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Title: SU-F-J-30: Application of Intra-Fractional Imaging for Pretreatment CBCT of Breath-Hold Lung SBRT

Abstract

Purpose: Clinical implementation of gated lung SBRT requires tools to verify the accuracy of the target positioning on a daily basis. This is a particular challenge on Elekta linacs where the XVI imaging system does not interface directly to any commercial gating solution. In this study, we used the Elekta’s intra-fractional imaging functionality to perform the pretreatment CBCT verifications and evaluated both the image quality and gating accuracy. Methods: To use intrafraction imaging tools for pretreatment verifications, we planned a 360-degree arc with 1mmx5mm MLC opening. This beam was designed to drive the gantry during the gated CBCT data collection. A Catphan phantom was used to evaluate the image quality for the intra-fractional CBCT. A CIRS lung phantom with a 3cm sphereinsert and a moving chest plate were programmed with a simulated breathhold breathing pattern was used to check the gating accuracy. A C-Rad CatalystHD surface mapping system was used to provide the gating signal. Results: The total delivery time of the arc was 90 seconds. The uniformity and low contrast resolution for the intra-fractional CBCT was 1.5% and 3.6%, respectively. The values for the regular CBCT were 1.7% and 2.5%, respectively. The spatial resolution was 7 line-pairs/cm and themore » 3D spatial integrity was less than 1mm for the intra-fractional CBCT. The gated CBCT clearly demonstrated the accuracy of the gating image acquisition. Conclusion: The intra-fraction CBCT capabilities on an Elekta linac can be used to acquire pre-treatment gated images to verify the accuracy patient positioning. This imaging capability should provide for accurate patient alignments for the delivery of lung SBRT. This research was partially supported by Elekta.« less

Authors:
; ; ;  [1]
  1. Swedish Cancer Institute, Seattle, WA (United States)
Publication Date:
OSTI Identifier:
22632165
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; ACCURACY; BIOMEDICAL RADIOGRAPHY; CHEST; COMPUTERIZED TOMOGRAPHY; IMAGES; LINEAR ACCELERATORS; LUNGS; PATIENTS; PHANTOMS; POSITIONING; SPATIAL RESOLUTION; VERIFICATION

Citation Formats

Cao, D, Jermoumi, M, Mehta, V, and Shepard, D. SU-F-J-30: Application of Intra-Fractional Imaging for Pretreatment CBCT of Breath-Hold Lung SBRT. United States: N. p., 2016. Web. doi:10.1118/1.4955938.
Cao, D, Jermoumi, M, Mehta, V, & Shepard, D. SU-F-J-30: Application of Intra-Fractional Imaging for Pretreatment CBCT of Breath-Hold Lung SBRT. United States. doi:10.1118/1.4955938.
Cao, D, Jermoumi, M, Mehta, V, and Shepard, D. Wed . "SU-F-J-30: Application of Intra-Fractional Imaging for Pretreatment CBCT of Breath-Hold Lung SBRT". United States. doi:10.1118/1.4955938.
@article{osti_22632165,
title = {SU-F-J-30: Application of Intra-Fractional Imaging for Pretreatment CBCT of Breath-Hold Lung SBRT},
author = {Cao, D and Jermoumi, M and Mehta, V and Shepard, D},
abstractNote = {Purpose: Clinical implementation of gated lung SBRT requires tools to verify the accuracy of the target positioning on a daily basis. This is a particular challenge on Elekta linacs where the XVI imaging system does not interface directly to any commercial gating solution. In this study, we used the Elekta’s intra-fractional imaging functionality to perform the pretreatment CBCT verifications and evaluated both the image quality and gating accuracy. Methods: To use intrafraction imaging tools for pretreatment verifications, we planned a 360-degree arc with 1mmx5mm MLC opening. This beam was designed to drive the gantry during the gated CBCT data collection. A Catphan phantom was used to evaluate the image quality for the intra-fractional CBCT. A CIRS lung phantom with a 3cm sphereinsert and a moving chest plate were programmed with a simulated breathhold breathing pattern was used to check the gating accuracy. A C-Rad CatalystHD surface mapping system was used to provide the gating signal. Results: The total delivery time of the arc was 90 seconds. The uniformity and low contrast resolution for the intra-fractional CBCT was 1.5% and 3.6%, respectively. The values for the regular CBCT were 1.7% and 2.5%, respectively. The spatial resolution was 7 line-pairs/cm and the 3D spatial integrity was less than 1mm for the intra-fractional CBCT. The gated CBCT clearly demonstrated the accuracy of the gating image acquisition. Conclusion: The intra-fraction CBCT capabilities on an Elekta linac can be used to acquire pre-treatment gated images to verify the accuracy patient positioning. This imaging capability should provide for accurate patient alignments for the delivery of lung SBRT. This research was partially supported by Elekta.},
doi = {10.1118/1.4955938},
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}
}