Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-22T05:11:17.840Z Has data issue: false hasContentIssue false
  • English
  • Français

The experience of a developing country using an electronic portal imaging device for the verification of patient positioning and dosimetry in radiotherapy for prostate cancer

Published online by Cambridge University Press:  05 March 2018

Leila Farhat ,
N. Fourati ,
W. Mnejja  and
J. Daoud
Leila Farhat*
Affiliation:
Oncology Radiotherapy Department, Habib Bourguiba Hospital, Sfax, Tunisia
N. Fourati
Affiliation:
Oncology Radiotherapy Department, Habib Bourguiba Hospital, Sfax, Tunisia
W. Mnejja
Affiliation:
Oncology Radiotherapy Department, Habib Bourguiba Hospital, Sfax, Tunisia
J. Daoud
Affiliation:
Oncology Radiotherapy Department, Habib Bourguiba Hospital, Sfax, Tunisia
*
Author for correspondence: Leila Farhat, Oncology Radiotherapy Department, Habib Bourguiba Hospital, El Ain Roade km 1,5, 3000 Sfax, Tunisia. Tel: +00216 5812 7798. E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Purpose

This is a retrospective study to evaluate the efficacy and safety of routine use of electronic portal imaging device (EPID) in intensity-modulated radiation therapy for localised prostate cancer.

Materials and methods

Data from 20 patients with localised prostate cancer treated by radical radiotherapy using intensity-modulated technique in Habib Bourguiba Hospital were analysed to define the action levels for pretreatment planer dose distribution of 100 treatment fields and the set-up errors of 418 portal imaging. Pretreatment planar dose distribution was measured with the EPID. The additional dose from repeated portal imaging was determined with treatment planning system.

Results

For all 100 fields, the predicted and the measured planar dose distribution agrees well with mean±standard deviation value for γmax=2·31±0·57, γavg=0·36±0·07 and γ%≤1=98·94%±0·71%, respectively. For the evaluation of set-up errors, the mean total errors with 1 SD in the lateral, longitudinal and vertical directions were 0·11±0·44 cm; 0·02±0·37 cm and −0·02±0·21 cm, respectively. The imaging additional dose was evaluated as 1 cGy per monitor unit.

Conclusion

EPID is a useful tool to verify pretreatment dose distribution and to assess the correct field position without a significant increase in the absorbed dose due to the repetition of portal imaging.

Keywords

EPIDIMRTportal dosimetryportal imagingprostate cancer
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 17 , Issue 3 , September 2018 , pp. 297 - 301
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. Viani, G A, Stefano, E J, Afonso, S L. Higher-than-conventional radiation doses in localized prostate cancer treatment: a meta-analysis of randomized, controlled trials. Int J Radiat Oncol Biol Phys 2009; 74 (5): 1405–1418.Google Scholar
2. Zaorsk, N G, Palmer, J D, Hurwitz, M D, Keith, S W, Dicker, A P, Den, R B. What is the ideal radiotherapy dose to treat prostate cancer? A meta-analysis of biologically equivalent dose escalation. Radiother Oncol 2015; 115 (3): 295–300.Google Scholar
3. Herman, M G, Balter, J M, Jaffray, D A et al. Clinical use of electronic portal imaging: report of AAPM Radiation Therapy Committee Task Group 58. Med Phys 2001; 28 (5): 712–737.Google Scholar
4. Van Esch, A, Depuydt, T, Huyskens, D P. The use of an aSi-based EPID for routine absolute dosimetric pre-treatment verification of dynamic IMRT fields. Radiother Oncol 2004; 71 (2): 223–234.Google Scholar
5. Warkentin, B, Steciw, S, Rathee, S, Fallone, B G. Dosimetric IMRT verification with a flat‐panel EPID. Med Phys 2003; 30 (12): 3134–3155.Google Scholar
6. Hurkmans, C W, Remeijer, P, Lebesque, J V, Mijnheer, B J. Set-up verification using portal imaging; review of current clinical practice. Radiother Oncol 2001; 58 (2): 105–120.Google Scholar
7. Moran, J M, Dempsey, M, Eisbruch, A et al. Safety considerations for IMRT: executive summary. Med phys 2011; 38 (9): 5067–5072.Google Scholar
8. Jursinic, P A, Nelms, B E. A 2‐D diode array and analysis software for verification of intensity modulated radiation therapy delivery. Med Phys 2003; 30 (5): 870–879.Google Scholar
9. Poppe, B, Blechschmidt, A, Djouguela, A et al. Two‐dimensional ionization chamber arrays for IMRT plan verification. Med Phys 2006; 33 (4): 1005–1015.Google Scholar
10. Low, D A, Harms, W B, Mutic, S, Purdy, J A. A technique for the quantitative evaluation of dose distributions. Med Phys 1998; 25 (5): 656–661.Google Scholar
11. Van Herk, M, Remeijer, P, Rasch, C et al. The probability of correct target dosage: dose-population histograms for deriving treatment margins in radiotherapy. Int J Radiat Oncol Biol Phys 2000; 47 (4): 1121–1135.Google Scholar
12. Van Herk, M. Errors and margins in radiotherapy. Semin Radiat Oncol 2004; 14 (1): 52–64.Google Scholar
13. Bahadur, Y A, Naseem, H M, Fawzy, E E. A comparison study of radiation dose received during cone beam computerized tomography and portal imaging techniques. Med J Cairo Univ 2009; 77 (1): 171–177.Google Scholar
14. Alber, M, Broggi, S, Wagter, C D et al. Guidelines for the Verification of IMRT. ESTRO Booklet no. 9. Brussels: ESTRO, 2008.Google Scholar
15. Varatharaj, C, Moretti, E, Ravikumar, M, Malisan, M R, Supe, S S, Padovani, R. Implementation and validation of a commercial portal dosimetry software for intensity-modulated radiation therapy pre-treatment verification. J Med Phys 2010; 35 (4): 189–196.Google Scholar
16. Sharma, D S, Mhatre, V, Heigrujam, M et al. Portal dosimetry for pretreatment verification of IMRT plan: a comparison with 2D ion chamber array. J Appl Clin Med Phys 2010; 11 (4): 238–248.Google Scholar
17. Howell, R M, Smith, I P, Jarrio, C S. Establishing action levels for EPID-based QA for IMRT. J Appl Clin Med Phys 2008; 9 (3): 16–25.Google Scholar
18. Party, B W. Geometric Uncertainties in Radiotherapy . London: The British Institute of Radiology, 2003.Google Scholar
19. McGarry, C K, Cosgrove, V P, Fleming, V A L, O’Sullivan, J M, Hounsell, A R. An analysis of geometric uncertainty calculations for prostate radiotherapy in clinical practice. Br J Radiol 2009; 82 (974): 140–147.Google Scholar
20. Enmark, M, Korreman, S, Nyström, H. IGRT of prostate cancer; is the margin reduction gained from daily IG time-dependent? Acta Oncol 2006; 45 (7): 907–914.Google Scholar
21. Osei, E K, Jiang, R, Barnett, R, Fleming, K, Panjwani, D. Evaluation of daily online set-up errors and organ displacement uncertainty during conformal radiation treatment of the prostate. Br J Radiol 2009; 82 (973): 49–61.Google Scholar
22. De Crevoisier, R, Pommier, P, Latorzeff, I, Chapet, O, Chauvet, B, Hennequin, C. Prostate cancer external beam radiotherapy. Cancer Radiother 2016; 20: S200–S209.Google Scholar
23. Goyal, S, Kataria, T. Image guidance in radiation therapy: techniques and applications. Radiol Res Prac 2014; 2014: 1–10. doi.org/10.1155/2014/705604.Google Scholar
24. Vetterli, D, Riem, H, Aebersold, DM et al. Introduction of a novel dose saving acquisition mode for the PortalVision™ aS500 EPID to facilitate on‐line patient setup verification. Med Phys 2004; 31 (4): 828–831.Google Scholar
25. Reilly, A J. Uniform Framework for the Objective Assessment and Optimisation of Radiotherapy Image Quality . Edinburgh: University of Edinburgh, 2011.Google Scholar