Cyclotrons2019 - Table of Session: TUB (Cyclotron Applications: Medical)

Paper	Title	Page
TUB01	Status of the Development of a Fully Iron-free Cyclotron for Proton Beam Radiotherapy Treatment
	D. Winklehner MIT, Cambridge, Massachusetts, USA L. Bromberg, J.V. Minervini, A. Radovinsky MIT/PSFC, Cambridge, Massachusetts, USA
	Funding: This work was supported by the US Department of Energy under award number DE-SC0013499. Superconducting cyclotrons are increasingly employed for proton beam radiotherapy treatment. The use of superconductivity in a cyclotron design can reduce its mass by an order of magnitude and size by a factor of 3-4 over conventional resistive magnet technology, yielding significant reduction in overall cost of the device, the accelerator vault, and its infrastructure. In the presented work, we go a step further and remove the iron yoke, generating the magnetic field with a combination of superconducting coils only. Eliminating the iron yoke has two key benefits. First and foremost, the overall weight can be reduced by almost another order of magnitude. Secondly, eliminating all magnetic iron from the flux circuit results in a linear relationship between field and coil current, which allows smooth scaling of the magnetic field and thus the output energy, thereby removing the need for a degrader. Here we describe the status of the design of such an iron-free cyclotron, currently under development at the Plasma Science and Fusion Center at MIT, with coil and cryostat calculations as well as beam dynamics studies and treatment plan considerations pertaining to this type of cyclotron.
	Slides TUB01 [5.954 MB]
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TUB02	JINR PROJECTS of CYCLOTRON FOR PROTON THERAPY	140
	O. Karamyshev, K. Bunyatov, S. Gurskiy, G.A. Karamysheva, D.P. Popov, G. Shirkov, S.G. Shirkov, V.L. Smirnov, S.B. Vorozhtsov JINR, Dubna, Moscow Region, Russia V. Malinin JINR/DLNP, Dubna, Moscow region, Russia
	Physical design of the compact superconducting cyclotron SC230 (91.5MHz) has been performed. The cyclotron can deliver up to 230 MeV beam for proton therapy and medico-biological research. As the cyclotron will have a relatively small magnet field, it is possible to use both superconducting and resistive coil. Besides a superconducting cyclotron we simulate design of the cyclotron with a conventional copper water-cooled coil. Such a solution allows us to achieve a lower price compared to superconducting options, but it becomes a bit heavier.
	Slides TUB02 [8.397 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-TUB02
About •	paper received ※ 15 September 2019 paper accepted ※ 26 September 2019 issue date ※ 20 June 2020
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TUB03	MRI-Guided-PT: Integrating an MRI in a Proton Therapy System	144
	E. van der Kraaij, J. Smeets IBA, Louvain-la-Neuve, Belgium L. Bertora, A. Carrozzi, A. Serra ASG, Genova, Italy S. Gantz, A. Hoffmann, L. Karsch, A. Lühr, J. Pawelke, S. Schellhammer OncoRay, Dresden, Germany B. Oborn CMRP, Wollongong, Australia
	Integration of magnetic resonance imaging (MRI) in proton therapy (PT) has the potential to improve tumor-targeting precision. However, it is technically challenging to integrate an MRI scanner at the beam isocenter of a PT system due to space constraints and electromagnetic interactions between the two systems. We assessed the technical risks and challenges, and present a concept for the mechanical integration of a 0.5T MRI scanner (ASG MR-Open) into a PT gantry (IBA ProteusONE). Finite element simulations assess the perturbation of the gantry’s elements on the homogeneity of the scanner’s static magnetic field. MC simulations estimate the effect of the scanner’s magnetic field on the proton dose deposition. To test the technical feasibility, a first experimental setup was realized at the PT center in Dresden, combining a 0.22T open MRI scanner with a static proton beam line. Results show that the image quality is not degraded by proton beam irradiation if the acquisition is synchronized with beam line operation. The beam energy dependent proton beam deflection due to the scanner’s magnetic field is significant and needs to be corrected for in treatment planning and dose delivery.
	Slides TUB03 [1.866 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-TUB03
About •	paper received ※ 14 September 2019 paper accepted ※ 26 September 2019 issue date ※ 20 June 2020
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TUB04	On-Line Dynamic Beam Intensity Control in a Proton Therapy Cyclotron	148
	S. Psoroulas, P. Fernandez Carmona, D. Meer, D.C. Weber PSI, Villigen PSI, Switzerland D.C. Weber KRO, Bern, Switzerland D.C. Weber University of Zurich, University Hospital, Zurich, Switzerland
	Modern proton therapy facilities use the pencil beam scanning (PBS) technique for the treatment of tumours: the beam is scanned through the tumour volume sequentially, i.e. stopping the beam at each position in the tumour for the amount of time necessary to deliver the prescribed dose for that position, and then moving to the next position (dose-driven delivery). This technique is robust against fluctuations in the beam current. Modern cyclotrons however offer very stable beam currents, and allow regulating the beam intensity online to match the requested beam intensity profile as a function of time (’time-driven’ delivery). To realise time-driven delivery at the COMET cyclotron at PSI, we have designed a beam intensity controller* which is able to partially compensate for the non-linearity and the delay introduced by the physical limitations of the beam line elements and its drivers; this is particularly important when trying to achieve a very fast modulation of the beam, as required by the clinical plans. Experimental results have shown good performance for most current clinical scenarios, though we are investigating more advanced solutions for higher dose rates scenarios. () Klimpki, G., et al. (2018). PMB, 63(14), 145006 (*) Fernandez Carmona, P., et al., (2018) Proceedings of PCaPAC2018, FRCC2
	Slides TUB04 [10.992 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-TUB04
About •	paper received ※ 14 September 2019 paper accepted ※ 26 September 2019 issue date ※ 20 June 2020
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Paper

Title

Page

TUB01

Status of the Development of a Fully Iron-free Cyclotron for Proton Beam Radiotherapy Treatment

D. Winklehner
MIT, Cambridge, Massachusetts, USA
L. Bromberg, J.V. Minervini, A. Radovinsky
MIT/PSFC, Cambridge, Massachusetts, USA

Funding: This work was supported by the US Department of Energy under award number DE-SC0013499.
Superconducting cyclotrons are increasingly employed for proton beam radiotherapy treatment. The use of superconductivity in a cyclotron design can reduce its mass by an order of magnitude and size by a factor of 3-4 over conventional resistive magnet technology, yielding significant reduction in overall cost of the device, the accelerator vault, and its infrastructure. In the presented work, we go a step further and remove the iron yoke, generating the magnetic field with a combination of superconducting coils only. Eliminating the iron yoke has two key benefits. First and foremost, the overall weight can be reduced by almost another order of magnitude. Secondly, eliminating all magnetic iron from the flux circuit results in a linear relationship between field and coil current, which allows smooth scaling of the magnetic field and thus the output energy, thereby removing the need for a degrader. Here we describe the status of the design of such an iron-free cyclotron, currently under development at the Plasma Science and Fusion Center at MIT, with coil and cryostat calculations as well as beam dynamics studies and treatment plan considerations pertaining to this type of cyclotron.

Slides TUB01 [5.954 MB]

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TUB02

JINR PROJECTS of CYCLOTRON FOR PROTON THERAPY

140

O. Karamyshev, K. Bunyatov, S. Gurskiy, G.A. Karamysheva, D.P. Popov, G. Shirkov, S.G. Shirkov, V.L. Smirnov, S.B. Vorozhtsov
JINR, Dubna, Moscow Region, Russia
V. Malinin
JINR/DLNP, Dubna, Moscow region, Russia

Physical design of the compact superconducting cyclotron SC230 (91.5MHz) has been performed. The cyclotron can deliver up to 230 MeV beam for proton therapy and medico-biological research. As the cyclotron will have a relatively small magnet field, it is possible to use both superconducting and resistive coil. Besides a superconducting cyclotron we simulate design of the cyclotron with a conventional copper water-cooled coil. Such a solution allows us to achieve a lower price compared to superconducting options, but it becomes a bit heavier.

Slides TUB02 [8.397 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-TUB02

About •

paper received ※ 15 September 2019 paper accepted ※ 26 September 2019 issue date ※ 20 June 2020

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUB03

MRI-Guided-PT: Integrating an MRI in a Proton Therapy System

144

E. van der Kraaij, J. Smeets
IBA, Louvain-la-Neuve, Belgium
L. Bertora, A. Carrozzi, A. Serra
ASG, Genova, Italy
S. Gantz, A. Hoffmann, L. Karsch, A. Lühr, J. Pawelke, S. Schellhammer
OncoRay, Dresden, Germany
B. Oborn
CMRP, Wollongong, Australia

Integration of magnetic resonance imaging (MRI) in proton therapy (PT) has the potential to improve tumor-targeting precision. However, it is technically challenging to integrate an MRI scanner at the beam isocenter of a PT system due to space constraints and electromagnetic interactions between the two systems. We assessed the technical risks and challenges, and present a concept for the mechanical integration of a 0.5T MRI scanner (ASG MR-Open) into a PT gantry (IBA ProteusONE). Finite element simulations assess the perturbation of the gantry’s elements on the homogeneity of the scanner’s static magnetic field. MC simulations estimate the effect of the scanner’s magnetic field on the proton dose deposition. To test the technical feasibility, a first experimental setup was realized at the PT center in Dresden, combining a 0.22T open MRI scanner with a static proton beam line. Results show that the image quality is not degraded by proton beam irradiation if the acquisition is synchronized with beam line operation. The beam energy dependent proton beam deflection due to the scanner’s magnetic field is significant and needs to be corrected for in treatment planning and dose delivery.

Slides TUB03 [1.866 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-TUB03

About •

paper received ※ 14 September 2019 paper accepted ※ 26 September 2019 issue date ※ 20 June 2020

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUB04

On-Line Dynamic Beam Intensity Control in a Proton Therapy Cyclotron

148

S. Psoroulas, P. Fernandez Carmona, D. Meer, D.C. Weber
PSI, Villigen PSI, Switzerland
D.C. Weber
KRO, Bern, Switzerland
D.C. Weber
University of Zurich, University Hospital, Zurich, Switzerland

Modern proton therapy facilities use the pencil beam scanning (PBS) technique for the treatment of tumours: the beam is scanned through the tumour volume sequentially, i.e. stopping the beam at each position in the tumour for the amount of time necessary to deliver the prescribed dose for that position, and then moving to the next position (dose-driven delivery). This technique is robust against fluctuations in the beam current. Modern cyclotrons however offer very stable beam currents, and allow regulating the beam intensity online to match the requested beam intensity profile as a function of time (’time-driven’ delivery). To realise time-driven delivery at the COMET cyclotron at PSI*, we have designed a beam intensity controller** which is able to partially compensate for the non-linearity and the delay introduced by the physical limitations of the beam line elements and its drivers; this is particularly important when trying to achieve a very fast modulation of the beam, as required by the clinical plans. Experimental results have shown good performance for most current clinical scenarios, though we are investigating more advanced solutions for higher dose rates scenarios.
(*) Klimpki, G., et al. (2018). PMB, 63(14), 145006
(**) Fernandez Carmona, P., et al., (2018) Proceedings of PCaPAC2018, FRCC2

Slides TUB04 [10.992 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-TUB04

About •

paper received ※ 14 September 2019 paper accepted ※ 26 September 2019 issue date ※ 20 June 2020

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)