Developments in Particle Therapy using Nuclear Science and - PowerPoint PPT Presentation

WIR SCHAFFEN WISSEN – HEUTE FÜR MORGEN Marco Schippers, Paul Scherrer Institut, Villigen Developments in Particle Therapy using Nuclear Science and Technology Helsinki, NUSPRASEN workshop, November 26, 2019 Helsinki, Nov 2019 1

3.3.2 OUTLINE • Proton Therapy • Recent developments in dose delivery and p.th.-accelerators • Current major topics of research:  Treatment when organs are moving  High intensity  Proton range determination NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 2

Why Particle therapy? X-ray beams Proton beams from 7 directions from 3 directions Protons X-rays heart heart lung lung Spinal cord Spinal cord pictures: Medaustron NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 3

Proton therapy facility accelerator IBA NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 4

Accelerators for Proton therapy Cyclotron Synchrotron NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 5

Recent Developments in dose delivery and accelerators NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 6

Dose delivery techniques Scatter technique: Scatter syst. Collimator From nucl physics lab: Pencil Beam Scanning NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 7

compact “Gantry - 1” at PSI (1996) scanning proton pencil beam 4 m Eros Pedroni NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 8

Typical Gantry ~1996… 10-12 m Schär Engineering - Munich Roberts Proton Therapy Center Philladelphia NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 9

NEW: gantries with SC magnets ProNova Toshiba, NIRS NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 10

NEW: optics in SC gantry design Proton SC Gantry (PSI)  NO Magnetic Field change for tumors Energy acceptance = ± 30% 15-30 cm NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 11

Vary depth: adjust beam energy E- change ges with Cyclot otron on All following magnets: 1% field change (5mm) Degrader unit in 50-80 ms (PSI) Q Q Q Steerer Kicker graphite 250 250 MeV Cyc yclotron multi-wedge degrader  238-70 MeV recent development: Gaphite  Boron Carbide Less scattering  less losses at low E NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 12

Vary depth: adjust beam energy # E-change ges with Synchrot otron on recent development: Energy is set per spill Energy adjustable 1 spill: during extraction several spills NIRS: Y. Iwata et al., MOPEA008, Proc . IPAC’10 NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 13

cyclotrons in proton therapy IBA (1996) , SHI Isochronous Cyclotron Varian (2005) IBA (2018) Isochronous Synchrocyclotron Cyclotron MEVION (2013) Pulsed beam: Synchrocyclotron Limits speed in dose delivery NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 14

In Production: Linac 230 MeV Spin-off from TERA and CERN: Coupled Cavity Linac  230 MeV E-change by: switching on/off power of cavity units AVO, ADAM: A. Degiovanni et al. 2016 NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 15

Laser driven proton accelerator Laser light creates plasma and thin foil, O + - pushes electrons out doped with OO ++ - O + - hydrogen + O - - - O + Laser light o + - ++ OO Electric field from electrons - -- + O o - + ++ OO pulls protons out of foil - - - protons + O - - + O - o + + O - But: more research needed for: now used: 6x10 17 W/mm 2 - 100x more power (for Ep) - MUCH higher pulse rate Pulsed at low rate - better energy spectrum C.M. Ma, Laser Physics, 2006, Vol. 16, No. 4, pp. 639 NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 16

Current major topics of research Treatment with moving organs High intensity + verification Range determination NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 17

organ / tumor motion Possible solutions: Organ motion • Gating • Adaptive scanning (tumor tracking) • Fast (+ rescanning) NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 18

Fast pencil beam scanning Cont. scanning “TV” mode kHz-Intensity modulation intensity 7 s for a 1 liter volume. 0 time (ms) 10 NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 19

Current major topics of research High intensity:  Reduces motion problems  FLASH irradiation: 0.03 Gy/s  40 Gy/s To be modified: • Source / accelerator / beam transport • How to verify? NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 20

21 scanning beam monitor beam delivery system proton pencil beams Light emitting Screen CCD or ….gas scintillation camera with a GEM Advantages of gas scintillation: No quenching at low E Very fast (  s) Sjirk Boon (1996), Enrica Seravalli (2003) NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 21

Current major topics of research Particle range in tissue Particle beams are sensitive to o CT Hounsfield number  Stopping Power accuracy o Organ motion o Change of patient’s anatomy  Uncertainty in range in patients ~3% ….. but impossible to measure range directly  Various methods are in development NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 22

Proton range in tissue protons: X-rays: Range 2 cm less Dose drops 11% Effect of: 3 cm bone Effect of: CT CT images: based on X- ray interaction.  Calibration to stopping power is needed  Range error CT - Hounsfield nr from CT calibr ~1% NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 23

Range measurements Protons create activation in tissue  Measure PET Activity!  3D activ.image 11 C Dose 13 N Paans and Schippers, IEEE 40(1993)1041 CURRENT STATUS: • Need to know tissue constituents and predict PET signal • Compare measured signal with prediction •  accuracy ~3mm • but new developments are coming …… NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 24

Range measurements patient prompt  CURRENT STATUS: Dependent on E  selection • • Know tissue constituents • Accuracy of range change : ~1mm e.g.: Verburg et al., PMB 60(2015)1019 NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 25

Range measurements Proton radiography U.Scheider and E.Pedroni Med. Phys. 22(1994), 353  Residual range  E-loss CURRENT STATUS: = Integrated stopping power along track • Range accuracy: ~1% Mumot et al, PMB (2010). • Proton CT:  3D stopping power NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 26

Conclusions What developments are needed and where can Nuclear Technology contribute? •  (SC) Magnets + Acc. Lower price (50%) • Faster (x …100)  Acc. + Nucl techn. •  Nucl. Techn. Motion detect., imaging •  Nucl. Techn. Range detection But take care when implementing new developments : • Do not propose a solution looking for a problem • Proven idea  clinic takes 10-20 years • Long term (>20 yr) commitment: service / upgrades … NUSPRASEN-workshop Marco Schippers, PSI Helsinki, Nov 2019 27

Thank you for your attention

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