Virtual Simulation in the Radiooncology Department of B-A-Z County Hospital Miskolc

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Virtual Simulation in the Radiooncology
Department of B-A-Z County Hospital Miskolc

• Imre Geszti
• Certificated Clinical Radiophysicist
• Miskolc
• Hungary

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Short History

• Early 60s Superficial Skin Therapy (Chaoul,
  Dermopan)
• 1974 Founded of the Department of Radiooncology,
  Teletherapy (Cs, Co therapy)
• 1975 Brachytherapy (GUA)
• 1977 National Therapy Planning Networking System
• Transverse sectioning device
• 1991 PC based therapy planning (van de Geijn)
• 1994 Theratron 780c, Gammamed 12i (Gammadot TPS
  for brachytherapy)
• 2002 Siemens Primus Dual Energy, digital linac
  machine, Siemens SimView NT conventional
  Simulator, real 3D CT based TPS (CMS XiO),
  connection to the hospital CT scanner via the
  network system
• 2005-2007 Intracranial Stereotaxia (Brainlab)
  (ended by politics)
• 2007 Siemens Oncor Impression linac, Siemens
  Somatom sensation Open CT Simulator (LAP Dorado
  laser system, Coherence Dosimetris Workstation)
• 2008 2nd Oncor linac
• 2014 ? IMRT, IGRT, (VMAT or RapidArc?), SRS, new
  Brachytarapy equipment, TPS

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Devices I.

• Conventional RT Simulator
• Siemens SimView NT (2002)
• Image intensifier
• DICOM Image server
• Every Images are DICOM based

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Conventional RT Simulator
Digitaly based imaging
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Devices II.

• CT Simulator
• Siemens SOMATOM Sensation Open (2007)
• CT with flat table top
• LAP Dorado Laser system
• Coherence Dosimetrist (Virtual Simulator
  Software) workstation

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Siemens Somatom Sensation Open CT simulator,
Coherence Dosimetrist ws
LAP Dorado laser system
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Devices III.

• For delineation, and verification
• Coherence Oncologist
• TPS
• CMS XiO
• Permedics Odyssey

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Virtual SimulationOlder methodology

• Presimulation in conventional Simulator
• Marking of the center of the region
• Processing CT Images
• In another department (not the same building)
• Sending via network (advanced version)
• Sending via CD-, DVD-ROM
• 3D Therapy Planning system
• Contouring
• Planning
• Processing of DRRs, hardcopy of isocentric plain
• Simulation after the planning
• Mark the sign of the Isocenter
• Verification
• Film
• EPID

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Virtual SimulationNewer methodology I.

• Pre- and postplanning processing in one step
• Patient positioning
• AP topogram (fix tube position)
• Selecting the region
• CT Imeges
• Possible postprocessing (changing kernels or
  other processing details slice thickness etc.)
• Sending the images

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Virtual Simulation Newer methodology II.

• VSim software
• Delineating (Skin, OAR, PTV)
• Reference point managment
• Other DICOM format images registration (fusion of
  images) (MRI, Diagnostic CT, PET etc.)
• Virtual beam simulation
• Room-, Beam eye view
• Virtual machine
• Without dose calculation

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Workflow diagram (CT Simulator)
Patient registration
Patient positioning
Defining laser origin
Starting position
CT topogram
Region selction
CT scanning
Image transfer
Image import
Ref. Point management
Ref. point marking
Skin Contouring
Laser, table coordinates
Marking on patient skin
Other details, postprocesses
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CT-CT fusion
Without contrast
With contrast
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CT-MR fusion
CT
MR
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CT-PET fusion
CT
PET
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More spectacular fusion of PET and CT

• Easier to find the correct place of tumor, and
  involved tissue volume

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Creation of the virtual beams
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Therapy planning preprocedure

• Plan calculation (3D TPSs)
• Parameter changing possibilities
  (comformalization of MLCs, selecting adequate
  beam energies, wedges etc.)
• Making hardcopies (images of slices, plan
  parametres)
• DRRs (paper based, and digitaly format)
• Parametres for RV (Lantis)

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Deviations

• Random error
• From inadequate positioning
• Changes of the patient weight
• From device (laser, table, light field etc.)

• Intended deviation
• Replace the reference point for better dose
  distribution
• For using different centre of treating volumes
  (whole breast vs. tumor bed)

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Verification I.

• Optivue 500 Flat panels on Oncor Impression
  linacs (semiconductor based EPID)
• Coherence Therapist workstations
• Dedicated for both of the Oncor machines
• Possibilities of Portal Imaging application
• Fusion of digital format Portal or Verificational
  Image with DRRs
• 3 directions (lat., long., vert.) eliminate
  deviations in 1 mm resolution

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Verification II.
DRR with contours
Portal Image (6MV X-ray EPID)
Fused Images
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Verification III. Bony structure based
Bony structure based registration
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Verification IV.Inplanted marker based
Relative to inplanted markers Prostate case More
precise if we can use some Gold markers
Differencies relative to DRR it needs to adjust
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Important considerations

• Accuracy of patient treatment
• Precise lasers,
• Table top (roll, tilt)
• Rotating
• Deflection
• Patient fixation
• Verification on Linacs
• No soft tissue sensitivity (relative to bony
  structure)
• No tissue moving or respiration tracking
• So we believe well have IGRT the near future
• Human factor. What do they contour, where is the
  real tumor or tumor bed?

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Thank you for your attention

• Happy birthday for Prof. Matula