Development and testing a model of energy absorption in biological objects from incorporated photon emitters

«Radiation and Risk», 2022, vol. 31, No. 2, pp.48-61

DOI: 10.21870/0131-3878-2022-31-2-48-61

Authors

Sazykina T.G. – Chief Researcher, D. Sc., Phys.-Math.
Kryshev A.I. – Head of Lab., D. Sc., Biol. RPA “Typhoon”. Contacts: 4 Pobedy str., Obninsk, Kaluga region, Russia, 249038. Tel.: +7 (484) 397-16-89; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. .
Research and Production Association “Typhoon”, Obninsk

Abstract

A new analytical method, previously developed for estimating beta absorbed fractions, was extended for analytical estimating photon absorbed fractions in soft-tissue bodies from internal uniformly distributed gamma emitters. The method involves a rescaling procedure with transformation of real bio-logical sizes to unitless effective ones combining information of both photon energy and object’s size. The rescaling was applied to large published datasets of photon absorbed fractions in soft-tissue spheres. A new effect was demonstrated: the rescaled data were united into a single smooth “universal curve” with saturation. The universal curve for photon absorbed fractions was described analytically as a function of a single argument – a rescaled effective radius. Practical applicability of the approach for non-spherical convex bodies (ellipsoids) was demonstrated. Examples of analytical estimating the internal dose coefficients for representative terrestrial animals were calculated. The new method now available for electron and photon internal dosimetry, provides an effective analytical tool for calculating radiation absorbed fractions in organs and bodies of soft-tissue organisms.

Key words
radiation dosimetry, internal exposure, photon absorbed fractions, soft-tissue spheres, ellipsoids, rescaling, unitless effective radius, universal curve, analytical model, dose assessment, nuclear medicine, biota, environment.

References

1. Loevinger R., Berman M. A revised schema for calculating the absorbed dose from biologically distributed radionuclides. MIRD Pamphlet No 1, revised. New York, Society of Nuclear Medicine, 1976, pp. 3-10.

2. Stabin M.G., Konijnenberg M.W. Re-evaluation of absorbed fractions for photons and electrons in spheres of various sizes. J. Nucl. Med., 2000, vol. 41, pp. 149-160.

3. Amato E., Lizio D., Baldari S. Absorbed fractions for photons in ellipsoidal volumes. Phys. Med. Biol., 2009, vol. 54, no. 20, pp. 479-487.

4. Amato E., Lizio D., Baldari S. Absorbed fractions for electrons in ellipsoidal volumes. Phys. Med. Biol., 2011, vol. 56, no. 2, pp. 357-365.

5. Amato E., Italiano A. An analytical model for calculating internal dose conversion coefficients for non-human biota. Radiat. Environ. Biophys., 2014, vol. 53, no. 2, pp. 455-459.

6. Ulanovsky A., Pröhl G. A practical method for assessment of dose conversion coefficients for aquatic biota. Radiat. Environ. Biophys., 2006, vol. 45, no. 3, pp. 203-214.

7. Ulanovsky A., Pröhl G., Gomez-Ros J.M. Methods for calculating dose conversion coefficients for terrestrial and aquatic biota. J. Environ. Radioact., 2008, vol. 99, no. 9, pp. 1440-1448.

8. Ulanovsky A., Pröhl G. Tables of dose conversion coefficients for estimating internal and external radiation exposures to terrestrial and aquatic biota. Radiat. Environ. Biophys., 2008, vol. 47, no. 2, pp. 195-203.

9. Sazykina T.G., Kryshev A.I. Model for calculating energy absorption in environmental objects from incorporated sources of monoenergetic electrons. Radiatsiya i Risk – Radiation and Risk, 2021, vol. 30, no. 2, pp. 113-122. (In Russian).

10. Sazykina T.G., Kryshev A.I. A new analytical method for estimating electron-absorbed fractions in soft-tissue biological volumes. Radiat. Environ. Biophys., 2021, vol. 60, no. 1, pp. 141-149.

11. ICRU, 1993. Quantities and units in radiation protection dosimetry. ICRU Report 51. Bethesda, MD, ICRU, 1993.

12. Mashkovich V.P., Kudryavtseva A.V. Protection from ionizing radiation. Moscow, Energoatomizdat, 1995. 494 p. (In Russian).

13. Ellett W., Humes R. Absorbed fractions for small volumes containing photon-emitting radioactivity. MIRD Pamphlet No 8. New York, Society of Nuclear Medicine, 1972.

14. Brownell G., Ellett W., Reddy R. Absorbed fractions for photon dosimetry. MIRD Pamphlet No 3. New York, Society of Nuclear Medicine, 1968.

15. ICRP, 2017. Dose coefficients for non-human biota environmentally exposed to radiation. ICRP Publication 136. Ann. ICRP, 2017, vol. 46, no. 2, pp. 1-136.

16. Shultis J.K., Faw R.E. Radiation shielding. New Jersey, Prentice Hall, 1996.

17. Stabin M.G. Radiation protection and dosimetry. Springer, 2007. 389 pp.

18. Hubbard L.B. Absorbed fractions for small bodies: the cube-root-of-mass dependence. Radiat. Res., 1974, vol. 57, pp. 1-8.

19. Stepanenko V.F., Yaskova E.K., Belukha I.G., Petriev V.M., Skvortsov V.G., Kolyzhenkov T.V., Petukhov A.D., Dubov D.V. The calculation of internal irradiation of nano-, micro- and macro-biostructures by electrons, beta particles and quantum radiation of different energy for the development and research of new radiopharmaceuticals in nuclear medicine. Radiatsiya i risk – Radiation and Risk, 2015, vol. 24, no. 1, pp. 35-57. (In Russian).

20. ICRP, 2008. Nuclear decay data for dosimetric calculations. ICRP Publication 107. Ann. ICRP, 2008, vol. 38, no. 3, pp. 1-96.

21. ICRP, 2003. A framework for assessing the impact of ionizing radiation to non-human species. ICRP Publication 91. Ann. ICRP, 2003, vol. 33, no. 3, pp. 201-266.

22. ICRP, 2008. Environmental protection – the concept and use of reference animals and plants. ICRP Publication 108. Ann. ICRP, 2008, vol. 38, no. 4-6, pp. 1-242.

Full-text article (in Russian)