Development of a head and neck Phantom for remote-audit program of IMRT treatment

Youngyih Han, Sae Byeong Lee, Eun Hyuk Shin, Jae Kyun Kim, Sang Gyu Ju, Myonggeun Yoon, Yong Chan Ahn, Chunil Lim, Hee Kyo Jeong, Hun Jin Oh

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Purpose: Accurate delivery of the most-up-todate treatment techniques such as Intensity-modulated radiation therapy (IMRT) is essential. In order to conduct a remoteaudit program, which allows evaluation of institution’s accuracy in delivering IMRT, an anthropomorphic phantom has been designed and constructed. The dosimetric characteristics in the phantom were investigated. Method: The phantom has a shape of a cylinder with one target and three organ-at-risks (OARs) inside. The target and OARs were shaped analogous to those of nasopharynx cancer patients and were manufactured to be able to detect with CT images. Inside the target and OARs, TLD holders were inserted for absolute dose measurements. The phantom allows measurements with thimble chambers at the TLD locations, thereby affording an inter-comparison between two dosimeters. For the measurement of relative dose distribution across the target and OARs, two film slots were orthogonally placed near the center of phantom, which also enables inhomogeneity insertion near the target. Measurement with TLDs and IC were done for three cases. The first was an anterior one port 6MV X-ray (Primus, Siemens, USA) delivery to the phantom; the second was the same beam geometrically, but with inhomogeneties inserted, and the third was IMRT delivery to the phantom without inhomogeneities. For each case, four sets of TLDs were used to reduce the statistical uncertainty. Results: In anterior one port X-ray delivery to homogeneous phantom, the deviation between the IC and TLD measurements normalized to IC dose, ranged from 1.13% to 3.9%. With inhomogeneous insertion, the range increased to 2.7%- 3.3%. In IMRT delivery, the differences between IC and TLD measurements were 3.7-5.6%. Standard deviation of TLD measurements were small, ranging from 0.4% to 1.2%. Conclusion: Our preliminary results show the developed phantom allows the measurements with TLDs and IC within 4% uncertainty. More investigation is necessary to reduce the uncertainty range.

Original languageEnglish
Title of host publicationIFMBE Proceedings
PublisherSpringer Verlag
Pages2020-2023
Number of pages4
Volume14
Edition1
Publication statusPublished - 2007
Externally publishedYes
Event10th World Congress on Medical Physics and Biomedical Engineering, WC 2006 - Seoul, Korea, Republic of
Duration: 2006 Aug 272006 Sep 1

Other

Other10th World Congress on Medical Physics and Biomedical Engineering, WC 2006
CountryKorea, Republic of
CitySeoul
Period06/8/2706/9/1

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ASJC Scopus subject areas

  • Biomedical Engineering
  • Bioengineering

Cite this

Han, Y., Lee, S. B., Shin, E. H., Kim, J. K., Ju, S. G., Yoon, M., ... Oh, H. J. (2007). Development of a head and neck Phantom for remote-audit program of IMRT treatment. In IFMBE Proceedings (1 ed., Vol. 14, pp. 2020-2023). Springer Verlag.