The Advantages of Particle Therapy and the Status of the Heidelberg Iontherapy Center Thomas Haberer, Scientific Technical Director, Heidelberg Ion Therapy Center
Situation / Indications 2/3 patients suffer from a local disease at the time of diagnosis In 18% local treatment modalities fail => 280.000 organ at risk tumor Locations: brain, base of the skull, prostate, liver, lung Profile: deep-seated and radioresistant tumor close to organs at risk deaths/year in the EC Protons and ions have the potential to cure 30.000 patients/year in the EC Th. Haberer, Heidelberg Ion Therapy Center tumor-conformal dose distribution
Rationale / Physics Advantageous physical characteristics: inverted depth-dose distribution Th. Haberer, Heidelberg Ion Therapy Center
Rationale / Physics Advantageous physical characteristics: small lateral scattering Th. Haberer, Heidelberg Ion Therapy Center
Rationale / Radiobiology RBE microscopic dose distributions Th. Haberer Depth in tissue cell nucleus [mm H 2 O]
H, Li, C, N, O? RBE for fractionated RT of gut crypt cells of mice (Berkeley) Proton data: Tepper et al. 1977 Ion data: Goldstein et al. 1981 Which Ion is optimal: Li, C, N, O? And: for which clinical indication?
Goal The key element to improve the clinical outcome is local control! entrance channel: low physical dose low rel. biol. effiency tumour: high physical dose high rel. biol. effiency
Reformulated Goal Delivery of biologically optimized and intensity-modulated dose distributions using a minimum amount of fractions even in the presence of organ motion.
Standard Approach Facilities being built at existing research accelerators Fixed energy machines with moderate flexibility (if at all) Dose delivery not exactly tumor-conform Th. Haberer, Heidelberg Ion Therapy Center
Standard / System + Dose Distr. typical set-up (Tsukuba) Distal edge shaping using a bolus pulls dose back into healthy tissue Th. Haberer, Heidelberg Ion Therapy Center
Carbon Ion Therapy at NIRS (June 1994-August 2004) Rectum 15 (1.2%) Eye 13 (1.0%) Miscell. 148 (11.4%) Pancreas 18 (1.4%) Lung 245 (18.9%) Base of skull 20 (1.5%) Esophagus 23 (1.8%) Brain 74 (5.7%) Total 2,297 Head & Neck 207 (16.0%) Uterus 78 (6.0%) Bone/ soft tissue 121 (9.3%) Liver 145 (11.2%) Prostate 190 (14.6%)
Results Before RT 48 months after RT Malignant melanoma 57.6GyE/16fx (NIRS)
Carbon Ion Therapy @ GSI Th. Haberer, Heidelberg Ion Therapy Center
Dose Delivery Concept Idea: Dose distributions of utmost tumor conformity can be produced by superimposing many thousands Bragg-peaks in 3D. Sophisticated requirements concerning the beam delivery system, the accelerator, the treatment planning, QA,... result from this approach. Realization: Dissect the treatment volume into thousands of voxels. Use small pencil beams with a spatial resolution of a few mm to fill each voxel with a precalculated amount of stopping particles taking into account the underlying physical and biological interactions. => Extreme intensity modulation Th. Haberer, Heidelberg Ion Therapy Center
Rasterscan Method scanning of focussed ion beams in fast dipole magnets active variation of the energy, focus and intensity in the accelerator and beam lines utmost precision via active position and intensity feed back loops intensity-controlled rasterscan technique @ GSI Haberer et al., NIM A, 1993
Rasterscan Method Protons (Pedroni et al., PSI): spot scanning gantry (1D magnetic pencil beam scanning) plus passive range stacking (digital range shifter) Ions (Haberer et al.): raster scanning (2D magnetic pencil beam scanning) plus active range stacking (spot size, intensity) in the accelerator Maximum dose conformality via pencil beam scanning Th. Haberer, Heidelberg Ion Therapy Center
Fluence Distribution of a Single Slice Th. Haberer, Heidelberg Ion Therapy Center
Advanced / Plan Comparison Ions vs. IMRT (precise X-rays) IMRT 9 fields Carbon 2 fields Th. Haberer, Heidelberg Ion Therapy Center
Key Developments @ GSI Scanning-ready pencil beam library (25.000 combinations): 253 energies (1mm range steps) x 7 spot sizes x 15 intensity steps Rasterscan method incl. approved controls and safety Beammonitors follow the scanned beams (v <= 40 m/s) in real-time Biological interactionmodel based on 25 years of radiobiological research Physical beam transportmodel Planningsystem TRiP In-beam Positron Emission Tomography QA system... Th. Haberer, Heidelberg Ion Therapy Center
Pre OP Results Post OP dose [%] chondro sarcoma rasterscanned carbon ions
FSRT / IMRT vs FSRT / IMRT+C12 at the locally advanced adenoid-cystic carzinoma survival acute toxicity acceptable late toxicity > CTC Grad 2 < 5% local control Schulz-Ertner, Cancer 2005 Th. Haberer
Heidelberg Ion Therapy Center compact design full clinical integration rasterscanning only low-let modality: Protons (later He) high-let modality: Carbon (Oxygen) ion selection within minutes world-wide first scanning ion gantry > 1000 patients/year > 15.000 fractions/year Th. Haberer, Heidelberg Ion Therapy Center
Germany: Ion Some Facility Facts of the Heidelberg Start of construction: November 2003 Effective area 5.027 m² Completion of building and acc.: June 2006 Concrete 30.000 tons First patient planned: End of 2008 Constructional steel 7.500 tons Capital Investment 100 M Project Partners: University pays, owns and operates the facility GSI built the accelerator Siemens supplies all components related to patient environment DKFZ is a research partner
HIT / General Requirements ions : p 3 He 2+ 12 C 6 16 O 8+ energies (MeV/u) : 48 72 88 102 (255 steps) -220-330 -430-430 beam spot size : 4-10 mm (2d-gaussian) ( 4 steps) treatment caves : 3 (2 horizontal, 1 iso-centric gantry) QA and research : 1 (1 horizontal) Th. Haberer, Heidelberg Ion Therapy Center
Injector RFQ + IH-DTL Ion sources Th. Haberer, Heidelberg Ion Therapy Center
high energy beam transport synchrotron Th. Haberer, Heidelberg Ion Therapy Center
Medical Equipment Identical patient positioning systems fixed beam gantry Workflow optimization automated QA procedures automated patient hand over from shuttle treatment chair Inroom position verification 2D 3D Cone beam CT Open for future applications and workflows Th. Haberer, Heidelberg Ion Therapy Center
Patient Positioning System Key Requirements Absolute position accuracy independent from patient weight R 0,5 mm Position correction in 6 degrees of freedom Roll & pitch in the isocenter in every treatment position Max. patient weight 200 kg Intuitive Handling Automated QA sequences Implementation of future applications via software only Prepared for automated patient table handover (external immobilization, immobile patients) Prepared for attachment of treatment chair
Patient Positioning System Functionality Isocentric Rotation +/-100 Pitch max. +/-15 Step On Position 650 mm Roll max. +/-15
Position Verification System Key Requirements 2D Orthogonal DR Imaging Flexible adjustment of X-ray projection axis Position verification in every treatment position 3D Cone Beam Imaging Integrated workflow for position correction X-ray system prepared for monitoring of moving organs
Patient Positioning System Workflow Optimization & Outlook Docking Mechanism with connectors QA Table Top with Water Phantom Automated Patient Hand Over Adaptation of Treatment Chair
Position Verification System Functionality
Status & Next Steps preliminary scanner commissioning result Protons@maximum energy recorded in a verification film no feedback loops for beam intensity or position (courtesy S.O. Grözinger et al., Siemens Medical Solutions)
Motivation Gantry Advantage of a rotating beamline Pancreas, supine position via gantry advantageous Th. Haberer
Scanning Ion Gantry optimum dose application world-wide first ion gantry world-wide first integration of beam scanning 13m diameter 25m length 600to overall weight 0,5mm max. deformation prototype segment tested at GSI MT Aerospace MT Mechatronics Th. Haberer, Heidelberg Ion Therapy Center
Mounting
Gantry / Medtech
Gantry: first beam at the isocenter
Outlook Particle therapy will cover the full spectrum of radiotherapeutical indications Per 10 million inhabitants one particle therapy facility may be required. Upcoming: CNAO/Pavia, Rhön-Klinikum/Marburg, Kiel, MedAustron/Wiener Neustadt... GSI linac Th. Haberer, Heidelberg Ion Therapy Center CNAO Pavia Italy
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