Comparison of two dosimetric verification methods of IMRT using Detector729
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Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science, Tianjin 300192, China
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Corresponding author:
Xiaochun Wang, wxc3188@126.com
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Received Date:
2014-01-20
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Abstract
Objective To compare and analyze the dose distribution of IMRT between fixed-gantry and unfixed-gantry dosimetric verification. Methods Thirteen patients treated by IMRT were chosen randomly for this study.For each case, 2 different plans(fixed-gantry plan and unfixed-gantry plan)were worked out with Pinnacle 8.0 m planning system.The dose verification for each plan was carried out with Varian 23EX by using Detector729 with the octagonal phantom OCTAVIUS.The verification results of the dose distribution between the treatment planning system calculation and the measurement were done by the gamma analysis quantization with dose difference and distance to agreement of 3%(3 mm), 3%(4 mm) and 4%(4 mm) respectively, and the data were analyzed by Statistical Analysis System. Results The repeatability of Detector729 was within 0.3%.According to the gamma analysis, the overall average passing rate of unfixed-gantry verification for the dosimetric deviation of 3%(3 mm), 3%(4 mm)and 4%(4 mm) were 91.2%, 92.4% and 95.6%, which were slightly lower compared with the passing rate of fixed-gantry verification of 2.2%(t=-2.04, P=0.053), 2.2%(t=-2.02, P=0.055) and 1.4%(t=-1.97, P=0.060) respectively, and the difference between the two verification methods was not statistically significant. Conclusions The Detector729 is a reliable and accurate dosimeter.The two dosimetric verification methods of IMRT by using Detector729 are efficient and valuable.The radiotherapy department should select suitable and available dosimetric verification method for radiotherapy.
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References
[1]
|
Low DA, Moran JM, Dempsey JF, et al.Dosimetry tools and techniques for IMRT[J].Med Phys, 2011, 38(3): 1313-1338. |
[2]
|
Van Esch A, Clermont C, Devillers M, et al.On-line quality assurance of rotational radiotherapy treatment delivery by means of a 2D ion chamber array and the Octavius phantom[J].Med Phys, 2007, 34(10): 3825-3837. |
[3]
|
Syamkumar SA, Padmanabhan S, Sukumar P, et al.Characterization of responses of 2d array seven29 detector and its combined use with octavius phantom for the patient-specific quality assurance in rapidarc treatment delivery[J].Med Dosim, 2012, 37(1): 53-60. |
[4]
|
Poppe B, Blechschmidt A, Djouguela A, et al. Two-dimensional ionization chamber arrays for IMRT plan verification[J].Med Phys, 2006, 33(4): 1005-1015. |
[5]
|
Hussein M, Adams EJ, Jordan TJ, et al.A critical evaluation of the PTW 2D-ARRAY seven29 and OCTAVIUS Ⅱ phantom for IMRT and VMAT verification[J].J Appl Clin Med Phys, 2013, 14(6): 274-292. |
[6]
|
Low DA, Harms WB, Mutic S, et al. A technique for the quantitative evaluation of dose distributions[J]. Med Phys, 1998, 25(5): 656-661. |
[7]
|
Low DA, Dempsey JF. Evaluation of the gamma dose distribution comparison method[J]. Med Phys, 2003, 30(9): 2455-2464. |
[8]
|
Fraass B, Doppke K, Hunt M, et al.American Association of Physicists in Medicine Radiation Therapy Committee Task Group 53: quality assurance for clinical radiotherapy treatment planning[J].Med Phys, 1998, 25(10): 1773-1829. |
[9]
|
Saminathan S, Manickam R, Chandraraj V, et al. Dosimetric study of 2D ion chamber array matrix for the modern radiotherapy treatment verification[J].J Appl Clin Med Phys, 2010, 11(2): 116-127. |
[10]
|
Spezi E, Angelini AL, Romani F, et al.Characterization of a 2D ion chamber array for the verification of radiotherapy treatments[J].Phys Med Biol, 2005, 50(14): 3361-3373. |
[11]
|
International Electrotechnical Commission.Medical electrical equipment—Dosimeters with ionization chambers as used in radiotherapy Paperback[S].Geneva: IEC, 2011. |
[12]
|
Shimohigashi Y, Araki F, Tominaga H, et al.Angular dependence correction of MatriXX and its application to composite dose verification[J].J Appl Clin Med Phys, 2012, 13(5): 198-214. |
[13]
|
Bayouth JE.Siemens multileaf collimator characterization and quality assurance approaches for intensity-modulated radiotherapy[J].Int J Radiat Oncol Biol Phys, 2008, 71(Suppl 1): S93-97. |
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Proportional views
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