Skip to main content

Advertisement

SpringerLink
Log in

Reducing shield thickness and backscattered radiation using a multilayered shield for 6–10 MeV electron beams

  • Scientific Note
  • Published:
Australasian Physical & Engineering Sciences in Medicine Aims and scope Submit manuscript

Abstract

Intraoral and external electron shields used in radiotherapy are designed to minimize radiation exposure to non-treatment tissue. Sites where shields are used include but are not limited to, the treatment of lips, cheeks and ears whilst shielding the underlying oral cavity, tongue, gingival or temporal region. A commonly known and published effect, concerns the enhancement in dose that can occur on the beam side on an electron shield caused by an increase in electron backscatter radiation. In this work a lead shield has been designed incorporating copper, aluminium and wax in a step down filter arrangement to minimise backscatter whilst minimizing overall shield thickness for better clinical setup and ease of use. For electron beams ranging from 6 to 10 MeV, a standard shield design of 4 mm lead, 0.6 mm copper, 1.0 mm aluminium and 1.5 mm wax (3.1 mm added filtration, 7.1 mm total thickness) provided adequate backscatter and transmission reduction to match a standard 4.5 mm lead and 10 mm wax (total thickness 14.5 mm) electron shield. Dose enhancement values of no more than 10 % were measured utilising this shield design with a 50 % reduction in shield thickness. The thinner shield will not only allow easier patient set up but should be tolerated better by patients when mucosal reactions occur as they place less physical pressure on these sites during treatment due to their smaller size.

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

Access this article

Log in via an institution

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

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

References

  1. Gerbi BJ, Antolak JA, Deibel FC et al (2009) Recommendations for clinical electron beam dosimetry: supplement to the recommendations of Task Group 25. Med Phys 36(7):3239–3279

    Article  PubMed  Google Scholar 

  2. Hogstrom KR (2004) Electron beam therapy: dosimetry, planning, and techniques. In: Halperin EC, Perez CA, Brady IW (eds) Perez and Brady’s principles and practice of radiation oncology. Lippincott, Williams & Wilkins, Baltimore, pp 252–258

    Google Scholar 

  3. Vaeth JM, Meyer JL (1991) The role of high energy electrons in the treatment of cancer., Frontiers of radiation therapy and oncology seriesKarger, San Francisco

    Google Scholar 

  4. Tapley N (1976) Clinical application of the electron beam. Wiley, New York

    Google Scholar 

  5. Klevenhagen SC, Lambert GD, Arbabi A (1982) Backscattering in electron beam therapy for energies between 3 and 35 MeV. Phys Med Biol 27:363–373

    Article  PubMed  CAS  Google Scholar 

  6. Lambert GD, Klevenhagen SC (1982) Penetration of backscattered electrons in polystyrene for energies between 1 and 25 MeV. Phys Med Biol 27:721–725

    Article  CAS  Google Scholar 

  7. Khan (2003) The physics of radiation therapy, 3rd edn. Philadelphia, Lippincott, Williams and Wilkins 2003

    Google Scholar 

  8. Weatherburn H, McMillan KT, Stedeford B (1975) Durrant KR Letter: Physical measurements and clinical observation on the backscatter on 10 MeV electrons from lead shielding. Br J Radiol 48(567):229–230

    Article  PubMed  CAS  Google Scholar 

  9. Khan FM, Werner BL, Deibel FC Jr (1981) Lead shielding for electrons. Med Phys 8(5):712–713

    Article  PubMed  CAS  Google Scholar 

  10. Klevenhagen SC (1990) Electron backscattering. Implication to electron dosimetry. Radiol Med 80(4 Suppl 1):160–162

    PubMed  CAS  Google Scholar 

  11. Tabata T, Ito R (1992) Simple calculation of the electron-backscatter factor. Med Phys 19(6):1423–1426

    Article  PubMed  CAS  Google Scholar 

  12. Verhaegen F (2003) Interface perturbation effects in high-energy electron beams. Phys Med Biol 48(6):687–705

    Article  PubMed  Google Scholar 

  13. Hopley S, Cassidy D, Rattray G, Grocott R, Bonnell P (1999) Intra-oral shielding for electrons. Radiographer 46(3):147–151

    Google Scholar 

  14. Sathiyan S, Ravikumar M, Supe S (2006) Measurement of backscattered dose at metallic interfaces using high energy electron beams. Rep Pract Oncol Radiother 11(3):117–121

    Article  Google Scholar 

  15. Chow JC, Grigorov GN (2008) Monte Carlo simulation of backscatter from lead for clinical electron beams using EGSnrc. Med Phys 35(4):1241–1250

    Article  PubMed  Google Scholar 

  16. Chow JC, Owrangi AM (2009) Solid water as phantom material for dosimetry of electron backscatter using low-energy electron beams: a Monte Carlo evaluation. Med Phys 36(5):1587–1594

    Article  PubMed  Google Scholar 

  17. Pérez-Calatayudt J, Ballester F, Serrano MA, Lluch JL, Casal E, Carmona V (2000) Dosimetric characteristics of backscattered electrons in lead. Phys Med Biol 45(7):1841–1849

    Article  PubMed  Google Scholar 

  18. Shiu AS, Tung SS, Gastorf RJ, Hogstrom KR, Morrison WH, Peters LJ (1996) Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment. Int J Radiat Oncol Biol Phys 35:599–604

    Article  PubMed  CAS  Google Scholar 

  19. Niroomand-Rad A, Blackwell CR, Coursey BM, Gall KP, Galvin JM, McLaughlin WL, Meigooni AS, Nath R, Rodgers JE, Soares CG (1998) Radiochromic film dosimetry: recommendations of AAPM Radiation Therapy Committee Task Group 55. American Association of Physicists in Medicine. Med Phys 25(11):2093–2115

    Article  PubMed  CAS  Google Scholar 

  20. Butson MJ, Yu KN, Cheung T, Metcalfe PE (2003) Radiochromic film for medical radiation dosimetry. Mater Sci Eng R: Rep 41:61–120

    Article  Google Scholar 

  21. Brown TA, Hogstrom KR, Alvarez D, Matthews KL 2nd, Ham K, Dugas JP (2012) Dose-response curve of EBT, EBT2, and EBT3 radiochromic films to synchrotron-produced monochromatic X-ray beams. Med Phys 39(12):7412–7417

    Article  PubMed  CAS  Google Scholar 

  22. Cheung T, Butson MJ, Yu KN (2005) Post irradiation coloration of Gafchromic EBT radiochromic film. Phys Med Biol 50:N281–N285

    Article  PubMed  Google Scholar 

  23. Butson MJ, Cheung T, Yu KN (2005) Absorption spectra variations of EBT radiochromic film from radiation exposure. Phys Med Biol 50:N135–N140

    Article  PubMed  CAS  Google Scholar 

  24. Butson MJ, Yu PKN, Cheung T, Alnawaf H (2010) Energy response of the new EBT2 radiochromic film to x-ray radiation. Radiat Meas 45:836–839

    Article  CAS  Google Scholar 

  25. Arjomandy B, Tailor R, Zhao L, Devic S (2012) EBT2 film as a depth-dose measurement tool for radiotherapy beams over a wide range of energies and modalities. Med Phys 39(2):912–921

    Article  PubMed  CAS  Google Scholar 

  26. Butson MJ, Cheung T, Yu PK (2009) Evaluation of the magnitude of EBT Gafchromic film polarization effects. Australas Phys Eng Sci Med 32(1):21–25

    Article  PubMed  CAS  Google Scholar 

  27. Butson MJ, Cheung T, Yu PKN (2006) Scanning orientation effects on EBT Gafchromic film dosimetry. Australas Phys Eng Sci Med 29:281–284

    Article  PubMed  CAS  Google Scholar 

  28. Yu PKN, Butson M, Cheung T (2006) Does mechanical pressure on radiochromic film affect optical absorption and dosimetry? Australas Phys Eng Sci Med 29(3):285–287

    Article  PubMed  CAS  Google Scholar 

  29. National Institute of Standards and Technology. http://physics.nist.gov/PhysRefData/Star/Text/method.html. Accessed Mar 2014

  30. Weidlich GA, Nuesch CE, Fuery JJ (1996) Added aluminum shielding to attenuate back scatter electrons from intra-oral lead shields. Med Dosim 21(3):165–167

    Article  PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Chris O’Brien Lifehouse, Missenden Rd, Camperdown, NSW, Australia

    Martin Butson & Robin Hill

  2. Genesis Care - Mater Sydney Radiation Oncology, Sydney, Australia

    Tom Chen, James Lee, Gerald Fogarty & Michael Izard

  3. Macarthur Cancer Therapy Centre, Campbelltown, Australia

    Somkhit Rattanavoang, James Hellyer, Alison Gray, Vinod Nelson, Richard Short & Satya Rajapakse

  4. Sydney Medical School, The University of Sydney, Sydney, Australia

    Michael Izard

Authors
  1. Martin Butson
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Tom Chen
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Somkhit Rattanavoang
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. James Hellyer
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Alison Gray
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Vinod Nelson
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Richard Short
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Satya Rajapakse
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. James Lee
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Gerald Fogarty
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Michael Izard
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Robin Hill
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Martin Butson.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Butson, M., Chen, T., Rattanavoang, S. et al. Reducing shield thickness and backscattered radiation using a multilayered shield for 6–10 MeV electron beams. Australas Phys Eng Sci Med 38, 619–626 (2015). https://doi.org/10.1007/s13246-015-0382-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13246-015-0382-1

Keywords

Search

Navigation