Transcript Medical Data and Hep - The Center of Nuclear Studies and Peaceful

Yves LEMOIGNE, ESI, Archamps, France
Medical Physics
(a Peacefull activity!)
Thanks to Nuclear Physics ….
Yves Lemoigne,
ESI-Archamps (near Geneva)
European School of Medical Physics (ESMP)
Note for this presentation:
- Slides with green background concern mainly
ESMP organisation
-Slides with yellow background concern mainly
Medical Physics taught during the School
(within other topics taught in Archamps…)
Yves LEMOIGNE, ESI, Archamps, France
Yves LEMOIGNE, ESI, Archamps, France
ESMP=6 weeks: 3 Imaging, 3 RT
Chicago
University
Yves LEMOIGNE, ESI, Archamps, France
Since More than 50 years Physics is a great
help to Medicine and Biomedical research :
• - Help to diagnosis
(anatomical imaging and
functional imaging) : MRI,
Echography, X-ray Radiology,
SPECT & PET…
• - Radiotherapy: tele- and
Brachy-therapy (with X-rays,
inserted radioactive products,
protons & Ions beams..)
Now: (X-rays)
Future: Protons / Ions
Yves LEMOIGNE, ESI, Archamps, France
Medical Physics & Nuclear Physics
They have clear links :
-Because techniques used in MP are directly
coming from Nuclear Physics :
Ex : Particle accelerators for
Radiotherapy (electrons,
protons, ions…) or radiotracer
production
EX : sealed sources used in
Brachytherapy
EX : Radiotracers with PET (SPECT)
cameras
The case of PET will be developped here
Yves LEMOIGNE, ESI, Archamps, France
Basic principles for Medical IMAGING
• X-ray imaging is “transmission imaging” and is
used mainly for “anatomy”
imaging”
• Nuclear medicine is
“emission imaging”
and is used for “functional
Imaging” (i.e. how this is
Working as function of time)
More powerful for oncology
CT-Scan
PET-Scan
Yves LEMOIGNE, ESI, Archamps, France
• Precise Medical Imaging is now compulsory for Radiotherapy
BEFORE and AFTER Radiotherapy
• BEFORE: - Diagnosis
- Input for Treatment plannings (accuracy…)
Needed
TPS
If available
Future….
•
AFTER:
- Treatment results
Yves LEMOIGNE, ESI, Archamps, France
• AFTER: - Treatment results
Estimated absolute yearly
rate (%) of 2nd cancer
Tumor site
3D whole-body PET imaging
X-rays IMXT Protons
Oesoph. & stomach
Colon
Breast
Lung
Thyroid
Bone & soft tissue
Leukemia
All 0.75
0.15
0.15
0.00
0.07
0.18
0.03
0.07
0.43
0.11
0.07
0.00
0.07
0.06
0.02
0.05
0.05
0.00
0.00
0.00
0.01
0.00
0.01
0.03
Compared to X-rays
1
0.6
0.07
BEFORE
AFTER
Yves LEMOIGNE, ESI, Archamps, France
• Radio tracers can be used to label the chemical
molecule we would like to follow inside the patient
body. Positrons emitters more used in PET are :
F18(110mn), C11 (20 mn), (in research :N13 (10 mn), O15 (2mn)….).
• They allow to see metabolism, while X-ray scan or
MRI are better to see the anatomy
• Nuclear medicine (imaging of metabolism using
molecules labeled with an appropriate radioisotope)
is therefore not in competition, but in complement
of imaging techniques such as X-ray, X-ray scan or
MRI (Magnetic Resonance Imaging).
Yves LEMOIGNE, ESI, Archamps, France
Specification of the GTV
Complementarity of imaging devices
Example of brain tumor :
Nuclear
Magnetic
Resonance
MRI
Excellent accuracy but specific
only in some cases (could give
functional imaging) : detects
resonance of atom nucleus
X-rays
CT
Good accuracy for
anatomical imaging
(Only density is measured)
Positron-electron
annihilation
PET
Modest accuracy but good for
functionnal imaging (very
good sensitivity) : because
their abnormal metabolism
tumor are avid of glucose
which emits photon from e+eannihilation if radiotracer
have been injected previously
Complementarity :
- CT-PET devices are available (Bodygraph-Siemens…)
- MRI-PET could be available soon for Small-Animal-PET
camera only (Biomedical research only)
Yves LEMOIGNE, ESI, Archamps, France
PET cameras for IMAGING
Positron Emission Tomography (PET) is one form of radiopharmaceutical diagnosis. It is a powerful technique whose
development owes Nuclear Research. Due to its good
sensitivity, PET allows disease-related changes in tissues and
organs could be detected long before serious symptoms set in.
Image fusion (CT + PET)
“Standard “is now CT+PET devices
Yves LEMOIGNE, ESI, Archamps, France
PET CAMERA : a child of Nuclear Physics
Matter – Antimatter annihilation e+ e- => g g
18
18
F
PN P P
PN N N P
P
PP NP
N N
N N
O
PN P P
PN N N P
P
PP NN
N N
N N
Because its principle :
y
180°±0.25
e+
e+ e-
y
e+ e- => g g
Yves LEMOIGNE, ESI, Archamps, France
Take care of Scale : 1 meter
PET camera
15 meters !
Versus
g detectors in
Nuclear Physics (detector @ CERN)
Colliding
point of the
two beams
circle around
In principle :
Particle
beam
Positron RadioTracer Emitter
inside the body
e+ e- => g g at 1024 KeV
Particle
beam
e+ e- => g g + …
because higher energy (100000000 KeV !)
Realisation:
In Hospitals …
Size and
cost are
different !
In Research centers (CERN, Geneva)
Yves LEMOIGNE, ESI, Archamps, France
Medical imaging / Nuclear Physics : Similar techniques
Inside a PET camera
(here CPET from Philips)
in 90’s
Scintillators + PM’s
Nuclear Physiscs research (ex: CMS exp @ CERN) have replaced
photomultipliers (PM) by Avalanche Photodiode (APD).
Medical imaging begins to do the same (ex: Lab-PET)
Yves LEMOIGNE, ESI, Archamps, France
Why PET
camera are
powerful …
From Y. Yongen (IBA)
Great selectivity due to the 3 conditions we are demanding:
-1- detect g with Energy selection ≈ 511 KeV
-2- detect two g in sharp time coincidence (≈ 10 nanosecond)
-3- detect two g in opposite directions (within a few degres)
Coincidence detection in a PET scanner
Yves LEMOIGNE, ESI, Archamps, France
Medical Physics &
Nuclear Physics
PET Photon detectors are
done like several Nuclear
Physics detectors.
Typically : Crystals, PM,
gantry, electronic chains
and controllers, computer
interfaces, hard discs or
tapes for mass storage,
displays devices…
Yves LEMOIGNE, ESI, Archamps, France
• A PET needs a complex
environment… Chemistry, BioChemistry, Physics, mathematics, computing and… medicine.
• A cyclotron to produce
radioactive tracers (F18, C11..)
is needed not too far…
• Previously only available
in big centres (USA, UE…).
• With modern transport
facilities, a regional centre
could supply hospitals in a 1500
km radius (about)…
• PET camera for biomedical
research can use “generator”
Ge68 - Ga68 => e+
(not for human use)
Yves LEMOIGNE, ESI, Archamps, France
ESMP organisation
• All these techniques are studied
during the three first weeks of
ESMP (111 hours) with some of
the best experts from Belgium,
France, Germany, Italy, Netherlands, Switzerland, USA….
+ One week of Medical computing
Simulation / modelling of Physics and/or Live systems, Networks,
Tools for computer simulation (GEANT4, EGS5…), Image reconstruction algoritms, Data compression and processing…
Yves LEMOIGNE, ESI, Archamps, France
Then ESMP students study the
sophisticated techniques of
tumors killing by use of radiations
(External sources for Radiotherapy,
internal sources for brachytherapy)
= 74 h
or teletherapy
or curiethérapie
Modern Radiotherapy is more and more obliged to use accurate medical
imaging of previous ESMP weeks (Role of Treatment Planning Systems)
Yves LEMOIGNE, ESI, Archamps, France
• External radiation therapy refers to radiation
applied externally to the body using a beam of highenergy x-rays (or proton / light ion beams) to kill
tumor cells (also called Tele-Therapy)
.
• Internal radiation therapy refers to the use of
small radioactive seeds implanted in the tumor tissue.
The seeds emit radiation over a period of time to kill
tumor cells (Brachytherapy or Curiethérapie).
Yves LEMOIGNE, ESI, Archamps, France
In Teletherapy linear accelerators
dominate
In the world radiation oncologists use 10 000
electron linacs delivering X-ray beams.
The planning of RadioTherapy treatment has been
revolutionized by the ability to delineate tumors.
To irradiate only the tumour oncologists use :
• collimator homothetic to tumor shape (Blocks)
• Multi-Leaf Collimator (static) : Conformal RT
• Dynamic MLC (position varying during the
irradiation). Driven by computer, it’s IMRT
(Intensity Modulated Radiation Therapy)
Screen
Blocks
or
IMRT is an advanced RT technique to treat
tumor and to spare surrounding tissue from
doses above tolerances.
Hight-tailored computing applications are needed to
perform optimisation and treatment simulation
(treatment planning)
Often limitations due to availibility of experienced
medical personnel (time consuming technique)…
High-level education needed…. (ESMP provides it)
21
Yves LEMOIGNE, ESI, Archamps, France
REGISTRATION
CENTRAL ROLE OF TPS
CT-SCAN
MRI or / and PET
• external contours
• densities
• anatomical structures
• beam data library
• anatomical structures
BEAM
DEFINITION
TREATMENT
PLANNING
SYSTEM
OPTIMISATION
• Reconstructed
radiographs
(DRR)
SIMULATOR
and/or
ELECTRONIC
PORTAL IMAGING
• Field shape
or
• Position of leaves
BLOCK CUTTING
DEVICE
or
MLC
• Dose distribution
• Dose-Volume Histograms
• Biological indices
• Treatment
parameters
• Treatment time
(monitor units)
ACCELERATOR
VERIFIY AND
RECORD
SYSTEM
Yves LEMOIGNE, ESI, Archamps, France
Specification of the Specification
GTVof the GTV
Nuclear
Magnetic
Resonance
X-rays
MRI
CT
Positron-electron
annihilation
PET
Impact of the imaging method on the Tumor Volume definition
Recall
Summary Volumes
and Margins
[ICRU-50 Supplement
of rules definitions]
PTV
ITV
CTV
GTV
Kneschaurek,
2002
Yves LEMOIGNE, ESI, Archamps, France
In case of deep tumor, it is better to
use “several” beams, all converging to
the tumor, to avoid excessive dose
irradiation of heathly tissues around
Beam 1
Target Volume
Proton
beam
@PSI
Beam 3
X-ray Beam
Beam 2
“Simplest” way : Rotate the accelerator or the patient
Yves LEMOIGNE, ESI, Archamps, France
"Conventional" Planning
Inverse Planning
Treated
Volume
Target Volume
Treated
Volume
OAR
Target Volume
OAR
OAR = Organ At Risk (for instance Spinal Cord)
which is compulsory to protect from high dose.
Inverse Planning
Yves LEMOIGNE, ESI, Archamps, France
Clinical Example
Modern RT technique : Intensity Modulated Radio-Therapy
(Dose Intensity is driven by computer following the previously
treatment planning calculating – only if precise imaging taken before)
Yves LEMOIGNE, ESI, Archamps, France
Accelerators for Hadrontherapy:
developed first in physics labs
They are used routinely in hospitals
Hadron Therapy
Courtesy of IBA
Around 9000 of the 17000 accelerators operating in the World today are used
for medicine. Very few ( less than 50) are hadron (P or light Ions) accelerators.
(Future ? Next slide : why they are better despite higher cost: the Bragg peak)
Yves LEMOIGNE, ESI, Archamps, France
Protons and ions spare healthy tissues
27 cm
tumour
200 MeV - 1 nA
protons
4800 MeV – 0.1 nA
carbon ions
which can control
radioresistant
tumours
target
charged hadron beam
that loses energy in matter
XPhotons
rays
Photons
protons or
Protons
Protons
carbon
ions
linac
cobalt 60
proton
tail
light ion
(carbon)
httt://global.mitsubishielectric.com/bu/particlebeam/index_b.html
Archamps - 17.11.08 – U.Amaldi
28
Yves LEMOIGNE, ESI, Archamps, France
Particle Therapy: Comparing Proton & photon Conventional RT
Photon
Conventional Radiotherapy:
Important dose outside the tumor
IMRT Photon
IMRT = Intensity
Modulated
Radio Therapy:
still non negligable dose
outside the tumor
Proton
Scattering technique :
Low dose outside
Y.Yongen (IBA)
Yves LEMOIGNE, ESI, Archamps, France
Proton Therapy is growing rapidly!
70,000
40
60,000
35
30
25
40,000
20
30,000
15
20,000
PT center under operation
10
10,000
0
1950
Operating facilities
Patients treated
50,000
5
1960
1970
1980
1990
2000
0
2010
Courtesy Janet Sisterson & PTCOG
Yves LEMOIGNE, ESI, Archamps, France
Example of IBA Proton Therapy System
•
•
•
•
•
•
Hadron therapy owe very much to Nuclear Research Centres experience
for accelerators, beam transport, detectors…
A Proton therapy system is a complex system, filling a Hospital building.
The treatment rooms are larger and complex (gantries),
The total investment is around 100 M€, about half for the equipment,
A Proton facility can treat 1500 patients/year mainly for special cases
(Proximity organ-at-risk tumors, radioresistive tumor, children tumor…)
Hadron facilities providing protons and carbon ions are more costly….
Yves LEMOIGNE, ESI, Archamps, France
The accelerators used today in
hadrotherapy are “circular”
Teletherapy with protons (200-250 MeV)
CYCLOTRONS (Normal or SC)
SYNCHROTRONS
OR
6-9 metres
4-5 metres
Teletherapy with carbon ions (4800 MeV = 400 MeV/u)
SYNCHROTRONS
18-25 metres
Archamps - 17.11.08 - UA
32
Yves LEMOIGNE, ESI, Archamps, France
Effect of ΔE/Δx = LET
Why light Ions (C12) are better than protons (photons):
LET > 20 keV/μm = 200 MeV/cm =40 eV/(2 nm)
Production of many unreparable localized double strand breaks and
clustered damages
DNA- double strand
2 nm
size
Yves LEMOIGNE, ESI, Archamps, France
Accelerators for protontherapy
LOMA-LINDA :
since 1992 : first
Hospital-based
Proton therapy centre
2005 : 160 sessions
per day
Yves LEMOIGNE, ESI, Archamps, France
• In the world protontherapy has already treated 55'000 patients.
carbon ion therapy has already treated 4500 patients (Japan, RFA)
• Close Future : CNAO in Italy
The synchrotron (proton and C12 ions ): beams ready in summer 2009
25 m synchrotron and
3 treatment rooms
Other centres in progress:
Germany (Heidelberg,
Marburg)
France (Lyon, Caen, Orsay),
USA, China, India…
Concepts directly transferred from Nuclear Physics Reasearch centres (CERN, DESY, Fermilab…)
Yves LEMOIGNE, ESI, Archamps, France
A new concept: Cyclinac=Cyclotron+ Linac for Image Guided HadronTherapy
2 Modules tested at
LNS, Catania, Italy
This project would allow radiotracer production cyclotrons to
be transformed at raisonable
cost in hadrontherapy facility :
A real breakthrough !
now in Microcosm at CERN
Yves LEMOIGNE, ESI, Archamps, France
A few words about
Brachytherapy :
Local Eradication of a Tumor
by Radioactive Implants
Example of
Prostate cancer
Real advantage in case of
tumor on moving organs (abdomen)… Note the spectacular progress when seeds are
implanted under Magnetic
Resonance Imaging (Geneva)
Brachytherapy
Yves LEMOIGNE, ESI, Archamps, France
Last Part of ESMP :
RADIOPROTECTION in Medical Physics
Public (and media) are very concerned by this topic !
Yves LEMOIGNE, ESI, Archamps, France
Origin of participants involved in EUROPEAN SCHOOL OF MEDICAL PHYSICS
MORE THAN 1000 STUDENTS WENT IN ARCHAMPS-GENEVA SINCE THE SETTING UP OF THE SCHOOL
IN EUROPE….
.
*
… And IN The WORLD
EGYPT (as 6 other neighbouring
countries) is eligible to a
subsidy from NATO Scientific
Department in the frame of the
“South Mediterranean Dialogue
group of countries”
ESMP is known by all European countries (and farer…)
Medical Physicists (or students
in MP) can contact the
secretariat :
[email protected]
*
Yves LEMOIGNE, ESI, Archamps, France
Please, Visit our website :
www.cur-archamps.fr/esi
Or the EFOMP website :
www.efomp.org
For further information and
application form for ESMP
2009 (deadline : June 2009)
School activities are on both
sides of the border :
- French side : Archamps
- Swiss side : Geneva
but as Switzerland recently
joined the “schengen System”,
only one visa is needed !!
Yves LEMOIGNE, ESI, Archamps, France
As a Conclusion-1 :
Correlations between Physics & Medicine (from Nobel Prize Robert Hofstadter, Stanford University in 1983)still true
Physics
Medicine application in
Statics (mechanics)
Orthopaedics
Dynamics (mechanics)
Heart motion
Elasticity and strength of materials
Orthopaedics
Fluid statics
Blood pressure
Fluid dynamics
Blood flow in vascular system
Sound and acoustics
Stethoscope, ultrasound, acoustic microscope
Electricity
All life processes, ion transfer at membranes
Magnetism
Nuclear magnetic resonance imaging
Atomic physics and spectroscopy
"Chemical shift" in NMR imaging, lasers in medicine
Molecular physics
Genetics, antibodies, protein structure, electron microscope
Ultraviolet and infrared energy
Skin treatment and imaging
X-rays
Radiology, CT imaging
Quantum mechanics
Electron diffraction microscope
Crystallography
Structure of proteins
Solid-state physics & semiconductors
Computers in medicine, scintigraphy, Fast electronics
Nuclear physics
Radioisotope labelling, nuclear medicine, radiation therapy
Radioactivity
Positron emission tomography (PET), Radiotracers
Elementary particle physics
Proton & ion therapy, Huge & complex devices
Accelerators, cyclotrons, etc
Tumour therapy,
etc….
etc…
Yves LEMOIGNE, ESI, Archamps, France
CONCLUSION-2
The 50-year tenure of Nuclear Physics in Medicine and Biology has
coincided with some of the most important developments in oncology
and radiological science, including the introduction of artificial
radioactivity, computers and 3D imaging into medicine. These events
have profoundly influenced the development of Medicine
Fundamental breakthroughs in physics are continuing to yield new
medical technologies for identifying and treating a range of diseases.
In conclusion, there is no doubt that the contribution of
Medical Physics (and thus Nuclear Physics) is not
negligible in the better efficiency of Medicine during the
past decades. This is why a high level education in
Medical Physics, done by first class experts deeply
involved in this science branch, is absolutely compulsory .
18.11.2006
ESMP 2006
Key Areas
for Biomedicine
Yves LEMOIGNE, ESI, Archamps, France
Further information :
www.cur-archamps.fr/esi
or www.efomp.org
Yves LEMOIGNE, ESI, Archamps, France