Heavy Ion Tumor Therapy

1
Heavy Ion Tumor Therapy

• Michael Scholz
• GSI Darmstadt

2
Introduction

• Advantage of ion beams for therapy
• Physical aspects
• Inverted depth dose profile
• Defined penetration depth
• Reduced lateral scattering
• Biological aspects
• Increased effectiveness
• Reduced oxygen effect
• Increased effectiveness depends on many
  parameters like e.g.
• dose, Z, LET, or depth, which have to be taken
  into account for
• treatment planning

3
Depth Dose Profile
Penetration Depth cm
Relative Dose
4
Die höhere Wirkung schwerer Ionen

• Die RBE hängt ab von
• Dosis
• Strahlenergie
• Ionensorte
• Reparaturvermögen
• der Zelle

5
Depth Dose Profile
6
Survival Dependence of RBE on Cell Type
7
Biological Verification of Treatment Plans
Head Phantom
8
Biological Verification of Treatment Plans II
9
Local Effect Model
10
Comparison of LEM with Exp. Data
11
Heavy ion induced foci
Cell Nucleus
p21 response
CDKN1A/p21 green DNA red
Tracks in CR39
Pb-ions, 3.1 MeV/u, 3x106/cm2
Ca-ions, 10.1 MeV/u, 2x106/cm2
12
Visualization of tracks
13
Rasterscan
14
Heavy Ion Therapy

• Carbon advantage of RBE
• 3 Blocks / 4 weeks per year
• 1015 Patients / Block
• 140 Patients total since Dec. 1997
• 2/3 carbon alone
• 1/3 photons carbon boost
• Tumors head and neck, few pelvic
• chordoma, chondrosarcoma, ACC, meningeoma

15
Therapy Online Monitor
16
Treatment Room
17
Heavy Ion Therapy Technical Aspects

• Horizontal fixed beam
• Active magnetic scanning energy variation
• 250 energies, 7 focus steps, 15 intensity steps
• 2-4 fields per patient and treatment day
• Typical treatment time 45 min
• Typical irradiation time/field 510min
• Verification of distal field edge by PET using
  11C

18
Current Activities

• Moving targets
• Installation of patient chair
• PET with protons (FZ Rossendorf, W. Enghardt et
  al.)
• Preparation of the dedicated clinical facility
  at Heidelberg

19
Schedule for Heidelberg Facility

• 2002 Call for tender
• Refine specifications
• Prepare Component manufacturing
• Building construction documentation
• 2003 Component manufacturing
• Construction work
• 2004 Component manufacturing
• Component acceptance trials
• Begin 2005 Systemtests
• Mid 2005 Commissioning
• Mid 2006 Pre-clinical operations
• End 2006 Clinical operation

20
The Biophysics Group