Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-30T18:52:26.643Z Has data issue: false hasContentIssue false

Dosimetric evaluation of electron beams on scalp using EBT2 films and rando phantom

Published online by Cambridge University Press:  08 January 2018

Nafise Hasoomi*
Affiliation:
Department of Nuclear Engineering, Islamic Azad University, Science and Research Branch, Tehran, Iran
Mansour Naderi
Affiliation:
Department of Nuclear Engineering, Islamic Azad University, Science and Research Branch, Tehran, Iran
Akbar Sarabi Asl
Affiliation:
Department of Nuclear Engineering, Faculty of Advanced Science & Technologies, University of Isfahan, Isfahan, Iran
*
Correspondence to: Nafise Hasoomi, Department of Nuclear Engineering, Islamic Azad University, Science and Research Branch, Tehran, Iran. Tel: +98 2155429553. E-mail: [email protected]

Abstract

Background

In radiotherapy, electron beam irradiation is an effective modality for superficial tumours. Electron beams have good coverage of tumours which involve the skin, however there is an issue about electron scattering and tissue heterogeneity. This subsequently demands dosimetric analysis of electron beam behaviour, particularly in the treatment of lesions on the scalp requiring the application of treatment to scalp curvatures. There are various methods which are used to treat scalp malignancies including photons and electrons, but, the later needs precise dosimetry before each session of treatment. The purpose of the study was to undertake a detailed analysis of the dosimetry of electron beams when applied to the curved surface of the scalp using Gafchromic® EBT2 films.

Methods and materials

A rando phantom and Gafchromic® EBT2 films were used for dosimetric analysis. A gafchromic calibration curve was plotted and an in-treatment beam dosimetric analysis was carried out using dosimetry films placed on the scalp. Electron behaviour was assessed by introducing five electron fields in particular curvature regions of scalp.

Result

There was an acceptable dose range through all five fields and hotspots occurred in the curved borders. In our study, skin doses and doses at the field junctions, with no gaps, were between 78–97% and 80–97%, respectively.

Conclusions

Electron beams are a good modality for treating one flat field, but in the special topography of the scalp, whole scalp treatment requires precise field matching and dosimetry. In undertaking this detailed dosimetric analysis using a rando phantom and Gafchromic® EBT2 films, it is concluded that this method requires further detailed analysis before using in clinics.

Type
Technical Note
Copyright
© Cambridge University Press 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Tung, S S, Shiu, A S, Starkschall, G, Morrison, W H, Hogstrom, K R. Dosimetric evaluation of total scalp irradiation using a lateral electron-photon technique. Int J Radiat Oncol Biol Phys 1993; 27 (1): 153160.Google Scholar
2. Liebmann, A, Pohlmann, S, Heinicke, F, Hildebrandt, P D G. Helmet mold-based surface brachytherapy for homogeneous scalp treatment: a case report. Strahlenther Onkol 2007; 183 (4): 211214.Google Scholar
3. Able, C M, Mills, M D, McNeese, M D, Hogstrom, K R. Evaluation of a total scalp electron irradiation technique. Int J Radiat Oncol Biol Phys 1991; 21 (4): 10631072.Google Scholar
4. Song, J H, Jung, J-Y, Park, H-W et al. Dosimetric comparison of three different treatment modalities for total scalp irradiation: the conventional lateral photon–electron technique, helical tomotherapy, and volumetric-modulated arc therapy. J Radiat Res 2014; 56 (4): 717726.Google Scholar
5. Mellenberg, D E, Schoeppel, S L. Total scalp treatment of mycosis fungoides: the 4× 4 technique. Int J Radiat Oncol Biol Phys 1993; 27 (4): 953958.Google Scholar
6. Walker, C, Wadd, N, Lucraft, H. Novel solutions to the problems encountered in electron irradiation to the surface of the head. Br J Radiol 1999; 72 (860): 787791.Google Scholar
7. Akazawa, C. Treatment of the scalp using photon and electron beams. Med Dosim 1988; 14 (2): 129131.Google Scholar
8. Orton, N, Jaradat, H, Welsh, J, Tomé, W. Total scalp irradiation using helical tomotherapy. Med Dosim 2005; 30 (3): 162168.Google Scholar
9. Chan, M F, Song, Y, Burman, C, Chui, C S, Schupak, K. (eds), The treatment of extensive scalp lesions combining electrons with intensity-modulated photons. 28th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2006 EMBS’06. IEEE, 2006. New York.Google Scholar
10. Ostheimer, C, Janich, M, Hübsch, P, Gerlach, R, Vordermark, D. The treatment of extensive scalp lesions using coplanar and non-coplanar photon IMRT: a single institution experience. Radiat Oncol 2014; 9 (1): 82.Google Scholar
11. Caivano, R, Fiorentino, A, Pedicini, P, Califano, G, Fusco, V. A radiotherapy technique for palliative total scalp irradiation. Ann Palliat Med 2015; 4 (1): 3538.Google Scholar
12. Wojcicka, J B, Lasher, D E, McAfee, S S, Fortier, G A. Dosimetric comparison of three different treatment techniques in extensive scalp lesion irradiation. Radiother Oncol 2009; 91 (2): 255260.Google Scholar
13. Hardcastle, N, Soisson, E, Metcalfe, P, Rosenfeld, A B, Tomé, W A. Dosimetric verification of helical tomotherapy for total scalp irradiation. Med Phys 2008; 35 (11): 50615068.Google Scholar
14. Niroomand‐Rad, A, Blackwell, CR, Coursey, BM et al. Radiochromic film dosimetry: recommendations of AAPM radiation therapy committee task group 55. Med Phys 1998; 25 (11): 20932115.Google Scholar
15. Andreo, P, Burns, D, Hohlfeld, K et al. IAEA TRS-398–Absorbed dose determination in external beam radiotherapy: an international code of practice for dosimetry based on standards of absorbed dose to water. Vienna, Astria: International Atomic Energy Agency, 2000.Google Scholar
16. Khan, F M, Gibbons, J P. Khan’s the Physics of Radiation Therapy. Philadelphia, USA: Lippincott Williams & Wilkins, 2014; 590pp.Google Scholar
17. Pathak, P, Mishra, P K, Singh, M, Mishra, P K. Analytical study of flatness and symmetry of electron beam with 2D array detectors. J Cancer Sci Ther 2015: 294301.Google Scholar
18. Lynch, B D, Kozelka, J, Ranade, M K, Li, J G, Simon, W E, Dempsey, J F. Important considerations for radiochromic film dosimetry with flatbed CCD scanners and EBT GAFCHROMIC® film. Med Phys 2006; 33 (12): 45514556.Google Scholar
19. Xu, L B. Commissioning of a GafChromic EBT film dosimetry protocol at Ionizing Radiation Standards group of National Research Council: Mcgill University; 2009.Google Scholar
20. Mayers, S. Characterisation of gafchromic EBT2 film for use in radiation therapy dosimetry. 2011: 98.Google Scholar
21. Sim, G, Wong, J, Ng, K. The use of radiochromic EBT2 film for the quality assurance and dosimetric verification of 3D conformal radiotherapy using Microtek ScanMaker 9800XL flatbed scanner. J Appl Clin Med Phys 2013; 14 (4): 8595.Google Scholar
22. GafchromicVR E. Self-developing film for radiotherapy dosimetry. ISP White Paper. 2010. International Speciality Products A Business Unit of ISP, Wayne, NJ, USA.Google Scholar
23. Andreo, P, Huq, M S, Westermark, M et al. Protocols for the dosimetry of high-energy photon and electron beams: a comparison of the IAEA TRS-398 and previous international codes of practice. Phys Med Biol 2002; 47 (17): 3033.Google Scholar