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Artifacts in conventional computed tomography (CT) and free breathing four-dimensional CT induce uncertainty in gross tumor volume determination

Fredberg Persson, Gitte ; Nygaard, Ditte Eklund ; Af Rosenschöld, Per Munck LU orcid ; Richter Vogelius, Ivan ; Josipovic, Mirjana ; Specht, Lena and Korreman, Stine Sofia (2011) In International Journal of Radiation Oncology Biology Physics 80(5). p.1573-1580
Abstract

Purpose: Artifacts impacting the imaged tumor volume can be seen in conventional three-dimensional CT (3DCT) scans for planning of lung cancer radiotherapy but can be reduced with the use of respiration-correlated imaging, i.e., 4DCT or breathhold CT (BHCT) scans. The aim of this study was to compare delineated gross tumor volume (GTV) sizes in 3DCT, 4DCT, and BHCT scans of patients with lung tumors. Methods and Materials: A total of 36 patients with 46 tumors referred for stereotactic radiotherapy of lung tumors were included. All patients underwent positron emission tomography (PET)/CT, 4DCT, and BHCT scans. GTVs in all CT scans of individual patients were delineated during one session by a single physician to minimize systematic... (More)

Purpose: Artifacts impacting the imaged tumor volume can be seen in conventional three-dimensional CT (3DCT) scans for planning of lung cancer radiotherapy but can be reduced with the use of respiration-correlated imaging, i.e., 4DCT or breathhold CT (BHCT) scans. The aim of this study was to compare delineated gross tumor volume (GTV) sizes in 3DCT, 4DCT, and BHCT scans of patients with lung tumors. Methods and Materials: A total of 36 patients with 46 tumors referred for stereotactic radiotherapy of lung tumors were included. All patients underwent positron emission tomography (PET)/CT, 4DCT, and BHCT scans. GTVs in all CT scans of individual patients were delineated during one session by a single physician to minimize systematic delineation uncertainty. The GTV size from the BHCT was considered the closest to true tumor volume and was chosen as the reference. The reference GTV size was compared to GTV sizes in 3DCT, at midventilation (MidV), at end-inspiration (Insp), and at end-expiration (Exp) bins from the 4DCT scan. Results: The median BHCT GTV size was 4.9 cm 3 (0.1-53.3 cm 3). Median deviation between 3DCT and BHCT GTV size was 0.3 cm 3 (-3.3 to 30.0 cm 3), between MidV and BHCT size was 0.2 cm 3 (-5.7 to 19.7 cm 3), between Insp and BHCT size was 0.3 cm 3 (-4.7 to 24.8 cm 3), and between Exp and BHCT size was 0.3 cm 3 (-4.8 to 25.5 cm 3). The 3DCT, MidV, Insp, and Exp median GTV sizes were all significantly larger than the BHCT median GTV size. Conclusions: In the present study, the choice of CT method significantly influenced the delineated GTV size, on average, leading to an increase in GTV size compared to the reference BHCT. The uncertainty caused by artifacts is estimated to be in the same magnitude as delineation uncertainty and should be considered in the design of margins for radiotherapy.

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author
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publishing date
type
Contribution to journal
publication status
published
subject
keywords
Artifacts, Breathhold CT, Four-dimensional CT, Gross tumor volume, Lung cancer
in
International Journal of Radiation Oncology Biology Physics
volume
80
issue
5
pages
1573 - 1580
publisher
Elsevier
external identifiers
  • pmid:21163584
  • scopus:79960077324
ISSN
0360-3016
DOI
10.1016/j.ijrobp.2010.10.036
language
English
LU publication?
no
additional info
Funding Information: This work has been supported by grants from the Danish Research Council , the Lundbeck Foundation Center for interventional Research in Radiation Oncology (CIRRO), and Varian Medical Systems . Funding Information: Conflict of interest: Gitte Fredberg Persson, Mirjana Josipovic, Lena Specht, Stine Korreman, and Per Munck af Rosenschöld have been involved in educational activities arranged in cooperation with Varian Medical Systems. Stine Korreman has received scientific grants from Varian Medical Systems. Per Munck af Rosenschöld has a research agreement with Varian Medical Systems.
id
6dda7527-6d4e-4cf1-a682-79f212d87f96
date added to LUP
2023-07-19 17:07:00
date last changed
2024-02-03 15:18:57
@article{6dda7527-6d4e-4cf1-a682-79f212d87f96,
  abstract     = {{<p>Purpose: Artifacts impacting the imaged tumor volume can be seen in conventional three-dimensional CT (3DCT) scans for planning of lung cancer radiotherapy but can be reduced with the use of respiration-correlated imaging, i.e., 4DCT or breathhold CT (BHCT) scans. The aim of this study was to compare delineated gross tumor volume (GTV) sizes in 3DCT, 4DCT, and BHCT scans of patients with lung tumors. Methods and Materials: A total of 36 patients with 46 tumors referred for stereotactic radiotherapy of lung tumors were included. All patients underwent positron emission tomography (PET)/CT, 4DCT, and BHCT scans. GTVs in all CT scans of individual patients were delineated during one session by a single physician to minimize systematic delineation uncertainty. The GTV size from the BHCT was considered the closest to true tumor volume and was chosen as the reference. The reference GTV size was compared to GTV sizes in 3DCT, at midventilation (MidV), at end-inspiration (Insp), and at end-expiration (Exp) bins from the 4DCT scan. Results: The median BHCT GTV size was 4.9 cm <sup>3</sup> (0.1-53.3 cm <sup>3</sup>). Median deviation between 3DCT and BHCT GTV size was 0.3 cm <sup>3</sup> (-3.3 to 30.0 cm <sup>3</sup>), between MidV and BHCT size was 0.2 cm <sup>3</sup> (-5.7 to 19.7 cm <sup>3</sup>), between Insp and BHCT size was 0.3 cm <sup>3</sup> (-4.7 to 24.8 cm <sup>3</sup>), and between Exp and BHCT size was 0.3 cm <sup>3</sup> (-4.8 to 25.5 cm <sup>3</sup>). The 3DCT, MidV, Insp, and Exp median GTV sizes were all significantly larger than the BHCT median GTV size. Conclusions: In the present study, the choice of CT method significantly influenced the delineated GTV size, on average, leading to an increase in GTV size compared to the reference BHCT. The uncertainty caused by artifacts is estimated to be in the same magnitude as delineation uncertainty and should be considered in the design of margins for radiotherapy.</p>}},
  author       = {{Fredberg Persson, Gitte and Nygaard, Ditte Eklund and Af Rosenschöld, Per Munck and Richter Vogelius, Ivan and Josipovic, Mirjana and Specht, Lena and Korreman, Stine Sofia}},
  issn         = {{0360-3016}},
  keywords     = {{Artifacts; Breathhold CT; Four-dimensional CT; Gross tumor volume; Lung cancer}},
  language     = {{eng}},
  month        = {{08}},
  number       = {{5}},
  pages        = {{1573--1580}},
  publisher    = {{Elsevier}},
  series       = {{International Journal of Radiation Oncology Biology Physics}},
  title        = {{Artifacts in conventional computed tomography (CT) and free breathing four-dimensional CT induce uncertainty in gross tumor volume determination}},
  url          = {{http://dx.doi.org/10.1016/j.ijrobp.2010.10.036}},
  doi          = {{10.1016/j.ijrobp.2010.10.036}},
  volume       = {{80}},
  year         = {{2011}},
}