Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.
4D-CBCT (Symmetry) – a useful tool to verify and treat
traditional ITV without 4D-CT simulation in treatment of
lung cance...
Introduction
• Challenges in modern radiotherapy.
• What to do about it???
Image guidance
EPID
4D-CBCT (Symmetry)
Ling et al defined IGRT more broadly as ―the use of
imaging for detection and Diagnosis, Delineation of target
and organs ...
Lung Tumour Motion While Free Breathing
Motion Artifact
AAMP: American Association of Physicists in Medicine
AAPM TG-76 (Report 91)
• Accounting for Respiratory Motion
• Motion-e...
CONCLUSIONS:
Systematic and random baseline variations constitute a substantial
portion of the geometric variability prese...
Immobilization
 Combination of Thermoplastic Mask and Vac Lock
For Thorax Region.
Patient preparation
 Instruct patient to breathe in 3
phase
 Normal Breathing
 Deep Inspiration
 Deep Expiration
You H...
CT Simulation
 Whole Thorax region
 3 phase respiration
CT
 Slice thickness 3mm
 Patient aligned to the
fiducials & la...
GTV: Gross Tumour Volume
CTV: Clinical Target
Volume
ITV: Internal Target Volume
PTV: Planning Target Volume
ITV = CTV + I...
Contouring
GT
V
XVI Imaging and 4D Symmetry
 Pre-RT evaluation.
Daily XVI Imaging was done.
4D CBCT (Symmetry) First Day and repeated
w...
4D (Symmetry) Pre RT Evaluation
4D (Symmetry) After 20 #
Results
• The defined ITV margin is adequate to cover the moving
target in free respiratory cycle.
• 30 4D-CBCT
• 130 XVI ...
Setup Errors
Transitional Setup
Error
Lateral Longitudinal Vertical
Mean (cm) 0.1165 -0.1055 -0.187
standard deviation
(SD...
Conclusion
• Accuracy
• Precision
• Verification
FUTURE???
4D-CBCT (Symmetry) - a useful tool to verify and treat traditional ITV without 4D-CT simulation in treatment of lung cancer.
Próxima SlideShare
Cargando en…5
×

4D-CBCT (Symmetry) - a useful tool to verify and treat traditional ITV without 4D-CT simulation in treatment of lung cancer.

4D-CBCT is latest software gadget in field of radiation oncology. It will calculate breathing movement during treatment of lung cancer and help in delineate the target better.
This presentation will convince you that even if you do not have 4D-CT simulation, you can confidently use 4D-CBCT at optimal level.

  • Sé el primero en comentar

4D-CBCT (Symmetry) - a useful tool to verify and treat traditional ITV without 4D-CT simulation in treatment of lung cancer.

  1. 1. 4D-CBCT (Symmetry) – a useful tool to verify and treat traditional ITV without 4D-CT simulation in treatment of lung cancer. Dr. Malhar Patel DNB (Radiation Oncology)
  2. 2. Introduction • Challenges in modern radiotherapy. • What to do about it??? Image guidance EPID 4D-CBCT (Symmetry)
  3. 3. Ling et al defined IGRT more broadly as ―the use of imaging for detection and Diagnosis, Delineation of target and organs at risk (OARs), Determining biological attributes, Dose distribution design, Dose delivery assurance, and Deciphering treatment response, a so-‖ called six-dimensional definition. 6D Definition
  4. 4. Lung Tumour Motion While Free Breathing Motion Artifact
  5. 5. AAMP: American Association of Physicists in Medicine AAPM TG-76 (Report 91) • Accounting for Respiratory Motion • Motion-encompassing methods (Free Breathing) • Respiratory Gating Techniques • Breath-hold Techniques • Forced shallow breathing - abdominal compression • Real-time tumor-tracking The Management of Respiratory Motion in Radiation Oncology SUPERIOR - INFERIOR ANTERIOR – POSTERIOR LEFT - RIGHT 0 – 18.5 mm 0 – 9.5 mm 0 – 10 mm
  6. 6. CONCLUSIONS: Systematic and random baseline variations constitute a substantial portion of the geometric variability present in the treatment of patients with lung cancer and require generous safety margins when relying on accurate setup/immobilization or bony anatomy-driven correction strategies. The 4D-CBCT has the ability to accurately monitor tumor trajectory shape and baseline variations and drive image-guided correction strategies that allows safe margin reduction. Int J Radiat Oncol Biol Phys. 2008 Feb 1;70(2):590-8. Epub 2007 Nov 26
  7. 7. Immobilization  Combination of Thermoplastic Mask and Vac Lock For Thorax Region.
  8. 8. Patient preparation  Instruct patient to breathe in 3 phase  Normal Breathing  Deep Inspiration  Deep Expiration You Have 4D CT SCAN??
  9. 9. CT Simulation  Whole Thorax region  3 phase respiration CT  Slice thickness 3mm  Patient aligned to the fiducials & laser marks  IV contrast to enhance target & critical organs  DICOM images transferred through networking FiducialFiducial
  10. 10. GTV: Gross Tumour Volume CTV: Clinical Target Volume ITV: Internal Target Volume PTV: Planning Target Volume ITV = CTV + IM (Internal Margin) PTV = ITV + SM (Setup Margin)
  11. 11. Contouring GT V
  12. 12. XVI Imaging and 4D Symmetry  Pre-RT evaluation. Daily XVI Imaging was done. 4D CBCT (Symmetry) First Day and repeated weekly.
  13. 13. 4D (Symmetry) Pre RT Evaluation
  14. 14. 4D (Symmetry) After 20 #
  15. 15. Results • The defined ITV margin is adequate to cover the moving target in free respiratory cycle. • 30 4D-CBCT • 130 XVI (CBCT) Organ Motion Longitudinal (Superior-Inferior) Vertical (Anterior-Posterior) Lateral (Left Right) 4.9 mm 2.56 mm 1.89 mm SUPERIOR - INFERIOR ANTERIOR – POSTERIOR LEFT - RIGHT 0 – 18.5 mm 0 – 9.5 mm 0 – 10 mm AAMP
  16. 16. Setup Errors Transitional Setup Error Lateral Longitudinal Vertical Mean (cm) 0.1165 -0.1055 -0.187 standard deviation (SD) 0.066447 0.324877 0.093529
  17. 17. Conclusion • Accuracy • Precision • Verification FUTURE???

×