Transcript SEPnet RDI Kick-off meeting 19.04.10

Detector technologies:
from particle physics to
radiotherapy
B. Camanzi
STFC – RAL & University of Oxford
Outline
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Why cancer
The detector challenges: dosimetry and
imaging
Positron Emission Tomography (PET)
Time-Of-Flight PET
Future activities
Conclusions
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
2/22
The challenge of cancer in UK
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Cancer is the leading cause of mortality in
people under the age of 75. 1 in 4 people
die of cancer overall.
293k people/year diagnosed with cancer,
155k people/year die from cancer.
Incidence of cancer is rising due to:
1.
2.
3.
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Population ageing
Rise in obesity levels
Change in lifestyle
Cancer 3rd largest NHS disease programme.
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
3/22
Radiotherapy and cancer in UK
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Radiotherapy given to 1/3 of cancer patients
(10-15% of all population).
Overall cure rate = 40%. In some instances
90-95% (for ex. breast and stage 1 larynx
cancers).
Radiotherapy often combined with other
cancer treatments:
1.
2.
3.
Surgery
Chemotherapy
Hormone treatments
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
4/22
Radiotherapy treatments
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External beam radiotherapy:
X-ray beam
2. Electron beam
3. Proton/light ion beam
1.
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Internal radiotherapy:
1.
2.
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Sealed sources (brachytherapy)
Radiopharmaceuticals
Binary radiotherapy:
1.
2.
Boron Neutron Capture Therapy (BNCT)
Photon Capture Therapy (PCT)
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
5/22
The technological challenges
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The challenge of radiotherapy from the
patient end
Make sure that the right dose is delivered at
the right place = improved dosimetry +
improved imaging
The challenge of early diagnosis
“See” smaller tumours = improved imaging
New advanced technologies desperately
needed for dosimetry and imaging
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
6/22
How particle physics can help
"The significant advances achieved during the last decades in
material properties, detector characteristics and high-quality
electronic system played an ever-expanding role in different
areas of science, such as high energy, nuclear physics and
astrophysics. And had a reflective impact on the development
and rapid progress of radiation detector technologies used in
medical imaging."
“The requirements imposed by basic research in particle physics
are pushing the limits of detector performance in many regards,
the new challenging concepts born out in detector physics are
outstanding and the technological advances driven by
microelectronics and Moore's law promise an even more
complex and sophisticated future.”
D. G. Darambara "State-of-the-art radiation detectors for medical imaging: demands and trends"
Nucl. Inst. And Meth. A 569 (2006) 153-158
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
7/22
In-vivo dosimetry
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Radiation sensitive MOSFET
transistors (RadFETs) used
in particle physics experiments
(BaBar, LHC, etc.) for real-time,
online radiation monitoring.
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Development of RadFET based miniaturised
wireless dosimetry systems to be implanted
in patient body at tumour site for real-time,
online, in-vivo dosimetry.
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
8/22
Imaging
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Most medical imaging systems, CT, gamma
cameras, SPECT, PET, use particle physics
technologies: scintillating materials, photon
detectors, CCDs, etc.
CT scanner
Scintillator
Gamma
camera
(SPECT)
Diode
Collimator
Courtesy Mike Partridge
(RMH/ICR)
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
9/22
Positron Emission Tomography
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511 keV g
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18F
labelled glucose given to patients:
e+ annihilates in two back-to-back
511 keV g.
A ring of scintillating crystals and
PMTs detects the g.
511 keV g
Courtesy Mike Partridge (RMH/ICR)
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
10/22
Conventional PET
Conventional PET scanner:
1.
2.
3.
Coincidences formed within a very
short time window
Straight line-of-response reconstructed
Position of annihilation calculated
probabilistically
Courtesy Mike Partridge (RMH/ICR)
PET
B. Camanzi
RAL & Oxford University
CT
PET + CT
SEPnet RDI Kick-off Meeting 19/04/10
11/22
Time-Of-Flight PET (TOF-PET)
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TOF-PET scanner:
1. Time difference between signals from two crystals measured
2. Annihilation point along line-of-response directly calculated
time-of-flight
envelope
D1
line of
response
D2
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Goal: 100 ps timing resolution (ideally 30 ps and below) = 3 cm
spatial resolution (ideally sub-cm)
Advantages: higher sensitivity and specificity, improved S/N
Technology needed: fast scintillating materials and fast photon
detectors
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
12/22
Fast scintillating materials
Decay time
(ns)
Light yield
(g/keV)
Density
(g/cm3)
Latt at 511keV
(cm)
LaBr3(Ce)
BrilLanCeTM380
16
63
5.3
2.23
LYSO
PreLudeTM420
41
32
7.1
1.20
LSO
40
27
7.4
1.14
BGO
300
9
7.1
1.04
GSO
60
8
6.7
1.43
BaF2
0.8
1.8
4.9
2.20
NaI(Tl)
250
38
3.7
2.91
BrilLanCeTM380 and PreLudeTM420 produced by Saint-Gobain Cristaux et Detecteurs
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
13/22
Photon detectors: SiPMs
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Array of Silicon Photodiodes
on common substrate each
operating in Geiger mode
SiPMs have speed (sub ns)
and high gain (106), small size
and work in high magnetic
fields (7T)
1x1 mm2
3x3 mm2
Hamamatsu Inc.
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
14/22
Tests on TOF-PET prototypes
2500
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B. Camanzi
RAL & Oxford University
2000
Counts
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LaBr3(Ce) and LYSO scintillating
crystals from Saint-Gobain
SiPMs from Hamamatsu, SensL
and Photonique
Various two-channel demonstrator
systems tested at RAL and RMH
Timing resolution analysis still
ongoing
1500
1000
500
0
-8
0
-7
0
-6
0
-5
0
-4
0
-3
0
-2
0
-1
0
0
10
20
30
40
50
60
70
80
90
10
0
11
0
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SEPnet RDI Kick-off Meeting 19/04/10
Time Difference (ps)
15/22
Preliminary results
SiPM timing resolution with blue LED
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600.00
Timing resolution (ps)
500.00
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400.00
1.
SiPM single
300.00
Best SiPMs: Hamamatsu (electrical
problem with 11-25) and SensL.
Best timing resolutions measured:
SiPM pair
2.
200.00
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100.00
0.00
Ham
Ham
11-100 11-50
Ham
Ham
Ham
11-25 33-100 33-50
Ham
33-25
SensL SensL
11
33
Phot
11
20 ps for single SiPM
40 ps for pairs of SiPMs
Hamamatsu performance as function
of pitch still under investigation.
Phot
33
2-channel prototype timing resolution with sources
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Prototypes with Hamamatsu 3x3
best of all. SensL blind to LaBr3.
Best timing resolutions measured:
1.
2.
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mm3
430 ps with 3x3x10
LYSO
3
790 ps with 3x3x30 mm LaBr3
Performance of prototypes with LaBr3
highly dependent from SiPM-crystal
coupling.
B. Camanzi
RAL & Oxford University
4
3.5
Timing resolution (ns)
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mm2
3
LYSO 5mm Na22
2.5
LYSO 10mm Na22
2
LaBr3 Na22
LYSO 5mm F18
1.5
LaBr3 F18
1
0.5
0
Ham Ham Ham Ham Ham Ham
11-100 11-50 11-25 33-100 33-50 33-25
SEPnet RDI Kick-off Meeting 19/04/10
SensL SensL
11
33
Phot
11
Phot
33
16/22
Where next
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Preliminary results very encouraging. Need to
investigate technology further: build a dualhead demonstrator system. Two planar
heads with identical number of channels.
Use of fast scintillators can be expanded to
other imaging systems (CT, SPECT, etc.).
Use of SiPMs opens up the possibility of
designing a compact PET/MRI scanner.
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
17/22
Future activities
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Participation through Oxford to FP7 project
ENVISION (European NoVel Imaging
Systems for ION therapy).
Development of a technology roadmap for
cancer care, to move toward a multi-modality
approach to radiotherapy.
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
18/22
ENVISION
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Participation in WP2: development of TOF
in-beam PET systems.
Oxford/STFC contributions:
1.
2.
3.
4.
Characterisation of scintillating materials
(LYSO and LaBr3)
Characterisation of SiPMs
Construction and test of a TOF-PET dualhead demonstrator system
Simulations of component (crystals and
SiPMs) and system performance
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
19/22
My vision: toward multi-modality
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Multi-modality = bringing together the
different forms of radiotherapy treatments:
1.
2.
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Select best treatment depending on tumour type
Combine different treatments when appropriate
New advanced imaging and dosimetry
systems of paramount importance →
Technology roadmap
Roadmap to be developed in consultation
with end-user groups, universities, etc.
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
20/22
Conclusions
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Cancer is a leading cause of mortality in UK.
Its incidence is rising.
Radiotherapy is and will be given to a large
number of patients.
Patients will benefit from a multi-modality
approach to radiotherapy. This requires the
development of new, advanced technologies.
Particle physics holds the key to the
development of these technologies.
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
21/22
Acknowledgements
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Prof Ken Peach (John Adams Institute)
Dr Phil Evans and Dr Mike Partridge (Royal
Marsden Hospital / Institute of Cancer
Research)
Gareth Derbyshire (STFC Healthcare Futures
Programme)
Dr John Matheson and Matt Wilson (STFCRAL)
B. Camanzi
RAL & Oxford University
SEPnet RDI Kick-off Meeting 19/04/10
22/22