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Title: SU-F-T-563: Delivered Dose Reconstruction of Moving Targets for Gated Volumetric Modulated Arc Therapy (VMAT)

Abstract

Purpose: Actual delivered dose of moving tumors treated with gated volumetric arc therapy (VMAT) may significantly differ from the planned dose assuming static target. In this study, we developed a method which reconstructs actual delivered dose distribution of moving target by taking into account both tumor motion and dynamic beam delivery of gated VMAT, and applied to abdominal tumors. Methods: Fifteen dual-arc VMAT plans (Eclipse, Varian Medical Systems) for 5 lung, 5 pancreatic, and 5 liver cancer patients treated with gated VMAT stereotactic body radiotherapy (SBRT) were studied. For reconstruction of the delivered dose distribution, we divided each original arc beam into control-point-wise sub-beams, and applied beam isocenter shifting to each sub-beam to reflect the tumor motion. The tumor positions as a function of beam delivery were estimated by synchronizing the beam delivery with the respiratory signal which acquired during treatment. For this purpose, an in-house program (MATLAB, Mathworks) was developed to convert the original DICOM plan data into motion-involved treatment plan. The motion-involved DICOM plan was imported into Eclipse for dose calculation. The reconstructed delivered dose was compared to the plan dose using the dose coverage of gross tumor volume (GTV) and dose distribution of organs at risk (OAR).more » Results: The mean GTV dose coverage difference between the reconstructed delivered dose and the plan dose was 0.2 % in lung and pancreas cases, and no difference in liver cases. Mean D1000cc of ipsilateral lungs was reduced (0.8 ± 1.4cGy). Conclusion: We successfully developed a method of delivered dose reconstruction taking into account both respiratory tumor motion and dynamic beam delivery, and applied it to abdominal tumors treated with gated VAMT. No significant deterioration of delivered dose distribution indicates that interplay effect would be minimal even in the case of gated SBRT. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2015038710)« less

Authors:
;  [1]; ;  [2]
  1. Department of Nuclear Engineering, Korea Advanced Institute of Science and Technology, Daejon (Korea, Republic of)
  2. Deparment of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)
Publication Date:
OSTI Identifier:
22649138
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 43; Journal Issue: 6; Other Information: (c) 2016 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 61 RADIATION PROTECTION AND DOSIMETRY; DELIVERY; LUNGS; NEOPLASMS; PANCREAS; RADIATION DOSE DISTRIBUTIONS; RADIOTHERAPY

Citation Formats

Chung, H, Cho, S, Jeong, C, and Cho, B. SU-F-T-563: Delivered Dose Reconstruction of Moving Targets for Gated Volumetric Modulated Arc Therapy (VMAT). United States: N. p., 2016. Web. doi:10.1118/1.4956748.
Chung, H, Cho, S, Jeong, C, & Cho, B. SU-F-T-563: Delivered Dose Reconstruction of Moving Targets for Gated Volumetric Modulated Arc Therapy (VMAT). United States. doi:10.1118/1.4956748.
Chung, H, Cho, S, Jeong, C, and Cho, B. Wed . "SU-F-T-563: Delivered Dose Reconstruction of Moving Targets for Gated Volumetric Modulated Arc Therapy (VMAT)". United States. doi:10.1118/1.4956748.
@article{osti_22649138,
title = {SU-F-T-563: Delivered Dose Reconstruction of Moving Targets for Gated Volumetric Modulated Arc Therapy (VMAT)},
author = {Chung, H and Cho, S and Jeong, C and Cho, B},
abstractNote = {Purpose: Actual delivered dose of moving tumors treated with gated volumetric arc therapy (VMAT) may significantly differ from the planned dose assuming static target. In this study, we developed a method which reconstructs actual delivered dose distribution of moving target by taking into account both tumor motion and dynamic beam delivery of gated VMAT, and applied to abdominal tumors. Methods: Fifteen dual-arc VMAT plans (Eclipse, Varian Medical Systems) for 5 lung, 5 pancreatic, and 5 liver cancer patients treated with gated VMAT stereotactic body radiotherapy (SBRT) were studied. For reconstruction of the delivered dose distribution, we divided each original arc beam into control-point-wise sub-beams, and applied beam isocenter shifting to each sub-beam to reflect the tumor motion. The tumor positions as a function of beam delivery were estimated by synchronizing the beam delivery with the respiratory signal which acquired during treatment. For this purpose, an in-house program (MATLAB, Mathworks) was developed to convert the original DICOM plan data into motion-involved treatment plan. The motion-involved DICOM plan was imported into Eclipse for dose calculation. The reconstructed delivered dose was compared to the plan dose using the dose coverage of gross tumor volume (GTV) and dose distribution of organs at risk (OAR). Results: The mean GTV dose coverage difference between the reconstructed delivered dose and the plan dose was 0.2 % in lung and pancreas cases, and no difference in liver cases. Mean D1000cc of ipsilateral lungs was reduced (0.8 ± 1.4cGy). Conclusion: We successfully developed a method of delivered dose reconstruction taking into account both respiratory tumor motion and dynamic beam delivery, and applied it to abdominal tumors treated with gated VAMT. No significant deterioration of delivered dose distribution indicates that interplay effect would be minimal even in the case of gated SBRT. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2015038710)},
doi = {10.1118/1.4956748},
journal = {Medical Physics},
number = 6,
volume = 43,
place = {United States},
year = {Wed Jun 15 00:00:00 EDT 2016},
month = {Wed Jun 15 00:00:00 EDT 2016}
}