Heavy Ion Tumor Therapy Michael Scholz GSI Darmstadt

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

Depth Dose Profile Penetration Depth [cm] Relative Dose

Die höhere Wirkung schwerer Ionen Die RBE hängt ab von: Dosis Strahlenergie Ionensorte Reparaturvermögen der Zelle

Depth Dose Profile

Survival: Dependence of RBE on Cell Type

Biological Verification of Treatment Plans “Head Phantom”

Biological Verification of Treatment Plans II

Local Effect Model

Comparison of LEM with Exp. Data

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

Visualization of tracks sample holder sample holder

Rasterscan

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

Therapy Online Monitor

Treatment Room

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

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

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

The Biophysics Group