@misc{oai:repo.qst.go.jp:00076831,
 author = {Inaniwa, Taku and Sato, Shinji and Muramatsu, Masayuki and Noda, Akira and Iwata, Yoshiyuki and Inaniwa, Taku and Sato, Shinji and Muramatsu, Masayuki and Noda, Akira and Iwata, Yoshiyuki},
 month = {Sep},
 note = {Introduction: Merging MR imaging and charged-particle therapy (MRiPT) has gained interest to increase the targeting accuracy of radiations. The radiochromic films are suited to measure the 2D dose distribution of charged particle beams with high special resolution. However, the dose response of the films under magnetic fields to the charged-particle beams has never been studied intensively.
The purpose of this study is to investigate the effect of longitudinal and perpendicular magnetic fields, BL and BP, on radiochromic EBT3 file response to therapeutic carbon-ion beams.
Methods and Materials: A water-cooled solenoid (dipole) magnet was used to produce a magnetic field longitudinal (perpendicular) to the carbon-ion beams. The radiochromic EBT3 films placed within the bore (gap)of the magnet were exposed t0 low (12 keV/μm) and high (50 keV/μm) linear energy transfer (LET) carbon-ion beams of 5 Gy dose under BL (BP) of 0, 0.3, and 0.6 T. The dose-monitor output was calibrated with the ionization chamber for each LET beams without the magnetic field. The optical density (OD) of the films was measured in red color channels of a scanner. The change in ODs by the orientation and the strength of magnetic fields were investigated for each LET beams based on t-test.
Results: Under BL of 0.3 and 0.6 T, the ODs decreased significantly by l .0% and 0.6% for low LET beams and by 1.4% and 1.3% for high LET beams from the ODs without BL. Similarly, under BP of 0.3 and 0.6 T, the ODs decreased significantly by 1.0% and 0.8% for low LET beams and by 1.3% and 1.1% for high LET beams from the ODs without BP. 
Conclusion: We observed small (~ 1%) but significant reductions in ODs of radiochromlc EBT3 films exposed to low and high LET carbon-ion beams by the longitudinal and perpendicular magnetic fields., 24th International conference on Medical physics (ICMP2019)},
 title = {Effect of longitudinal and perpendicular magnetic fields on radiochromic EBT3 film response to carbon-ion beams},
 year = {2019}
}