How have advances in CT dosimetry software impacted estimates of CT radiation dose and cancer incidence? A comparison of CT dosimetry software: Implications for past and future research

Susannah Maxwell, Richard Fox, Donald McRobbie, Max Bulsara, Jenny Doust, Peter O'Leary, John Slavotinek, John Stubbs, Rachael Moorin

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)
47 Downloads (Pure)

Abstract

Objective

Organ radiation dose from a CT scan, calculated by CT dosimetry software, can be combined with cancer risk data to estimate cancer incidence resulting from CT exposure. We aim to determine to what extent the use of improved anatomical representation of the adult human body "phantom" in CT dosimetry software impacts estimates of radiation dose and cancer incidence, to inform comparison of past and future research.

Methods

We collected 20 adult cases for each of three CT protocols (abdomen/pelvis, chest and head) from each of five public hospitals (random sample) (January-April inclusive 2010) and three private clinics (self-report). Organ equivalent and effective dose were calculated using both ImPACT (mathematical phantom) and NCICT (voxelised phantom) software. Bland Altman plots demonstrate agreement and Passing-Bablok regression reports systematic, proportional or random differences between results. We modelled the estimated lifetime attributable risk of cancer from a single exposure for each protocol, using age-sex specific risk-coefficients from the Biologic Effects of Ionizing Radiation VII report.

Results

For the majority of organs used in epidemiological studies of cancer incidence, the NCICT software (voxelised) provided higher dose estimates. Across the lifespan NCICT resulted in cancer estimates 2.9%-6.6% and 14.8%-16.3% higher in males and females (abdomen/pelvis) and 7.6%-19.7% and 12.9%-26.5% higher in males and females respectively (chest protocol). For the head protocol overall cancer estimates were lower for NCICT, but with greatest disparity, >30% at times.

Conclusion

When the results of previous studies estimating CT dose and cancer incidence are compared to more recent, or future, studies the dosimetry software must be considered. Any change in radiation dose or cancer risk may be attributable to the software and phantom used, rather than or in addition to changes in scanning practice. Studies using dosimetry software to estimate radiation dose should describe software comprehensively to facilitate comparison with past and future research.

Original languageEnglish
Article numbere0217816
Number of pages18
JournalPLoS One
Volume14
Issue number8
DOIs
Publication statusPublished - 14 Aug 2019

Fingerprint

Dosimetry
Software
Radiation
incidence
neoplasms
Incidence
dosage
Neoplasms
Network protocols
pelvis
chest
Pelvis
abdomen
Abdomen
Thorax
Head
Computerized tomography
Ionizing radiation
Public Hospitals
Ionizing Radiation

Cite this

Maxwell, Susannah ; Fox, Richard ; McRobbie, Donald ; Bulsara, Max ; Doust, Jenny ; O'Leary, Peter ; Slavotinek, John ; Stubbs, John ; Moorin, Rachael. / How have advances in CT dosimetry software impacted estimates of CT radiation dose and cancer incidence? A comparison of CT dosimetry software: Implications for past and future research. In: PLoS One. 2019 ; Vol. 14, No. 8.
@article{8a1e7224fe194564adb599ab902fdcbe,
title = "How have advances in CT dosimetry software impacted estimates of CT radiation dose and cancer incidence?: A comparison of CT dosimetry software: Implications for past and future research",
abstract = "ObjectiveOrgan radiation dose from a CT scan, calculated by CT dosimetry software, can be combined with cancer risk data to estimate cancer incidence resulting from CT exposure. We aim to determine to what extent the use of improved anatomical representation of the adult human body {"}phantom{"} in CT dosimetry software impacts estimates of radiation dose and cancer incidence, to inform comparison of past and future research.MethodsWe collected 20 adult cases for each of three CT protocols (abdomen/pelvis, chest and head) from each of five public hospitals (random sample) (January-April inclusive 2010) and three private clinics (self-report). Organ equivalent and effective dose were calculated using both ImPACT (mathematical phantom) and NCICT (voxelised phantom) software. Bland Altman plots demonstrate agreement and Passing-Bablok regression reports systematic, proportional or random differences between results. We modelled the estimated lifetime attributable risk of cancer from a single exposure for each protocol, using age-sex specific risk-coefficients from the Biologic Effects of Ionizing Radiation VII report.ResultsFor the majority of organs used in epidemiological studies of cancer incidence, the NCICT software (voxelised) provided higher dose estimates. Across the lifespan NCICT resulted in cancer estimates 2.9{\%}-6.6{\%} and 14.8{\%}-16.3{\%} higher in males and females (abdomen/pelvis) and 7.6{\%}-19.7{\%} and 12.9{\%}-26.5{\%} higher in males and females respectively (chest protocol). For the head protocol overall cancer estimates were lower for NCICT, but with greatest disparity, >30{\%} at times.ConclusionWhen the results of previous studies estimating CT dose and cancer incidence are compared to more recent, or future, studies the dosimetry software must be considered. Any change in radiation dose or cancer risk may be attributable to the software and phantom used, rather than or in addition to changes in scanning practice. Studies using dosimetry software to estimate radiation dose should describe software comprehensively to facilitate comparison with past and future research.",
author = "Susannah Maxwell and Richard Fox and Donald McRobbie and Max Bulsara and Jenny Doust and Peter O'Leary and John Slavotinek and John Stubbs and Rachael Moorin",
year = "2019",
month = "8",
day = "14",
doi = "10.1371/journal.pone.0217816",
language = "English",
volume = "14",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "8",

}

How have advances in CT dosimetry software impacted estimates of CT radiation dose and cancer incidence? A comparison of CT dosimetry software: Implications for past and future research. / Maxwell, Susannah; Fox, Richard; McRobbie, Donald; Bulsara, Max; Doust, Jenny; O'Leary, Peter; Slavotinek, John; Stubbs, John; Moorin, Rachael.

In: PLoS One, Vol. 14, No. 8, e0217816, 14.08.2019.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - How have advances in CT dosimetry software impacted estimates of CT radiation dose and cancer incidence?

T2 - A comparison of CT dosimetry software: Implications for past and future research

AU - Maxwell, Susannah

AU - Fox, Richard

AU - McRobbie, Donald

AU - Bulsara, Max

AU - Doust, Jenny

AU - O'Leary, Peter

AU - Slavotinek, John

AU - Stubbs, John

AU - Moorin, Rachael

PY - 2019/8/14

Y1 - 2019/8/14

N2 - ObjectiveOrgan radiation dose from a CT scan, calculated by CT dosimetry software, can be combined with cancer risk data to estimate cancer incidence resulting from CT exposure. We aim to determine to what extent the use of improved anatomical representation of the adult human body "phantom" in CT dosimetry software impacts estimates of radiation dose and cancer incidence, to inform comparison of past and future research.MethodsWe collected 20 adult cases for each of three CT protocols (abdomen/pelvis, chest and head) from each of five public hospitals (random sample) (January-April inclusive 2010) and three private clinics (self-report). Organ equivalent and effective dose were calculated using both ImPACT (mathematical phantom) and NCICT (voxelised phantom) software. Bland Altman plots demonstrate agreement and Passing-Bablok regression reports systematic, proportional or random differences between results. We modelled the estimated lifetime attributable risk of cancer from a single exposure for each protocol, using age-sex specific risk-coefficients from the Biologic Effects of Ionizing Radiation VII report.ResultsFor the majority of organs used in epidemiological studies of cancer incidence, the NCICT software (voxelised) provided higher dose estimates. Across the lifespan NCICT resulted in cancer estimates 2.9%-6.6% and 14.8%-16.3% higher in males and females (abdomen/pelvis) and 7.6%-19.7% and 12.9%-26.5% higher in males and females respectively (chest protocol). For the head protocol overall cancer estimates were lower for NCICT, but with greatest disparity, >30% at times.ConclusionWhen the results of previous studies estimating CT dose and cancer incidence are compared to more recent, or future, studies the dosimetry software must be considered. Any change in radiation dose or cancer risk may be attributable to the software and phantom used, rather than or in addition to changes in scanning practice. Studies using dosimetry software to estimate radiation dose should describe software comprehensively to facilitate comparison with past and future research.

AB - ObjectiveOrgan radiation dose from a CT scan, calculated by CT dosimetry software, can be combined with cancer risk data to estimate cancer incidence resulting from CT exposure. We aim to determine to what extent the use of improved anatomical representation of the adult human body "phantom" in CT dosimetry software impacts estimates of radiation dose and cancer incidence, to inform comparison of past and future research.MethodsWe collected 20 adult cases for each of three CT protocols (abdomen/pelvis, chest and head) from each of five public hospitals (random sample) (January-April inclusive 2010) and three private clinics (self-report). Organ equivalent and effective dose were calculated using both ImPACT (mathematical phantom) and NCICT (voxelised phantom) software. Bland Altman plots demonstrate agreement and Passing-Bablok regression reports systematic, proportional or random differences between results. We modelled the estimated lifetime attributable risk of cancer from a single exposure for each protocol, using age-sex specific risk-coefficients from the Biologic Effects of Ionizing Radiation VII report.ResultsFor the majority of organs used in epidemiological studies of cancer incidence, the NCICT software (voxelised) provided higher dose estimates. Across the lifespan NCICT resulted in cancer estimates 2.9%-6.6% and 14.8%-16.3% higher in males and females (abdomen/pelvis) and 7.6%-19.7% and 12.9%-26.5% higher in males and females respectively (chest protocol). For the head protocol overall cancer estimates were lower for NCICT, but with greatest disparity, >30% at times.ConclusionWhen the results of previous studies estimating CT dose and cancer incidence are compared to more recent, or future, studies the dosimetry software must be considered. Any change in radiation dose or cancer risk may be attributable to the software and phantom used, rather than or in addition to changes in scanning practice. Studies using dosimetry software to estimate radiation dose should describe software comprehensively to facilitate comparison with past and future research.

UR - http://www.scopus.com/inward/record.url?scp=85070689440&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0217816

DO - 10.1371/journal.pone.0217816

M3 - Article

VL - 14

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 8

M1 - e0217816

ER -