Medical A pppp ylications of Particle Physics: from the ... · 2. Md di ldi iModern medical...
Transcript of Medical A pppp ylications of Particle Physics: from the ... · 2. Md di ldi iModern medical...
Medical Applications of Particle Physics:Medical Applications of Particle Physics:pp ypp yfrom the First Radiography to Hadrontherapyfrom the First Radiography to Hadrontherapy
Saverio BracciniSaverio Braccini
Albert Einstein Albert Einstein Center for Fundamental PhysicsCenter for Fundamental PhysicsLHEPLHEP –– Laboratory for High Energy PhysicsLaboratory for High Energy PhysicsLHEP LHEP Laboratory for High Energy PhysicsLaboratory for High Energy Physics
University of Bern, SwitzerlandUniversity of Bern, Switzerland
Rome - 15-18.03.10 - SB - 1/8 [email protected]@cern.ch
OutlineOutline
1.1. Introduction: a historical overviewIntroduction: a historical overview1.1. Introduction: a historical overviewIntroduction: a historical overviewoo Physics and medicine: two paths, many crossroadsPhysics and medicine: two paths, many crossroadsoo The first radiography and the concept of doseThe first radiography and the concept of dose
22 M d di l di iM d di l di i2.2. Modern medical diagnosticsModern medical diagnostics3.3. Particle accelerators for medicineParticle accelerators for medicine44 Conventional radiation therapyConventional radiation therapy4.4. Conventional radiation therapyConventional radiation therapy5.5. Basic principles of hadrontherpyBasic principles of hadrontherpy6.6. Present and future of hadrontherapyPresent and future of hadrontherapy7.7. A tour in a hadrontherapy centreA tour in a hadrontherapy centre8.8. Specific topics in hadrontherapySpecific topics in hadrontherapy
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Fundamental research in particle physics and modern medicineFundamental research in particle physics and modern medicineFundamental research in particle physics and modern medicineFundamental research in particle physics and modern medicine
Two paths, many crossroadsTwo paths, many crossroads
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The starting point The starting point
•• November 1895 : discovery of X raysNovember 1895 : discovery of X rays
Wilhelm Conrad RöntgenWilhelm Conrad Röntgen
•• December 1895 : first radiographyDecember 1895 : first radiography
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…the real first medical radiography……the real first medical radiography…
Important points:Important points:
•• XX--rays penetrate matterrays penetrate matterXX rays penetrate matterrays penetrate matter
•• XX--rays are differently absorbed by bone and rays are differently absorbed by bone and muscle tissuesmuscle tissues
E ti 15 i tE ti 15 i t•• Exposure time 15 minutesExposure time 15 minutes
•• Exposure nowadays for a hand radiography:Exposure nowadays for a hand radiography:
•• 1/25 to 1/50 second1/25 to 1/50 second1/25 to 1/50 second1/25 to 1/50 second
•• Dose: about <0.1 mSv (natural Dose: about <0.1 mSv (natural background 1background 1--2 mSv/year)2 mSv/year)
Radiography of the hand of Radiography of the hand of
CuriositiesCuriosities
•• Roentgen convinced his wife to participate Roentgen convinced his wife to participate in an experimentin an experiment
Roentgent’s wife BerthaRoentgent’s wife Bertha •• Bertha was horrified and saw in the image a Bertha was horrified and saw in the image a premonition of deathpremonition of death
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Basic unitsBasic units•• The The physical dosephysical dose absorbed by matter is measured in Grayabsorbed by matter is measured in Gray
•• 1 Gy = 1 J / 1 Kg1 Gy = 1 J / 1 Kg
•• Used in radiation therapyUsed in radiation therapy•• Used in radiation therapyUsed in radiation therapy
•• In radioprotection the In radioprotection the dose equivalent dose equivalent is measured in Sievertis measured in Sievert
•• Dose Equivalent = (Physical dose) x Wr Dose Equivalent = (Physical dose) x Wr
•• Wr takes into account the biological effects of specific radiationWr takes into account the biological effects of specific radiation
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Basic unitsBasic units
•• In radioprotection the In radioprotection the effective doseeffective dose is defined asis defined as
•• Effective dose = (Physical dose) x Wr x Wt Effective dose = (Physical dose) x Wr x Wt
•• Wt takes into account the sensitivity to radiation of different organs for Wt takes into account the sensitivity to radiation of different organs for stochastic effectsstochastic effects
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Dose equivalent and effective doseDose equivalent and effective dose
•• Wr is a multiplicative factor to take into account the “biological effectiveness” Wr is a multiplicative factor to take into account the “biological effectiveness” of radiationof radiation
•• Wt has a different meaningWt has a different meaning
•• Σ Wt = 1Σ Wt = 1
•• If the dose is “full body” If the dose is “full body” dose equivalent = effective dosedose equivalent = effective dose
•• If the irradiation is not homogeneous (ex. The dose is given only to one If the irradiation is not homogeneous (ex. The dose is given only to one ) th ff ti d t th d i l t i t th f ll) th ff ti d t th d i l t i t th f llorgan) the effective dose represents the dose equivalent given to the full organ) the effective dose represents the dose equivalent given to the full
body which produces the same risk. body which produces the same risk.
•• Risk for stochastic effects:Risk for stochastic effects:Annual limit for radio exposed workers
Risk for stochastic effects:Risk for stochastic effects:
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Stochastic and deterministic effects of radiationStochastic and deterministic effects of radiation
•• The cancer induction risk factor is estimated at 4% SvThe cancer induction risk factor is estimated at 4% Sv--1 for a population of 1 for a population of workers and at 5 % Svworkers and at 5 % Sv--1 for the general population (children included!)1 for the general population (children included!)
•• The threshold dose of deterministic effects is situated at 0.5 Gy.The threshold dose of deterministic effects is situated at 0.5 Gy.
•• Deterministic effects:Deterministic effects:
•• The aim of radiation therapy is to cure i.e. to produce deterministic effectsThe aim of radiation therapy is to cure i.e. to produce deterministic effects
•• The doses are therefore large (of the order of 60The doses are therefore large (of the order of 60--80 Gy) and there are no limits 80 Gy) and there are no limits g (g ( y)y)for patients coming form laws on radiation protectionfor patients coming form laws on radiation protection
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XX--rays: what we know today…rays: what we know today…
XX--ray tube : accelerated electrons ray tube : accelerated electrons yyinteract and radiate photonsinteract and radiate photons
==
XX--ray productionray production
XX ray energy spectrumray energy spectrum
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XX--ray energy spectrumray energy spectrum
Production of X and Production of X and γγ “quanta” “quanta”
atom
ionization
Physicists:Physicists:
keV → X quantakeV → X quanta
M VM V ttionization MeV → MeV → γγ quantaquanta
Medical doctors:Medical doctors:nucleus
Medical doctors:Medical doctors:
They are all X rays!They are all X rays!
3 MeVquantum
heavy nucleus
electron acceleratedto 10 MeV
nucleus
scattered electron7 MeV
electromagneticfield drawn
by the electron
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The physical processThe physical process
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Photons interact with matterPhotons interact with matterXX--rays interact with matter (material Z) rays interact with matter (material Z) through different mechanisms:through different mechanisms:
•• PhotoPhoto--electric effectelectric effect
•• Compton effectCompton effect ProbabilityProbabilityCompton effectCompton effect
•• Electron Positron pair productionElectron Positron pair production
(Threshold : 2 x 511 keV)(Threshold : 2 x 511 keV)
yy
( )( )
What happens to a photon beam ?What happens to a photon beam ?
II00 I = II = I00 ee--μμss μμ attenuation coefficientattenuation coefficientDepends on:Depends on:pp
•• The material (z)The material (z)
•• The densityThe density
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ss •• The energy of the photonsThe energy of the photons
The attenuation coefficientThe attenuation coefficient
Why water?Why water?Water is the main component of tissuesWater is the main component of tissues
“Water equivalent” a very used concept in“Water equivalent” a very used concept in
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Water equivalent a very used concept in Water equivalent a very used concept in medical applicationsmedical applications
Water and other materialsWater and other materials
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Let’s get back to RoentgenLet’s get back to Roentgen
Many XMany X--rays stop in the tissuesrays stop in the tissues
Dose to the patient!Dose to the patient!
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The beginning of modern physics andThe beginning of modern physics andmedical physicsmedical physics
An accelerator of 1897An accelerator of 18971895 1895 –– starting date of four starting date of four magnificent years in magnificent years in experimental physicsexperimental physics
18951895
experimental physicsexperimental physics
discovery of X raysdiscovery of X raysWilhelm Conrad Wilhelm Conrad RöntgenRöntgen
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J.J. Thomson and the electronJ.J. Thomson and the electron
The beginning of modern physics andThe beginning of modern physics andmedical physicsmedical physics
Henri Becquerel Henri Becquerel (1852(1852--1908)1908)
1896:1896:
Discovery of naturalDiscovery of natural
radioactivityradioactivity
18981898Thesis of Mme. Curie – 1904
18981898
Discovery of radiumDiscovery of radiumα, β, γ in magnetic field
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MariaMariaSkSkłodowska Curiełodowska Curie
(1867 (1867 –– 1934)1934)
About one hundred years agoAbout one hundred years agoPierre CuriePierre Curie(1859 (1859 –– 1906)1906)
First applications in cancer therapyFirst applications in cancer therapy
Basic conceptBasic conceptLocal control Local control of the tumourof the tumour
1908 : first attempts of skin cancer 1908 : first attempts of skin cancer radiation therapy in France radiation therapy in France (“(“CuriethérapieCuriethérapie”)”)
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(( pp ))
A big step forward…A big step forward…
…in physics and in…in physics and in
•• Medical diagnostics Medical diagnostics
•• Cancer radiation therapyCancer radiation therapyCancer radiation therapyCancer radiation therapy
due to the development of threedue to the development of threeM. S. Livingston and E. LawrenceM. S. Livingston and E. Lawrence
with the 25 inches cyclotronwith the 25 inches cyclotron
due to the development of three due to the development of three fundamental toolsfundamental tools
•• Particle acceleratorsParticle accelerators
P i l dP i l d•• Particle detectorsParticle detectors
•• ComputersComputers
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GeigerGeiger--MMüller counter built byüller counter built byE. Fermi and his group in RomeE. Fermi and his group in Rome
1930: invention of the cyclotron1930: invention of the cyclotron1930: the beginning of 1930: the beginning of four other magnificent four other magnificent
yearsyears
Spiral trajectory of an Spiral trajectory of an accelerated nucleusaccelerated nucleus
Ernest Lawrence Ernest Lawrence
(1901 (1901 –– 1958)1958)
Modern cyclotronModern cyclotron A copy is on display at A copy is on display at CERN MicrocosmCERN Microcosm
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CERN MicrocosmCERN Microcosm
The invention of the cyclotronThe invention of the cyclotron
•• Magnet of 9 inches = 22.8 cm Magnet of 9 inches = 22.8 cm
•• Magnetic field of 15 000 gauss = 1.5 TMagnetic field of 15 000 gauss = 1.5 Tg gg g
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E. O. Lawrence and M. S. Livingston, Physical Review, 38 (1931) 834.
The Lawrence brothersThe Lawrence brothers
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Ernst Lawrence and his brother John Lawrence at the control panel of the 60‐inch (152 cm) cyclotron shortly.
The Lawrence brothersThe Lawrence brothers
John Lawrence, brother of John Lawrence, brother of Ernest, was a medical doctorErnest, was a medical doctor
They were both working in They were both working in BerkleyBerkley
First use of artificially produced First use of artificially produced isotopes for medical diagnostics isotopes for medical diagnostics p gp gand therapyand therapy
Beginning of nuclear medicineBeginning of nuclear medicineBeginning of nuclear medicineBeginning of nuclear medicine
An interdisciplinary An interdisciplinary environment helps environment helps
innovation!innovation!
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Discovery of the neutronDiscovery of the neutron
19321932
James ChadwickJames Chadwick
(1891 (1891 –– 1974)1974)
Neutrons are used today toNeutrons are used today to
Student of Student of
Ernest RutherfordErnest Rutherford
•• Produce isotopes for medical diagnostics Produce isotopes for medical diagnostics and therapyand therapy
•• Cure some kind of cancer Cure some kind of cancer
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Ernest RutherfordErnest Rutherford
Matter and antimatter...Matter and antimatter...
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1932 1932 –– discovery of antimatter: the positrondiscovery of antimatter: the positron
Slowed-down
ti lparticleCLOUD
CHAMBER
Positive fast particle
Lead layer
Carl D. Anderson Carl D. Anderson -- CaltechCaltech
pcoming from below
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The positron is at the basis of Positron Emission Tomography (PET)The positron is at the basis of Positron Emission Tomography (PET)
Discovery of the effectiveness of slow neutronsDiscovery of the effectiveness of slow neutrons
O. D’Agostino E. Segrè E. Amaldi F. Rasetti E. FermiO. D’Agostino E. Segrè E. Amaldi F. Rasetti E. FermiO. D Agostino E. Segrè E. Amaldi F. Rasetti E. FermiO. D Agostino E. Segrè E. Amaldi F. Rasetti E. Fermi
19341934First radioisotope of IodineFirst radioisotope of Iodine
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among fifty new artificial speciesamong fifty new artificial species
Also for physicists, patents are important!Also for physicists, patents are important!
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Istituto Superiore di Sanità Istituto Superiore di Sanità -- 19341934
“Il tubo”“Il tubo”
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“Il tubo” “Il tubo” –– 1 MeV Cockcroft1 MeV Cockcroft--Walton ion accelerator Walton ion accelerator --1938193819381938
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Fermi and the use of radio isotopes in medicineFermi and the use of radio isotopes in medicine
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Four other crucial years: the synchrotronFour other crucial years: the synchrotron
19441944
principle of phase stabilityprinciple of phase stabilityVertical magnetic
field principle of phase stabilityprinciple of phase stability
Circular trajectory of the Circular trajectory of the particles accelerated in a particles accelerated in a
field
1 GeV electron synchrotron1 GeV electron synchrotron
Frascati Frascati -- INFN INFN -- 19591959
“synchrotron”“synchrotron”
Veksler visits McMillanVeksler visits McMillan
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1959 1959 -- BerkeleyBerkeley
RadioRadio--frequency linacs for protons and ionsfrequency linacs for protons and ions
Linear accelerator (linac)Linear accelerator (linac)
200 MHzλ= 1.5 m
L AlvarezL Alvarez100 MeV linac on display 100 MeV linac on display L. AlvarezL. Alvarez
1946 1946 –– Drift Tube LinacDrift Tube Linacat CERN Microcosmat CERN Microcosm
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The electron linacThe electron linac
Sigurd VarianSigurd Varian William W. HansenWilliam W. Hansen
Russell VarianRussell Varian
19391939
Invention of the klystronInvention of the klystron
~ 1 m~ 1 m
Invention of the klystronInvention of the klystron1947 1947
first linac for electronsfirst linac for electrons4 5 M V d 3 GH4 5 M V d 3 GH
The electron linac is used today in The electron linac is used today in hospital based conventional radiation hospital based conventional radiation
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4.5 MeV and 3 GHz4.5 MeV and 3 GHzpptherapy facilitiestherapy facilities
The beginning of CERN 50 years agoThe beginning of CERN 50 years ago
1952: Pierre Auger Edoardo Amaldi1952: Pierre Auger Edoardo Amaldi
Secretary GeneralSecretary General
19521952--5454
Isidor RabiIsidor Rabi
UNESCO talk in 1950UNESCO talk in 1950
19521952--5454
at the meeting that created the provisional CERNat the meeting that created the provisional CERN
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At CERN we have linacs and strongAt CERN we have linacs and strong--focusing synchrotronsfocusing synchrotronsLLarge
HadronCollider
(7+7) TeV8.5 km8.5 km
(7 7) TeV
In 1952 the “strongIn 1952 the “strong--focusing” methodfocusing” methodThe PS in 1959The PS in 1959 gg gg
invented at BNL (USA)invented at BNL (USA)
was chosen for the CERN PSwas chosen for the CERN PS
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Accelerators running in the worldAccelerators running in the world
~120High Energy acc (E >1GeV)NUMBER IN USE (*)NUMBER IN USE (*)CATEGORY OF ACCELERATORSCATEGORY OF ACCELERATORS
>100>100~200~200
Synchrotron radiation sourcesSynchrotron radiation sourcesMedical radioisotope productionMedical radioisotope production
120High Energy acc. (E >1GeV)
~1000Research acc. included biomedical research
> 7500> 7500Radiotherapy acceleratorsRadiotherapy accelerators 90009000
>7000Ion implanters, surface modification
~1500Acc. for industrial processing and research
> 17500> 17500TOTALTOTAL
(*) W. Maciszewski and W. Scharf: Int. J. of Radiation Oncology, 2004
Ab t h lf d f biAb t h lf d f bi di l li tidi l li tiRome - 15-18.03.10 - SB - 1/8 38
•• About half are used for bioAbout half are used for bio--medical applicationsmedical applications
Particle detectorsParticle detectors
Th th “ ” f ti l h i i tTh th “ ” f ti l h i i tThey are the “eyes” of particle physicistsThey are the “eyes” of particle physicists
A very impressive development in the last 100 yearsA very impressive development in the last 100 years
–– From the Geiger counter to ATLAS and CMS at CERN!From the Geiger counter to ATLAS and CMS at CERN!
Crucial in many medical applicationsCrucial in many medical applicationsCrucial in many medical applicationsCrucial in many medical applications
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One example: the multiwire proportional chamberOne example: the multiwire proportional chamber
Georges Charpak, CERN Georges Charpak, CERN physicist since 1959,physicist since 1959,
Nober prize 1992Nober prize 1992
•• Invented in 1968, launched the era of fully electronic particle detectionInvented in 1968, launched the era of fully electronic particle detection
Nober prize 1992Nober prize 1992
, y p, y p•• Used for biological research and could eventually replace photographic recording Used for biological research and could eventually replace photographic recording in applied radioin applied radio--biologybiology•• The increased recording speeds translate into faster scanning and lower body The increased recording speeds translate into faster scanning and lower body
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doses in medical diagnostic tools based on radiation or particle beamsdoses in medical diagnostic tools based on radiation or particle beams
Radiography and imaging with radiationsRadiography and imaging with radiations
General features:General features:
Sensitivity of the detector = less dose to the patientSensitivity of the detector = less dose to the patient
Granularity of the detector = better image definitionGranularity of the detector = better image definitionGranularity of the detector = better image definitionGranularity of the detector = better image definition
Speed of the detector = detection of movementsSpeed of the detector = detection of movements
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End of part IEnd of part I
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