title: Comparison of measured with calculated dose distribution from a 120-MeV electron beam from a laser-plasma accelerator.
abstract: OBJECTIVE
  To evaluate the dose distribution of a 120-MeV laser-plasma accelerated electron beam which may be of potential interest for high-energy electron radiation therapy.
  
  
  METHODS
  In the interaction between an intense laser pulse and a helium gas jet, a well collimated electron beam with very high energy is produced. A secondary laser beam is used to optically control and to tune the electron beam energy and charge. The potential use of this beam for radiation treatment is evaluated experimentally by measurements of dose deposition in a polystyrene phantom. The results are compared to Monte Carlo simulations using the geant4 code.
  
  
  RESULTS
  It has been shown that the laser-plasma accelerated electron beam can deliver a peak dose of more than 1 Gy at the entrance of the phantom in a single laser shot by direct irradiation, without the use of intermediate magnetic transport or focusing. The dose distribution is peaked on axis, with narrow lateral penumbra. Monte Carlo simulations of electron beam propagation and dose deposition indicate that the propagation of the intense electron beam (with large self-fields) can be described by standard models that exclude collective effects in the response of the material.
  
  
  CONCLUSIONS
  The measurements show that the high-energy electron beams produced by an optically injected laser-plasma accelerator can deliver high enough dose at penetration depths of interest for electron beam radiotherapy of deep-seated tumors. Many engineering issues must be resolved before laser-accelerated electrons can be used for cancer therapy, but they also represent exciting challenges for future research.
authors: Laboratoire d'Optique Appliquée, ENSTA, École Polytechnique, CNRS, 91761 Palaiseau, France. olle.lundh@fysik.lth.se
authors: O
authors: O
authors: Lundh
authors: C
authors: C
authors: Rechatin
authors: J
authors: J
authors: Faure
authors: A
authors: A
authors: Ben-Ismaïl
authors: J
authors: J
authors: Lim
authors: C
authors: C
authors: De Wagter
authors: W
authors: W
authors: De Neve
authors: V
authors: V
authors: Malka
mesh_terms: D004583:Electrons / Q000627:therapeutic use*; D005240:Feasibility Studies; D007834:Lasers; D010315:Particle Accelerators; D019047:Phantoms, Imaging; D058626:Plasma Gases; D011829:Radiation Dosage; D011874:Radiometry; D011878:Radiotherapy / Q000295:instrumentation*; D011879:Radiotherapy Dosage
chemical_list: D058626:Plasma Gases