The impact of iodinated contrast media on intravascular and extravascular absorbed doses in X-ray imaging: A microdosimetric analysis

Harbron, Richard W; Ainsbury, Elizabeth A.; Bouffler, Simon; Tanner, R.J.; Pearce, Mark S.; Eakins, Jonathan

doi:10.1016/j.ejmp.2018.02.001

Cited by 9 publications

(12 citation statements)

References 29 publications

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“…Comparing the slope values of the ex vivo calibration curves established in this study, the slope for the CA-samples was 1.7 times higher than the slope for the noCA-samples. The increase of DNA damage after the application of iodinated contrast agents could be caused by increased energy deposition, as suggested by Harbron et al who performed Monte Carlo modelling to obtain dose enhancement factors (DEFs) to blood for different blood vessel models and iodine concentrations [37]. For an iodine concentration of 5.0 mg mL −1 , (which is similar to our experiments) they calculated a DEF of 1.63 for the intraluminal part of an artery model (120 kV tube voltage) [37].…”

Section: Discussionmentioning

confidence: 99%

DNA Damage in Blood Leukocytes of Prostate Cancer Patients Undergoing PET/CT Examinations with [68Ga]Ga-PSMA I&T

Schumann

Scherthan

Frank

et al. 2020

Cancers

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The aim was to investigate the induction and repair of radiation-induced DNA double-strand breaks (DSBs) as a function of the absorbed dose to the blood of patients undergoing PET/CT examinations with [68Ga]Ga-PSMA. Blood samples were collected from 15 patients before and at four time points after [68Ga]Ga-PSMA administration, both before and after the PET/CT scan. Absorbed doses to the blood were calculated. In addition, blood samples with/without contrast agent from five volunteers were irradiated ex vivo by CT while measuring the absorbed dose. Leukocytes were isolated, fixed, and stained for co-localizing γ-H2AX+53BP1 DSB foci that were enumerated manually. In vivo, a significant increase in γ-H2AX+53BP1 foci compared to baseline was observed at all time points after administration, although the absorbed dose to the blood by 68Ga was below 4 mGy. Ex vivo, the increase in radiation-induced foci depended on the absorbed dose and the presence of contrast agent, which could have caused a dose enhancement. The CT-dose contribution for the patients was estimated at about 12 mGy using the ex vivo calibration. The additional number of DSB foci induced by CT, however, was comparable to the one induced by 68Ga. The significantly increased foci numbers after [68Ga]Ga-PSMA administration may suggest a possible low-dose hypersensitivity.

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Section: Discussionmentioning

confidence: 99%

DNA Damage in Blood Leukocytes of Prostate Cancer Patients Undergoing PET/CT Examinations with [68Ga]Ga-PSMA I&T

Schumann

Scherthan

Frank

et al. 2020

Cancers

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“…The impact of CA's on absorbed radiation dose in organs and tissues has recently been challenged by a few studies, which demonstrate a dose increase in the presence of iodine [2,[13][14][15]. However, research on the subject has been mostly restricted to simplified geometrical models, homogenous organ structures, and single CT acquisitions.…”

Section: Introductionmentioning

confidence: 99%

“…The use of contrast agents (CAs) is essential in medical imaging to opacify lesions and tissues. In CT alone, 50–60% of all procedures use iodine CA to ensure diagnostic quality [ 1 , 2 ]. A considerable amount of literature has been published on the safety of clinical CA’s, and it is well acknowledged that respecting guidelines provides its safe and effective use [ 3 , 4 ].…”

Section: Introductionmentioning

confidence: 99%

The presence of contrast agent increases organ radiation dose in contrast-enhanced CT

et al. 2021

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Objectives Routine dosimetry calculations do not account for the presence of iodine in organs and tissues during CT acquisition. This study aims to investigate the impact of contrast agent (CA) on radiation dose. Methods First, relation between absorbed radiation dose and iodine concentrations was investigated using a cylindrical water phantom with iodine-saline dilution insertions. Subsequently, a retrospective study on abdominal dual-energy CT (DECT) patient data was performed to assess the increase of the local absorbed radiation dose compared to a non-contrast scan. Absorbed doses were estimated with Monte Carlo simulations using the individual CT voxel data of phantom and patients. Further, organ segmentations were performed to obtain the dose in liver, liver parenchyma, left kidney, right kidney, aorta, and spleen. Results In the phantom study, a linear relation was observed between the radiation dose normalized by computed tomography dose index (CTDI) and CA concentrations Iconc (mg/ml) for three tube voltages; $$ \frac{D_{80 kVp}}{CTDI_{vol}} $$ D 80 kVp CTDI vol = 0.14 × Iconc + 1.02, $$ \frac{D_{120 kVp}}{CTDI_{vol}} $$ D 120 kVp CTDI vol = 0.16 × Iconc + 1.21, $$ \frac{D_{140 kVp}}{CTDI_{vol}} $$ D 140 kVp CTDI vol = 0.16 × Iconc + 1.24, and for DECT acquisition; $$ \frac{D_{DECT}}{CTDI_{vol}} $$ D DECT CTDI vol = 0.15 × Iconc + 1.09. Similarly, a linear relation was observed between the dose increase and the organ iodine contents (R2 = 0.86 and pvalue < 0.01) in the patient study. The relative doses increased in the liver (21 ± 5%), liver parenchyma (20 ± 5%), right kidney (37 ± 7%), left kidney (39 ± 7%), aorta (34 ± 6%) and spleen (26 ± 4%). In addition, the local dose distributions changed based on patient’s anatomy and physiology. Conclusions Compared to a non-contrast scan, the organ doses increase by 30% in contrast-enhanced abdominal CT. This study suggests considering CA in dosimetry calculations, epidemiological studies, and organ dose estimations while developing new CT protocols. Key Points • The presence of contrast media increases radiation absorption in CT, and this increase is related to the iodine content in the organs. • The increased radiation absorption due to contrast media can lead to an average 30% increase in absorbed organ dose. • Iodine should be considered in CT radiation safety studies.

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“…In the area of radiobiology, key recent outputs include development and validation of cytogenetic and genetic biomarkers of radiation exposure in medically exposed populations to underpin dose assessment (Cruz-Garcia et al, 2018;Einbeck et al, 2018;Moquet et al, 2018;O'Brien et al, 2018;Tichy et al, 2018), development of a new method of premature chromosome condensation to increase the speed of biological assessment of higher doses (Sun et al, 2019(Sun et al, , 2020, development of a new protocol for rapid gene-expression-based dose estimation (Polozov et al, 2019), and identification of further new genes suitable for biodosimetric purposes using rapid long-read DNA sequencing methods (Cruz-Garcia et al, 2020). Other major contributions include publication of peer-reviewed papers focused on the dose to the lens of the eye following CT scan exposures (Harbron et al, 2019), and the limited impact of iodinated contrast media on doses to haematopoietic stem cells (Harbron et al, 2017b(Harbron et al, , 2018b.…”

Section: Nihr Hpru Radiation Themementioning

confidence: 99%

“…For example, epidemiologists at the University of Newcastle have increased the size of the UK CT scan study cohort to over 450,000 individuals (Bernier et al., 2019), which has provided a sufficiently large population for the Radiation Theme partners to investigate how computed tomography (CT) risks might be modified by underlying health conditions (Harbron, 2016) or other confounders (e.g. transplantation status) (Harbron et al., 2018a), together with improved dose assessment (Harbron et al., 2016) and overall risk of cancers (Journy et al., 2016, 2017; Harbron et al., 2017a, 2018a) for low-dose medically exposed populations. In the area of radiobiology, key recent outputs include development and validation of cytogenetic and genetic biomarkers of radiation exposure in medically exposed populations to underpin dose assessment (Cruz-Garcia et al., 2018; Einbeck et al., 2018; Moquet et al., 2018; O’Brien et al., 2018; Tichy et al., 2018), development of a new method of premature chromosome condensation to increase the speed of biological assessment of higher doses (Sun et al., 2019, 2020), development of a new protocol for rapid gene-expression-based dose estimation (Polozov et al., 2019), and identification of further new genes suitable for biodosimetric purposes using rapid long-read DNA sequencing methods (Cruz-Garcia et al., 2020).…”

Section: Interdisciplinary Working Stakeholder Involvement and Ementioning

confidence: 99%

The 2019 Bo Lindell Laureate Lecture: On the use of interdisciplinary, stakeholder-driven, radiation protection research in support of medical uses of ionising radiation

Ainsbury

2020

Ann ICRP

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Medical exposures form the largest manmade contributor to total ionising radiation exposure of the UK population. In recent years, new technologies have been developed to improve treatment and prognosis of individuals treated with radiation for diseases such as cancer. However, there is evidence of public, patient, and medical professional concern that radiation protection regulations and practices, as well as understanding of potential long-term adverse health effects of radiation exposure (in the context of other health risks), have not always ‘kept pace’ with technological developments in this field. This is a truly complex, multi-disciplinary problem for the modern world. The ‘Radiation Theme’ of the Public Health England and Newcastle University Health Protection Research Unit on ‘Chemical and Radiation Threats and Hazards’ is addressing this need, with a key focus on a genuinely interdisciplinary approach bringing together world-leading epidemiologists, radiation biologists, clinicians, statisticians, and artists. In addition, the project has a strong grounding in public, patient, and medical professional involvement in research. Similarly, the EU-CONCERT-funded LDLensRad project seeks to understand the mechanisms of action of low-dose ionising radiation in the lens of the eye, and the potential contribution to the development of cataract – in contemporary research, such projects will only be considered successful when they make use of expertise from a variety of fields and when they are able to demonstrate that the outputs are not only of benefit to society, but that society understands and welcomes the benefits. Finally, successful engagement, training, and retention of early career scientists within this field is crucial for sustainability of the research. Herein, the contribution of embedded interdisciplinary working, stakeholder involvement, and training of early career scientists to recent advancements in the field of medical (and wider) radiation protection research is discussed and considered.

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The impact of iodinated contrast media on intravascular and extravascular absorbed doses in X-ray imaging: A microdosimetric analysis

Cited by 9 publications

References 29 publications

DNA Damage in Blood Leukocytes of Prostate Cancer Patients Undergoing PET/CT Examinations with [68Ga]Ga-PSMA I&T

DNA Damage in Blood Leukocytes of Prostate Cancer Patients Undergoing PET/CT Examinations with [68Ga]Ga-PSMA I&T

The presence of contrast agent increases organ radiation dose in contrast-enhanced CT

The 2019 Bo Lindell Laureate Lecture: On the use of interdisciplinary, stakeholder-driven, radiation protection research in support of medical uses of ionising radiation

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