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Cyclotrons and production of radioactive isotopes

at Rigshospitalet

Holger Jensen,

Cyklotronchef,

Fysiker Lic. Scient.

PET- og Cyklotronenheden,

Afsnit 3982, Rigshospitalet,

Blegdamsvej 9,

2100 København Ø.

Danmark.

Tlf. +45 3545 1866

E-mail: [email protected]

mailto:[email protected]

Agenda

1. A few words about “the PET and Cyclotron unit” in numbers and

hardware

2. A few words about PET.

3. A few words about cyclotrons in Denmark.

4. A few words about small and big cyclotrons.

5. A few words about cyclotron theory.

6. A few words about isotope production.

Side 2

Agenda


hardware

2. A few words about PET. Maybe??

3. A few words about cyclotrons in Denmark. Skip

4. A few words about small and big cyclotrons. Skip

5. A few words about cyclotron theory. YES

6. A few words about isotope production. YES

Side 3

1A The PET and Cyclotron unit in numbers and hardware

Side 4

The hospital:

• 1200 beds, 12.000 employees, 800 M Euro budget, +2000 publications.

Department of Clinical Physiology, Nuclear Medicine & PET:

• “0 beds”, ≈200 employees, 16 (+8) M Euro budget, +165 publications ,

• Equipment for ≈ 65 M Euro

• +120.000 patient investigations, …

1B The PET and Cyclotron unit in numbers and hardware

Side 5

PET and Cyclotron unit:

• 60-70 employee,

• 1 PET

• 5 PET/CT,

• 1 PET/MR,

• 1 HRRT brain scanner,

• 1 µPET

• 9000 PET- and 1000 RTP scans per year,

Radiochemistry unit: • 5 radiochemistry GMP labs,

• 14 hot cells.

• 10 chemist, 2 radio pharmacist, 5 lab. technicians for chemistry

• Marketing authorisation for two products: FDG and 81Rb/81mKr

1C The PET and Cyclotron unit in numbers and hardware

Radiopharmaceuticals

Apoptosis:

• [18F] Annexin V

Angiogenesis:

• 64Cu-NODAGA-cRGDyK

• 64Cu-NODAGA-E[cRGDyK]2

• 68Ga-NODAGA-cRGDyK

EGFRvIII:

• [18F]FALGEA

uPAR:

• Radiolabelled AE105

Brain imaging:

• 5-HT7 receptors

• Nicotinic receptors

Tracers available

for human use

• [18F]FDG

• [18F]FLT

• [18F]FET

• [18F]Altanserin

• [11C]PIB

• [11C]DASB

• [11C]Flumazenil

• [11C]SB207145

• [11C]CUMI-101

• [13N]NH3

• [15O]H2O

• [68Ga]DOTATOC

• [64Cu]DOTATATE (Risø)

• [18F]Fluoride (Risø)

• [18F]Choline (Risø)

Tracers expected to be

available in the near future

• [11C]Cimbi-36

• [11C]AZ10419369

• [64Cu]ATSM (Risø)

New tracers

available for preclinical use

Side 6

1D The PET and Cyclotron unit in numbers and hardware

Side 7

Cyclotron unit:

• Scanditronix MC32 (1992) and CTI/Siemens RDS Eclipse HP (2005)

• 2 physicist, 4 cyclotron technicians, 6 physics students (=operators),

• “No” service contracts,

• 18F, 11C, (13N) at both cyclotrons (11 and 16 MeV)

• 15O, 82Rb/82mKr, 111mCd and 211At only at MC32 (d- and α-beams and 16/32 MeV)

• 18F and 11C our major isotopes.

• Average success rate since 2006: 99.1%

Agenda


hardware √

2. A few words about PET. Maybe??



5. A few words about cyclotron theory. YES

6. A few words about isotope production GOTO 6A

Side 8

PET = Positron Emission Tomography

511 keV

511 keV

e-

b+

Result: Two photons on an almost straight line

that nearly contains the point of decay

2A: A few words about PET (Ref. S. Holm)

PET should really be named

ART =Annihilation Radiation Tomography

p n + e+ + ν

Side 9

A PET scanner counts coincidences

time d1

d2

e-

e+

detector

d1

detector

d2 Tube or Line Of

Response (LOR)

Coincidences 1 2 3 4 5

Coincidence

window Dt

|t1-t2|<Dt? t1

t2

coincidence

yes

Dt ~4-12 ns

PET radiation detection

2B: A few words about PET (Ref. S. Holm)

Side 10

30 cm/ns

Coincidence events determine sampling

paths (Lines Of Response)

2C: A few words about PET (Ref. S. Holm)

GE Advance PET (1993)

Typical resolution 4-6 mm

Side 11

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Sidefod distribution of tracer

function / physiology

Annihilation

CT PET

attenuation of photons

structure / anatomy

2D: A few words about PET/CT (Ref. T.L. Klausen)

Side 12

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PET/CT December 2001

CT PET PET/CT

2E: A few words about PET/CT (Ref. L. Højgaard)

Side 13

CT PET PET/CT

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PET HRRT brain scanner with 120,000 crystals

Resolution 1.2 mm

2F: A few words about PET (Ref. L. Højgaard)

Typical resolution for normal scanners 4-5 mm

c = 3 x 108m/s = 30 cm/ns

∆x = 1.2 mm ∆t = 4 ps.

Side 14

Finito, basta,

Finito, basta, …

Side 16

Agenda


hardware √

2. A few words about PET. √

3. A few words about cyclotrons in Denmark. SKIP

4. A few words about small and big cyclotrons. SKIP

5. A few words about cyclotron theory. GOTO 5

6. A few words about isotope production

Side 17

Side 18

1. 1938-1994, Niels Bohr Instituttet.

• One of the ”first” cyclotrons in Europe.

• One of the longest running cyclotrons.

3A: Cyclotrons in Denmark

2. 1992-2048+, Rigshospitalet

• Scanditronix MC32

• The John and Birthe Meyer foundation.

3. 1994, Århus PET center.

• GE, PETtrace

4. 2005, Rigshospitalet. (d. 17/01/2005)

• CTI/Siemens, RDS Eclipse HP

• The John and Birthe Meyer foundation.

5. 2005, Risø. (d. 22/01/2005)

• GE, PETtrace

Side 19

6. 2007, Odense PET center.

• GE, PETtrace.

3B: Cyclotrons in Denmark

7. 2009, Herlev

• IBA, Cyclone 18/9

8. 2010, Århus PET center.

• IBA, Cyclone 18/9

9. 2011, Risø.

• GE, ”Micro-cyclotron” PT600

10. 2019, Dansk Center for Partikelterapi

• Varian Medical Systems

11. 201?, Aalborg, Herning, …

• ???

Agenda


hardware √


3. A few words about cyclotrons in Denmark. √

4. A few words about small and big cyclotrons.



Side 20

4A: Some history – the beginning of it all

M.K. Craddock, TRIUMF, Canada.

4B: Some history – the beginning of it all


4C: Some history – the beginning of it all


Scanditronix MC32, 1992, 32 MeV

CTI, RDS Eclipse HP, 2005, 11 MeV

4D: Our cyclotrons at Rigshospitalet.

Beam power: 100µA*32MeV = 3,2 kW

Total power: 130 kW (EF=40,6)

svarer til 26 typiske parcelhuse

( à 5 kW). Side 24

4E: The real big and heavy

25

PSI, Villigen, 1974, 590 MeV,

1990 t, d=9.3 m

P=2,4mA * 590 MeV ≈ 1.4 MW

Indiana UCF, 1975, 220 MeV, 2000 t

Beam power ≈≈ 283 houses

EF=40 58 MW energy consumption

or 11500 bungalows Side 25

4F: Sektor- separeret AVF cyklotron

26

Sektor-separeret cyklotron, H-,

TRIUMF, Vancouver, Cananda.

1977

Variabel energi 183-520 MeV,

4000 t, d=18 m,

18500 A til magnet

Side 26

SRC superconducting ring

cyclotron, RIKEN, 2006,

2600 MeV, 8300 t, d=12.4 m

4G: The world record

Side 27

Agenda


hardware. √


3. A few words about cyclotrons in Denmark. √

4. A few words about small and big cyclotrons. √



Side 28

4A: The classical cyclotron

Beskrivelsen kan let gøres kompliceret og give en hver fysiker ”tårer i øjnene” over

den smukke matematik/fysik, men jeg har forsøgt at gøre det så simpelt at alle kan

følge med.

Page 29

4B: The 5 main components in a cyclotron

1. Ion source til at genere elektrisk ladede partikler, q, m

2. Magnetic field B til at fastholde partiklerne i “cirkulære”

baner

3. Vacuum for at undgå kollisioner med restgas.

4. RF-system til acceleration

5. Exstraction system.

Page 30

5C: De 5 hovedbestanddele i en cyklotron - ionkilde

1. Ionkilde til at genere elektrisk ladede partikler

Lånt fra IBA, S2C2 design. Side 31

5D: Den klassiske cyklotron - RF

32

De første cyklotroner blev bygget i 1930-32 af E. Lawrence og

M.S. Livingston (plus studenter) i Berkeley, USA.

Et stærkt homogent magnetisk felt B0 tvinger

elektrisk ladede partikler (ladning q og masse m) til

at følge ”cirkulære” baner i en plan vinkelret på B-

feltet. Lorentz kraften (F = q v x B0) giver:

FL = qvB0 = mv2 / r (F = q v x B0)

eller

p = mv = qB0r

Revolution time T is given by

T = 2 π r / v = 2 π m / qB0

The revolution frequency

fCYK = 1/T

is named the cyclotron-frequency or the resonanse frequency

fCYK = 1/T = q B0 / 2 π m

5E: Den klassiske cyklotron - RF

H- D- He++

q/m 1 ½ ½

h 1 2 2

33

RF frekvensen skal altså være et multipla af

cyklotronfrekvensen:

fRF = h • fCYK , h = 1, 2, 3, …

B og f hænger tæt sammen. Ved en justering af

faseforskellen mellem AC- spændingerne på

cyklotronens duanter og ved at benytte

specielle udformninger af disse kan partikler

med forskellige q/m forhold accelereres.

Det harmoniske nummer h indgår også i disse

tricks.

Revolution time T

T = 2 π r / v = 2 π m / qB0

is independent of radius r (and v)

A commen acceleration voltage Udee for the

dee’s can be used to accelerate all particles.

5F: Den klassiske cyklotron - RF

Eksempel på dee-struktur i vores Scanditronix MC32.

Side 34

5H: Den klassiske cyklotron - vacuum

• Accelererede partikler vil vekselvirke med en eventuel restgas i maskinen.

• Derved mistes energi og partiklerne spredes (ændrer retning).

• Beamets fokusering mistes og ekstraktionen bliver dårligere.

• Der sker en aktivering af cyklotronens indre.

Side 36

• Pumper:

a) mek. for-pumpe,

b) diffusions-pumper,

c) kølebaffler

5G: Den klassiske cyklotron - vacuum

Side 37


Side 38


Side 39


• Diffusionspumper

Side 41



Side 43



Side 44

Side 45

• We are working on having less back streaming.

• Our CTI RDS Eclipse uses SantoVac and

is anyway growing black.

• But it has no baffles.

• Expected to affect the

ion source performance.

• MC32 has baffles and

is growing black too.


• Regular service:

a) Oil change for MP every ½ year.

b) Full service for DP every 2 year.

c) Even oil from MP can be seen in

Vacuum (Stefan Johansson, Turko)

• Improved cooling of baffles:

a) Present cooling water temperature: 12-14ºC.

b) Replacement with HSR BFC 400 multi baffles

with PCF145-Z refrigerator.

c) Both water and refrigerant (R134a) cooled.

d) T = -13-17ºC

e) Can be cooled with LN2 too.

f) Back streaming down by a factor 10.

• Better oil:

a) Replacement of the Baltzer 71A mineral oil with DC 704 silicon oil.

b) Pfeiffer+HSR/Balzers promises a factor 10 reduction in back streaming.

c) I want to know more about the effect of SantoVac oil. It is also very expensive.

P46


3J Vacuum upgrade

P47

• First question from IS- experts at TRIUMF was

“what is your vacuum in the central region”

• A good vacuum is essential for negative ion machines.

• Improving the pumping conductance in the central region by new dummy-dee-

support plates is one step in this direction.

• I want to do Monte Carlo Simulations to predict the effect.

• New baffles and better oil is another step in this direction.

http://test-molflow.web.cern.ch/sites/test-molflow.web.cern.ch/files/imagepicker/3/molflow_logo2.jpg

5H: Den klassiske cyklotron - kinematik

H- D- He++

q/m 1 ½ ½

q2/m 1 ½ 1

h 1 2 2

Tmax 32 16 32 Dette giver følgende maksimale energier i vores MC32:

Tmax(H-) = Tmax(He++) = 32 MeV og Tmax(D

-) = 16 MeV

Dette svarer f.eks. til en hastighed på ca. 78.000 km/s for protoner eller ca. 2 gange

rundt om ækvator pr. sekund eller 26% af lysets hastighed!

Hertil kommer at vi har variable energier 16-32 og 8-16 for h.h.v. H- og D-.

Maksimal energi, Tmax, ved maksimal radius R er givet som

T ≈ ½ m v2 og da v = qB0r/m fås Tmax = q2B02R2 / 2m

H- og He++ har samme værdi for q2 /m ( = 1) og derfor også for Tmax

For deuteroner D- haves q2/m = ½

Tmax(D-) ½ Tmax(H

-, He++).

Side 48

5I: Den klassiske cyklotron - ekstraktion

Positiv ion cyklotroner: Beamet kan ekstraheres ved hjælp af en elektrostatisk

deflektor (men giver desværre ofte et meget radioaktivt septum).

Dette giver faste energier for det ekstraherede/eksterne beam.

Interne bestrålinger på en probe, som kan give variable energier, blev benyttet i

begyndelsen. (Selvom vi så at Lawrence allerede havde ideen til en deflektor i

1932.)

Vi producerer f.eks. 211At ved en sådan intern bestråling.

Negativ ion cyklotroner: Den nye generation af cyklotroner. Ion kilderne

er vanskelige og kræver bedre vakuum.

Ekstraktion sker ved hjælp stripper folier, og giver 100% extraktion.

Næsten ingen aktivering af cyklotronen bortset fra targets.

Variabel energi mulig, men tilbydes desværre kun på få maskiner idag.

Side 49

5J: Limitations of the classical cyclotron

Det relativistiske tilfælde/problem:

H.E. Bethe og M.E. Rose forudsagde allerede i 1937 maksimale beam energier som følge af relativistiske effekter, m = m0γ.

32 MeV protoner har f.eks. en -værdi på 1,034!

Impulsen p=m0v (=qBr) må erstattes med det relativistiske udtryk m0v i bevægelsesligningerne!

Resonance condition

fCYK = 1/T = q B / 2 π m

can be obtained for an increasing B-field with radius, which balance out the relativistic mass increase:

B(r) = B0 (r).

But but but this gives axial de-focusing and radial focusing effect. Has been a problem ever since 1937.

Side 50

5K: Den klassiske cyklotrons begrænsning

Voksende B-felt med radius:

B = B0 (r). • Radial fokuserende effekt

• Aksial de-fokuserende effekt

Faldende B-felt med radius:

• Radial de-fokuserende effekt

• Aksial fokuserende effekt

Side 51

5L: Den klassiske cyklotrons begrænsning – og løsning

Frekvens-modulerede cyklotroner, synchrocyclotrons, 1945, var en løsning på dette problem.

RF-frekvensen justeres for hvert beam-puls til at kompensere for den voksende omløbstid med voksende radius/hastighed.

Beam ”Duty-cycle” ≈ 1000 dårligere, men meget høje energier kan opnås.

But the old solution for high energies for nuclear physics research

Side 52

IBA, S2C2 design.

Synchrocyclotron with

superconducting coils

Side 52

Aksial fokusering fra E-feltet:

Det elektriske felt giver en aksial

fokuserende effekt.

a) Statisk felt giver også en fokusering

b) RF- giver en fase afhængig effekt.

Page 53

5M: Axsial focusing in the classical cyclotron

5N: Den klassiske cyklotrons begrænsning – og løsning

Llewellyn Thomas kom med en løsning til det relativistiske (og det aksiale de-

fokuserings) problem allerede i 1938.

B = B(r,θ)

Variationen i B(θ) giver en netto fokuserende effekt i aksial retning. Samtidig giver

B(r) den ønskede radiale fokusering og løser det relativistiske problem.

Thomas vinklen κ skal være > 0 og virker i praksis kun for E<45 MeV.

Offentligt tilgængelige resultater/løsninger kom først i 1956. Side 54

•Scanditronix, 1992.

•Negative ions (H- and D- beams).

• Magnetic field can be reversed for acceleration of positive ions for

internal bombardments (i.e. H+, D+, He++-beam).

• Dual beam exit possible.

• Variable energies 16-32 MeV and 8-16 MeV for H-, He++ and D-

respectively.

•Sector focused, AVF.

•Internal ion source, cold cathode Penning source with two

chimneys.

•The main isochronous magnet field is approxi-mately 1.6 T.

•Resonance frequency 24.3 MHz.

•Magnet 58 tons.

•Vacuum 2x10-6 mbar (beam on) and 3x10-7 mbar (beam off).

•Total power consumption 130 kW.

5P: Scanditronix MC32

Side 56

• Negative ion (H-), 11 MeV.

• Penning type ion source.

• Deep valley (27:1) magnet design.

• Peak hill field, 1.9 T. Trimbars.

• Resonance frequency fCYK=18 MHz.

• 4 x 30-degree dees.

• fRF = 72 MHz

• 10 + 40 ton

• Total power consumption ≈ 25 kW.

• Dual beam exit.

• 4 target per port.

• 18F, 11C, 13N, 15O, 64Cu, …?

• 18F yield, 7 Ci in 2 hours, dual beam, 2x60 µA.

• 11C yield, 1.8 Ci in 40 min,

5Q: CTI/Siemens RDS Eclipse HP

Side 57

Agenda


hardware. √

2. A few words about PET. GOTO 2

3. A few words about cyclotrons in Denmark. SKIP

4. A few words about small and big cyclotrons. SKIP

5. A few words about cyclotron theory. √

6. A few words about isotope production √

Side 58

6A: Short T½ implies a local production

Isotop Halveringstid Isotop Halveringstid 10

C 19.255 S 62Cu 9.74 M

11C 20.39 M 64

Cu 12.700 H 13

N 9.965 M 81Rb 4.576 H

15O 2.037 M 124

I 4.15 D 18

F 109.77 M 131Ba 11.5 D

111mCd 48.54 M

211At 7.214 H

Side 59

Henfaldsligningen:

𝐴 𝑡 = 𝐴0 𝑒−λ𝑡 = 𝐴0

1

2

𝑡

𝑇½

med henfaldskonstanten

λ = ln(2) / T½

6B: Where and how are the isotopes of the universe made?

Some people claims that God created everything. Physicists do not always agree!

Big-bang? Yes, mainly light isotopes.

Super nova explosions? Yes, mainly the heavy isotopes.

Nuclear reactors? Yes, fission fracments and neutron activation processes.

Massefordeling ved fission af 235U

Neutronindfangningstværsnit

Page 60

A-bombs? Yeah, gives fission products!

We still see the remains from the test explosions.

Research in nuclear physics during the last 70-80 years is the basis for all productions of radioisotopes today.

Almost all relevant isotopes can be produced with accelerators today.

6D: Where and how are the isotopes of the universe made?

Some people claims that God created everything. Physicists do not always agree!

Big-bang? Yes, mainly light isotopes.

Super nova explosions? Yes, mainly the heavy isotopes.

Nuclear reactors? Yes, fission fracments and neutron activation processes.

Page 62

6E: Some nuclear physics

Coulomb force: FCoulomb = (e2/40)•(Z1 Z2/r2).

The strong nuclear forces/interactions between the nucleons - FSI - will be

stronger than the Coulomb force for distances of a few fm (= 10-15 m).

For the reaction p + 18O 19Fex the Coulomb barrier energy is around 2-3

MeV corresponding to a velocity of the projectile/proton of 20-24.000 km/s!

Z1

Z2

A strong accelerator (for example a

cyclotron) is necessary.

Side 63

We operates with nuclear reaction

cross sections σ18O(p,n)18F

Typically only 1 out of 10000

particles will react. The rest will only

deposit heat in the target.

6F: One example

64

Production of 211At, for particle therapy of cancers:

209Bi(,2n)211At, E = 28 MeV, I = 18 A

209Bi (a,xn/t) At/Po

1,0E-02

1,0E-01

1,0E+00

1,0E+01

1,0E+02

1,0E+03

1,0E+04

15 20 25 30 35 40 45

E_beam [MeV]

Sig

ma [

mb

]211At: W.J. Ramler et al.

211At: R.M. Lambrecht et al.

210At: W.J.Ramler et al.

210At: R.M. Lambrecht et al.

209At: W.J. Ramler et al.

210Po: W.J. Ramler et al.

Before

α

209Bi

n

n

211At

After

Dt 10-21–10-16 s

The used reaction channel must be

optimized with respect to competing

channels.

Target- composition, thickness,

reaction-energy, irradiation time and

chemical separation/purifications is

used for this.

6G: Renhed og konkurrerende reaktionskanaler

65

64Ni

0.926%

60Ni

26.22%

62Ni

3.634%

61Ni

1.140%

58Ni

68.08%

61Co

1.650 H

57Co

271.7D

58Co

70.86 H

59Co

100.0%

60Co

5.271Y

65Cu

30.83%

63Cu

69.17%

61Cu

3.333H

62Cu

9.74M

64Cu

12.70H

60Cu

23.7M

Ep = 15-20 MeV

p + 64Ni ( 65Cu* ) 64Cu + n 200 mb

Det er svært at finde rene reaktioner!

61Co + 20 mb

63Cu + 2n ( 20 mb?)

1 g 64Ni, 97.0% berigning koster 200.000 – 300.000 Dkr.

6H: Another example, production of 18F for FDG, FET, FLT, …

Bestråling af væske-target til fremstilling af 18F, til 18F-FDG:

18O(p,n)18F,

Kølevand ind

Kølevand ud

·

+

P

Ag/Ti/Nb/Ta

target body

HAVAR- foil

Beriget H218O vand

Vi producerer p.t. 100-300 GBq 18F 8-10 gange pr. uge med dette target design.

Bestråling af væske-target til fremstilling af 18F, til 18F-FDG:

18O(p,n)18F, Ep = 16-18(11) MeV, Ip = 35-50(60+) A

He-køling/

Grid

Side 66

6I: Produktion af isotoper, væske target, 18F, IBA

• Kostede ≈ 500.000,00 Dkr i 2002

• Fungerer stadig.

•Vi har 2 stk. idag.

Side 67

6J: ”Home made” target for 18F

• Samarbejde mellem Lund, Uppsala og Rigshospitalet.

• Koster under 100.000,00 Dkr.

• Plus vi nu har 100% kontrol over

alle detailler.

Side 68

6O: Typical reactions used

73

Produktion af 211At, til alfa-terapi (SCX):

209Bi(,2n)211At, E = 28 MeV, I = 18 A

Bestråling af metal-target til fremstilling af 64Cu, 64Cu-ATSM (CTI):

64Ni(p,n)64Cu, Ep = 11 MeV, Ip = 40 A, 5-8 timer.

Bestråling af væske-target til fremstilling af 18F, til 18F-FDG (SCX+CTI):

18O(p,n)18F, Ep = 16-18(11) MeV, Ip = 20-35(60+) A

Bestråling af gas-target til produktion af 11C, til 11C-CH4 (CO2) (SCX+CTI):

14N(p,)11C, Ep = 16 (11) MeV, Ip = 25-30(60+) A

Bestråling af gas-target til produktion af 15O-H2O (SCX):

14N(d,n)15O, Ed = 8 MeV, Id = 5 A

Bestråling af væske-target til produktion af 13N, til 13N-NH3 (SCX):

16O(p,)13N, Ep = 16 MeV, Ip = 23 A

6Q: Our new solid-target for 62Zn/62Cu

Agenda


hardware. √

2. A few words about PET. √ GOTO 2



5. A few words about cyclotron theory. √ GOTO 5

6. A few words about isotope production √

Side 76

Finito, basta,

Finito, basta, …

Side 77

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