Organ doses evaluation for chest computed tomography procedures with TL dosimeters: Comparison with Monte Carlo simulations

Louise Giansante, Juliana C. Martins, Denise Y. Nersissian, Karen C. Kiers, Fernando Uliana Kay, Marcio V.Y. Sawamura, Choonsik Lee, Eloisa M.M.S. Gebrim, Paulo R. Costa

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Purpose: To evaluate organ doses in routine and low-dose chest computed tomography (CT) protocols using an experimental methodology. To compare experimental results with results obtained by the National Cancer Institute dosimetry system for CT (NCICT) organ dose calculator. To address the differences on organ dose measurements using tube current modulation (TCM) and fixed tube current protocols. Methods: An experimental approach to evaluate organ doses in pediatric and adult anthropomorphic phantoms using thermoluminescent dosimeters (TLDs) was employed in this study. Several analyses were performed in order to establish the best way to achieve the main results in this investigation. The protocols used in this study were selected after an analysis of patient data collected from the Institute of Radiology of the School of Medicine of the University of São Paulo (InRad). The image quality was evaluated by a radiologist from this institution. Six chest adult protocols and four chest pediatric protocols were evaluated. Lung doses were evaluated for the adult phantom and lung and thyroid doses were evaluated for the pediatric phantom. The irradiations were performed using both a GE and a Philips CT scanner. Finally, organ doses measured with dosimeters were compared with Monte Carlo simulations performed with NCICT. Results: After analyzing the data collected from all CT examinations performed during a period of 3 yr, the authors identified that adult and pediatric chest CT are among the most applied protocol in patients in that clinical institution, demonstrating the relevance on evaluating organ doses due to these examinations. With regards to the scan parameters adopted, the authors identified that using 80 kV instead of 120 kV for a pediatric chest routine CT, with TCM in both situations, can lead up to a 28.7% decrease on the absorbed dose. Moreover, in comparison to the standard adult protocol, which is performed with fixed mAs, TCM, and ultra low-dose protocols resulted in dose reductions of up to 35.0% and 90.0%, respectively. Finally, the percent differences found between experimental and Monte Carlo simulated organ doses were within a 20% interval. Conclusions: The results obtained in this study measured the impact on the absorbed dose in routine chest CT by changing several scan parameters while the image quality could be potentially preserved.

Original languageEnglish (US)
JournalJournal of Applied Clinical Medical Physics
DOIs
StateAccepted/In press - Jan 1 2018

Fingerprint

Dosimeters
chest
organs
dosimeters
Tomography
Pediatrics
Thorax
tomography
dosage
evaluation
Dosimetry
National Cancer Institute (U.S.)
simulation
Modulation
Image quality
X-Ray Computed Tomography Scanners
Lung
tubes
Radiology
Monte Carlo simulation

Keywords

  • computed tomography
  • dosimetry/exposure assessment
  • image quality
  • Monte Carlo simulations
  • organ dose

ASJC Scopus subject areas

  • Radiation
  • Instrumentation
  • Radiology Nuclear Medicine and imaging

Cite this

Organ doses evaluation for chest computed tomography procedures with TL dosimeters : Comparison with Monte Carlo simulations. / Giansante, Louise; Martins, Juliana C.; Nersissian, Denise Y.; Kiers, Karen C.; Kay, Fernando Uliana; Sawamura, Marcio V.Y.; Lee, Choonsik; Gebrim, Eloisa M.M.S.; Costa, Paulo R.

In: Journal of Applied Clinical Medical Physics, 01.01.2018.

Research output: Contribution to journalArticle

Giansante, Louise ; Martins, Juliana C. ; Nersissian, Denise Y. ; Kiers, Karen C. ; Kay, Fernando Uliana ; Sawamura, Marcio V.Y. ; Lee, Choonsik ; Gebrim, Eloisa M.M.S. ; Costa, Paulo R. / Organ doses evaluation for chest computed tomography procedures with TL dosimeters : Comparison with Monte Carlo simulations. In: Journal of Applied Clinical Medical Physics. 2018.
@article{db935429331b4f23b7c3f772d47f0f0f,
title = "Organ doses evaluation for chest computed tomography procedures with TL dosimeters: Comparison with Monte Carlo simulations",
abstract = "Purpose: To evaluate organ doses in routine and low-dose chest computed tomography (CT) protocols using an experimental methodology. To compare experimental results with results obtained by the National Cancer Institute dosimetry system for CT (NCICT) organ dose calculator. To address the differences on organ dose measurements using tube current modulation (TCM) and fixed tube current protocols. Methods: An experimental approach to evaluate organ doses in pediatric and adult anthropomorphic phantoms using thermoluminescent dosimeters (TLDs) was employed in this study. Several analyses were performed in order to establish the best way to achieve the main results in this investigation. The protocols used in this study were selected after an analysis of patient data collected from the Institute of Radiology of the School of Medicine of the University of S{\~a}o Paulo (InRad). The image quality was evaluated by a radiologist from this institution. Six chest adult protocols and four chest pediatric protocols were evaluated. Lung doses were evaluated for the adult phantom and lung and thyroid doses were evaluated for the pediatric phantom. The irradiations were performed using both a GE and a Philips CT scanner. Finally, organ doses measured with dosimeters were compared with Monte Carlo simulations performed with NCICT. Results: After analyzing the data collected from all CT examinations performed during a period of 3 yr, the authors identified that adult and pediatric chest CT are among the most applied protocol in patients in that clinical institution, demonstrating the relevance on evaluating organ doses due to these examinations. With regards to the scan parameters adopted, the authors identified that using 80 kV instead of 120 kV for a pediatric chest routine CT, with TCM in both situations, can lead up to a 28.7{\%} decrease on the absorbed dose. Moreover, in comparison to the standard adult protocol, which is performed with fixed mAs, TCM, and ultra low-dose protocols resulted in dose reductions of up to 35.0{\%} and 90.0{\%}, respectively. Finally, the percent differences found between experimental and Monte Carlo simulated organ doses were within a 20{\%} interval. Conclusions: The results obtained in this study measured the impact on the absorbed dose in routine chest CT by changing several scan parameters while the image quality could be potentially preserved.",
keywords = "computed tomography, dosimetry/exposure assessment, image quality, Monte Carlo simulations, organ dose",
author = "Louise Giansante and Martins, {Juliana C.} and Nersissian, {Denise Y.} and Kiers, {Karen C.} and Kay, {Fernando Uliana} and Sawamura, {Marcio V.Y.} and Choonsik Lee and Gebrim, {Eloisa M.M.S.} and Costa, {Paulo R.}",
year = "2018",
month = "1",
day = "1",
doi = "10.1002/acm2.12505",
language = "English (US)",
journal = "Journal of Applied Clinical Medical Physics",
issn = "1526-9914",
publisher = "American Institute of Physics Publising LLC",

}

TY - JOUR

T1 - Organ doses evaluation for chest computed tomography procedures with TL dosimeters

T2 - Comparison with Monte Carlo simulations

AU - Giansante, Louise

AU - Martins, Juliana C.

AU - Nersissian, Denise Y.

AU - Kiers, Karen C.

AU - Kay, Fernando Uliana

AU - Sawamura, Marcio V.Y.

AU - Lee, Choonsik

AU - Gebrim, Eloisa M.M.S.

AU - Costa, Paulo R.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Purpose: To evaluate organ doses in routine and low-dose chest computed tomography (CT) protocols using an experimental methodology. To compare experimental results with results obtained by the National Cancer Institute dosimetry system for CT (NCICT) organ dose calculator. To address the differences on organ dose measurements using tube current modulation (TCM) and fixed tube current protocols. Methods: An experimental approach to evaluate organ doses in pediatric and adult anthropomorphic phantoms using thermoluminescent dosimeters (TLDs) was employed in this study. Several analyses were performed in order to establish the best way to achieve the main results in this investigation. The protocols used in this study were selected after an analysis of patient data collected from the Institute of Radiology of the School of Medicine of the University of São Paulo (InRad). The image quality was evaluated by a radiologist from this institution. Six chest adult protocols and four chest pediatric protocols were evaluated. Lung doses were evaluated for the adult phantom and lung and thyroid doses were evaluated for the pediatric phantom. The irradiations were performed using both a GE and a Philips CT scanner. Finally, organ doses measured with dosimeters were compared with Monte Carlo simulations performed with NCICT. Results: After analyzing the data collected from all CT examinations performed during a period of 3 yr, the authors identified that adult and pediatric chest CT are among the most applied protocol in patients in that clinical institution, demonstrating the relevance on evaluating organ doses due to these examinations. With regards to the scan parameters adopted, the authors identified that using 80 kV instead of 120 kV for a pediatric chest routine CT, with TCM in both situations, can lead up to a 28.7% decrease on the absorbed dose. Moreover, in comparison to the standard adult protocol, which is performed with fixed mAs, TCM, and ultra low-dose protocols resulted in dose reductions of up to 35.0% and 90.0%, respectively. Finally, the percent differences found between experimental and Monte Carlo simulated organ doses were within a 20% interval. Conclusions: The results obtained in this study measured the impact on the absorbed dose in routine chest CT by changing several scan parameters while the image quality could be potentially preserved.

AB - Purpose: To evaluate organ doses in routine and low-dose chest computed tomography (CT) protocols using an experimental methodology. To compare experimental results with results obtained by the National Cancer Institute dosimetry system for CT (NCICT) organ dose calculator. To address the differences on organ dose measurements using tube current modulation (TCM) and fixed tube current protocols. Methods: An experimental approach to evaluate organ doses in pediatric and adult anthropomorphic phantoms using thermoluminescent dosimeters (TLDs) was employed in this study. Several analyses were performed in order to establish the best way to achieve the main results in this investigation. The protocols used in this study were selected after an analysis of patient data collected from the Institute of Radiology of the School of Medicine of the University of São Paulo (InRad). The image quality was evaluated by a radiologist from this institution. Six chest adult protocols and four chest pediatric protocols were evaluated. Lung doses were evaluated for the adult phantom and lung and thyroid doses were evaluated for the pediatric phantom. The irradiations were performed using both a GE and a Philips CT scanner. Finally, organ doses measured with dosimeters were compared with Monte Carlo simulations performed with NCICT. Results: After analyzing the data collected from all CT examinations performed during a period of 3 yr, the authors identified that adult and pediatric chest CT are among the most applied protocol in patients in that clinical institution, demonstrating the relevance on evaluating organ doses due to these examinations. With regards to the scan parameters adopted, the authors identified that using 80 kV instead of 120 kV for a pediatric chest routine CT, with TCM in both situations, can lead up to a 28.7% decrease on the absorbed dose. Moreover, in comparison to the standard adult protocol, which is performed with fixed mAs, TCM, and ultra low-dose protocols resulted in dose reductions of up to 35.0% and 90.0%, respectively. Finally, the percent differences found between experimental and Monte Carlo simulated organ doses were within a 20% interval. Conclusions: The results obtained in this study measured the impact on the absorbed dose in routine chest CT by changing several scan parameters while the image quality could be potentially preserved.

KW - computed tomography

KW - dosimetry/exposure assessment

KW - image quality

KW - Monte Carlo simulations

KW - organ dose

UR - http://www.scopus.com/inward/record.url?scp=85058047748&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85058047748&partnerID=8YFLogxK

U2 - 10.1002/acm2.12505

DO - 10.1002/acm2.12505

M3 - Article

C2 - 30508315

AN - SCOPUS:85058047748

JO - Journal of Applied Clinical Medical Physics

JF - Journal of Applied Clinical Medical Physics

SN - 1526-9914

ER -