DOI QR코드

DOI QR Code

A SOLUTION TO THE PROBLEM WITH ABSORBED DOSE

  • Braby, Leslie A. (Nuclear Engineering Department, Texas A&M University College Station)
  • Published : 2008.12.31

Abstract

In some situations, for example at very low doses, in microbeam irradiation experiments, or around high energy heavy ion tracks, use of the absorbed dose to describe the energy transferred to the irradiated target can be misleading. Since absorbed dose is the expected value of energy per mass it takes into account all of the targets which do not have any energy deposition. In many situations that results in numerical values, in Joules per kg, which are much less than the energy deposited in targets that have been crossed by a charged particle track. This can lead to confusion about the biochemical processes that lead to the consequences of irradiation. There are a few alternative approaches to describing radiation that avoid this potential confusion. Examples of specific situations that can lead to confusion are given. It is concluded that using the particle radiance spectrum and the exposure time, instead of absorbed dose, to describe these irradiations minimizes the potential for confusion about the actual nature of the energy deposition.

References

  1. L. A. Braby, A. L. Brooks and N. F. Metting, 'Cellular effects of individual high-linear energy transfer particles and implications for tissue response at low doses.' Radiat. Res. 148, S108 (1997)
  2. C. L. Wingate and J. W. Baum, 'Measured Radial Distributions of Dose and LET for Alpha and Proton Beams in Hydrogen and Tissue-equivalent Gas' Radiat. Res., 65, p.1 (1976) https://doi.org/10.2307/3574282
  3. Z. Chunxiang, D. E. Dunn and R. Katz, 'Radial Distribution of Dose and Cross-sections for the Inactivation of Dry Enzymes and Viruses' Radiat. Prot. Dosim., 13, p. 215 (1985) https://doi.org/10.1093/oxfordjournals.rpd.a079581
  4. N. F. Mettin, H. H. Rossi, L. A. Braby, P. J. Kliauga, J.Howard, M. Zaider, W. Schimmerling, M. Wong and M. Rapkin, 'Microdosimetry near the trajectory of high-energy heavy ions' Radiat. Res., 116, p. 183 (1988) https://doi.org/10.2307/3577456
  5. G. Randers-Pehrson, C. R. Geard, G. Johnson, C. D. Elliston and D. J. Brenner, 'The Columbia University single-ion microbeam' Radiat. Res. 156, p. 210 (2001) https://doi.org/10.1667/0033-7587(2001)156[0210:TCUSIM]2.0.CO;2
  6. ICRU, International Commission on Radiation Units and Measurements. Microdosimetry. ICRU Report 36, ICRU, Bethesda, MD (1983)
  7. A. Chatterjee and H. J. Schaefer, 'Microdosimetric Structure of Heavy Ion Tracks in Tissue' Radiat. Environ. Biophys., 13, p. 215 (1976) https://doi.org/10.1007/BF01330766
  8. M. Kramer, W. K. Weyrather and M. Scholz, 'The Increased Biological Effectiveness of Heavy Charged Particles: From Radiobiology to Treatment Planning' Tech. in Cancer Res. and Therap.' 2 p. 353 (2003) https://doi.org/10.1177/153303460300200501
  9. M. Folkard, B. Vojnovic, K. M. Prise, A. G. Bowey, R. J. Locke, G. Schettino and B. D. Michael, 'A chargedparticle microbeam: I. Development of an experimental system for targeting cells individually with counted particles', Int. J. Radiat. Biol. 72, p. 375 (1997a) https://doi.org/10.1080/095530097143158
  10. ICRU, International Commission on Radiation Units and Measurements, Fundamental Quantities and Units for Ionizing Radiation, ICRU Report 60, ICRU, Bethesda, MD (1998)
  11. W. F. Morgan, 'Non-targeted and delayed effects of exposure to ionizing radiation: I. Radiation-Induced genomic instability and bystander effects in vitro' Radiat. Res., 159, p. 567 (2003) https://doi.org/10.1667/0033-7587(2003)159[0567:NADEOE]2.0.CO;2