HEAVY-ION TUMOR THERAPYepileptologie-bonn.de/.../lehnertz/RNakate-HITTbasics.pdfRelative biological...
Transcript of HEAVY-ION TUMOR THERAPYepileptologie-bonn.de/.../lehnertz/RNakate-HITTbasics.pdfRelative biological...
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HEAVY-ION TUMOR THERAPY
By- Rashmi Nakate
July 8, 2019Bonn University1111
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Motivation
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Stopping of heavy-ions
Stopping of heavy-ions
Dose deposition Dose deposition
Nuclear Fragmentation
Nuclear Fragmentation
Treatment planning
Treatment planning
Relative biological
effectiveness
Relative biological
effectiveness
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INTRODUCTION
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• Radiation Therapy
• Proton Therapy
• Heavy Ion therapy
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Bethe-Bloch Formula
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Energy loss is described by Bothe-Bloch formula.Energy loss is described by Bothe-Bloch formula.
‘I’ is Ionization Energy‘I’ is Ionization Energy
‘C/Zt’ is Shell correction term.‘C/Zt’ is Shell correction term.
‘ is density effect correction term.‘ is density effect correction term.
Energy loss is described by Bothe-Bloch formula.Energy loss is described by Bothe-Bloch formula.
‘I’ is Ionization Energy‘I’ is Ionization Energy
‘C/Zt’ is Shell correction term.‘C/Zt’ is Shell correction term.
‘ is density effect correction term.‘ is density effect correction term.
Stopping of heavy-IonsStopping of heavy-Ions
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Stopping Power Curve
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Stopping of heavy-IonsStopping of heavy-Ions
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Range
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Stopping of heavy-IonsStopping of heavy-Ions
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Bragg Peak
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Stopping of heavy-IonsStopping of heavy-Ions
Look at energy loss as function of absorber depthLook at energy loss as function of absorber depth
Expect sharp peak near stopping point due to Expect sharp peak near stopping point due to
Broadening of the peak due to statistical fluctuations of energy loss
Broadening of the peak due to statistical fluctuations of energy loss
Look at energy loss as function of absorber depthLook at energy loss as function of absorber depth
Expect sharp peak near stopping point due to Expect sharp peak near stopping point due to
Broadening of the peak due to statistical fluctuations of energy loss
Broadening of the peak due to statistical fluctuations of energy loss
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Range StragglingRange Straggling
Range Straggling
Calculation of path length
R(E) =
Calculation of path length
R(E) =
Statistical fluctuationStatistical fluctuation
Vivilov Distributions� many Collisions
Gaussian )
Vivilov Distributions� many Collisions
Gaussian )
R(E) =R(E) =
Statistical fluctuationStatistical fluctuation
Vivilov Distributions� many Collisions
Gaussian )
Vivilov Distributions� many Collisions
Gaussian )
Calculation of pathlength
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Dose depositionDose deposition
Energy Loss and Range of ions
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Dose depositionDose deposition
Dose deposition by Iron ion
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Dose depositionDose deposition
Dose deposition by Neon ion
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Lateral Beam SpreadLateral Beam Spread
Lateral Beam Spread
Elastic Coulomb ScatteringElastic Coulomb Scattering
Small Angular Distribution Approximately Gaussian
d = Absorber thickness,
Small Angular Distribution Approximately Gaussian
d = Absorber thickness,
Elastic Coulomb ScatteringElastic Coulomb Scattering
Small Angular Distribution Approximately Gaussian
d = Absorber thickness,
Small Angular Distribution Approximately Gaussian
d = Absorber thickness,
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Nuclear FragmentationNuclear Fragmentation
Nuclear Fragmentation
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Nuclear FragmentationNuclear Fragmentation
� Stopping process is governed by collisions with atomic
electrons.
� What happens if nuclear reaction occurs?
� Use Abrasion-Ablation Model.
� Loss of primary beam particles
� Secondary particles have longer range than primary beam
particles.
� There are other model describing fragmentation: E.g.
Intranuclear cascade model
� Fragmentation leads to dose tail behind the brag peak.
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Importance Of TreatmentImportance Of Treatment
Importance of Treatment
Carbon Ions Photons
Variation of Energy and positionVariation of Energy and position
Spread out Bragg PeakSpread out Bragg Peak
Uniform Exposure of TumorUniform Exposure of Tumor
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Treatment PlanningTreatment Planning
Treatment Planning
� Determine the location of the target
volume(tumor) using modern imaging techniques
e.g. CT, MRI
� Form a 3D model of the treatment geometry
� Use this model to find suitable beam entrance
points avoiding critical structures
� Adapt the dose distribution to the planned target
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Treatment MethodsTreatment Methods
Treatment Methods
Today: Photon beamsToday: Photon beams
Future: Heavy Ion / Proton BeamsFuture: Heavy Ion / Proton Beams
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Relative Biological EffectivenessRelative Biological Effectiveness Relative Biological
Effectiveness (RBE).
RBE = RBE =
Links conventional radiotherapy to the case of heavy ionsLinks conventional radiotherapy to the case of heavy ions
Depends on the dose, particle type, energy, tissue, biological end pointDepends on the dose, particle type, energy, tissue, biological end point
Can vary drastically within the tumor volumeCan vary drastically within the tumor volume
RBE = dose of x rays/dose of ion radiation that results in the same biological effect
RBE = dose of x rays/dose of ion radiation that results in the same biological effect
Links conventional radiotherapy to the case of heavy ionsLinks conventional radiotherapy to the case of heavy ions
Depends on the dose, particle type, energy, tissue, biological end pointDepends on the dose, particle type, energy, tissue, biological end point
Can vary drastically within the tumor volumeCan vary drastically within the tumor volume
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Relative Biological EffectivenessRelative Biological Effectiveness Relative Biological
Effectiveness (RBE).
LET: Linear Energy Transfer
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Relative Biological EffectsRelative Biological Effects
Biological Effects
Radiation Damage ( Photons)
Radiation Damage ( Heavy-Ions)
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Comparison of X-ray , Protons and Heavy ions
Comparison of X-ray , Protons and Heavy ions
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Further researchFurther research Helium Ions and Anti
protons
On-going DebateOn-going Debate
Production ProblematicalProduction Problematical
Good Depth-Dose-ProfileGood Depth-Dose-Profile
Annihilation: imaging possibilityAnnihilation: imaging possibility
Helium Ions Anti Protons
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CONCLUSIONCONCLUSION
� protons and heavy ions have a advantageous depth-dose profile
� range straggling and lateral beam spread ! � beam shaping
� nuclear fragmentation (useful for PET)
� heavy ions: bigger ionization density
Heavy ions in tumor therapy: no outstanding method for everything
but:
important improvement compared to photons
Heavy ions in tumor therapy: no outstanding method for everything
but:
important improvement compared to photons
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ReferencesReferences
�Dieter Schradt, Thilo Elsaesser, Daniela Schulz-Ertner:
Heavy-ion tumor therapy: Physical and radiobiological benefits
Reviews of modern physics, volume 82, 19th February 2010
�Ugo Amaldi, Gerhard Kraft:
Recent applications of Synchrotrons in cancer therapy with Carbon Ions
Europhysics News, volume 32, july 2005
�Ugo Amaldi, Gerhard Kraft:
European Developments in Radiotherapy with Beams of Large Radiobiological
Effectiveness
Journal of radiation research, volume 48 Suppl A, February 2007
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ReferencesReferences
� Kraemer et al.:
A systematic review of antiproton radiotherapy
Frontiers in physics, 16 January 2014
� Bittner et al.:
Helium ions for radiotherapy? Physical and biological verications of a novel
treatment modality
Medical Physics, volume 43, 30 March 2016
� https://www- zeuthen.desy.de/technischesseminar=texte=siliconre=sld015:htm
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THANK YOU