Topics for Medical Therapy Accelerators Topics for Medical Therapy Accelerators Part 2 Part 2 ------ Feb. 2, 2008Feb. 2, 2008

Presented by George Presented by George CoutrakonCoutrakon, PhD, PhDLoma Linda University Medical CenterLoma Linda University Medical Center

Loma Linda, CALoma Linda, CATheory of operation for clinical electron Theory of operation for clinical electron linacslinacsTheory and operation of cyclotrons and Theory and operation of cyclotrons and synchrotrons for proton therapy synchrotrons for proton therapy Who are the vendors? What are they selling? Who are the vendors? What are they selling? Heavy Ion Therapy and the Heidelberg Ion Heavy Ion Therapy and the Heidelberg Ion

Therapy projectTherapy project

Review of Accelerator requirementsReview of Accelerator requirements(Clinical electron (Clinical electron linacslinacs))

Compact design ( 1 to 2 meter length) with accelerator Compact design ( 1 to 2 meter length) with accelerator installed on a gantry that rotates around the patientinstalled on a gantry that rotates around the patientEnergy range of interest for eEnergy range of interest for e-- 6 to 25 6 to 25 MeVMeVIntensity range 1 to 300 Intensity range 1 to 300 μμAmpsAmps (1 (1 mAmA for electron for electron treatments and 300 treatments and 300 μμAmpsAmps for Xfor X--ray Treatmentsray TreatmentsStable intensity throughout treatment for uniform doseStable intensity throughout treatment for uniform doseAbility to switch energies readily between treatments; for Ability to switch energies readily between treatments; for example 6, 10, 15, 20 and 23 example 6, 10, 15, 20 and 23 MeVMeV may be the library of may be the library of energies available (i.e., not continuously selectable energy)energies available (i.e., not continuously selectable energy)

Electron linear accelerator Electron linear accelerator mounted on a gantrymounted on a gantry

Electron acceleration in wave guideElectron acceleration in wave guide

Two basic types of eTwo basic types of e-- linacslinacsA. Traveling wave acceleratorA. Traveling wave accelerator

Energy controlled by EM frequency, fEnergy controlled by EM frequency, fwave velocity = f wave velocity = f λλ ((λλ fixed by cell spacing)fixed by cell spacing)Synchronize electron velocity from gun with Synchronize electron velocity from gun with

initial wave velocity at the entrance. Surfer initial wave velocity at the entrance. Surfer analogy explains accelerationanalogy explains acceleration

B. Standing wave acceleratorB. Standing wave acceleratorEnergy controlled by EM amplitudeEnergy controlled by EM amplitudeRegions of null electric field can be Regions of null electric field can be

displaced out of the beam line forming side displaced out of the beam line forming side coupled cells or cavities, thus shortening the coupled cells or cavities, thus shortening the overall length in half. overall length in half.

Electron acceleration in a traveling wave Electron acceleration in a traveling wave accelerator accelerator

Diagram of electron accelerator control pathsDiagram of electron accelerator control paths

Time structure of electron pulses from a Time structure of electron pulses from a linaclinac

Modulator pulse On for 3 Modulator pulse On for 3 μμsecsec every 3 every 3 msecmsecWithin each 3 Within each 3 μμsecsec pulse is the 3 GHz time structure pulse is the 3 GHz time structure

of the RF accelerating EM fieldof the RF accelerating EM field

XX--ray and Electron Treatment Headray and Electron Treatment Headelectron current required for Xelectron current required for X--ray ray TxTx is 300 is 300 μμampamp

electron current for eelectron current for e-- TxTx is 1 is 1 μμampamp (3 (3 GyGy/min)/min)Beam current controlled by electron filament currentBeam current controlled by electron filament current

Review Review HadronHadron accelerator requirementsaccelerator requirements

Proton energy range 70 to 250 Proton energy range 70 to 250 MeVMeVvelocity range 0.37c to 0.6c velocity range 0.37c to 0.6c water penetration range 3 cm to 37 cmwater penetration range 3 cm to 37 cmCarbon energy range 200 to 430 Carbon energy range 200 to 430 MeV/amuMeV/amuCarbon velocity range 0.3c to 0.7cCarbon velocity range 0.3c to 0.7cWater penetration range 3 cm to 32 cmWater penetration range 3 cm to 32 cmStable intensity Stable intensity Ability to change energies rapidly for scanning Ability to change energies rapidly for scanning applications in IMPTapplications in IMPT

Cyclotrons and Cyclotrons and SyncrotronsSyncrotrons

Therapy cyclotrons have high intensity and fixed Therapy cyclotrons have high intensity and fixed energy with 3 to 4 meter diameter, Protons spiral energy with 3 to 4 meter diameter, Protons spiral out from center of large circular dipole magnet as out from center of large circular dipole magnet as they accelerate. Fixed energy extraction requires they accelerate. Fixed energy extraction requires ““a blocka block”” of material to degrade the energy. of material to degrade the energy. Therapy synchrotrons have adequate but lower Therapy synchrotrons have adequate but lower intensity and variable intensity . Protons are intensity and variable intensity . Protons are injected at low energy (2 to 7 injected at low energy (2 to 7 MeVMeV) into annular ) into annular ring of dipole magnets and proton radius is fixed ring of dipole magnets and proton radius is fixed as acceleration ( up to 250 as acceleration ( up to 250 MeVMeV) occurs by ) occurs by ramping the dipole fields. Sizes are typically 6 to 7 ramping the dipole fields. Sizes are typically 6 to 7 meters in diameter. meters in diameter.

Cyclotron ConceptCyclotron Concept

250 250 MeVMeV AVM isochronous AVM isochronous proton cyclotronproton cyclotron

IBA 230 IBA 230 MeVMeV Cyclotron Cyclotron (fixed energy)(fixed energy)

Ion Beam Applications Ion Beam Applications (Belgium)(Belgium)

Uses fixed energy (235 Uses fixed energy (235 MeVMeV) cyclotron with energy ) cyclotron with energy degrader for lower energy deliverydegrader for lower energy deliveryOffers scanning and passive systemsOffers scanning and passive systemsAdvanced scanning system still under developmentAdvanced scanning system still under developmentHave built 2 complete systemsHave built 2 complete systemsHave 3 others under constructionHave 3 others under constructionReputation as the Reputation as the ““price leaderprice leader”” in the fieldin the field

Energy Degrader for Fixed Energy Energy Degrader for Fixed Energy Cyclotrons Cyclotrons

Varian 250 Varian 250 MeVMeV proton cyclotronproton cyclotron

AccelAccel ( Germany)( Germany)Have worldHave world’’s only super conducting cyclotron s only super conducting cyclotron for proton therapy at fixed energy, approx. 250 for proton therapy at fixed energy, approx. 250 MeVMeVWorldWorld’’s most compact design, 2 m diameters most compact design, 2 m diameterOffers only scanning beam delivery systemsOffers only scanning beam delivery systemsPresently commissioning first unit in Munich, Presently commissioning first unit in Munich, GE with 3 gantries with scanning beams GE with 3 gantries with scanning beams Teaming with CMS for Teaming with CMS for TxTx Planning systemPlanning systemFirst patient treatment scheduled for this yearFirst patient treatment scheduled for this year

SynchrotronsSynchrotrons

OptivusOptivus Technology (San Technology (San Bernardino, CA)Bernardino, CA)

Presently marketing Presently marketing ““turn keyturn key”” system using 250 system using 250 MeVMeVFermilabFermilab synchrotron with enhancements( in use for 15 synchrotron with enhancements( in use for 15 years)years)Company was formed as a Company was formed as a ““spin offspin off”” from Loma Linda from Loma Linda engineering group in 1995engineering group in 1995Offer scanning beam and passive beam delivery systems Offer scanning beam and passive beam delivery systems At the Loma Linda facility they have built At the Loma Linda facility they have built a) passive beam delivery systems for clinical use a) passive beam delivery systems for clinical use b) New accelerator control systemsb) New accelerator control systemsc) 1c) 1stst Digital imaging system for patient alignment Digital imaging system for patient alignment Intensity is 2.4 x 10Intensity is 2.4 x 101010 pppppp with 2.2 sec cycle time, but with 2.2 sec cycle time, but

have plans for upgraded intensityhave plans for upgraded intensity

Hitachi Proton Therapy SynchrotronHitachi Proton Therapy Synchrotron

Accelerator cycle Accelerator cycle can be synchronized can be synchronized with respiration with respiration cyclecyclePatented RF driven Patented RF driven extraction for fast extraction for fast beam on/off and beam on/off and uniform intensity uniform intensity (+/(+/-- 15%) to patient 15%) to patient Dose rate = 2 Dose rate = 2 GyGy/min/liter with FS /min/liter with FS = 25 x 25 cm = 25 x 25 cm 2 accelerators built 2 accelerators built and commissionedand commissionedFDA approved in FDA approved in USAUSA

Hitachi 250 Hitachi 250 MeVMeV Proton Therapy SynchrotronProton Therapy Synchrotron7 7 MeVMeV multimulti--turn injectionturn injectionRF driven slow extractionRF driven slow extraction

Dynamic beam gating with respiration cycleDynamic beam gating with respiration cycle

Timing Diagram for Hitachi breath gating techniqueTiming Diagram for Hitachi breath gating techniqueSynchrotron begins acceleration triggered by phase Synchrotron begins acceleration triggered by phase

of breathing cycleof breathing cycle

Hitachi RF driven extraction systemHitachi RF driven extraction system

Excite selected Excite selected betatronbetatronfrequencies for slow extraction frequencies for slow extraction

Hitachi (Power and Industries)Hitachi (Power and Industries)Synchronizes accelerator cycle with respiration cycle Synchronizes accelerator cycle with respiration cycle for chest tumors( typically 4 sec long)for chest tumors( typically 4 sec long)Capable of 1 x 10Capable of 1 x 101111 pppppp with 2 sec cycle timewith 2 sec cycle timeOffers scanning and passive beam spreadingOffers scanning and passive beam spreadingPresently has delivered one complete system and three Presently has delivered one complete system and three subsystems in Japan and one in commissioning phase subsystems in Japan and one in commissioning phase in Houston, TX in Houston, TX Patented RF driven extraction system for slow smooth Patented RF driven extraction system for slow smooth extraction. extraction. Can build all components Can build all components ““in housein house””

Siemens/Heidelburg Heavy ion Synchrotron with RF Siemens/Heidelburg Heavy ion Synchrotron with RF driven extractiondriven extraction

Multiturn injection

Multiple extraction

0,5 bis 10 sec

• compact design

• proven technology

• multiturn-injection => high intensities

• rasterscanningoptimized, extremelyflexible beam extraction

• fast variationof energy(range)

Siemens Siemens Only commercial vendor of Proton and Carbon beamsOnly commercial vendor of Proton and Carbon beamsUses a 20 meter diameter synchrotron to accommodate CUses a 20 meter diameter synchrotron to accommodate C6+6+

as well as Protonsas well as ProtonsOffers proton gantries and horizontal beams for CarbonOffers proton gantries and horizontal beams for CarbonPresently building facility in Heidelberg, GE. Presently building facility in Heidelberg, GE. Lab partner at the GSI nuclear lab ( Darmstadt, GE) is Lab partner at the GSI nuclear lab ( Darmstadt, GE) is building massive 400 ton Carbon gantry ( compared to building massive 400 ton Carbon gantry ( compared to Loma LindaLoma Linda’’s 90 ton gantry)s 90 ton gantry)Offers only scanned beam delivery systemsOffers only scanned beam delivery systems

Mitsubishi 250 Mitsubishi 250 MeVMeV SynchrotronSynchrotron

2 machines in 2 machines in Japan and 2 more Japan and 2 more under contractunder contractCurrently used for Currently used for passively scattered passively scattered beams onlybeams onlyNot currently Not currently being sold in the being sold in the USUS

MitsubishiMitsubishi

Uses 3 Uses 3 MeVMeV multi turn injection to synchrotronmulti turn injection to synchrotronCapable of 5 x 10Capable of 5 x 101010 pppppp with 2 sec cycle timewith 2 sec cycle timeBeam deliver system is passive only (no Beam deliver system is passive only (no scanning)scanning)One working facility in One working facility in ShizoukaShizouka, Japan with 3 , Japan with 3 to 4 Treatment roomsto 4 Treatment roomsBuilt subsystems for other Japanese facilitiesBuilt subsystems for other Japanese facilitiesThey have not yet pursued nonThey have not yet pursued non-- Japanese market Japanese market

Vendor ListVendor List

Hitachi ( 250 Hitachi ( 250 MeVMeV synchrotron)synchrotron)Mitsubishi ( 250 Mitsubishi ( 250 MeVMeV Synchrotron)Synchrotron)Siemens ( 250 Siemens ( 250 MeVMeV Proton and CProton and C6+6+ synchrotron)synchrotron)Ion Beam Applications ( 235 Ion Beam Applications ( 235 MeVMeV cyclotron) cyclotron) AccelAccel ( 250 ( 250 MeVMeV super conducting cyclotron)super conducting cyclotron)OptivusOptivus Technology (250 Technology (250 MeVMeV synchrotron)synchrotron)

Current Vendor Activity ScoreCurrent Vendor Activity ScoreIBA Hitachi Mitsu-

bishiOptivus Accel Siemens

Complete Built

2 1 1 0 1 0

CompleteIn Prog.

3 1 0 0 0 1

Partial Sys. Built

2 3 3 1 1 0

North America = 5Europe = 7 + 1 carbon

Japan = 6 + 2 carbon

Southern Hemisphere = 1

23 PROTON AND 3 CARBON ION THERAPY FACILITIES IN 2005

Russia = 3

China = 1

August 2006: 25 proton facilities, 2 new facilities opened in USA

Accelerator ComparisonsAccelerator Comparisons