ard status report seminar series towards a bay area hadron therapy center eric r. colby on behalf of...

ARD Status Report Seminar Series

Towards a Bay Area Hadron Therapy Center

Eric R. Colby

On behalf of the Hadron Radiotherapy Facility Task Force

October 20, 2009

Outline

• Motivation for Particle Therapy

• The Stanford Initiative

• Accelerator Physics Issues

• Proposed Accelerator R&D

• Facility Layout

• The Path Forward

Protons StopPhotons keepgoing!

Slide credit: R. Hoppe, SMS.

Increased Biologic Effect of Carbon Ions

Carbon ions have additional potential biologic advantages

RBE=3 x protons

Slide credit: R. Hoppe, SMS.

Example: Medulloblastoma

Slide credit: J. Dorfan, SLAC.

Operational Particle Therapy Facilities


Proposed Particle Therapy Facilities


Operational and Proposed Facilities


Outline





• Facility Layout


“…a focused study on the advisability and feasibility of establishing such a hadron radiation therapy center (HRTC) at Stanford.”

Parameters of the HRTC:

• Must be a treatment facility, with R&D beamlines supporting a strong accelerator and radiobiology R&D program

• SLAC will collaborate, providing expertise to (1) upgrade the initial, commercial machine, and (2) provide new technologies that offer significant cost and performance improvements over existing technologies, to be incorporated a decade after treatment begins.

• The HRTC should be close to Stanford

Task Force Charge:

• Survey particle therapy technologies, centers, and R&D programs.

• Select between proton-only or proton and carbon-ion

• Recommend the initial (commercial) accelerator to purchase.

• Examine extant SLAC and SU accelerator technologies for development for the HRTC upgrade. Assess risk, cost, and outline the R&D program required to implement.

• Map out the radiobiology and clinical R&D programs, and incorporate their needs into the HRTC infrastructure

• Scope out the size, layout, staffing, capital and operating costs of the HRTC facility

• Construct a detailed business plan.

Process Timeline

• Charge to task force: Late October 2008

• Task force work substantially done: June 2009

• Exploratory discussions with UCSF, LBNL, financiers, vendors, and consultants:

May-August 2009• Report to Sponsors:

August 25, 2009• Decision on next steps:

September 22, 2009• Definition of SLAC’s role:

November 2009• Definition of Stanford/UC collaboration:

by end 2009

The HRTF Task Force

Accelerator R&D:

Chris AdolphsenKirk BertscheVinod BharadwajMark CappelliEric Colby, ChairValery DolgashevMark HoganAnatoly KrasnykhJohnny NgBob NobleFlavio Poehlmann-MartinsTor RaubenheimerGreg ReikerAndrei SeryiSami TantawiBill E. White

Business Plan:

Stephanie EdelmanDiana HoRichard HoppeBenjie LoanzonPaul KeallJames McCaugheySridhar Seshadri, Chair

Clinical Operations:

Sonia DieterichSarah DonaldsonRich Hoppe, ChairChris KingAlbert KoongQuynh LeMike LinkJim McCaugheyGeoff RubinScott SoltysPhuoc Tran

Facility:

Tinny ChaiJonathan Dorfan, ChairWilliam Davies-WhiteGeorge Tingwald

Radiobiology and Clinical R&D:

Sonja DieterichAmato GiacciaEdward GravesPaul Keall, ChairQuynh LeBill LooGeoff RubinLei Xing


Task Force Chair: Jonathan Dorfan

Outline





• Facility Layout


Accelerator RequirementsProton (H+)

70-250 MeV

109-1010 pps

Focusable to 4 mm DIA at patient

Dose accuracy 1% or better

Rapid E,x,y modulation

E range up to 50 MeV

x,y sweep range up to ±10 cm

>98% uptime

All beam orientations, with 60% preference for cardinal directions

Carbon Ion (12C6+)

Up to 430 MeV/u

109-1010 pps

Focusable to 4 mm DIA at patient

Dose accuracy 1% or better

Rapid E,x,y modulation

E range up to 50 MeV

x,y sweep range up to ±10 cm

>98% uptime

All beam orientations, with 60% preference for cardinal directions

Examples of 3D Beam Delivery Techniques

…but many tumors move during treatment

Delivering beam from all possible directions is harder than it sounds..

Slide credit: S. Combs, Univ. Heidelberg.

Present Market Capability

The full promise of PT has yet to be realized

Energy modulation is too slow and results in beam degradation• For cyclotrons, “rapid” energy modulation is achieved with a carbon

degrader that is limited to ~msec response time and degrades the emittance as well

• Commercial synchrotrons provide fixed-energy spills, hence different energies require different acceleration cycles

Desire a machine that can provide shot-by-shot energy change without compromising on the emittance

Organ motion compensation is by gating or averaging Desire a machine that can use realtime tumor imaging data to guide the

accelerator beam

With these issues in mind, we examined SLAC and Stanford technologies to see if we could solve these problems.

Outline





• Facility Layout


Accelerator Technology Selection Process

• WGs formed to look at the four technologies in detail:– Prof. Sami Tantawi – High Gradient RF

• Path 1: Extension of SLAC’s microwave copper accelerator technologies to operate in a short-pulse, slow-wave mode

• Path 2: Innovative approach using microwave-powered dielectric-lined tapered waveguides

– Dr. Anatoly Krasnykh – Induction Accelerators• Extension of induction linac concept to high gradient with solid-state

switching (DSRD) and high-gradient dielectric-wall insulator

– Prof. Mark Cappelli – Plasma Deflagration Gun• Novel concept using plasma discharge in gas-filled coaxial transmission

line

– Dr. Mark Hogan – Laser-Driven Plasma Concepts• Novel concept using very high laser powers to (1) ablate, (2) expel the

electrons, and (3) accelerate ions out of a solid target

Standing Wave HGRF Accelerator

• Direct application of the best practices learned to date to a graded- accelerator

• Average gradient approaching 100 MV/m over =0.3-0.6 range

• Designed for short pulse, high group velocity• Requires power coupling innovation to provide rf to each

accelerator cell• Designs at both s-band and x-band explored; shorter fill-

time at x-band is a clear advantage.

Travelling-Wave HGRF Accelerator

• High-field, high group velocity dielectric structures—a novel adaptation of the “Plane Wave Transformer” concept

• Very short rf pulse (60 ns)• Ceramic loading in outer PW

section provides loading of phase velocity and support of copper irises

Figure 2. TW /2 11.424 GHz structure Electric field plots

Ep=70 MeV

Ep=100 MeV

Ep=200 MeV

Ep=250 MeV

Slide credit: S. Tantawi, SLAC.

……

…

Solid-State Switched Induction Linac

• Extension of drift step-recovery-diode technology by 10x

• Extension of Induction linac gradient by ~50x

• Synchronism condition set by trigger timing

• Comparatively simple technology

• Short timescales (e.g. 3 ns discharge time) mean very large currents, and many DRSDs in parallel

• DSRD R&D is synergistic with ILC kicker development

Slide credit: A. Krasnykh, SLAC.

Plasma Deflagration GunProf. Mark Cappelli, Stanford Mechanical Engineering Deparment

• Originally an ion thruster concept• Charged coax transmission line• Gas puffed into line ignites discharge

(H, CO2)

• ExB forces in discharge wave accelerate electrons and ions

• Small portion of accelerated spectrum is many times the anode-cathode voltage

• Experimentally demonstrated: ~10x voltage multiplication

• Believe ~100x should be possibleSlide credit: M. Cappelli, Stanford Univ.

Slide credit: M. Hogan, SLAC.

Structuring the target can improve energy spectrum, but spread is still significant (e.g. ~25%).

Consequently, severe collimation is required to filter the spectrum and reject non-treatment ion species.

Peak power requirements are formidable.

As computational models evolve in sophistication, the predicted power required to achieve clinical energies is steadily rising. Presently: >5 TW !

Primary Issues with Laser-Driven Targets

250 MeV

5 PW ~107 particles in 2% BW


• For each technology the “main accelerator” was sketched out and technical details specified.– Excluded: supporting components such as the injector, beam filter,

gantries, diagnostics– Included: major unique supporting infrastructure componentsPresentations of these concepts are uploaded on the DocuShare site in the “Accelerator Sub Committee Meetings” folder

https://docushare.stanford.edu/dsweb/View/Collection-12316

• Subsequently, each technology was assessed according to the following criteria:– Expected performance capabilities vs. required capabilities– Risk of failure in terms of (1) performance degradation and (2)

increased final product cost– R&D effort required in terms of FTE-years (incomplete)– Programmatic overlap with existing and planned SLAC/SU programsThe assessment table is uploaded on the DocuShare site in the “Sub-Group Accelerator R&D” folder https://docushare.stanford.edu/dsweb/View/Collection-12275


• The selection outcome was then defined:– Primary R&D effort resulting in a patient-ready machine

in 10 years, commanding ~90% of the R&D resources– Secondary R&D effort aimed at a machine in the ≥15

year time-frame, charged with providing evidence of success on all major R&D issues in ~5 years, commanding ~10% of the R&D resources.

• The assessment table was reviewed against the requirements, and the selection made.

Summary Assessment of the Four Accelerator Technologies

Accelerator Technology Selection• HGRF and SLIM are both medium-risk and sufficiently mature to meet the 10-

year-to-market requirement.• HGRF has direct overlap with the SLAC/DOE HGRF program, with ample expertise

and lab infrastructure extant.• SLIM will require significant growth in expertise, the addition of modest lab

infrastructure, and has poorer programmatic overlap. High Gradient RF is selected for the primary research focus.

• PDG and LDT are both high-risk and insufficiently researched to meet the 10-year-to-market requirement. Both potentially offer significant performance improvements and deserve attention for the next generation of machines.

• PDG has direct program overlap with the SU Ion Thruster program, with expertise and lab infrastructure in place. The experiment will require some additional skills (simulation) and lab infrastructure (shielding vault). The cost of R&D required to gain confidence in the solubility of the R&D issues is modest. Final machine cost low compared to the LDT.

• LDT has poor program overlap, with little expertise or lab infrastructure in place. Initial experiments could be done at other facilities, but eventually a very expensive multi-petawatt laser lab must be constructed. One R&D question (achieving rep rate) does not have a clear solution. Significant staff hires will be required to gain world-class standing in this already well populated research area. Final machine cost is high compared to the PDG.

The Plasma Deflagration Gun is selected for the secondary research focus.

Outline





• Facility Layout


HRTC Level 1 (Accelerator, Technical Areas)


240 feet

180

feet

Level 2: Patient Level


240 feet18

0 fe

et

Level 3: Offices


240 feet18

0 fe

et

Elevation Views


Outline





• Facility Layout


Process Timeline

• Charge to task force: Late October 2008

• Task force work substantially done: June 2009

• Exploratory discussions with UCSF, LBNL, financiers, vendors, and consultants:

May-August 2009• Report to Sponsors:

August 25, 2009• Decision on next steps:

September 22, 2009• Definition of SLAC’s role:

November 2009• Definition of Stanford/UC collaboration:

by end 2009

Berkeley’s CTWG Process

• Carbon Therapy Working Group (CTWG) begins meeting January 2009

• First contact between Stanford/Berkeley Efforts February 2009

• LDRD Funding Sought (400k$/1 yr) ~March 2009

• First SLAC/LBNL discussions of collaboration April 2009

• LDRD Funding awarded (~80k$) September, 2009

• Definition of SLAC-LBNL MOU on accelerator research: by end 2009

• Definition of broader SLAC-SU-UC-LBNL MOU on PT Center:by end 2009

Berkeley’s R&D Interests

• Multi-ion high brightness sources

• NS-FFAG lattices

• High-field superconducting cyclotrons

• Advanced superconducting beam delivery systems

• Extraction spill structure of synchrotron

• Detectors for dosimetry; C10 dose verification methods

Recommendations of the TF Report• Recommendation #1 Stanford University must take aggressive steps to insert

itself, as a leader, into the development of particle beam cancer therapy or face a future that is limited to its current leadership role in photon-based therapy.

• Recommendation #2 To achieve a leadership role in the future of particle radiation therapy, the Task Force recommends that Stanford University become a partner in a local Particle Radiation Center (PRC) that permits both clinical and accelerator R&D and that provides comprehensive treatment options. Intrinsic to this recommendation are the following additional requirements:

– The PRC must be situated no further than an hour’s drive from Stanford University: siting it on Stanford land is the most desirable option.

– The PRC must be capable, from its inception, of producing protons and heavy ions (at a minimum carbon ions). While it is clearly foreseen that treatment with protons will precede that with carbon, the Task Force strongly recommends against a facility limited to protons alone.

– The PRC, by virtue of its design and its business model, must be capable of supporting treatment for a wide variety of tumor sites, and in particular must include a comprehensive capability to treat pediatric patients.

• Recommendation #3 To be fully successful, Stanford must combine its strengths at the School of Medicine (SOM), Stanford Hospital & Clinics (SHC) & the Lucille Packard Children’s Hospital (LPCH) with those at the SLAC National Accelerator Laboratory.

Recommendations of the TF Report• Recommendation #4: The Task Force stands strongly behind Recommendations #1-3 should

Stanford University proceed alone or join with suitable partners. However, the Task Force strongly favors joining with the already-aligned team of the University of California, San Francisco (UCSF) and Lawrence Berkeley National Laboratory (LBNL) and recommends that this equal-partnership path be expeditiously pursued.

• Recommendation #5: The Task Force, recognizing that by far the largest challenge is raising the initial capital investment, recommends that success is most likely to come by pursuing a capital funding model built from diverse sources. It appears that private funding and/or donations will have to underpin any viable funding plan. Other components of the mix may include : existing funds, debt, third-party financing, Federal funds or State funds. Partnering with UCSF/LBNL will significantly ease the burden of raising the needed capital. The Task Force recommends against third-party financing that cedes operational control of the PRC to the third party.

• Recommendation #6: The Task Force recommends the expeditious formation of a Particle Radiation Center Proposal Office (PRCPO). The PRCPO will carry out three primary, and largely separate, functions:

– Develop a credible funding plan for the PRC, including the identification of potential donors and/or private fund sources.

– Form a team of clinicians, physicists and engineers to generate, and document, a mature design for the PRC, starting from the preliminary design done by the Task Force. It would be preferable to have a specific site identified with this design.

– Facilitate and launch a joint accelerator R&D program between SLAC and LBNL. – If Stanford moves forward on a joint venture with UCSF/LBNL, the PRCPO should be an equal-share, joint

venture.

Scope of SLAC’s Involvement

• Produce design specifications for a commercially purchased machine. Scope: 4-5 FTEs, 1 year duration.

• Design and implement upgrades to the commercial machine to support rapid beam scanning. Scope 2-4 FTEs, ongoing with operations.

• Engage in basic R&D to adapt HGRF technology to graded-beta proton accelerators. 4 FTEs x 6 years+1.2M$ M&S.

• [Stanford continues to pursue the PDG concept under NIH funding]

• Work with a commercial vendor (e.g. Varian, Siemens, Mitsubishi, etc.) to provide the HGRF components of a treatment machine that is predominantly engineered and built by industry.

Timeline


Conclusions• There is very strong interest in constructing a Bay Area

particle therapy center that would lead in not only treatment, but in accelerator and clinical R&D as well“great opportunity for world leadership”, “compelling”, “exciting”

• Technologies in-hand can make a significant improvement in performance and cost of particle therapy, and the R&D efforts needed are synergistic with existing programs

• Collaborations are forming between Stanford/UCSF to define the clinical programs and SLAC/LBNL to define the initial machine, its upgrades, and R&D programs to provide the next generation of machines capable of realizing the full potential of particle therapy

ard status report seminar series towards a bay area hadron therapy center eric r. colby on behalf of...

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