TY - GEN
T1 - Development of a head and neck Phantom for remote-audit program of IMRT treatment
AU - Han, Youngyih
AU - Lee, Sae Byeong
AU - Shin, Eun Hyuk
AU - Kim, Jae Kyun
AU - Ju, Sang Gyu
AU - Yoon, Myonggeun
AU - Ahn, Yong Chan
AU - Lim, Chunil
AU - Jeong, Hee Kyo
AU - Oh, Hun Jin
N1 - Publisher Copyright:
© International Federation for Medical and Biological Engineering 2007.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2007
Y1 - 2007
N2 - 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.
AB - 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.
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U2 - 10.1007/978-3-540-36841-0_507
DO - 10.1007/978-3-540-36841-0_507
M3 - Conference contribution
AN - SCOPUS:84884645930
SN - 9783540368397
T3 - IFMBE Proceedings
SP - 2020
EP - 2023
BT - IFMBE Proceedings
A2 - Kim, Sun I.
A2 - Suh, Tae Suk
PB - Springer Verlag
T2 - 10th World Congress on Medical Physics and Biomedical Engineering, WC 2006
Y2 - 27 August 2006 through 1 September 2006
ER -