Clinical Implementation of a 3D Dosimeter for Accurate IMRT and VMAT Patient Specific QA

DOI: 10.4236/ojbiphy.2013.31A013   PDF   HTML   XML   5,975 Downloads   11,453 Views   Citations


The Delta4 3D dose verification device was commissioned in the current work for pre-treatment quality assurance (QA) of Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) plans. The cross calibration and relative array calibration were performed to enable absolute dose comparison. The linearity of response with dose and temperature sensitivity tests were also conducted to investigate dosimetric properties of the Delta4 device. The need to modify the original CT image of the Delta4 phantom for accurate dose calculation and comparison is addressed in this work, applying a CT extension algorithm. A number of test plans varying from simple 4—field conformal to IMRT and VMAT plans were measured to evaluate the accuracy of this device. It was found that the Delta4 device measured dose accurately to within ±1%. In order to maintain this level of accuracy the machine output fluctuations need to be corrected prior to each measurement and the relative array calibration needs to be performed every six months.

Share and Cite:

T. Pham and J. Luo, "Clinical Implementation of a 3D Dosimeter for Accurate IMRT and VMAT Patient Specific QA," Open Journal of Biophysics, Vol. 3 No. 1A, 2013, pp. 99-111. doi: 10.4236/ojbiphy.2013.31A013.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] J. V. Dyk, “The Modern Technology of Radiation Oncology: A Compendium for Medical Physicists and Radiation Oncologist,” Medical Physics Publishing, Vol. 2, 2005.
[2] ScandiDos, “User Technical Help Manual,” ScandiDos, Uppsala, 2010
[3] R. Sadagopan, J. A. Bencomo, R. L. Martin, G. Nilsson, T. Matzen and P. A. Balter, “Characterization and Clinical Evaluation of a Novel IMRT Quality Assurance System,” Journal of Applied Clinical Medical Physics, Vol. 10, No. 2, 2009, p. 2928. doi:10.1120/jacmp.v10i2.2928
[4] D. A. Low, W. B. Harms, S. Mutic and J. A. Purdy, “A Technique for the Quantative Evaluation of Dose Distributions,” Medical Physics, Vol 25, No. 5, 1998, pp. 656-661. doi:10.1118/1.598248
[5] V. Feygelman, D. Opp, K. Javedan, A. J. Saini and G. Zhang, “Evaluation of a 3D Diode Array Dosimeter for Helical Tomotherapy Delivery QA,” Medical Dosimetry, Vol. 35, No. 4, 2010, pp. 324-329. doi:10.1016/j.meddos.2009.10.007
[6] M. S. Geurts, J. M. Gonzalez and P. Serrano-Ojeda, “Longitudinal Study Using a Diode Phantom for Helical Tomotherapy IMRT QA,” Medical Physics, Vol. 36, No. 11, 2009, pp. 4977-4983.
[7] J. L. Bedford, Y. K. Lee, P. Wai, C. P. South and A. P. Warrington, “Evaluation of the Delta4 Phantom for IMRT and VMAT Verification,” Physics in Medicine and Biology, Vol. 54, No. 9, 2009, pp. 167-176. doi:10.1088/0031-9155/54/9/N04
[8] S. Korreman, J. Medin and F. Kjær-Kristoffersen, “Dosimetric Verification of RapidArc Treatment Delivery,” Acta Oncologica, Vol. 48, No. 2, pp.185-191, 2009. doi:10.1080/02841860802287116
[9] V. Feygelman, G. Zhang and C. Stevens, “Initial Dosimetric Evaluation of SmartArc—A Novel VMAT Treatment Planning Module Implemented in a Multi-Vendor Delivery Chain,” Journal of Applied Clinical Medical Physics, Vol. 11, No. 1, 2009, p. 3169.
[10] G. A. Ezzell, J. W. Burmeister, N. Dogan, T. J. LoSasso, J. G. Mechalakos, D. Mihailidis, A. Molineu, J. R. Palta, C. R. Ramsey, B. J. Salter, J. Shi, P. Xia, N. J. Yue and Y. Xiao, “IMRT Commissioning: Multiple Institution Planning and Dosimetry Comparisons,” American Association of Medical Physics, Vol. 36, No. 11, 2009, pp. 5359-5373.
[11] I. Fotina, G. Kragl, B. Kroupa, R. Trausmuth and D. Georg, “Clinical Comparison of Dose Calculation Using the Enhanced Collapsed Cone Algorithm vs. a New Monte Carlo Algorithm,” Strahlentherapie und Onkologie, Vol. 187, No. 7, 2011, pp. 433-441. doi:10.1007/s00066-011-2215-9
[12] Secondary Dosimetry Standard Laboratory, “Departmental Calibration Report on a Therapy Ionization,” Australian Radiation Protection and Nuclear Safety Agency, Miranda, 2010.
[13] IAEA, “Technical Reports Series 398, Absorbed Dose Determination in External Beam Radiotherapy, an International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water,” International Atomic Energy Agency, Vienna, 2000
[14] ELEKTA, “Precise Digital Accelerator Synergy MLCi2,” ELEKTA Limited, Sydney, 2010.
[15] Philips Medical Systems, “Pinnacle3 Radiation Therapy Planning System,” Version 9, 2010.
[16] Mathworks Inc., “Matlab Version 2010a,” 2010.
[17] M. Millar, J. Cramb, et al., “Supplement ACPSEM Position Paper, Recommendation for the Safe Use of External Beams and Sealed Brachytherapy Sources in Radiation Oncology,” Australasian Physical and Engineering Sciences in Medicine, Vol. 20, No. 3, 1997, pp. 1-35.
[18] J. G. Li, G. Yan and C. Liu, “Comparison of Two Commercial Detector Arrays for IMRT Quality Assurance,” Journal of Applied Clinical Medical Physics, Vol. 10, No. 2, 2009, p. 2942. doi:10.1120/jacmp.v10i2.2942
[19] IBA Dosimetry, “OmniPro IMRT 2D Array,” IBA, Germany, 2001.

comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.