Radiation Oncology Journal

The Korean Society for Radiation Oncology (대한방사선종양학회)
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Feasibility of normal tissue dose reduction in radiotherapy using low strength magnetic field

  • Jung, Nuri Hyun (Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine) ;
  • Shin, Youngseob (Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine) ;
  • Jung, In-Hye (Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine) ;
  • Kwak, Jungwon (Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine)
  • Received : 2015.06.11
  • Accepted : 2015.08.31
  • Published : 2015.09.30
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Abstract

Purpose: Toxicity of mucosa is one of the major concerns of radiotherapy (RT), when a target tumor is located near a mucosal lined organ. Energy of photon RT is transferred primarily by secondary electrons. If these secondary electrons could be removed in an internal cavity of mucosal lined organ, the mucosa will be spared without compromising the target tumor dose. The purpose of this study was to present a RT dose reduction in near target inner-surface (NTIS) of internal cavity, using Lorentz force of magnetic field. Materials and Methods: Tissue equivalent phantoms, composed with a cylinder shaped internal cavity, and adjacent a target tumor part, were developed. The phantoms were irradiated using 6 MV photon beam, with or without 0.3 T of perpendicular magnetic field. Two experimental models were developed: single beam model (SBM) to analyze central axis dose distributions and multiple beam model (MBM) to simulate a clinical case of prostate cancer with rectum. RT dose of NTIS of internal cavity and target tumor area (TTA) were measured. Results: With magnetic field applied, bending effect of dose distribution was visualized. The depth dose distribution of SBM showed 28.1% dose reduction of NTIS and little difference in dose of TTA with magnetic field. In MBM, cross-sectional dose of NTIS was reduced by 33.1% with magnetic field, while TTA dose were the same, irrespective of magnetic field. Conclusion: RT dose of mucosal lined organ, located near treatment target, could be modulated by perpendicular magnetic field.

Keywords

References

  1. Werner-Wasik M, Yorke E, Deasy J, Nam J, Marks LB. Radiation dose-volume effects in the esophagus. Int J Radiat Oncol Biol Phys 2010;76(3 Suppl):S86-93. https://doi.org/10.1016/j.ijrobp.2009.05.070
  2. Kavanagh BD, Pan CC, Dawson LA, et al. Radiation dose-volume effects in the stomach and small bowel. Int J Radiat Oncol Biol Phys 2010;76(3 Suppl):S101-7. https://doi.org/10.1016/j.ijrobp.2009.05.071
  3. Rancati T, Schwarz M, Allen AM, et al. Radiation dose-volume effects in the larynx and pharynx. Int J Radiat Oncol Biol Phys 2010;76(3 Suppl):S64-9. https://doi.org/10.1016/j.ijrobp.2009.03.079
  4. Yoon H, Oh D, Park HC, et al. Predictive factors for gastroduodenal toxicity based on endoscopy following radiotherapy in patients with hepatocellular carcinoma. Strahlenther Onkol 2013;189:541-6. https://doi.org/10.1007/s00066-013-0343-0
  5. Verma J, Sulman EP, Jhingran A, et al. Dosimetric predictors of duodenal toxicity after intensity modulated radiation therapy for treatment of the para-aortic nodes in gynecologic cancer. Int J Radiat Oncol Biol Phys 2014;88:357-62. https://doi.org/10.1016/j.ijrobp.2013.09.053
  6. Marcu L, Bezak E, Allen BJ. Biomedical physics in radiotherapy for cancer. New York, NY: Springer; 2012. p. 62.
  7. Raaijmakers AJ, Raaymakers BW, Lagendijk JJ. Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength. Phys Med Biol 2008;53:909-23. https://doi.org/10.1088/0031-9155/53/4/006
  8. Kumar S, Deshpande DD, Nahum AE. Monte-Carlo-derived insights into dose-kerma-collision kerma inter-relationships for 50 keV-25 MeV photon beams in water, aluminum and copper. Phys Med Biol 2015;60:501-19. https://doi.org/10.1088/0031-9155/60/2/501
  9. Zelefsky MJ, Levin EJ, Hunt M, et al. Incidence of late rectal and urinary toxicities after three-dimensional conformalradiotherapy and intensity-modulated radiotherapy for localized prostate cancer. Int J Radiat Oncol Biol Phys 2008;70:1124-9. https://doi.org/10.1016/j.ijrobp.2007.11.044
  10. Mohammed N, Kestin L, Ghilezan M, et al. Comparison of acute and late toxicities for three modern high-dose radiation treatmenttechniques for localized prostate cancer. Int J Radiat Oncol Biol Phys 2012;82:204-12. https://doi.org/10.1016/j.ijrobp.2010.10.009
  11. Nettelbeck H, Takacs GJ, Rosenfeld AB. Effect of transverse magnetic fields on dose distribution and RBE of photon beams: comparing PENELOPE and EGS4 Monte Carlo codes. Phys Med Biol 2008;53:5123-37. https://doi.org/10.1088/0031-9155/53/18/018
  12. Chu JC, Reiffel L, Hsi WC, Saxena VA. Modulation of radiotherapy photon beam intensity using magnetic field. Int J Cancer 2001;96 Suppl:131-7. https://doi.org/10.1002/ijc.10352
  13. Raaijmakers AJ, Raaymakers BW, Lagendijk JJ. Integrating a MRI scanner with a 6 MV radiotherapy accelerator: dose increase at tissue-air interfaces in a lateral magnetic field due to returning electrons. Phys Med Biol 2005;50:1363-76. https://doi.org/10.1088/0031-9155/50/7/002
  14. van Heijst TC, den Hartogh MD, Lagendijk JJ, van den Bongard HJ, van Asselen B. MR-guided breast radiotherapy: feasibility and magnetic-field impact on skin dose. Phys Med Biol 2013;58:5917-30. https://doi.org/10.1088/0031-9155/58/17/5917
  15. Oborn BM, Metcalfe PE, Butson MJ, Rosenfeld AB. Monte Carlo characterization of skin doses in 6 MV transverse field MRI-linac systems: effect of field size, surface orientation, magnetic field strength, and exit bolus. Med Phys 2010;37:5208-17. https://doi.org/10.1118/1.3488980
  16. Yang YM, Geurts M, Smilowitz JB, Sterpin E, Bednarz BP. Monte Carlo simulations of patient dose perturbations in rotational-type radiotherapy due to a transverse magnetic field: a tomotherapy investigation. Med Phys 2015;42:715-25. https://doi.org/10.1118/1.4905168

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