Skip to main content

End-to-end test to evaluate the comprehensive geometric accuracy of a proton rotating gantry using a cone-shaped scintillator screen detector


In this study, we aim to evaluate the comprehensive geometric accuracy of proton rotating gantries by performing an end-to-end test using a cone-shaped scintillator screen detector, known as XRV-124. The XRV-124 comprises a cone-shaped sheet-like scintillator and charge-coupled device camera that detects the scintillation light. First, the results of the Winston–Lutz and end-to-end XRV-124 tests performed on a conventional linear accelerator were compared to confirm the reliability of the XRV-124, and the snout position dependency of the geometric accuracy was evaluated for the proton rotating gantry as a pre-verification process. Thereafter, an end-to-end test including computed tomography imaging and irradiation in 30° steps from 0° to 330° for two proton rotating gantries, which have the same specifications, was performed. The results of the pre-verification indicated that sufficient accuracy was obtained for the end-to-end test of the proton rotating gantry. The end-to-end test results showed a peak-to-peak deviation of up to 2 mm for some of the coordinate axes. The two gantries exhibited almost similar results in terms of the absolute quantity; however, a few trends were different. Thus, the beam axis deviations were confirmed to be within the safety margin, as expected in clinical practice. Based on the results of this study, the XRV-124 can be used as a comprehensive end-to-end constancy test tool, as it enables a comparative verification of multiple rotating gantries and geometric accuracy verification of different treatment modalities.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9


  1. 1.

    Klein EE, Hanley J, Bayouth J, Yin FF, Simon W, Dresser S, Serago C, Aguirre F, Ma L, Arjomandy B, Liu C, Sandin C, Holmes T, Task Group 142, American Association of Physicists in Medicine. Task Group 142 report: quality assurance of medical accelerators. Med Phys. 2009;36(9):4197–212.

    Article  Google Scholar 

  2. 2.

    Lutz W, Winston KR, Maleki N. A system for stereotactic radiosurgery with a linear accelerator. Int J Radiat Oncol Biol Phys. 1988;14(2):373–81.

    CAS  Article  Google Scholar 

  3. 3.

    Du W, Johnson JL, Jiang W, Kudchadker RJ. On the selection of gantry and collimator angles for isocenter localization using Winston-Lutz tests. J Appl Clin Med Phys. 2016;17(1):167–78.

    Article  Google Scholar 

  4. 4.

    Fuse H, Sakae T, Terunuma T, Sato M, Aoki S. An isocenter detection and verification device for use in proton therapy. Rev Sci Instrum. 2012;83(12):125109.

    CAS  Article  Google Scholar 

  5. 5.

    Ciangaru G, Yang JN, Oliver PJ, Bues M, Zhu M, Nakagawa F, Chiba H, Nakamura S, Yoshino H, Umezawa M, Smith AR. Verification procedure for isocentric alignment of proton beams. J Appl Clin Med Phys. 2007;8(4):2671.

    Article  Google Scholar 

  6. 6.

    Moyers MF, Lesyna W. Isocenter characteristics of an external ring proton gantry. Int J Radiat Oncol Biol Phys. 2004;60(5):1622–30.

    Article  Google Scholar 

  7. 7.

    Hansen P, Hu D. An isocenter estimation tool for proton gantry alignment. Rev Sci Instrum. 2017;88(12):125102.

    Article  Google Scholar 

  8. 8.

    Wang I, Xing I, Nelson B. A novel daily QA system for robotic image guided radiosurgery with variable aperture collimator. Med Phys. 2014;41(6):330.

    Article  Google Scholar 

  9. 9.

    Cai W, Oesten H, Clasie B, Winey B, Jee KW. Semi-automated IGRT QA using a cone-shaped scintillator screen detector for proton pencil beam scanning treatments. Phys Med Biol. 2019;64(8):085004.

    Article  Google Scholar 

  10. 10.

    Rana S, Samuel EJJ. Feasibility study of utilizing XRV-124 scintillation detector for quality assurance of spot profile in pencil beam scanning proton therapy. Phys Med. 2019;66:15–20.

    Article  Google Scholar 

  11. 11.

    BeamWorksTM for the XRV-100 and XRV-124 user manual; version 2.31

  12. 12.

    DoseLab USER MANUAL; version 6.6

  13. 13.

    Kato T, Yamazaki Y, Sagara T. A new concept for verifying the isocentric alignment of the proton-rotational gantry for radiation control. Radiol Phys Technol. 2019.

    Article  PubMed  Google Scholar 

  14. 14.

    Kerstiens J, Johnstone GP, Johnstone PAS. Proton facility economics: single-room centers. J Am Coll Radiol. 2018;15(12):1704–8.

    Article  Google Scholar 

Download references


The authors would like to thank the staff of Fujidenolo CO. LTD. for their assistance.

Author information



Corresponding author

Correspondence to Takahiro Kato.

Ethics declarations

Conflict of interest

The authors have no conflicts of interest to declare.

Ethical approval

This article does not contain any studies performed with human participants or animals.

Additional information

Publisher's Note

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

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kato, T., Yamazaki, Y., Kato, R. et al. End-to-end test to evaluate the comprehensive geometric accuracy of a proton rotating gantry using a cone-shaped scintillator screen detector. Radiol Phys Technol 13, 144–151 (2020).

Download citation


  • End-to-end test
  • Proton beam
  • Quality assurance
  • Rotating gantry
  • Scintillator screen detector