D CRT and IMRT
IMRT and ARC IMRT forward IMRT inverse IMRT Static Arc Vmat Tomo
IMRT and ARC
What is IGRT · The use of frequent imaging during a course of radiation therapy to improve the precision and accuracy of the delivery of treatment. · It is possible to re-plan
IGRT
LIMITATIONS · Only coplanar beams · Constant tx parameters - Gantry speed - Table speed - Beam width(affects longitudinal modulation) - Dose rate · No static beam for simple case · Only 6MV & no electrons · Hot dose & Interval 추가적 단점으로 HOT DOSE
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