Evaluation of the dosimetric accuracy for a couch-based tracking system (CBTS)

Kyung Hwan Chang, Suk Lee, Kwang Hyeon Kim, Jang Bo Shim, Dae Sik Yang, Young Je Park, Won Sup Yoon, Chul Yong Kim, Yuanjie Cao

Research output: Contribution to journalArticlepeer-review


In this study, the geometric and dosimetric accuracy of an in-house-developed couch-based tracking system (CBTS) was investigated using both film and in-house-developed polymer gel dosimeters. We evaluated the 1D and the 2D motion accuracies of our couch system by using Gafchromic EBT film. For the 1D test, the couch system was moved 5, 10, and 20 mm in the X, Y, and Z directions, respectively. Meanwhile, for the 2D test, it was moved along the XY, YZ, and ZX directions. We compared the profiles, full widths at half maximum (FWHMs), and penumbras between the static and the tracking fields. For the 3D test, we quantitatively compared the dose distribution between the static and the tracking fields by using the polymer gel dosimeter when it was simultaneously moved in the XYZ directions. We confirmed that the film was moved according to motion amplitudes of 5, 10, and 20 mm in the X, Y, and Z directions, respectively, in the 1D and 2D motion tests. The value of the FWHM of the static field and the three tracking fields were 51.88, 53.28, 57.67, and 64.43 mm, respectively. Two types of penumbras became wider with increasing amplitudes compared to the static field. For the 3D test, the dose distribution of the XYZ tracking field was qualitatively larger than that of the static field. We conclude that this CBTS has the potential for pre-clinical applications in adaptive radiation therapy.

Original languageEnglish
Pages (from-to)241-247
Number of pages7
JournalJournal of the Korean Physical Society
Issue number2
Publication statusPublished - 2016 Jul 1

Bibliographical note

Publisher Copyright:
© 2016, The Korean Physical Society.


  • Dosimetric accuracy
  • Gel dosimeter
  • Patient motion
  • Robotic couch
  • Tumor tracking

ASJC Scopus subject areas

  • General Physics and Astronomy


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