300 likes | 315 Views
Progress in the Application of Hadron Therapy (protons or ions). Marco Schippers. The boost in particle therapy. more hospital based. mostly in labs. Loma Linda ( Ca , USA). Particle therapy group : until 2015 > 150.000 patients treated www.ptcog.ch. Contents.
E N D
Progress in the Application of Hadron Therapy (protons or ions) Marco Schippers
The boost in particle therapy more hospital based mostly in labs Loma Linda (Ca, USA) Particletherapygroup: until 2015 > 150.000 patientstreated www.ptcog.ch
Contents • Introduction: particletherapy • Accelerators • Synchrotron • Cyclotron • Treatment facilities • Whatis so special?
X-ray dose X-ray beams (IMRT ) from 7 directions X-rays heart lung Spinal cord
Dose profile of protons Bragg peak Dose (a.u.) 0 2 4 6 8 10 12 14 16 18 Depth in tissue (cm)
Protons heart lung Spinal cord X-rays vs. Protons Proton beams from 3 directions X-ray beams (IMRT ) from 7 directions X-rays heart lung Spinal cord pictures: Medaustron
Biological effect of Carbon ions RBE>1: Less dose for same cell killing RBE= 1.1 RBE≈ 3 electron track (or energy) density at nm scale effects RBE ( this means: RBE≠ 1 )
Pencil beam scanning intensity 0 time (ms) 10 Spot scanning: step&shoot Continuous scanning kHz-Intensity modulation allows fast target repainting: 15-30 scans / 2 min.
e.g: Boston Florida Seoul Wanjie PSI München Orsay e.g.: Loma Linda Houston Tsukuba 3.5 m Present accelerator choice cyclotron synchrotron Protons in use, 3.5-5 m in use, 8-10 m Carbon ionsin design, 6 m in use, 25 m
Synchrotron Heidelberg Hitachi Ltd Extracted beam Protons only: ( ~8 m) synchrotron Proton source + injector synchrotron Ions (p-C): ( ~25 m) Extracted beam Injector Ion sources
1-10 sec 0.5-1 sec Synchrotron beam structure in time Beam intensity Time in development • “spill” time • fill ring with ~1011 particles • accelerate to desired energy • extract slowly during 1-10 sec • decelerate and dump unused particles
250 MeV (ACCEL/Varian,2005) SC coils: diam 3.5 m, 100 tons 230 MeV (IBA, SHI,1996) iam. 5 m, 200 tons Cyclotron
E-adjustment with cyclotron 250 MeV cyclotron All following magnets: 1% field change in 50-80 ms At PSI: Graphite degrader 238-70 MeV
Small cyclotron fRF time very strong magnetic field: Synchro-Cyclotron Bdecreases with radius Tcircleincreases with radius. SO: decrease fRF with radius and extract Repeat 1000 x per sec 1 ms Each pulse: set intensity at source within ms (=> typ 10-30% accuracy) => Spot scanning requires >2 pulses per spot.
Synchro-Cyclotron 8-10 T 250 MeV Synchro-cyclotron on a gantry First system installed in 2013
Accelerator status (protons) cyclotron synchrotron small synchro- cyclotron linac Current Useability => Quality FFAG laser Dielectr. wall linac Plasma wake field Now Mañana Time until useable
At cyclotron: degrader+ energy selection beam transport gantries Cyclotron or synchrotron Proton therapy: multi-room facility IBA
Gantries 10-12 m IBA ~90 t Loma Linda (Optivus)
PSI Gantry-2: fast 3D scanning PSI-”Gantry-2” Eros Pedroni David Meer
Gantry for carbon-therapy HIT, Heidelberg
NEW: SC gantries SC dipoles NIRS, Japan SC dipoles Scanning XY Pronova, Knoxville, USA
PSI’s superconducting gantry design combined function, achromatic bending • Degrader mounted on the gantry • Momentum acceptance of approx. ±12.5 % • Treatment of the small tumors without change of the SC magnet field Collimators Degrader Scanning magnets Rotation axis Isocenter
Acc.Lab Hospital What is so special? Operators Technicians Experienced workshops More improvised actions Radiologistoperates CE/FDA-certification: PROCEDURES Localtechnicians:onlysmallrepairs Service byequipmentcompany
SafetyAvailability Separate interlock systems e.g. : Machineinterlocks: all componentstechnically OK More speciallyfortreatments Area access & area dose: Doors closed, dose rate < µSv/h Patient safety: Dose deliveryasplanned
Redundancy measurement BEAM off Alarm level stop Redundancy Redundancy Patient safety interlock system stop stop Alarm level stop
Operation: non-acceleratorexperts Whathashappened ? Strong needfor ERGONOMIC display of: Status Instructions NO BEAM
Accelerators for Medical Application What is so special? • Technics: dedicated, but not on thelimitoftechnology ….but… • Reliable, Reproducible, Reliable, Reproducible • Operation:by non-acceleratorexperts • strictlyaccordingprocedures • Control andsafety: • VERY DEDICATED and SPECIAL : • Reliable & Redundant, but not too sensitive
SUMMARY • Dose: • finite range • maximum dose at end of track • Apply the dose by Pencil Beam Scanning • Accelerators for Medical Application: • Cyclotron • Synchrotron • Medical applications: VERY Special Operation • Facilities: Gantry aims the beam from all directions • Recent development: SC magnets
…. Motivation …. first scanning gantry : PSI, 1996 Thank you !! Gantry: Eros Pedroni Tumours in kids: Beate Timmermann, Gudrun Goitein