[13] Wolf, R. & Bortfeld, T. An analytical solution to proton Bragg peak deflection in a magnetic field. Phys. Med. Biol. 57 , N329–N337 (2012). 

[14] Moteabbed, M., Schuemann, J. & Paganetti, H. Dosimetric feasibility of real-time MRI-guided proton therapy. Med. Phys. 41 , 111713 1–11 (2014). 

[15] Oborn, B. M. et al. Proton beam deflection in MRI fields: Implications for MRI-guided proton therapy. Med. Phys. 42 , 2113–2124 (2015). 

[16] Hartman, J. et al. Dosimetric feasibility of intensity modulated proton therapy in a transverse magnetic field of 1.5 T. Phys. Med. Biol. 60 , 5955–5969 (2015). 

[17] Fuchs, H., Moser, P., Gr¨ oschl, M. & Georg, D. Magnetic field effects on particle beams and their implications for dose calculation in MR guided particle therapy. Medical Physics 44 , 1149–1156 (2017). 

[18] Schellhammer, S. M. & Hoffmann, A. L. Prediction and compensation of magnetic beam deflection in MR-integrated proton therapy: A method optimized regarding accuracy, versatility and speed. Phys. Med. Biol. 62 , 1548–1564 (2017). 

[19] Zhao, L. & Das, I. J. Gafchromic EBT film dosimetry in proton beams. Phys. Med. Biol. 55 , N291–N301 (2010). 

[20] Wang, J., Rubinstein, A., Ohrt, J., Ibbott, G. & Wen, Z. Effect of a strong magnetic field on TLDs, OSLDs, and Gafchromic films using an electromagnet. Med. Phys. 43 , 3873–3874 (2016). 

[21] Gantz, S. Characterization of the magnetic field of a 0.95 T permanent dipole magnet and experimental validation of proton beam deflection in a magnetic field within tissue-equivalent material . Master’s thesis, TU Dresden (2017). 

[22] Agostinelli, S. et al. Geant4 - a simulation toolkit. Nuclear Instruments and Methods in Physics Research Section A 506 , 250 – 303 (2003). 

[23] Allison, J. et al. Geant4 developments and applications. IEEE Transactions on Nuclear Science 53 , 270–278 (2006). 

[24] Arjomandy, B., Tailor, R., Zhao, L. & Devic, S. EBT2 film as a depth-dose measurement tool for radiotherapy beams over a wide range of energies and modalities. Med. Phys. 39 , 912–921 (2012). 

[25] Perles, L. A., Mirkovic, D., Anad, A., Titt, U. & Mohan, R. LET dependence of the response of EBT2 films in proton dosimetry modeled as a bimolecular chemical reaction. Phys. Med. Biol. 58 , 8477–8491 (2013). 

[26] Vacuumschmelze. Selten-Erd-Dauermagnete Vacodym Vacomax . Gr¨ uner Weg 37, 63450 Hanau/Germany (2014). 

[27] Reynoso, F. J. et al. Technical Note: Magnetic field effects on Gafchromic-film response in MR-IGRT. Med. Phys. 43 , 6552–6556 (2016). 

[28] Zeil, K., Beyreuther, E., Lessmann, E., Wagner, W. & Pawelke, J. Cell irradiation setup and dosimetry for radiobiological studies at ELBE. Nuclear Instruments and Methods in Physics Research B 267 , 2403–2410 (2009). 

[29] Sorriaux, J. et al. Evaluation of Gafchromic EBT3 films characteristics in therapy photon, electron and proton beams. Physica Medica (2012). 

[30] Wohlfahrt, P., M¨ ohler, C., Richter, C. & Greilich, S. Evaluation of stopping-power prediction by dual- and single-energy computed tomography in an anthropomorphic ground-truth phantom. IJROBP (2017). Under review. 

[31] Bortfeld, T. An analytical approximation of the Bragg curve for therapeutic proton beams. Med. Phys. 24 , 2024–2033 (1997). 

[32] Berger, M. J., Coursey, J. S., Zucker, M. A. & Chang, J. ESTAR, PSTAR, and ASTAR: Computer Programs for Calculating Stopping-Power and Range Tables for Electrons, Protons, and Helium Ions . National Institute of Standards and Technology, Gaithersburg, MD (2005). Version 1.2.3, Retrieved Apr 27, 2015. 

[33] Almhagen, E. Development and validation of a scanned proton beam model for dose distribution verification using Monte 

