Skip to main content
SpringerLink
Log in

Pre-treatment verification of intensity modulated radiation therapy plans using a commercial electronic portal dosimetry system

  • Original Paper
  • Published:
Australasian Physical & Engineering Sciences in Medicine Aims and scope Submit manuscript

Abstract

We commissioned a commercially available portal dosimetry system for quality assurance of intensity modulated radiation therapy (IMRT) treatment plans. The system included gamma analysis software to compare the measured and predicted fluence maps from individual IMRT fields. The portal dosimetry system was tested using six head and neck IMRT patient plans, and we demonstrated that the accuracy of the alignment of measured and predicted images improved by retracting and repositioning the electronic portal imaging device (EPID) at each new gantry angle. The mean gamma score (fraction of pixels passing the gamma criteria) for the six test plans (after initial testing and using the EPID retracting and repositioning method) was 0.987 (2SD = 0.018), using gamma criteria of a dose difference of 2% of the maximum field dose and 2 mm distance to agreement. The mean gamma score was 0.989 (2SD = 0.017) for 24 head and neck IMRT patient plans carried out with portal dosimetry. Using gamma criteria of 2% maximum field dose and 2 mm distance to agreement, a gamma score tolerance of 0.980 is a useful way of highlighting only those fields requiring further analysis. Portal dosimetry is a quick way of assessing individual field fluence distributions and can be integrated into an IMRT quality assurance programme.

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

Similar content being viewed by others

References

  1. Mijnheer B, Georg D (2008) ESTRO booklet no. 9: guidelines for the verification of IMRT, 2008. http://www.estro-education.org/publications/Pages/ESTROPhysicsBooklets.aspx

  2. Dogan N, Leybovich LB, Sethi A (2002) Comparative evaluation of Kodak EDR2 and XV2 films for verification of intensity modulated radiation therapy. Phys Med Biol 47(22):4121–4130

    Article  PubMed  Google Scholar 

  3. Winkler P, Zurl B, Guss H, Kindl P, Stuecklschweiger G (2005) Performance analysis of a film dosimetric quality assurance procedure for IMRT with regard to the employment of quantitative evaluation methods. Phys Med Biol 50(4):643–654

    Article  PubMed  Google Scholar 

  4. Budgell GJ, Perrin BA, Mott JHL, Fairfoul J, Mackay RI (2005) Quantitative analysis of patient-specific dosimetric IMRT verification. Phys Med Biol 50(1):103–119

    Article  CAS  PubMed  Google Scholar 

  5. Childress NL, White RA, Bloch C, Salehpour M, Dong L, Rosen II (2005) Retrospective analysis of 2D patient-specific IMRT verifications. Med Phys 32(4):838–850

    Article  PubMed  Google Scholar 

  6. Bucciolini M, Buonamici FB, Casati M (2004) Verification of IMRT fields by film dosimetry. Med Phys 31(1):161–168

    Article  PubMed  Google Scholar 

  7. Renner WD, Sarfaraz M, Earl MA, Yu CX (2003) A dose delivery verification method for conventional and intensity-modulated radiation therapy using measured field fluence distributions. Med Phys 30(11):2996–3005

    Article  PubMed  Google Scholar 

  8. De Martin E, Fiorino C, Broggi S, Longobardi B, Pierelli A, Perna L, Cattaneo GM, Calandrino R (2007) Agreement criteria between expected and measured field fluences in IMRT of the head and neck cancer: the importance and use of the gamma histograms statistical analysis. Radiother Oncol 85:399–406

    Article  PubMed  Google Scholar 

  9. Buonamici FB, Compagnucci A, Marrazzo L, Russo S, Bucciolini M (2007) An intercomparison between film dosimetry and diode matrix for IMRT quality assurance. Med Phys 34(4):1372–1379

    Article  PubMed  Google Scholar 

  10. Jursinic PA, Nelms BE (2003) A 2-D diode array and analysis software for verification of intensity modulated radiation therapy delivery. Med Phys 30(5):870–879

    Article  PubMed  Google Scholar 

  11. Warkentin B, Steciw S, Rathee S, Fallone BG (2003) Dosimetric IMRT verification with a flat-panel EPID. Med Phys 30(12):3143–3155

    Article  CAS  PubMed  Google Scholar 

  12. Van Esch A, Depuydt T, Huyskens DP (2004) The use of an aSi-based EPID for routine absolute dosimetric pre-treatment verification of dynamic IMRT fields. Radiother Oncol 71(2):223–234

    Article  PubMed  Google Scholar 

  13. Talamonti C, Casati M, Bucciolini M (2006) Pretreatment verification of IMRT absolute dose distributions using a commercial a-Si EPID. Med Phys 33(11):4367–4378

    Article  CAS  PubMed  Google Scholar 

  14. Howell RM, Smith IPN, Jarrio CS (2008) Establishing action levels for EPID-based QA for IMRT. J Appl Clin Med Phys 9(3):16–25

    Article  Google Scholar 

  15. Wendling M, Louwe RJW, McDermott LN, Sonke J-J, Van Herk M, Mijnheer BJ (2006) Accurate two-dimensional IMRT verification using a back-projection EPID dosimetry method. Med Phys 33(2):259–273

    Article  PubMed  Google Scholar 

  16. Van Zijtveld M, Dirkx MLP, De Boer HCJ, Heijmen BJM (2007) 3D dose reconstruction for clinical evaluation of IMRT pretreatment verification with an EPID. Radiother Oncol 82(2):201–207

    Article  PubMed  Google Scholar 

  17. El-Mohri Y, Antonuk LE, Yorkston J, Jee K-W, Maolinbay M, Lam KL, Siewerdsen JH (1999) Relative dosimetry using active matrix flat-panel imager (AMFPI) technology. Med Phys 26(8):1530–1541

    Article  CAS  PubMed  Google Scholar 

  18. Greer PB, Popescu CC (2003) Dosimetric properties of an amorphous silicon electronic portal imaging device for verification of dynamic intensity modulated radiation therapy. Med Phys 30(7):1618–1627

    Article  PubMed  Google Scholar 

  19. Grein EE, Lee R, Luchka K (2002) An investigation of a new amorphous silicon electronic portal imaging device for transit dosimetry. Med Phys 29(10):2262–2268

    Article  CAS  PubMed  Google Scholar 

  20. McCurdy BMC, Luchka K, Pistorius S (2001) Dosimetric investigation and portal dose image prediction using an amorphous silicon electronic portal imaging device. Med Phys 28(6):911–924

    Article  CAS  PubMed  Google Scholar 

  21. Kavuma A, Glegg M, Currie G, Elliott A (2008) Assessment of dosimetrical performance in 11 Varian a-Si500 electronic portal imaging devices. Phys Med Biol 53(23):6893–6909

    Article  PubMed  Google Scholar 

  22. Louwe RJW, McDermott LN, Sonke J-J, Tielenburg R, Wendling M, Van Herk MB, Mijnheer BJ (2004) The long-term stability of amorphous silicon flat panel imaging devices for dosimetry purposes. Med Phys 31(11):2989–2995

    Article  CAS  PubMed  Google Scholar 

  23. Van Elmpt W, McDermott L, Nijsten S, Wendling M, Lambin P, Mijnheer B (2008) A literature review of electronic portal imaging for radiotherapy dosimetry. Radiother Oncol 88:289–309

    Article  PubMed  Google Scholar 

  24. Winkler P, Hefner A, Georg D (2007) Implementation and validation of portal dosimetry with an amorphous silicon EPID in the energy range from 6 to 25 MV. Phys Med Biol 52(15):N355–N365

    Article  PubMed  Google Scholar 

  25. Van Zijtveld M, Dirkx MLP, De Boer HCJ, Heijmen BJM (2006) Dosimetric pre-treatment verification of IMRT using an EPID; clinical experience. Radiother Oncol 81:168–175

    Article  PubMed  Google Scholar 

  26. McDermott LN, Wendling M, Van Asselen B, Stroom J, Sonke J-J, Van Herk M, Mijnheer BJ (2006) Clinical experience with EPID dosimetry for prostate IMRT pre-treatment dose verification. Med Phys 33(10):3921–3930

    Article  CAS  PubMed  Google Scholar 

  27. Van Elmpt W, Nijsten S, Mijnheer B, Dekker A, Lambin P (2008) The next step in patient-specific QA: 3D dose verification of conformal and intensity-modulated RT based on EPID dosimetry and Monte Carlo dose calculations. Radiother Oncol 86(1):86–92

    Article  PubMed  Google Scholar 

  28. Partridge M, Ebert M, Hesse B-M (2002) IMRT verification by three-dimensional dose reconstruction from portal beam measurements. Med Phys 29(8):1847–1858

    Article  CAS  PubMed  Google Scholar 

  29. McDermott LN, Wendling M, Sonke J-J, Van Herk M, Mijnheer BJ (2007) Replacing pretreatment verification with in vivo EPID dosimetry for prostate IMRT. Int J Radiat Oncol Biol Phys 67(5):1568–1577

    PubMed  Google Scholar 

  30. Van Zijtveld M, Dirkx M, Breuers M, De Boer H, Heijmen B (2009) Portal dose image prediction for in vivo treatment verification completely based on EPID measurements. Med Phys 36(3):946–952

    Article  PubMed  Google Scholar 

  31. Gafchromic EBT self-developing film for radiotherapy dosimetry: White paper (2007). http://online1.ispcorp.com/_layouts/Gafchromic/content/

  32. Zeidan OA, Stephenson SAL, Meeks SL, Wagner TH, Willoughby TR, Kupelian PA, Langen KM (2006) Characterisation and use of EBT radiochromic film for IMRT dose verification. Med Phys 33(11):4064–4072

    Article  PubMed  Google Scholar 

  33. Todorovic M, Fischer M, Cremers F, Thom E, Schmidt R (2006) Evaluation of GafChromic EBT prototype B for external beam dose verification. Med Phys 33(5):1321–1328

    Article  CAS  PubMed  Google Scholar 

  34. Greer PB (2005) Correction of pixel sensitivity variation and off-axis response for amorphous silicon EPID dosimetry. Med Phys 32(12):3558–3568

    Article  PubMed  Google Scholar 

  35. Low DA, Harms WB, Mutic S, Purdy JA (1998) A technique for the quantitative evaluation of dose distributions. Med Phys 25(5):656–661

    Article  CAS  PubMed  Google Scholar 

  36. Ackerly T, Geso M, O’Keefe G, Smith R (2004) Stereotactic radiosurgery planning with ictal SPECT images. Australas Phys Eng Sci Med 27(3):136–147

    Article  CAS  PubMed  Google Scholar 

  37. Both S, Alecu IM, Stan AR, Alecu M, Ciura A, Hansen JM, Alecu R (2007) A study to establish reasonable action limits for patient-specific quality assurance in intensity-modulated radiation therapy. J Appl Clin Med Phys 8(2):1–8

    PubMed  Google Scholar 

  38. Mayo C, Urie M (2004) Eclipse IMRT: a practical treatment planning guide. Varian Medical Systems, Las Vegas, NV, USA

    Google Scholar 

Download references

Acknowledgements

The authors would like to thank Phil Vial at the Royal North Shore Hospital, Sydney and Peter Greer at the Calvary Mater Newcastle Hospital, Newcastle, for helpful discussions during commissioning.

Author information

Authors and Affiliations

  1. William Buckland Radiotherapy Centre, The Alfred, Commercial Road, Melbourne, VIC, 3004, Australia

    Kathleen J. Roxby & Jeffrey C. Crosbie

  2. Centre for Women’s Health Research, Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia

    Jeffrey C. Crosbie

  3. Monash Centre for Synchrotron Science, Monash University, Clayton, VIC, Australia

    Jeffrey C. Crosbie

Authors
  1. Kathleen J. Roxby
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jeffrey C. Crosbie
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Kathleen J. Roxby.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Roxby, K.J., Crosbie, J.C. Pre-treatment verification of intensity modulated radiation therapy plans using a commercial electronic portal dosimetry system. Australas Phys Eng Sci Med 33, 51–57 (2010). https://doi.org/10.1007/s13246-010-0001-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13246-010-0001-0

Keywords

Search

Navigation