Challenges of dosimetry of ultra-short pulsed very high energy electron beams

Anna Subiel, Vadim Moskvin, Gregor H. Welsh, Silvia Cipiccia, David Reboredo, Colleen DesRosiers, Dino A. Jaroszynski

Research output: Contribution to journalArticle

Abstract

Very high energy electrons (VHEE) in the range from 100–250 MeV have the potential of becoming an alternative modality in radiotherapy because of their improved dosimetric properties compared with 6-20 MV photons generated by clinical linear accelerators (LINACs). VHEE beams have characteristics unlike any other beams currently used for radiotherapy: femtosecond to picosecond duration electron bunches, which leads to very high dose per pulse, and energies that exceed that currently used in clinical applications. Dosimetry with conventional online detectors, such as ionization chambers or diodes, is a challenge due to non-negligible ion recombination effects taking place in the sensitive volumes of these detectors. FLUKA and Geant4 Monet Carlo (MC) codes have been employed to study the temporal and spectral evolution of ultrashort VHEE beams in a water phantom. These results are complemented by ion recombination measurements employing an IBA CC04 ionization chamber for a 165 MeV VHEE beam. For comparison, ion recombination has also been measured using the same chamber with a conventional 20 MeV electron beam. This work demonstrates that the IBA CC04 ionization chamber exhibits significant ion recombination and is therefore not suitable for dosimetry of ultrashort pulsed VHEE beams applying conventional correction factors. Further study is required to investigate the applicability of ion chambers in VHEE dosimetry.
LanguageEnglish
Pages327-331
Number of pages5
JournalPhysica Medica
Volume42
Early online date11 May 2017
DOIs
Publication statusPublished - 30 Oct 2017

Fingerprint

high energy electrons
ion recombination
dosimeters
ionization chambers
electron beams
Electrons
Genetic Recombination
Ions
radiation therapy
Radiotherapy
detectors
linear accelerators
Particle Accelerators
chambers
diodes
Photons
dosage
photons
pulses
water

Keywords

  • very high energy electrons (VHEE)
  • Monte Carlo
  • ultrashort pulses
  • ion recombination

Cite this

Subiel, A., Moskvin, V., Welsh, G. H., Cipiccia, S., Reboredo, D., DesRosiers, C., & Jaroszynski, D. A. (2017). Challenges of dosimetry of ultra-short pulsed very high energy electron beams. Physica Medica, 42, 327-331. https://doi.org/10.1016/j.ejmp.2017.04.029
Subiel, Anna ; Moskvin, Vadim ; Welsh, Gregor H. ; Cipiccia, Silvia ; Reboredo, David ; DesRosiers, Colleen ; Jaroszynski, Dino A. / Challenges of dosimetry of ultra-short pulsed very high energy electron beams. In: Physica Medica. 2017 ; Vol. 42. pp. 327-331.
@article{15ba2f32e22143e1a725ba05870d58db,
title = "Challenges of dosimetry of ultra-short pulsed very high energy electron beams",
abstract = "Very high energy electrons (VHEE) in the range from 100–250 MeV have the potential of becoming an alternative modality in radiotherapy because of their improved dosimetric properties compared with 6-20 MV photons generated by clinical linear accelerators (LINACs). VHEE beams have characteristics unlike any other beams currently used for radiotherapy: femtosecond to picosecond duration electron bunches, which leads to very high dose per pulse, and energies that exceed that currently used in clinical applications. Dosimetry with conventional online detectors, such as ionization chambers or diodes, is a challenge due to non-negligible ion recombination effects taking place in the sensitive volumes of these detectors. FLUKA and Geant4 Monet Carlo (MC) codes have been employed to study the temporal and spectral evolution of ultrashort VHEE beams in a water phantom. These results are complemented by ion recombination measurements employing an IBA CC04 ionization chamber for a 165 MeV VHEE beam. For comparison, ion recombination has also been measured using the same chamber with a conventional 20 MeV electron beam. This work demonstrates that the IBA CC04 ionization chamber exhibits significant ion recombination and is therefore not suitable for dosimetry of ultrashort pulsed VHEE beams applying conventional correction factors. Further study is required to investigate the applicability of ion chambers in VHEE dosimetry.",
keywords = "very high energy electrons (VHEE), Monte Carlo, ultrashort pulses, ion recombination",
author = "Anna Subiel and Vadim Moskvin and Welsh, {Gregor H.} and Silvia Cipiccia and David Reboredo and Colleen DesRosiers and Jaroszynski, {Dino A.}",
year = "2017",
month = "10",
day = "30",
doi = "10.1016/j.ejmp.2017.04.029",
language = "English",
volume = "42",
pages = "327--331",
journal = "Physica Medica",
issn = "1120-1797",

}

Subiel, A, Moskvin, V, Welsh, GH, Cipiccia, S, Reboredo, D, DesRosiers, C & Jaroszynski, DA 2017, 'Challenges of dosimetry of ultra-short pulsed very high energy electron beams' Physica Medica, vol. 42, pp. 327-331. https://doi.org/10.1016/j.ejmp.2017.04.029

Challenges of dosimetry of ultra-short pulsed very high energy electron beams. / Subiel, Anna; Moskvin, Vadim; Welsh, Gregor H.; Cipiccia, Silvia; Reboredo, David; DesRosiers, Colleen; Jaroszynski, Dino A.

In: Physica Medica, Vol. 42, 30.10.2017, p. 327-331.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Challenges of dosimetry of ultra-short pulsed very high energy electron beams

AU - Subiel, Anna

AU - Moskvin, Vadim

AU - Welsh, Gregor H.

AU - Cipiccia, Silvia

AU - Reboredo, David

AU - DesRosiers, Colleen

AU - Jaroszynski, Dino A.

PY - 2017/10/30

Y1 - 2017/10/30

N2 - Very high energy electrons (VHEE) in the range from 100–250 MeV have the potential of becoming an alternative modality in radiotherapy because of their improved dosimetric properties compared with 6-20 MV photons generated by clinical linear accelerators (LINACs). VHEE beams have characteristics unlike any other beams currently used for radiotherapy: femtosecond to picosecond duration electron bunches, which leads to very high dose per pulse, and energies that exceed that currently used in clinical applications. Dosimetry with conventional online detectors, such as ionization chambers or diodes, is a challenge due to non-negligible ion recombination effects taking place in the sensitive volumes of these detectors. FLUKA and Geant4 Monet Carlo (MC) codes have been employed to study the temporal and spectral evolution of ultrashort VHEE beams in a water phantom. These results are complemented by ion recombination measurements employing an IBA CC04 ionization chamber for a 165 MeV VHEE beam. For comparison, ion recombination has also been measured using the same chamber with a conventional 20 MeV electron beam. This work demonstrates that the IBA CC04 ionization chamber exhibits significant ion recombination and is therefore not suitable for dosimetry of ultrashort pulsed VHEE beams applying conventional correction factors. Further study is required to investigate the applicability of ion chambers in VHEE dosimetry.

AB - Very high energy electrons (VHEE) in the range from 100–250 MeV have the potential of becoming an alternative modality in radiotherapy because of their improved dosimetric properties compared with 6-20 MV photons generated by clinical linear accelerators (LINACs). VHEE beams have characteristics unlike any other beams currently used for radiotherapy: femtosecond to picosecond duration electron bunches, which leads to very high dose per pulse, and energies that exceed that currently used in clinical applications. Dosimetry with conventional online detectors, such as ionization chambers or diodes, is a challenge due to non-negligible ion recombination effects taking place in the sensitive volumes of these detectors. FLUKA and Geant4 Monet Carlo (MC) codes have been employed to study the temporal and spectral evolution of ultrashort VHEE beams in a water phantom. These results are complemented by ion recombination measurements employing an IBA CC04 ionization chamber for a 165 MeV VHEE beam. For comparison, ion recombination has also been measured using the same chamber with a conventional 20 MeV electron beam. This work demonstrates that the IBA CC04 ionization chamber exhibits significant ion recombination and is therefore not suitable for dosimetry of ultrashort pulsed VHEE beams applying conventional correction factors. Further study is required to investigate the applicability of ion chambers in VHEE dosimetry.

KW - very high energy electrons (VHEE)

KW - Monte Carlo

KW - ultrashort pulses

KW - ion recombination

UR - http://www.sciencedirect.com/science/journal/11201797

U2 - 10.1016/j.ejmp.2017.04.029

DO - 10.1016/j.ejmp.2017.04.029

M3 - Article

VL - 42

SP - 327

EP - 331

JO - Physica Medica

T2 - Physica Medica

JF - Physica Medica

SN - 1120-1797

ER -

Subiel A, Moskvin V, Welsh GH, Cipiccia S, Reboredo D, DesRosiers C et al. Challenges of dosimetry of ultra-short pulsed very high energy electron beams. Physica Medica. 2017 Oct 30;42:327-331. https://doi.org/10.1016/j.ejmp.2017.04.029