Page 67 - 2014 Printable Abstract Book
P. 67
S16 THE PHYSICS & BIOLOGY OF VERY HIGH ENERGY ELECTRON BEAMS PRODCUED WITH LASER
PLASMA ACCELERATORS AND THEIR POTENTIAL IN RADIOTHERAPY
This symposium will explore the radiation physics and biophysics of Very High Energy Electrons (VHEE) in
the 150 to 200 MeV range produced with a novel pulsed laser plasma wake field accelerator technology.
Data and Monte Carlo based models suggest these beams of ultra-short bunches of ultra-relativistic
electrons have novel biophysical properties.
(S1601) An overview of VHEE beams produced with a laser plasma based wakefield accelerator.
Dino Jaroszynski, University of Strathclyde, Glasgow, United Kingdom
(S1602) Calibration and dosimetry of very high energy electrons (VHEE) as a new treatment modality
3
1
1
1;2
for radiotherapy. Anna Subiel ; Vadim Moskvin, PhD ; Gregor H. Welsh, PhD ; Silvia Cipiccia, PhD ; David
1
1
3
1
Reboredo ; Colleen DesRosiers, PhD ; Annette Sorensen, PhD ; Marie Boyd, PhD ; Marc S. Mendonca,
3
1
PhD ; and Dino A. Jaroszynski, Professor, University of Strathclyde, Glasgow, United Kingdom ; National
1
2
Physical Laboratory, Teddington, United Kingdom ; and Indiana University School of Medicine,
Indianapolis, IN
3
Very high energy electrons (VHEE) in the range from 100 to 250 MeV have the potential of becoming an
alternative modality in radiotherapy because of their improved dosimetry properties compared with MV
photons from contemporary medical linear accelerators. The rapid development of ultra-compact laser-
plasma wakefield accelerators (LWFAs) is now providing a potential low cost device for VHEE
radiotherapy. These beams have characteristics unlike other beams currently used for radiotherapy:
femotosecond radiation pulses, small field size and energies exceeding electron energies currently used
in clinical applications. Due to the need for accurate dosimetry of small field size VHEE beams we have
performed dose measurements using EBT2 Gafchromic® film. Film calibration has been carried out using
two different energy ranges: 20 MeV and 165 MeV electron beams from conventional radio frequency
linear accelerators. In addition, EBT2 film has been used for dose measurements with 135 MeV electron
beams produced by a laser-plasma wakefield accelerator. The dose response measurements and
percentage depth dose profiles have been compared with calculations carried out using the general-
purpose FLUKA Monte Carlo (MC) radiation transport code. The impact of induced radioactivity on film
response for VHEEs has been evaluated with the MC simulations. Neutron yield of the order of 10 -5
2
neutrons/cm per incident electron has been estimated and induced activity due to radionuclide
production is found to have a negligible effect on total dose deposition and film response. The study
demonstrates that EBT2 Gafchromic film is a reliable dosimeter with an energy-independent response
over a broad range of electron beam energies, which can be used for dosimetry of VHEE. Furthermore,
Monte Carlo calculations support experiment planning and are essential for verifying the radiobiological
effectiveness and validating LWFA VHEE radiotherapy and interpreting data.
65 | P a g e
PLASMA ACCELERATORS AND THEIR POTENTIAL IN RADIOTHERAPY
This symposium will explore the radiation physics and biophysics of Very High Energy Electrons (VHEE) in
the 150 to 200 MeV range produced with a novel pulsed laser plasma wake field accelerator technology.
Data and Monte Carlo based models suggest these beams of ultra-short bunches of ultra-relativistic
electrons have novel biophysical properties.
(S1601) An overview of VHEE beams produced with a laser plasma based wakefield accelerator.
Dino Jaroszynski, University of Strathclyde, Glasgow, United Kingdom
(S1602) Calibration and dosimetry of very high energy electrons (VHEE) as a new treatment modality
3
1
1
1;2
for radiotherapy. Anna Subiel ; Vadim Moskvin, PhD ; Gregor H. Welsh, PhD ; Silvia Cipiccia, PhD ; David
1
1
3
1
Reboredo ; Colleen DesRosiers, PhD ; Annette Sorensen, PhD ; Marie Boyd, PhD ; Marc S. Mendonca,
3
1
PhD ; and Dino A. Jaroszynski, Professor, University of Strathclyde, Glasgow, United Kingdom ; National
1
2
Physical Laboratory, Teddington, United Kingdom ; and Indiana University School of Medicine,
Indianapolis, IN
3
Very high energy electrons (VHEE) in the range from 100 to 250 MeV have the potential of becoming an
alternative modality in radiotherapy because of their improved dosimetry properties compared with MV
photons from contemporary medical linear accelerators. The rapid development of ultra-compact laser-
plasma wakefield accelerators (LWFAs) is now providing a potential low cost device for VHEE
radiotherapy. These beams have characteristics unlike other beams currently used for radiotherapy:
femotosecond radiation pulses, small field size and energies exceeding electron energies currently used
in clinical applications. Due to the need for accurate dosimetry of small field size VHEE beams we have
performed dose measurements using EBT2 Gafchromic® film. Film calibration has been carried out using
two different energy ranges: 20 MeV and 165 MeV electron beams from conventional radio frequency
linear accelerators. In addition, EBT2 film has been used for dose measurements with 135 MeV electron
beams produced by a laser-plasma wakefield accelerator. The dose response measurements and
percentage depth dose profiles have been compared with calculations carried out using the general-
purpose FLUKA Monte Carlo (MC) radiation transport code. The impact of induced radioactivity on film
response for VHEEs has been evaluated with the MC simulations. Neutron yield of the order of 10 -5
2
neutrons/cm per incident electron has been estimated and induced activity due to radionuclide
production is found to have a negligible effect on total dose deposition and film response. The study
demonstrates that EBT2 Gafchromic film is a reliable dosimeter with an energy-independent response
over a broad range of electron beam energies, which can be used for dosimetry of VHEE. Furthermore,
Monte Carlo calculations support experiment planning and are essential for verifying the radiobiological
effectiveness and validating LWFA VHEE radiotherapy and interpreting data.
65 | P a g e
