title: Effect of a static magnetic field on nanodosimetric quantities in a DNA volume.
abstract: OBJECTIVE
  With the advent of magnetic resonance imaging (MRI)-guided radiation therapy it is becoming increasingly important to consider the potential influence of a magnetic field on ionising radiation. This paper aims to study the effect of a magnetic field on the track structure of radiation to determine if the biological effectiveness may be altered.
  
  
  METHODS
  Using the Geant4-DNA (GEometry ANd Tracking 4) Monte Carlo simulation toolkit, nanodosimetric track structure parameters were calculated for electrons, protons and alpha particles moving in transverse magnetic fields up to 10 Tesla. Applying the model proposed by Garty et al., the track structure parameters were used to derive the probability of producing a double-strand break (DSB).
  
  
  RESULTS
  For simulated primary particles of electrons (200 eV-10 keV), protons (300 keV-30 MeV) and alpha particles (1-9 MeV) the application of a magnetic field was shown to have no significant effect (within statistical uncertainty limits) on the parameters characterizing radiation track structure or the probability of producing a DSB.
  
  
  CONCLUSIONS
  The null result found here implies that if the presence of a magnetic field were to induce a change in the biological effectiveness of radiation, the effect would likely not be due to a change in the track structure of the radiation.
authors.affiliation: Centre for Medical Radiation Physics (CMRP), University of Wollongong, NSW, Australia. pk97@uowmail.edu.au
authors.forename: Peter
authors.initials: P
authors.lastname: Lazarakis
authors.forename: Marion U
authors.initials: MU
authors.lastname: Bug
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Gargioni
authors.forename: Susanna
authors.initials: S
authors.lastname: Guatelli
authors.forename: Sebastien
authors.initials: S
authors.lastname: Incerti
authors.forename: Hans
authors.initials: H
authors.lastname: Rabus
authors.forename: Anatoly B
authors.initials: AB
authors.lastname: Rosenfeld
mesh_terms: D000512:Alpha Particles; D004247:DNA / Q000235:genetics; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D004583:Electrons; D060526:Magnetic Fields; D036103:Nanotechnology / Q000379:methods*; D011336:Probability; D011522:Protons; D011874:Radiometry; D012062:Relative Biological Effectiveness
chemical_list: D011522:Protons; D004247:DNA