Journal of Radiation Protection and Research

The Korean Association for Radiation Protection (대한방사선방어학회)
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Experimental Evaluation of Scattered X-Ray Spectra due to X-Ray Therapeutic and Diagnosis Equipment for Eye Lens Dosimetry of Medical Staff

  • Kowatari, Munehiko (National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology) ;
  • Nagamoto, Keisuke (University of Occupational and Environmental Health) ;
  • Nakagami, Koich (University of Occupational and Environmental Health) ;
  • Tanimura, Yoshihiko (Nuclear Science Research Institute, Japan Atomic Energy Agency) ;
  • Moritake, Takashi (National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology) ;
  • Kunugita, Naoki (University of Occupational and Environmental Health)
  • Received : 2021.05.27
  • Accepted : 2021.08.24
  • Published : 2022.03.31
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Abstract

Background: For proper monitoring of the eye lens dose, an appropriate calibration factor of a dosimeter and information about the mean energies of X-rays are indispensable. The scattered X-ray energy spectra should be well characterized in medical practices where eye lenses of medical staffs might be high. Materials and Methods: Scattered X-ray energy spectra were experimentally derived for three different types of X-ray diagnostic and therapeutic equipment, i.e., the computed tomography (CT) scan, the angiography and the fluoroscopy. A commercially available CdZnTe (CZT) spectrometer with a lead collimator was employed for the measurement of scattered X-rays, which was performed in the usual manner. Results and Discussion: From the obtained energy spectra, the mean energies of the scattered X-rays lied between 40 and 60 keV. This also agreed with that obtained by the conventional half value layer method. Conclusion: The scattered X-rays to which medical workers may be exposed in the region around the eyes were characterized by means of spectrometry. The obtained mean energies of the scattered X-rays were found to match the flat region of the dosimeter response.

Keywords

Acknowledgement

The authors wish to thank Mr. Tetsuya Ohishi of JAEA for his continuous encouragements. This work was supported by the Ministry of Health, Labour and Welfare (MHLW), Japan (Hojokin Grant No. 180501-01).

References

  1. Clement CH, Stewart FA, Akleyev AV, Hauer-Jensen M, Hendry JH, Kleiman NJ, et al. ICRP publication 118: ICRP statement on tissue reactions and early and late effects of radiation in normal tissues and organs: threshold doses for tissue reactions in a radiation protection context. Ann ICRP. 2012;41(1-2):1-322. https://doi.org/10.1016/j.icrp.2012.02.001
  2. Vanhavere F, Carinou E, Gualdrini G, Clairand I, Sans Merce M, Ginjaume M, et al. Oramed: optimization of radiation protection of medical staff (EURADOS Report 2012-02). Neuherberg, Germany: European Radiation Dosimetry Group; 2012.
  3. Asahara T, Hayashi H, Goto S, Kimoto N, Takegami K, Maeda T, et al. Evaluation of calibration factor of OSLD toward eye lens exposure dose measurement of medical staff during IVR. J Appl Clin Med Phys. 2020;21(11):263-271.
  4. Kromek. GR1 radiation detectors [Internet]. County Durham, UK: Kromek; c2021 [cited 2021 Dec 18]. Available from: https://www.kromek.com/nuclear/gr1-ctz-gamma-ray-detectors/.
  5. Matscheko G, Carlsson GA. Compton spectroscopy in the diagnostic x-ray energy range. I. Spectrometer design. Phys Med Biol. 1989;34(2):185-197. https://doi.org/10.1088/0031-9155/34/2/003
  6. Matscheko G, Carlsson GA, Ribberfors R. Compton spectroscopy in the diagnostic x-ray energy range. II. Effects of scattering material and energy resolution. Phys Med Biol. 1989;34(2):199-208. https://doi.org/10.1088/0031-9155/34/2/004
  7. Matscheko G, Carlsson GA. Measurement of absolute energy spectra from a clinical CT machine under working conditions using a Compton spectrometer. Phys Med Biol. 1989;34(2):209-222. https://doi.org/10.1088/0031-9155/34/2/005
  8. Maeda K, Matsumoto M, Taniguchi A. Compton-scattering measurement of diagnostic x-ray spectrum using high-resolution Schottky CdTe detector. Med Phys. 2005;32(6):1542-1547. https://doi.org/10.1118/1.1921647
  9. Tachibana M, Izumi T. An absorbed dose conversion factor due to the x-ray spectrum compare with the method by the half-value layer. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2002;58(3):383-389. https://doi.org/10.6009/jjrt.KJ00001364291
  10. Tanimura Y, Nishino S, Yoshitomi H, Kowatari M, Oishi T. Characteristics of commercially available CdZnTe detector as gamma-ray spectrometer under severe nuclear accident. Prog Nucl Sci Technol. 2019;6:134-138. https://doi.org/10.15669/pnst.6.134
  11. Kowatari M, Tanimura Y, Kessler P, Neumaier S, Roettger A. Development of a simultaneous evaluation method of radioactivity in soil and dose rate using CeBr3 and SrI2(Eu) scintillation detectors for environmental monitoring. Prog Nucl Sci Technol. 2019;6:81-85. https://doi.org/10.15669/pnst.6.81
  12. Reginatto M, Goldhagen P, Neumann S. Spectrum unfolding, sensitivity analysis and propagation of uncertainties with the maximum entropy deconvolution code MAXED. Nucl Instrum Methods Phys Res A. 2002;476(1-2):242-246. https://doi.org/10.1016/S0168-9002(01)01439-5
  13. Briesmeister JF. MCNP: a general Monte Carlo N-Particle transport cord [Internet]. Los Alamos, NM: Los Alamos National Laboratory; 2000 [cited 2021 Dec 18]. Available from: https://library.lanl.gov/TemporaryDocumentLink/p/la-13709.htm.
  14. Kowatari M, Yoshitomi H, Nishino S, Tanimura Y, Ohishi T, Yoshizawa M. The facility of radiation standards in Japan Atomic Energy Agency, present status and its research works on dosimetry. Proceedings of the 14th Congress of the International Radiation Protection Association; 2016 May 9-13; Cape Town, South Africa.
  15. Haga Y, Chida K, Kaga Y, Sota M, Meguro T, Zuguchi M. Occupational eye dose in interventional cardiology procedures. Sci Rep. 2017;7(1):569. https://doi.org/10.1038/s41598-017-00556-3
  16. Nagamoto K, Moritake T, Nakagami K, Morota K, Matsuzaki S, Nihei SI, et al. Occupational radiation dose to the lens of the eye of medical staff who assist in diagnostic CT scans. Heliyon. 2021;7(1):e06063. https://doi.org/10.1016/j.heliyon.2021.e06063
  17. Ota J, Yokota H, Kawasaki T, Taoka J, Kato H, Chida K, et al. Evaluation of radiation protection methods for assistant staff during CT imaging in high-energy trauma: lens dosimetry with a phantom study. Health Phys. 2021;120(6):635-640. https://doi.org/10.1097/HP.0000000000001391
  18. Masterson M, Cournane S, McWilliams N, Maguire D, McCavana J, Lucey J. Relative response of dosimeters to variations in scattered X-ray energy spectra encountered in interventional radiology. Phys Med. 2019;67:141-147. https://doi.org/10.1016/j.ejmp.2019.11.002
  19. Matsubara K, Takei Y, Mori H, Kobayashi I, Noto K, Igarashi T, et al. A multicenter study of radiation doses to the eye lenses of medical staff performing non-vascular imaging and interventional radiology procedures in Japan. Phys Med. 2020;74:83-91. https://doi.org/10.1016/j.ejmp.2020.05.004
  20. Platten DJ. A Monte Carlo study of the energy spectra and transmission characteristics of scattered radiation from x-ray computed tomography. J Radiol Prot. 2014;34(2):445-456. https://doi.org/10.1088/0952-4746/34/2/445
  21. Martin CJ. Eye lens dosimetry for fluoroscopically guided clinical procedures: practical approaches to protection and dose monitoring. Radiat Prot Dosimetry. 2016;169(1-4):286-291. https://doi.org/10.1093/rpd/ncv431