A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array.
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| Language: | English |
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University of Toledo Health Science Campus / OhioLINK
2014
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=mco1404933070 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-mco1404933070 |
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oai_dc |
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NDLTD |
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English |
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NDLTD |
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Biophysics Physics |
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Biophysics Physics Dance, Michael Joseph A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array. |
| author |
Dance, Michael Joseph |
| author_facet |
Dance, Michael Joseph |
| author_sort |
Dance, Michael Joseph |
| title |
A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array. |
| title_short |
A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array. |
| title_full |
A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array. |
| title_fullStr |
A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array. |
| title_full_unstemmed |
A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array. |
| title_sort |
comparative analysis for verification of imrt and vmat treatment plans using a 2-d and 3-d diode array. |
| publisher |
University of Toledo Health Science Campus / OhioLINK |
| publishDate |
2014 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=mco1404933070 |
| work_keys_str_mv |
AT dancemichaeljoseph acomparativeanalysisforverificationofimrtandvmattreatmentplansusinga2dand3ddiodearray AT dancemichaeljoseph comparativeanalysisforverificationofimrtandvmattreatmentplansusinga2dand3ddiodearray |
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1719436363993972736 |
| spelling |
ndltd-OhioLink-oai-etd.ohiolink.edu-mco14049330702021-08-03T06:25:46Z A Comparative Analysis for Verification of IMRT and VMAT Treatment Plans using a 2-D and 3-D Diode Array. Dance, Michael Joseph Biophysics Physics With the added complexity of current radiation treatment dose delivery modalities such as IMRT (Intensity Modulated Radiation Therapy) and VMAT (Volumetric Modulated Arc Therapy), quality assurance (QA) of these plans become multifaceted and labor intensive. To simplify the patient specific quality assurance process, 2D or 3D diode arrays are used to measure the radiation fluence for IMRT and VMAT treatments which can then be quickly and easily compared against the planned dose distribution. Because the arrays that can be used for IMRT and VMAT patient-specific quality assurance are of different geometry (planar vs. cylindrical), the same IMRT or VMAT treatment plan measured by two different arrays could lead to different measured radiation fluences, regardless of the output and performance of linear accelerator. Thus, the purpose of this study is to compare patient specific QA results as measured by the MapCHECK 2 and ArcCHECK diode arrays for the same IMRT and VMAT treatment plans to see if one diode array consistently provides a closer comparison to reference data.Six prostate and three thoracic spine IMRT treatment plans as well as three prostate and three thoracic spine VMAT treatment plans were produced. Radiotherapy plans for this study were generated using the Pinnacle TPS v9.6 (Philips Radiation Oncology Systems, Fitchburg, WI) using 6 MV, 6 MV FFF, and 10 MV x-ray beams from a Varian TrueBeam linear accelerator (Varian Medical Systems, Palo Alto, CA) with a 120-millenium multi-leaf collimator (MLC). Each IMRT and VMAT therapy plan was measured on Sun Nuclear’s MapCHECK 2 and ArcCHECK diode arrays. IMRT measured data was compared with planned dose distribution using Sun Nuclear’s 3DVH quality assurance software program using gamma analysis and dose-volume histograms for target volumes and critical structures comparison. VMAT arc plans measured on the MapCHECK 2 and ArcCHECK were compared using beam-by-beam analysis with the gamma evaluation method with Sun Nuclear’s SNC Patient™ analysis software. MapCHECK 2 showed a slightly better agreement with planned data for IMRT verifications with a mean pass rate of 99.4% for clinically used acceptance criteria of 3%/3mm. MapCHECK 2’s 99.4% mean pass rate for IMRT verifications was 1.4% higher than ArcCHECK’s mean pass rate. For VMAT verifications, the MapCHECK 2 had a mean pass rate of 99.6% and 100% for each arc respectively, resulting in a 1.25% to 1.92% higher mean passing rates than those measured by the ArcCHECK using an acceptance criteria of 3%/3mm. MapCHECK 2 showed consistently higher ROI-specific mean gamma passing rates, ranging from +0.2% to +5.6%. While neither diode array showed any advantage in regards to D95 measurements within the PTV, MapCHECK 2 again showed closer comparison data in the CTV/GTV with an absolute deviation of -1.14 Gy compared to -3.39 Gy as measured by the ArcCHECK. Lastly, while the MapCHECK 2 and ArcCHECK both closely matched with the reference doses within the PTV and CTV/GTV, the ArcCHECK consistently overestimated the maximum absolute dose to all ROI, from 0.026 Gy to 2.243 Gy. In conclusion, the MapCHECK 2 diode array measured data more closely matched with planned data compared to the ArcCHECK diode array for IMRT verifications. While MapCHECK 2 showed a marginally better gamma passing rates over the ArcCHECK diode array, the ArcCHECK’s ability to simultaneously measure flatness, symmetry, output, and MLC positional accuracy as a function of gantry angle make it a more realistic and efficient measurement device for VMAT verifications. 2014-10-10 English text University of Toledo Health Science Campus / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=mco1404933070 http://rave.ohiolink.edu/etdc/view?acc_num=mco1404933070 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |