Log in

Rotational output and beam quality evaluations for helical tomotherapy with use of a third-party quality assurance tool

  • Published:
Radiological Physics and Technology Aims and scope Submit manuscript

Abstract

Our aim was to determine whether a third-party quality assurance (QA) tool was suitable for the measurement of rotational output and beam quality in place of on-board detector signals. A Rotational Therapy Phantom 507 (507 Phantom) was used as a QA tool. The rotational output constancy (ROC507) and the beam quality index (\({\text{TPR}}_{10,5}^{507}\)) were evaluated by analysis of signals from an ion chamber inserted into the 507 Phantom. On-board detector signals were obtained for comparisons with the data from the 507 Phantom. The rotational output (ROCdetector) and beam quality (corrected cone ratio; CCR) were determined by analysis of on-board detector signals that were generated by irradiation. The tissue phantom ratio at depth 20 and 10 cm (TPR20, 10) was measured with a Farmer-type ionization chamber inserted in a plastic-slab phantom. For rotational output measurement, the correlation coefficient between ROC507 and ROCdetector values was 0.68 (p < 0.001). ROC507 and ROCdetector values showed a reduced coefficient of variation after magnetron replacement, which was done during the measurement period. In addition, ROC507 values were reduced significantly along with ROCdetector values after target replacement (p < 0.001). Regarding the beam quality index, \({\text{TPR}}_{10,5}^{507}\) showed a change similar to CCR and an increase similar to TPR20, 10 after magnetron/target replacement. This QA tool could check for daily rotational output and detect changes in rotational output and beam quality caused by magnetron or target failure as well as when on-board detector signals were used. Without needing a tomotherapy quality assurance license, we could effectively and quantitatively estimate the rotational output and beam quality at a low cost.

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

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

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

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

References

  1. Langen KM, Papanikolaou N, Balog J, Crilly R, Followill D, Goddu SM, et al. QA for helical tomotherapy: report of the AAPM Task Group 148. Med Phys. 2010;37:4817–53.

    Article  PubMed  Google Scholar 

  2. Hardcastle N, Bayliss A, Wong JH, Rosenfeld AB, Tomé WA. Improvements in dose calculation accuracy for small off-axis targets in high dose per fraction tomotherapy. Med Phys. 2012;39:4788–94.

    Article  PubMed  Google Scholar 

  3. Fenwick JD, Tomé WA, Jaradat HA, Hui SK, James JA, Balog JP, et al. Quality assurance of a helical tomotherapy machine. Phys Med Biol. 2004;49:2933–53.

    Article  CAS  PubMed  Google Scholar 

  4. Balog J, Holmes T, Vaden R. A Helical tomotherapy dynamic quality assurance. Med Phys. 2006;33:3939–50.

    Article  PubMed  Google Scholar 

  5. Broggi S, Cattaneo GM, Molinelli S, Maggiulli E, Del Vecchio A, Longobardi B, et al. Results of a two-year quality control program for a helical tomotherapy unit. Radiother Oncol. 2008;86:231–41.

    Article  PubMed  Google Scholar 

  6. Klein EE, Hanley J, Bayouth J, Yin FF, Simon W, Dresser S, et al. Task Group 142 report: quality assurance of medical accelerators. Med Phys. 2009;36:197–212.

    Google Scholar 

  7. Hui SK, Lusczek E, DeFor T, Dusenbery K, Levitt S. Three-dimensional patient setup errors at different treatment sites measured by the Tomotherapy megavoltage CT. Strahlenther Onkol. 2012;188:346–52.

    Article  CAS  PubMed  Google Scholar 

  8. Zhou J, Uhl B, Dewit K, Young M, Taylor B, Fei DY, et al. Analysis of daily setup variation with tomotherapy megavoltage computed tomography. Med Dosim. 2010;35:31–7.

    Article  PubMed  Google Scholar 

  9. Goddu SM, Yaddanapudi S, Pechenaya OL, Chaudhari SR, Klein EE, Khullar D, et al. Dosimetric consequences of uncorrected setup errors in helical Tomotherapy treatments of breast-cancer patients. Radiother Oncol. 2009;93:64–70.

    Article  PubMed  Google Scholar 

  10. Schubert LK, Westerly DC, Tomé WA, Mehta MP, Soisson ET, Mackie TR, et al. A comprehensive assessment by tumour site of patient setup using daily MVCT imaging from more than 3,800 helical tomotherapy treatments. Int J Radiat Oncol Biol Phys. 2009;73:1260–9.

    Article  PubMed Central  PubMed  Google Scholar 

  11. Kaiser A, Schultheiss TE, Wong JY, Smith DD, Han C, Vora NL, et al. Pitch, roll, and yaw variations in patient positioning. Int J Radiat Oncol Biol Phys. 2006;66:949–55.

    Article  PubMed  Google Scholar 

  12. Forrest LJ, Mackie TR, Ruchala K, Turek M, Kapatoes J, Jaradat H, et al. The utility of megavoltage computed tomography images from a helical tomotherapy system for setup verification purposes. Int J Radiat Oncol Biol Phys. 2004;60:1639–44.

    Article  PubMed  Google Scholar 

  13. Chen Q, Westerly D, Fang Z, Sheng K, Chen Y. TomoTherapy MLC verification using exit detector data. Med Phys. 2012;39:143–51.

    Article  PubMed  Google Scholar 

  14. Wooten HO, Goddu SM, Rodriguez V, Cates J, Grigsby P, Low DA. The use of exit detector sinograms to detect anatomical variations for patients extending beyond the TomoTherapy field of view: a feasibility study. Med Phys. 2012;39:6407–19.

    Article  PubMed  Google Scholar 

  15. Van de Vondel I, Tournel K, Verellen D, Duchateau M, Lelie S, Storme G. A diagnostic tool for basic daily quality assurance of a Tomotherapy Hi-Art machine. J Appl Clin Med Phys. 2009;10:151–64.

    Google Scholar 

  16. Althof V, van Haaren P, Westendorp R, Nuver T, Kramer D, Ikink M, et al. A quality assurance tool for helical tomotherapy using a step-wedge phantom and the on-board MVCT detector. J Appl Clin Med Phys. 2012;13:148–63.

    Google Scholar 

  17. Tolakanahalli R, Robeck L, Tewatia D. To study the impact of energy variation on cone ratio, PDD, TMR and IMRT doses for flattening filter free (FFF) beam of TomoTherapy Hi-Art (TM). Med Phys. 2013;40:289.

    Article  Google Scholar 

  18. Choi HH, Ho JP, Yang B, Cheung KY, Yu SK. Technical note: correlation between TQA data trends and TomoHD functional status. J Appl Clin Med Phys. 2014;15:4548.

    PubMed  Google Scholar 

  19. R Development Core Team: R, A language and environment for statistical computing. In R Foundation for Statistical Computing. Vienna, Austria 2009.

  20. Kinhikar RA, Jamema SV, Reenadevi PR, Zubin M, Gupta T, et al. Dosimetric validation of first helical tomotherapy Hi-Art II machine in India. J Med Phys. 2009;34:23–30.

    Article  PubMed Central  PubMed  Google Scholar 

  21. Jaradat HA. Dynamic comprehensive tomotherapy daily quality assurance. Riv Med. 2007;13:29–31.

    Google Scholar 

Download references

Acknowledgments

We thank Mrs. Georgia Johnson of Gammex, Inc., and Mr. Wataru Takahashi of TOYO MEDIC, Inc., for their helpful advice. We are grateful to Mr. Tadashi Nakabayashi of Accuracy Japan, Inc., for the analysis of on-board detector data. The authors would like to thank Enago (www.enago.jp) for the English language review.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hidetoshi Shimizu.

Ethics declarations

Conflict of interest

None.

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Shimizu, H., Sasaki, K., Iwata, M. et al. Rotational output and beam quality evaluations for helical tomotherapy with use of a third-party quality assurance tool. Radiol Phys Technol 9, 53–59 (2016). https://doi.org/10.1007/s12194-015-0333-2

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12194-015-0333-2

Keywords

Navigation