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 CDKN1A/p21: green DNA: red
Cell Nucleus
p21 response
CDKN1A/p21: green
DNA: red
Pb-ions, 3.1 MeV/u, 3x106/cm2
Tracks in CR39
Ca-ions, 10.1 MeV/u, 2x106/cm2

12. Visualization of tracks
sample holder
sample holder

13. Rasterscan

14. Heavy Ion Therapy Carbon: advantage of RBE 3 Blocks / 4 weeks per year
10…15 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: 5…10min
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