Skip to main content
SpringerLink
Log in

A dosimetric comparison of flattening filter free and conventional VMAT treatments for some common cancer sites

  • Scientific Note
  • Published:
Physical and Engineering Sciences in Medicine Aims and scope Submit manuscript

Abstract

The aim of this study was to assess the potential for treating various common cancer sites with flattening filter free (FFF) rather than conventionally flattened (cFF) treatment plans considering both in-field and out-of-field dosimetry. This study seeks to extend previous work by others to the Elekta Agility VMAT treatments commonly used at our clinic. Nine matched pairs of conventional and FFF 6X treatment plans for prostate, head and neck, and brain cancer sites were generated using the Monaco treatment planning system (Elekta AB, Stockholm, Sweden). Absorbed dose distribution statistics for target and healthy tissue volumes reported by the Monaco treatment planning system were compared. One matched pair of plans for each cancer site was experimentally validated by film and ion chamber measurements in an anthropomorphic phantom. Head leakage was measured at various positions in a small water tank and corrections made to the out-of-field dose distributions calculated by the treatment planning system. Out-of-field organ doses and effective whole body doses were calculated according to ICRP103 (Charles in Radiat Prot Dosim 129:500–507, 2008). The in-field target and organ dose statistics for the cFF and FFF plans were comparable whereas the out-of-field organ and whole body effective doses for plans delivered using 6X FFF were generally lower than those delivered with 6X cFF. A modest increase in monitor unit (MU) delivery rates was also observed with the FFF beams. We conclude that treatment plan delivery using FFF rather than cFF beams is feasible and may provide benefits in terms of reduced out-of-field doses and secondary cancer risks for some patients.

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
Fig. 3

Reference

  1. Xiao Y et al (2015) Flattening filter-free accelerators: a report from the AAPM therapy emerging technology assessment work group. J Appl Clin Med Phys 16(3):12–29

    Article  Google Scholar 

  2. Hrbacek J et al (2014) Dosimetric comparison of flattened and unflattened beams for stereotactic ablative radiotherapy of stage I non-small cell lung cancer. Med Phys 41(3):031709

    Article  Google Scholar 

  3. Treutwein M et al (2017) Volumetric-modulated arc therapy and intensity-modulated radiation therapy treatment planning for prostate cancer with flattened beam and flattening filter free linear accelerators. J Appl Clin Med Phys 18(5):307–314

    Article  Google Scholar 

  4. Zhuang M et al (2013) Volumetric modulation arc radiotherapy with flattening filter-free beams compared with conventional beams for nasopharyngeal carcinoma: a feasibility study. Chin J Cancer 32(7):397

    Article  Google Scholar 

  5. Lechner W, Kragl G, Georg D (2013) Evaluation of treatment plan quality of IMRT and VMAT with and without flattening filter using Pareto optimal fronts. Radiother Oncol 109(3):437–441

    Article  Google Scholar 

  6. Kry SF et al (2017) AAPM TG 158: Measurement and calculation of doses outside the treated volume from external-beam radiation therapy. Med Phys 44(10):e391–e429

    Article  Google Scholar 

  7. Cashmore J, Ramtohul M, Ford D (2011) Lowering whole-body radiation doses in pediatric intensity-modulated radiotherapy through the use of unflattened photon beams. Int J Radiat Oncol Biol Phys 80(4):1220–1227

    Article  Google Scholar 

  8. Bouchta YB et al (2018) Effects of 10 MV and flattening-filter-free Beams on peripheral dose in a cohort of pediatric patients. Int J Radiat Oncol Biol Phys 102(5):1560–1568

    Article  Google Scholar 

  9. Alderson SW et al (1962) An instrumented phantom system for analog computation of treatment plans. Am J Roentgenol Radium Ther Nucl Med 87:185

    CAS  PubMed  Google Scholar 

  10. ISO, IEC, BIPM, OIML (1995) Guide to the expression of uncertainty in measurement. International Organization for Standardization, Geneva, p 122

    Google Scholar 

  11. Charles MW (2008) ICRP publication 103: recommendations of the ICRP. Radiat Prot Dosim 129:500–507

    Article  Google Scholar 

  12. Diallo I et al (2009) Frequency distribution of second solid cancer locations in relation to the irradiated volume among 115 patients treated for childhood cancer. Int J Radiat Oncol Biol Phys 74(3):876–883

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Canterbury District Health Board, Christchurch, New Zealand

    J. P. Ronaldson, H. Bennett, J. Roberts, A. J. Ronaldson & A. T. Cousins

Authors
  1. J. P. Ronaldson
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. H. Bennett
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. J. Roberts
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. A. J. Ronaldson
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. A. T. Cousins
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to J. P. Ronaldson.

Ethics declarations

Conflict of interest

The authors declare that they have no conflicts of interest.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ronaldson, J.P., Bennett, H., Roberts, J. et al. A dosimetric comparison of flattening filter free and conventional VMAT treatments for some common cancer sites. Phys Eng Sci Med 43, 719–725 (2020). https://doi.org/10.1007/s13246-020-00877-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13246-020-00877-0

Keywords

Search

Navigation