Hostname: page-component-848d4c4894-tn8tq Total loading time: 0 Render date: 2024-07-01T23:30:20.102Z Has data issue: false hasContentIssue false
  • English
  • Français

Retrospective analysis of portal dosimetry pre-treatment quality assurance of prostate volumetric-modulated arc therapy (VMAT) plans

Published online by Cambridge University Press:  22 August 2017

Borna Maraghechi ,
Jack Davis ,
Shyam Badu ,
Andre Fleck ,
Johnson Darko  and
Ernest Osei
Borna Maraghechi
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, ON, Canada
Jack Davis
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, ON, Canada Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada
Shyam Badu
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, ON, Canada
Andre Fleck
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, ON, Canada Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
Johnson Darko
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, ON, Canada Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
Ernest Osei*
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, ON, Canada Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada Department of Systems Design, University of Waterloo, Waterloo, ON, Canada
*
Correspondence to: Dr Ernest Osei, Department of Medical Physics, Grand River Regional Cancer Centre, 835 King St W, Kitchener, ON, Canada, N2G 1G3. Tel: 519 749 4300, Ext: 5407. E-mail: ernest.osei@grhosp.on.ca
Get access Rights & Permissions [Opens in a new window]

Abstract

Background

Electronic portal imaging device (EPID) offers high-resolution digital image that can be compared with a predicted portal dose image. A very common method to quantitatively compare a measured and calculated dose distribution that is routinely used for quality assurance (QA) of volumetric-modulated arc therapy (VMAT) and intensity-modulated radiation therapy treatment plans is the evaluation of the gamma index. The purpose of this work was to evaluate the gamma passing rate (%GP), maximum gamma (γmax), average gamma (γave), maximum dose difference (DDmax) and the average dose difference (DDave) for various regions of interest using Varian’s implementation of three absolute dose gamma calculation techniques of improved, local, and combined improved and local.

Methods and materials

We analyzed 232 portal dose images from 100 prostate cancer patients’ VMAT plans obtained using the Varian EPID on TrueBeam Linacs.

Results

Our data show that the %GP, γmax and γave depend on the gamma calculation method and the acceptance criteria. Higher %GP values were obtained compared with both our current institutional action level and the American Association of Physicists in Medicine Task Group 119 recommendations.

Conclusions

The results of this study can be used to establish stricter action levels for pre-treatment QA of prostate VMAT plans. A stricter 3%/3 mm improved gamma criterion with a passing rate of 97% or the 2%/2 mm improved gamma criterion with a passing rate of 95% can be achieved without additional measurements or configurations.

Keywords

EPIDgamma indexportal dosimetryVMAT quality assurance
Type
Original Articles
Information
Journal of Radiotherapy in Practice , Volume 17 , Issue 1 , March 2018 , pp. 44 - 52
Check for updates
Copyright
© Cambridge University Press 2017 

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. Shaffer, R, Morris, WJ, Moiseenko, V et al. Volumetric modulated arc therapy and conventional intensity-modulated radiotherapy for simultaneous maximal intraprostatic boost: a Planning Comparison Study. Clin Oncol 2009; 21: 401–407.CrossRefGoogle ScholarPubMed
2. Zhang, P, Happersett, L, Hunt, M, Jackson, A, Zelefsky, M, Mageras, G. Volumetric modulated arc therapy: planning and evaluation for prostate cancer cases. Int J Radiat Oncol Biol Phys 2010; 76: 1456–1462.CrossRefGoogle ScholarPubMed
3. Maulana, A, Pawiro, SA. Dosimetry verification on VMAT and IMRT radiotherapy techniques: in the case of prostate cancer. J Phys Conf Ser 2016; 694: 012010.Google Scholar
4. Rout, B, Shekar, MC, Kumar, A, Muralidhar, K. Dosimetric study of RapidArc plans and conventional intensity modulated radiotherapy for prostate cancer involving seminal vesicles and pelvis lymph nodes. Int J Cancer Ther Oncol 2016; 4 (1): 418–425.Google Scholar
5. Otto, K. Volumetric modulated arc therapy: IMRT in a single gantry arc. Med Phys 2008; 35: 310–317.Google Scholar
6. Wolff, D, Stieler, F, Welzel, G et al. Volumetric modulated arc therapy (VMAT) vs. serial tomotherapy, step-andshoot IMRT and 3d-conformal RT for treatment of prostate cancer. Radiother Oncol 2009; 93: 226–233.Google Scholar
7. Kjr-Kristoffersen, F, Ohlhues, L, Medin, J, Korreman, S. RapidArc volumetric modulated therapy planning for prostate cancer patients. Acta Oncol 2009; 48: 227–232.CrossRefGoogle Scholar
8. Stojadinovic, S, Ouyang, L, Gu, X, Pompoš, A, Bao, Q, Solberg, TD. Breaking bad IMRT QA practice. J Appl Clin Med Phys 2015; 16: 154–165.CrossRefGoogle ScholarPubMed
9. Nelms, BE, Chan, MF, Jarry, G et al. Evaluating IMRT and VMAT dose accuracy: practical examples of failure to detect systematic errors when applying a commonly used metric and action levels. Med Phys 2013; 40: 111722.Google Scholar
10. Hussein, M, Rowshanfarzad, P, Ebert, MA, Nisbet, A, Clark, CH. A comparison of the gamma index analysis in various commercial IMRT/VMAT QA systems. Radiother Oncol 2013; 109: 370–376.Google Scholar
11. Vieillevigne, L, Molinier, J, Brun, T, Ferrand, R. Gamma index comparison of three VMAT QA Systems and evaluation of their sensitivity to delivery errors. Phys Med 2015; 31: 720–725.Google Scholar
12. Bailey, DW, Kumaraswamy, L, Bakhtiari, M, Malhotra, HK, Podgorsak, MB. EPID dosimetry for pretreatment quality assurance with two commercial systems. J Appl Clin Med Phys 2012; 13: 82–99.Google Scholar
13. Bakhtiari, M, Kumaraswamy, L, Bailey, DW, Boer, SD, Malhotra, HK, Podgorsak, MB. Using an EPID for patient-specific VMAT quality assurance. Med Phys 2011; 38: 1366–1373.Google Scholar
14. Fogliata, A, Clivio, A, Fenoglietto, P et al. Quality assurance of RapidArc in clinical practice using portal dosimetry. Br J Radiol 2011; 84: 534–545.Google Scholar
15. Nicolini, G, Vanetti, E, Clivio, A et al. The GLAaS algorithm for portal dosimetry and quality assurance of RapidArc, an intensity modulated rotational therapy. Radiat Oncol 2008; 3: 24.Google Scholar
16. Mans, A, Remeijer, P, Olaciregui-Ruiz, I et al. 3D dosimetric verification of volumetric-modulated arc therapy by portal dosimetry. Radiother Oncol 2010; 94: 181–187.Google Scholar
17. Song, JH, Kim, MJ, Park, SH et al. Gamma analysis dependence on specified low-dose thresholds for VMAT QA. J Appl Clin Med Phys 2015; 16: 263–272.Google Scholar
18. Howell, R, Smith, I, Jarrio, C. Establishing action levels for EPID-based QA for IMRT. J Appl Clin Med Phys 2008; 9: 16–25.Google Scholar
19. Greer, PB, Popescu, CC. Dosimetric properties of an amorphous silicon electronic portal imaging device for verification of dynamic intensity modulated radiation therapy. Med Phys 2003; 30: 1618–1627.Google Scholar
20. Low, DA, Harms, WB, Mutic, S, Purdy, JA. A technique for the quantitative evaluation of dose distributions. Med Phys 1998; 25: 656–661.Google Scholar
21. Bladh-Jonasson, C. Patient-specific quality assurance for helical tomotherapy: an evaluation of two different detector systems. M.Sc. dissertation, Lund University, Lund, Sweden, 2010.Google Scholar
22. Darko, J, Kiciak, A, Badu, S, Grigorov, G, Fleck, A, Osei, E. SU-F-T-272: patient specific quality assurance of prostate VMAT plans with portal dosimetry. Med Phys 2016; 43 (6): 3525.Google Scholar
23. Stasi, M, Bresciani, S, Miranti, A, Maggio, A, Sapino, V, Gabriele, P. Pretreatment patient-specific IMRT quality assurance: a correlation study between gamma index and patient clinical dose volume histogram. Med Phys 2012; 39: 7626.Google Scholar
24. Ezzell, GA, Burmeister, JW, Dogan, N et al. IMRT commissioning: multiple institution planning and dosimetry comparisons, a report from AAPM Task Group 119. Med Phys 2009; 36: 5359–5373.Google Scholar
25. Kim, JI, Park, SY, Kim, HJ, Kim, JH, Ye, SJ, Park, JM. The sensitivity of gamma-index method to the positioning errors of high-definition MLC in patient-specific VMAT QA for SBRT. Radiat Oncol 2014; 9: 167.Google Scholar
26. Heilemann, G, Poppe, B, Laub, W. On the sensitivity of common gamma-index evaluation methods to MLC misalignments in Rapidarc quality assurance. Med Phys 2013; 40: 031702.Google Scholar
27. Fredh, A, Scherman, JB, Fog, LS, Munck af Rosenschold, P. Patient QA systems for rotational radiation therapy: a comparative experimental study with intentional errors. Med Phys 2013; 40: 031716.Google Scholar
28. Steers, JM, Fraass, BA. IMRT QA: selecting gamma criteria based on error detection sensitivity. Med Phys 2016; 43: 1982–1994.Google Scholar
29.Varian Medical Systems. Portal Imaging and Portal Dosimetry Reference Guide, Varian Medical Systems, Palo Alto, CA, USA, 2008..Google Scholar