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New trends in ion beam therapy

Katia Parodi, Ph.D.

Ludwig-Maximilians University (LMU) Munich, Germany

(also affiliated to Heidelberg Ion Beam Therapy Center)

MPP Colloqium

München, July 21, 2015

Munich-Centre for Advanced Photonics

Surgery Radiotherapy

Survival Quality of life

Chemotherapy and others

The three columns in the fight against cancer

Localised tumour Metastatic tumour

Local tumour control, Palliative treatment

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Munich-Centre for Advanced Photonics

Surgery Radiotherapy Chemotherapy and others

The three columns in the fight against cancer

Survival Quality of life

Localised tumour Metastatic tumour

Local tumour control, Palliative treatment

08.06.2013 K.Frey, LMU – PTCOG 2013

Advantages of ion beams: depth conformality

Sparing of normal tissue in entrance channel

No / low dose in exit channel distal to the tumour

Water

Deph in water (cm)

Bio

logi

cal e

ffec

tive

do

se (

%)

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Treatment delivery uncertainties

But is what we see in TPS what we really deliver?

We want to exploit clinically the dosimetric advantages of ion beams

In-vivo verification

Tang et. al. Med.Phys. 2012

Organ at risk Tumor volume

Daily practice of compromising dose conformality for safe delivery

Range uncertainties result in conservative margin expansion and choice of beam angles avoiding Bragg peak before OARs

In-vivo verification could enable full exploitation of ion therapy potential

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X-ray

source

X-ray

imager

Current efforts for in-room imaging in ion beam therapy

- Anatomical confirmation via X-rays or transmitted ions

Imaging for confirmation of - Treatment geometry

Imaging for treatment verification

X-ray

source

X-ray

imager

PET

Current efforts for in-room imaging in ion beam therapy

- Anatomical confirmation via X-rays or transmitted ions

Prompt

gamma

Charged

secondary

particles

- Range monitoring via emerging secondary radiation or transmitted ions

Imaging for confirmation of - Treatment geometry - Treatment delivery

Imaging for treatment verification

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As in photon therapy, use integrated on-board X-ray imager for

volumetric so called cone beam imaging (CBCT)

In-room imaging for patient positioning

CBCT vs CT

10 Courtesy G. Landry

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+

Landry...Parodi Med. Phys. 2015

=

In-room imaging for dosimetric assessment

CBCT (and DIR)-based image guidance for dose recalculation on daily anatomy

However relying on CT-range calibration and dose calculation engine

• Nuclear reactions induce measurable emerging radiation

p or 12C

Target (e.g., 16O)

Projectile fragment (Z>1)

(vf ~ vp )

Target fragment (vt ~ 0 )

„Prompt“ p, d, t, n, g, …

„Delayed“ radioactive decay

• Primary ions are stopped somewhere within the patient, with dose

and range mainly dependent on Coulomb interaction

Only Positron-Emission-Tomography clinically investigated so far

In-vivo treatment visualization

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p in PMMA

12C ions in PMMA

K. Parodi et al, IEEE TNS 2005

In-vivo PET-based verification

g-emission

b+-emitter yield (15O, 11C,..., with T1/2 ~ 2,

20,... min) as by-product of irradiation

A(r) D(r)

Tradeoff between better spatial

correlation (12C) and stronger signal (p)

Dose-guidance from comparison of

measured vs expected b+-activity

p or 12C

15O, 11C, ...

15O, 11C, ...

(projectile fragmentation only for Z>1)

11C, 10C

PET/CT-based verification at HIT

Ion sources

Synchrotron

Gantry

Treatment places

Commercial PET/CT next to treatment rooms Heidelberg Ion Beam Therapy Center

PET/CT

Biograph mCT

Pelvis/Head/Neck

Liver

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Bauer, …, Parodi, Radiother Oncol 2013

Clinical examles of

offline PET/CT @HIT

PET Sim (on TP-CT) PET/CT Meas Dose

12C ions

Prompt gamma imaging

g-emission

p or 12C

In addition to b+- production, nuclear

reactions induce fast (sub-ns) prompt g

emission with broad energy spectrum

(up to several MeV)

Eliminate washout problematic

Lower cross section threshold than for

positron emitter production

Closer correlation to Bragg peak

H. Müller, FZD

Polf et al, PMB 2009

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Proposed prompt gamma detection schemes

Mechanical collimation

Ray (IPN Lyon)

Electronic collimation

Ray (IPN Lyon)

Different generation detectors: From 1D detection of last few mm beam penetration to 3D imaging

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Compton camera developments

Scatterer/Tracker DSSSD

Absorber LaBr3

z

x

y

e-

g

The MAP Compton camera

C. Lang, D. Habs, K. Parodi, P.G. Thirolf, JINST 2014

e , ee

Scatterer/ Tracker

Absorber

g ≥ 1 MeV

E‘g eg

Compton arc

Additional electron tracking of ee direction and energy Ee : origin of g can be restricted to an arc reconstruction of incompletely absorbed g events is possible

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• Nuclear reactions induce measurable emerging radiation

p or 12C

Target (e.g., 16O)

Projectile fragment (Z>1)

(vf ~ vp )

Target fragment (vt ~ 0 )

„Prompt“ p, d, t, n, g, …

„Delayed“ radioactive decay

What about electromagnetic interactions?

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21

Ionoacoustics

Particularly promising for highly pulsed delivery at laser-driven beams

W. Assmann, …, K. Parodi, Med Phys 2015

W. Assmann, S. Reinhardt, S. Lehrack, P.G. Thirolf, K. Parodi (LMU) M. Moser, G. Dollinger (UniBW) Kellnberger, M. Omar, V. Ntziachristos (IBMI/MHZ)

Transducer

The principle

Thermal expansion Acoustic wave

Localised energy deposition

Ionoacoustics at MLL

Experimental setup at the MLL Tandem accelerator:

• water phantom

• 3.5 – 10 MHz US detector, remotely controlled (scan)

• beam pulse width 8 ns – 4 ms

• 104 – 108 protons per pulse

W. Assmann et al Med Phys 2015

Systematic “ionoacoustic” investigations under ideal conditions

20 MeV protons, water

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Ion transmission imaging

Ion-based radiography / tomography could:

• Decrease range error via direct Relative Stopping Power determination

• Eliminate CT artifacts from metal / dental implants

• Replace X-ray imaging for daily, lower-dose image guidance

X-ray

source

X-ray

imager

Rinaldi, …, Parodi, PMB 58 2013

Rinaldi, …, Parodi, PMB 59 2014, 2014b

• 61 PPIC 30x30 cm2

• 3 mm PMMA absorber slabs

• 2 read-out modules of 32 channels

with real time controller

• Active scanning beam delivery system

Carbon ion radiography prototype using ionization

chambers @HIT

12C Ions X-rays

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08.06.2013 K.Frey, LMU – PTCOG 2013

A remaining challenge: compact and cost-effective instrumentation

… compared to modern photon LINAC

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08.06.2013 K.Frey, LMU – PTCOG 2013

The Munich new laser-driven infrastructure

08.06.2013 K.Frey, LMU – PTCOG 2013

Laser-driven ion sources with new targets (AG Prof. Schreiber)

aperture

quadrupoles

D+ D-

aperture or

spectrometer plate

Target

ATLAS laser

(60 J, 20 fs,

3 PW, 1-5 Hz)

Detectors for online Diagnostics (Dr. Reinhardt et al)

Beam diagnostics/monitoring

Experimental Beamline LION at LEX/CALA

Monte Carlo Simulations (Dr. Dedes et al) In-vivo Verification through prompt gammas (PD Dr. Thirolf et al)

e-

g

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Dosimetry and beam monitoring

Main ion diagnostics in LEX: RadEye1 sensor

S. Reinhardt et al, JINST 6 (2011), S. Reinhardt et al, JINST 8 (2013)

Simultaneous detection of protons and 6+C-ions

Linear response to intense pulses

Saturation limit: 107 p/cm2 (@20 MeV) 50 x 100 mm2 sensitive area

Ongoing investigations on new solutions for higher fluxes/energies @CALA

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Research lines

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Thank you

www.med.physik.uni-muenchen.de