Effect of Magnetic Fields on Dose Distribution, Range of Photon Beams and Charged Particles in Radiation Therapy

Radiotherapy in one of the main methods of tumor treatment and control. Today, the integrated radiation therapy-MRI systems have been developed. The magnetic fields of imaging systems can have effects on dose distribution in target volume. Therefore, the aim of this study was to investigate the effect of magnetic fields on dose distribution in radiation therapy.
This is a review article which was done through searching the google scholar and PubMed data bases by expressions: radiation therapy and magnetic field photon therapy and magnetic field, electron therapy and magnetic field, proton therapy and magnetic field. Related research papers were sorted and their results were summarized.
Magnetic fields can change the path of charged particles in the medium can enforce the primary charged particles, secondary electrons and positrons to experience a spiral path, if applied perpendicular to beam axes which leads to produce a peak dose. Longitudinal magnetic field decreases the penumbra and lateral deflection of electrons.
Magnetic fields influence the dose distribution in radiotherapy and modification of treatment plan is essential when applying integrated MRI-radiation therapy systems. Also, applying an intensity controlled transverse magnetic field can be an inexpensive approach to adjusting the maximum dose of charged particles in tumor volume while protecting normal tissues.