A Model Considering Secondary Particles Contribution in RBE of Primary Bremsstrahlung

Alexandr V. Belousov^1, , Alexandr P. Chernyaev¹ and Alexey S. Osipov¹

¹Physics Department, Lomonosov Moscow State University, Moscow, Russia

Cite this paper:
Alexandr V. Belousov, Alexandr P. Chernyaev and Alexey S. Osipov. A Model Considering Secondary Particles Contribution in RBE of Primary Bremsstrahlung. Biomedicine and Biotechnology. 2013; 1(2):6-8. doi: 10.12691/bb-1-2-1

Abstract

Passage of ionizing radiation through biological matter, for example during beam therapy, is followed by the production of secondary particles, which change the relative biological effectiveness (RBE) of the beam. The absorbed dose is represented by the sum of two components: the dose delivered by photons and secondary e⁺ and e^- and the dose from heavy charged particles. Therefore, in order to assess the overall biological effectiveness of the beam, it is necessary to consider RBE of all kinds of induced radiation. In this work a model theoretically describing the biological effectiveness of various types of ionizing radiation depending on their energies is proposed. A method for estimating the relative biological effectiveness taking into account the contribution of photonuclear reactions with the energy ranging from a threshold of photonuclear reactions on light elements (Z<10) to 50MeV is developed. The results obtained are compared to the experimental and calculated data of the other authors.

Keywords:
bremsstrahlung relative biological effectiveness photonuclear particles

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References:

[1]	Belousov A.V., Chernyaev A.P. “A model taking into account the contribution of secondary particles to the relative biological effectiveness of primary radiation”. Bulletin of the Russian Academy Science: Physics, vol. 72, no.7, pp. 981-984, 2008.
[2]	Belousov A.V., Chernyaev A.P., Yanushevskaya T.P. “Influence of photonuclear reactions on bremsstrahlung RBE” High Technologies. Number 10, 2004, pp. 3-10.
[3]	Online Available: http://nuclphys.sinp.msu.ru/cdfe.
[4]	Handbook on photonuclear data for applications cross-section and spectra. International Atomic Energy Agency. Tech. Doc. 1178, October 2000.
[5]	ICRU (1993a) “Stopping powers and ranges of protons and alpha particles with data disk” ICRU Report 49. International commission on Radiation Unit and Measurements, Bethesda, Maryland, USA.
[6]	I.Gudowska, A.Brahme, P.Andreo, W.Gudowski, J.Kierkegaard. “Calculation of absorbed dose and biological effectiveness from photonuclear reactions in a bremsstrahlung beam of end point 50 MeV”. Phys. Med. Biol. vol. 44, pp. 2099, 1999.
[7]	Tilikidis A, Lind B, Näfstadius P and Brahme A. “An estimation of the relative biological effectiveness of 50 MeV bremsstrahlung beams by dosimetric techniques”. Phys. Med. Biol., vol. 41, pp. 55, 1996.
[8]	Horsley R. J., Johns H.E. and Haslam R.N.H. “Energy absorption in human tissue by nuclear processes with high-energy x-rays”. Nucleonics, vol. 11, pp. 28, 1953.
[9]	Nath R., Epp E.R., Laughlin J.S., Swanson W.P., Bond W.P. “Neutrons from high energy x-ray medical accelerators: a estimate of risk to the radiotherapy patients”. Med. Phys. vol. 11, pp. 231-241, 1984.
[10]	Zackrisson B., Johansson B. and Ostbergh P. “Relative biological effectiveness of high energy photons (up to 50 MeV) and electrons (50 MeV)”. Radiat. Res., vol. 128, pp. 192, 1991.
[11]	Zackrisson B. and Karlsson M. “Relative biological effectiveness of 50 MeV x-rays on jejunal crypt survival in vivo”. Radiat. Res., vol. 132, pp. 112, 1992.
[12]	Tilikidis A., Brahme A. Lindborg L. “Microdosimetry in the build-up region of gamma ray beams”. Radiat. Prot. Dosim., vol. 31, pp. 227, 1990.
[13]	Tilikidis A., Iacobaeus C. and Brahme A. “Microdosimetric measurements in the build-up region of very pure photon and electron beams”. Phys. Med. Biol., vol. 38, pp.765, 1993.
[14]	A. Satherberg, L. Johansson. “Photonuclear reactions in tissue for different 50 MV bremsstrahlung beams”. Med. Phys., vol. 25, pp. 683, 1998.