Skip to main content
Log in

Relative biological damage in and out of field of 6, 10 and 18 MV clinical photon beams

  • Regular Article
  • Published:
The European Physical Journal Plus Aims and scope Submit manuscript

Abstract.

The lower energy of scattered radiation in and out of a megavoltage (MV) photon beam suggests that relative biological damage (RBD) may change from in- to out-of-field regions for unit absorbed dose. Because of high linear energy transfer (LET) and potential of causing severe damage to the DNA, low-energy (10 eV-1 keV) slowing down electrons should be included in radiation biological damage calculations. In this study RBD was calculated in and out of field of 6, 10 and 18 MV clinical photon beams including low-energy slowing down electrons in the track length estimated method. Electron spectra at energies higher than 2 keV were collected in a water phantom at different depths and off-axis points by using the MCNP code. A new extrapolation method was used to estimate the electron spectra at energies lower than 2 keV. The obtained spectra at energies lower than 2 keV merged with spectra at energies higher than 2 keV by using continuity of the spectra. These spectra were used as an input to a validated microdosimetric Monte Carlo (MC) code, MC damage simulation (MCDS), to calculate the RBD of induced DSB in DNA at points in and out of the primary radiation field under fully aerobic (100% O2 and anoxic (0% O2 conditions. There was an observable difference in the energy spectra for electrons for points in the primary radiation field and those points out of field. RBD had maximum variation, 11% in 6 MV photons at field size of 20×20 cm2. This variation was less than 11% for 10 and 18 MV photons and field sizes smaller than 20×20 cm2. Our simulations also showed that under the anoxic condition, RBD increases up to 6% for 6 and 10 MV photons and the 20×20 cm2 field size. This work supports the hypothesis that in megavoltage treatments out-of-field radiation quality can vary enough to have an impact on RBD per unit dose and that this may play a role as the radiation therapy community explores biological optimization as a tool to assist treatment planning.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. J. Valentin, Ann. ICRP 33, 1 (2003)

    Google Scholar 

  2. I. El Naqa, P. Pater, J. Seuntjens, Phys. Med. Biol. 57, R75 (2012)

    Article  ADS  Google Scholar 

  3. A.M. Kellerer, Radiat. Res. 158, 13 (2002)

    Article  Google Scholar 

  4. H. Liu, F. Verhaegen, Radiat. Prot. Dosim. 99, 425 (2002)

    Article  Google Scholar 

  5. V. Moiseenko, M. Mulligan, T. Kron, Health Phys. 87, 166 (2004)

    Article  Google Scholar 

  6. C. Kirkby, C. Field, M. Mackenzie, A. Syme, B.G. Fallone, Phys. Med. Biol. 52, 3563 (2007)

    Article  Google Scholar 

  7. A. Syme, C. Kirkby, R. Mirzayans, C. Field, M. Mackenzie, B.G. Fallone, Phys. Med. Biol. 54, 6623 (2009)

    Article  Google Scholar 

  8. L.S. Waters, MCNPX user’s manual Rev 0, LA-UR 99-6058 (1999)

  9. J. Baro, J. Sempau, J. Fernandez-Varea, F. Salvat, Nucl. Instrum. Methods A 100, 31 (1995)

    Article  Google Scholar 

  10. D. Rogers, B. Faddegon, G. Ding, C.M. Ma, J. We, T. Mackie, Med. Phys. 22, 503 (1995)

    Article  Google Scholar 

  11. S. Agostinelli, J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce et al., Nucl. Instrum. Methods A 506, 250 (2003)

    Article  ADS  Google Scholar 

  12. D. Rogers, Phys. Med. Biol. 51, R287 (2006)

    Article  ADS  Google Scholar 

  13. I.J. Chetty, B. Curran, J.E. Cygler, J.J. DeMarco, G. Ezzell, B.A. Faddegon et al., Med. Phys. 34, 4818 (2007)

    Article  Google Scholar 

  14. E. Spezi, G. Lewis, Radiat. Prot. Dosim. 131, 123 (2008)

    Article  Google Scholar 

  15. H. Nikjoo, D.T. Goodhead, Phys. Med. Biol. 36, 229 (1991)

    Article  Google Scholar 

  16. A. Ottolenghi, M. Merzagora, H.G. Paretzke, Radiat. Environ. Biophys. 36, 97 (1997)

    Article  Google Scholar 

  17. H. Nikjoo, P. O’Neill, M. Terrissol, D.T. Goodhead, Radiat. Environ. Biophys. 38, 31 (1999)

    Article  Google Scholar 

  18. S.J. Karnas, V.V. Moiseenko, E. Yu, P. Truong, J.J. Battista, Radiat. Environ. Biophys. 40, 199 (2001)

    Article  Google Scholar 

  19. P. Bernhardt, W. Friedland, R. Meckbach, P. Jacob, H.G. Paretzke, Radiat. Prot. Dosim. 99, 203 (2002)

    Article  Google Scholar 

  20. V.A. Semenenko, R.D. Stewart, Radiat. Res. 164, 194 (2005)

    Article  Google Scholar 

  21. V.A. Semenenko, R.D. Stewart, Phys. Med. Biol. 51, 1693 (2006)

    Article  Google Scholar 

  22. R.D. Stewart, V.K. Yu, A.G. Georgakilas, C. Koumenis, J.H. Park, D.J. Carlson, Radiat. Res. 176, 587 (2011)

    Article  Google Scholar 

  23. V. Semenenko, R. Stewart, Radiat. Res. 161, 451 (2004)

    Article  Google Scholar 

  24. S. Uehara, H. Nikjoo, D.T. Goodhead, Radiat. Res. 152, 202 (1999)

    Article  Google Scholar 

  25. R.D. Stewart, Monte Carlo Damage Simulation (MCDS) software (Washington University) available at the following link: http://faculty.washington.edu/trawets/mcds/ (accessed 26 September 2012)

  26. A.O. Ezzati, Y. Xiao, M. Sohrabpour, M.T. Studenski, Med. Biol. Eng. Comput. 53, 67 (2015)

    Article  Google Scholar 

  27. C. Kirkby, E. Ghasroddashti, Y. Poirier, M. Tambasco, R.D. Stewart, Phys. Med. Biol. 58, 5693 (2013)

    Article  Google Scholar 

  28. A.O. Ezzati, M. Sohrabpour, S.R. Mahdavi, I. Buzurovic, M.T. Studenski, Phys. Med. 30, 191 (2014)

    Article  Google Scholar 

  29. A.O. Ezzati, Eur. Phys. J. Plus 130, 150 (2015)

    Article  Google Scholar 

  30. O.N. Vassiliev, Phys. Med. Biol. 57, 1087 (2012)

    Article  Google Scholar 

  31. N. Tilly, J.M. Fernandez-Varea, E. Grusell, A. Brahme, Phys. Med. Biol. 47, 1303 (2002)

    Article  Google Scholar 

  32. R.N. Hamm, H.A. Wright, R. Katz, J.E. Turner, R.H. Ritchie, Phys. Med. Biol. 23, 1149 (1978)

    Article  Google Scholar 

  33. Y. Hsiao, R. Stewart, Phys. Med. Biol. 53, 233 (2008)

    Article  Google Scholar 

  34. S.B. Scarboro, D.S. Followill, R.M. Howell, S.F. Kry, Med. Phys. 38, 2619 (2011)

    Article  Google Scholar 

  35. W. Friedland, P. Jacob, H.G. Paretzke, M. Merzagora, A. Ottolenghi, Radiat. Environ. Biophys. 38, 39 (1999)

    Article  Google Scholar 

  36. H. Nikjoo, L. Lennart, Phys. Med. Biol. 55, R65 (2010)

    Article  ADS  Google Scholar 

  37. K.M. Prise, C.H.L. Pullar, B.D. Michael, Carcinogenesis 20, 905 (1999)

    Article  Google Scholar 

  38. Kühne, Martin, Gerhard Urban, Dieter Frankenberg, Markus Löbrich, Radiat. Res. 164, 669 (2005)

    Article  Google Scholar 

  39. Rothkamm, Kai, Markus Lobrich, Proc. Natl. Acad. Sci. 100, 5057 (2003)

    Article  ADS  Google Scholar 

  40. Seymour, B. Colin, Carmel Mothersill, Radiat. Res. 153, 508 (2000)

    Article  Google Scholar 

  41. Mothersill, Carmel, C.B. Seymour, Mutat. Res. Fund. Mol. M 597, 5 (2006)

    Article  Google Scholar 

  42. M.A. Hill, Radiat. Meas. 31, 15 (1999)

    Article  Google Scholar 

  43. Asur, Rajalakshmi, Karl T. Butterworth, Jose A. Penagaricano, Kevin M. Prise, Robert J. Griffin, Cancer Lett. 356, 52 (2015)

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to A. O. Ezzati.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ezzati, A.O. Relative biological damage in and out of field of 6, 10 and 18 MV clinical photon beams. Eur. Phys. J. Plus 131, 286 (2016). https://doi.org/10.1140/epjp/i2016-16286-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1140/epjp/i2016-16286-0

Navigation