Virtual Simulation in the Radiooncology Department of BAZ

Virtual Simulation in the Radiooncology Department of B-A-Z County Hospital Miskolc Imre Geszti Certificated Clinical Radiophysicist Miskolc Hungary

Short History • Early ’ 60 s 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 780 c, Gammamed 12 i (Gammadot TPS for brachytherapy) • 2002 Siemens Primus Dual Energy, digital linac machine, Siemens Sim. View NT conventional Simulator, real 3 D CT based TPS (CMS Xi. O), 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 2 nd Oncor linac • 2014 ? IMRT, IGRT, (VMAT or Rapid. Arc? ), SRS, new Brachytarapy equipment, TPS

Devices I. • Conventional RT Simulator – Siemens Sim. View NT (2002) – Image intensifier • DICOM Image server • Every Images are DICOM based

Conventional RT Simulator Digitaly based imaging

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

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

Devices III. • For delineation, and verification – Coherence Oncologist • TPS – CMS Xi. O – Permedics Odyssey

Virtual Simulation Older 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 • 3 D 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

Virtual Simulation Newer 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

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

Workflow diagram (CT Simulator) Patient registration Patient positioning Defining laser origin Region selction CT topogram Starting position CT scanning Image transfer Image import Ref. point marking Ref. Point management Skin Contouring Laser, table coordinates Marking on patient skin Other details, postprocesses

CT-CT fusion Without contrast With contrast

CT-MR fusion CT MR

CT-PET fusion CT PET

More spectacular fusion of PET and CT • Easier to find the correct place of tumor, and involved tissue volume

Creation of the virtual beams

Therapy planning preprocedure • Plan calculation (3 D 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 R&V (Lantis)

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)

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

Verification II. DRR with contours Fused Images Portal Image (6 MV X-ray EPID)

Verification III. Bony structure based registration

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

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 we’ll have IGRT the near future • Human factor. What do they contour, where is the real tumor or tumor bed?

Thank you for your attention Happy birthday for Prof. Matula