The Heidelberg Ion Therapy Center. Thomas Haberer Heidelberg Ion Therapy Center Hadron Therapy Workshop, Erice 2009

Transcription

1 The Heidelberg Ion Therapy Center Thomas Haberer Heidelberg Ion Therapy Center Hadron Therapy Workshop, Erice 2009

2 Goal The key element to improve the clinical outcome is local l control! entrance channel: tumour: low physical dose high physical dose low rel. biol. effiency high rel. biol. effiency

3 Reformulated Goal Delivery of biologically optimized and intensity-modulated dose distributions using a minimum amount of fractions even in the presence of organ motion.

4 Standard Approach Facilities being built at existing research accelerators Fixed energy machines with moderate flexibility (if at all) Dose delivery e not exactly tumor-conform Th. Haberer, Heidelberg Ion Therapy Center

5 Dose Delivery GSI/HIT Idea: Realization: Dose distributions of utmost Dissect the treatment volume tumor conformity can be into thousands of voxels. Use produced by superimposing small pencil beams with a many thousands Bragg-peaks spatial resolution of a few mm in 3D. to fill each voxel with a pre- Sophisticated t requirements calculated l amount of stopping concerning the beam delivery particles taking into account system, the accelerator, the the underlying physical and treatment planning, QA,... biological interactions. result from this approach. Extreme intensity modulation via rasterscanning Th. Haberer, Heidelberg Ion Therapy Center

6 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 GSI Haberer et al., NIM A, 1993

7 Comparison of Dose Distributions rasterscanned carbon GSI, 2 fields protons, passive ithemba, 2 fields Th. Haberer, Heidelberg Ion Therapy Center

8 Scanned Carbon vs. Intensity Modulated Photons scanned carbon 3 fields IMRT 9 fields reduced integral dose steeper dose gradients less fields increased biological effectiveness courtesy O. Jäkel, HIT

9 Key GSI Scanning-ready pencil beam library ( combinations): 253 energies (1mm range steps) x 7 spot sizes x 15 intensity it steps Rasterscan method incl. approved controls and safety Beammonitors follow the scanned beams (v <= 40 m/s) in real-time Biological interactionmodel (LEM) based on 25 years of radiobiological research Physical beam transportmodel Planningsystem TRiP In-beam Positron Emission Tomography QA system Prototype of the scanning ion gantry Th. Haberer, Heidelberg Ion Therapy Center

10 Heidelberg University Hospital

11 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 wide first scanning ion gantry > 1000 patients/year > fractions/year integrated R+D- infrastructure Th. Haberer, Heidelberg Ion Therapy Center

12 Some Milestones of HIT st intensity-controlled rasterscan performed at GSI 1992 LEM I (local effect model) published 1993 Four partners initiate the pilot project on ion beam therapy: 1997 Treatment of the first patients at GSI with carbon 1998 Submission of the HIT-proposal p M grant for the scanning ion gantry segment prototype 2000 GSI presents feasibility study and the technical proposal for HIT M grant to cover 50% of the investment 2004 Foundation stone ceremony 2005 Installation of the accelerator systems started in October First beam in treatment room H2 in March.

13 Foundation Stone Laying of the foundation stone: May, 12th 2004 Th. Haberer, Iontherapy, GSI

14 Germany: Ion Some Facility Facts of the Heidelberg Effective area m² Concrete tons Constructional steel tons Capital Investment 106 M Start of construction: November 2003 Completion of building and acc.: June 2006 Accelerator settings established: April 2008 First patient planned: 2 nd half of 2009 Project Partners: University pays, owns and operates the facility GSI built the accelerator Siemens supplies all components related to patient environment GSI, DKFZ, Siemens are research partners

15 Building Details Th. Haberer, Heidelberg Ion Therapy Center

16 IMPT Beam Scanning pencil beam library: ions : p 3 He C 6 16 O 8+ energies (MeV/u) : (255 steps,1.0/1.5 mm) beam spot size : 4 10 (20) mm, 2d-gaussian ( 4 (6) steps) (up to 20 mm for moving organ treatments) intensity variation: chopper system in front of the RFQ, variation factor: 1000 active energy variation: in the synchrotron + high-energy beam lines beam size variation: quads directly in front of the scanning systems beam extraction: established RF-knock-out out method (Himac > 10 years) gives high stability in time, position and spot size extraction switchable at flat-top top level Th. Haberer, Heidelberg Ion Therapy Center

17 HIT / Linac compact design proven technology fast change of the ion species fast intensity variation (1000-times) constant beam parameter Cooperation: GSI + IAP@ Univ. Frankfurt/M. Ion source RFQ Th. Haberer, Heidelberg Ion Therapy Center

18 Injector RFQ + IH-DTL Ion sources Th. Haberer, Heidelberg Ion Therapy Center

19 HIT / Synchrotron compact design proven technology multiturninjection => high intensities rasterscanning optimized, extremely flexible beam extraction Multiple extraction 05bis10sec 0,5 sec fast variation of energy (range) Multiturn injection Th. Haberer, Heidelberg Ion Therapy Center

20 high energy beam transport synchrotron Th. Haberer, Heidelberg Ion Therapy Center

21 Th. Haberer Synchroton/HEBT Commissioning

22 Status of pencil- beam libraries treatment quality since April 2008 Th. Haberer

23 Th. Haberer, Heidelberg Ion Therapy Center Beam Spot Library

24 Daily ACC-QA, March 2009 Th. Haberer, Heidelberg Ion Therapy Center

25 Accelerator Status Sources, injector and synchrotron fully commissioned for protons, carbon and oxygen (256 energies each) H1 / H2: pencil beam libraries ( E F I ) for protons and carbon in therapeutical quality reached in April, 2008 outstanding beam quality: very high position and focus stability, small intensity fluctuations R+D-cave: protons, carbon and oxygen energy libs established Gantry: proof of principle for protons and carbon (representative settings in the full phase space ( E F I α )) To do: intensity upgrade ( x3 ) under way (sources, LEBT, RFQ) Operation scheme: 2007: 24 h / 5 days 2008ff 24 h / 7 d 330 d 2 h td 14 d h 2008ff: 24 h / 7 days, 330 days, 2 shutdowns 14 days each Availability of the pencil H1/2: 98%

26 Dose Delivery and Medical Equipment Identical patient positioning systems fixed beam Gantry Workflow optimization automated t QA procedures automated patient hand over from shuttle Inroom position verification 2D 3D Cone beam CT Open for future applications and workflows Th. Haberer, Heidelberg Ion Therapy Center

27 Status & Next Steps preliminary scanner commissioning result energy recorded in a verification film no feedback loops for beam intensity or position (courtesy S.O. Grözinger et al., Siemens Medical Solutions)

28 Status & Next Steps preliminary scanner commissioning result medium energy recorded in a verification film no position feedback loop

29 Treatment Planning System skull base chordoma, fraction sequence for 2 proton plans Plan1_CTV_P 50 GyE + Plan2_GTV_P 24 GyE

30 Treatment Planning System Adenoid cystic carcinoma, IMRT (KonRad) 27 fx + Carbon boost 6 fx

31 Outlook: Multi field optimization for Ions Multiple field optimization simultaneous optimization field 1 field 2 final sum

32 Next Steps Stabilize the clinical workflow Finalize the bugfixing of the kick-off-version Perform the system integration ti and system tests t (~3000 test t cases) to fulfill the requirements of the Medical Device Directive (=> CE label) User training Approval for the full facility by the German authorities some pp y y weeks later

33 Scanning Ion Gantry / Rationale TPS studies (beam scanning only) give: Benefits for ~20% of skull base tumors Spinal/cervical chordoma benefit significantly (robustness of plans) Pancreatic/retroperitoneal tumors can be treated with a vertical beam but with a gantry improved treatments can be realized Some lung tumor situations may benefit No benefit for prostate/pelvic tumors was found

34 Motivation Gantry Advantage of a rotating beamline Pancreas, supine position via gantry advantageous Th. Haberer

35 Scanning Ion Gantry / Requirements Clinical: Isocentric set-up and a fixed floor Identical field size in all beamlines of 20 cm x 20 cm Integration of fluoroscopy systems in two planes (IGRT, organ movement) Technical / financial: Normal conducting elements (field quality of about 10-4 in 90-degree bending magnet, price, 330 days 24/7 op.) Full rotation (clinical workflow, minor saving) Barrell-type (less bending than cork-screw) Scanning upstream to the last bending (radius vs. weight) Edge focussing (large SAD) Truss-based structure

36 Gantry Segment GSI test of scanning gantry segment at GSI Th. Haberer, Heidelberg Ion Therapy Center

37 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 ACCEL / SEAG MT Mechatronics Th. Haberer, Heidelberg Ion Therapy Center

38 Mounting

39 Gantry / Medtech

40 Gantry: first beam at the isocenter January 4th, 2008

41 Thank you for your attention! (Intensity modulated raster scan, 12 C at 430 Mev/u, October 15 th 2007)