Radiation Therapy Treatment System Overview: From Source to … › event › 767986 ›...
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Radiation Therapy Treatment System
Overview: From Source to Patient
Jacob (Jake) Van DykProfessor Emeritus
Western University, London, Ontario, Canadaand
Past-President, MPWB
Accelerating the Future:Designing a Robust and Affordable Radiation Therapy Treatment System for Challenging Environments
Linac with IMRT & IGRT
kV x-ray source forCone-Beam CT (CBCT)Flat panel kV
x-ray detectorfor CBCT
Flat panel MV x-ray detectorElectronic Portal Imaging
Device (EPID)
MLC
AcceleratorTomoTherapyHelical “slice”
delivery & helical CT
2003
Varian HalcyonCone-beam delivery
(VMAT) &cone-beam CT
2017
Schematic: From Source to PatientElectron Beams
ConventionalPhoton Beams
Flattening Filter Free (FFF) Machine
Ma et al, Med. Phys. 46 (1), January 2019
x2
FFF
Monitor Ionization Chamber
http://www.uthgsbsmedphys.org/GS02-0113/Section1/Accelerator%202.pdf
IAEA slides
Controls:- Total dose- Flatness
- Symmetry
Multileaf Collimator
Huq et al, PMB 47: N159–N170; 2002
Varian
Elekta
TomoTherapy
Shielding Blocks
X XShielding tray _________
Courtesy TR Mackie
Accelerator
MagnetronCT Detectors
Binary MLC
PFN
HV PS
Control computer
Beam stop
ImageGuidanceTomoTherapy
Tomotherapy MV CT Image Guidance
9
Patient/
Beam
Shifts
MVCT
kVCT
Manual alignment or grey scale alignment with mutual information
algorithm
Nasopharynx … TomoTherapy
Dose Rate Cumulative Dose
… results similar to VMAT
Summary• Treatment system: source to patient
• Multiple designs
• Conventional … photons & electrons• IMRT, VMAT with photons
• Rotational slice imaging & treatment• Tomotherapy
• Rotational cone beam imaging, VMAT delivery• Halcyon