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. 2025 Jan;52(2):574-585.
doi: 10.1007/s00259-024-06902-8. Epub 2024 Oct 1.

Long-term trends in total administered radiation dose from brain [18F]FDG-PET in children with drug-resistant epilepsy

Antonio G Gennari  1   2   3   4 , Stephan Waelti  1   2   5 , Moritz Schwyzer  1   2 , Valerie Treyer  1   2 , Alexia Rossi  1   2 , Thomas Sartoretti  1   2 , Alexander Maurer  1   2 , Georgia Ramantani  2   3   6 , Ruth Tuura O'Gorman  2   6   4 , Christian J Kellenberger  6   7 , Martin W Hüllner  1   2 , Michael Messerli  8   9
Affiliations

Long-term trends in total administered radiation dose from brain [18F]FDG-PET in children with drug-resistant epilepsy

Antonio G Gennari et al. Eur J Nucl Med Mol Imaging. 2025 Jan.

Abstract

Purpose: To assess the trends in administered 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) doses, computed tomography (CT) radiation doses, and image quality over the last 15 years in children with drug-resistant epilepsy (DRE) undergoing hybrid positron emission tomography (PET) brain scans.

Methods: We retrospectively analyzed data from children with DRE who had [18F]FDG-PET/CT or magnetic resonance scans for presurgical evaluation between 2005 and 2021. We evaluated changes in injected [18F]FDG doses, administered activity per body weight, CT dose index volume (CTDIvol), and dose length product (DLP). PET image quality was assessed visually by four trained raters. Conversely, CT image quality was measured using region-of-interest analysis, normalized by signal-to-noise (SNR) and contrast-to-noise ratio (CNR).

Results: We included 55 children (30 male, mean age: 9 ± 6 years) who underwent 61 [18F]FDG-PET scans (71% as PET/CT). Annually, the injected [18F]FDG dose decreased by ~ 1% (95% CI: 0.92%-0.98%, p < 0.001), with no significant changes in administered activity per body weight (p = 0.51). CTDIvol and DLP decreased annually by 16% (95% CI: 9%-23%) and 15% (95% CI: 8%-21%, both p < 0.001), respectively. PET image quality improved by 9% year-over-year (95% CI: 6%-13%, p < 0.001), while CT-associated SNR and CNR decreased annually by 7% (95% CI: 3%-11%, p = 0.001) and 6% (95% CI: 2%-10%, p = 0.008), respectively.

Conclusion: Our findings indicate stability in [18F]FDG administered activity per body weight alongside improvements in PET image quality. Conversely, CT-associated radiation doses reduced. These results reaffirm [18F]FDG-PET as an increasingly safer and higher-resolution auxiliary imaging modality for children with DRE. These improvements, driven by technological advancements, may enhance the diagnostic precision and patient outcomes in pediatric epilepsy surgery.

Keywords: Drug-resistant epilepsy; Image quality; Pediatric; Radiation dose; [18F]FDG-PET.

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Conflict of interest statement

Declarations. Informed consent and ethics approval: The present study was approved by the local ethics committee (Number: 2020–03067) and was conducted in compliance with ICH-GCP rules and the Declaration of Helsinki. Written informed consent was waived for patients whose scan was acquired before January 2016. After January 2016, only patients with documented consent to the use of their medical data for research were included. Consent to publish: The datasets analyzed in the current study relies on brain scans, which hardly contain identifying characteristics, representing one of the exceptions to obtaining consent to publish. Competing interest: The University Hospital Zurich holds a research agreement with GE Healthcare (unrelated to the current study). PD Dr. Martin W. Hüllner is a recipient of research grants by GE Healthcare. Apart from that, the authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.

Figures

Fig. 1
Fig. 1
Flow diagram of the study group. CT: Computed tomography; CTDIvol: Computed tomography dose index volume; DLP: Dose-length product; DRE: Drug resistant epilepsy; [18F]FDG: 2-[18F]fluoro-2-deoxy-D-glucose; MR: Magnetic resonance; PET: Positron emission tomography
Fig. 2
Fig. 2
(A, B) Evolution of [18F]FDG-PET-associated parameters. Scatter plots detailing the injected (A) and [18F]FDG-administered activity per body weight (B) evolution over the last 15 years. Regression lines are based on quasi-Poisson regression analysis. (C, D) Estimates of the average trends of [18F]FDG-PET image quality and noise over the study period. Different grey symbols represent each rater’s average [18F]FDG-PET image quality and noise. Grey arrows detail the installation of digital PET/CT and PET/MR at our tertiary hospital. PET/MR was installed in 2014 but the first brain cases were acquired in 2016. CT: Computed tomography; [18F]FDG: 2-[18F]fluoro-2-deoxy-D-glucose; Kg: kilogram; MBq: Megabecquerel; MR: Magnetic resonance; PET: Positron emission tomography
Fig. 3
Fig. 3
Evolution of CT-associated parameters. (A, B, C, D) Estimates of the average trends of CTDIvol and DLP over the study period. Panels (A) and (B) present the evolution of CTDIvol and DLP based on PET/CT derived data. Panels (C) and (D) present a sensitivity analysis aimed to quantify the cumulative radiation reduction in the last 15 years in children with DRE fictitiously setting PET/MR CTDIvol and DLP values to 0. Arrows detail the installation of digital PET/CT and PET/MR at our tertiary hospital. PET/MR was installed in 2014 but the first brain cases were acquired in 2016. CT: Computed tomography; CTDIvol: Computed tomography dose index volume; DLP: Dose-length product; DRE: drug resistant epilepsy; mGy: milligray; MR: Magnetic resonance; PET: Positron emission tomography
Fig. 4
Fig. 4
Distribution of PET/CT tube currents according to date of scan and patient age. (A) Density plot representing age at scan according to different kVs. Lower kVs were usually employed to scan younger children. (C) Percent stacked bar chart highlighting the usage of different kVs according to different years. The introduction of digital PET/CT allowed the reduction of high-dose scans. Indeed, all the exams performed at 80 kV were acquired after 2016. Exemplificative cases acquired at different kVs are provided on the side. Compared with higher kVs images, those acquired at lower kVs impeded the differentiation between grey and white matter, made ventricles recognition challenging, and had an overall more granular appearance. The ability of newer scanners to use lower kV protocols, the reduction of the age at scan throughout the study period, and the use of lower kVs protocols in younger children concurred to reduce CT image through the study period. (B, D) Scatter plots detailing the evolution of SNR and CNR over the last 15 years. Regression lines are based on quasi-Poisson regression analysis. CT: Computed tomography; CNRCT: Contrast-to-noise ratio; PET: Positron emission tomography; SNRCT: Signal-to-noise ratio; kV: kilovolt
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References

    1. Aaberg KM, Gunnes N, Bakken IJ, Lund Soraas C, Berntsen A, Magnus P, et al. Incidence and Prevalence of Childhood Epilepsy: A Nationwide Cohort Study. Pediatrics. 2017;139. 10.1542/peds.2016-3908. - PubMed
    1. Camfield CS, Camfield PR, Gordon K, Wirrell E, Dooley JM. Incidence of epilepsy in childhood and adolescence: a population-based study in Nova Scotia from 1977 to 1985. Epilepsia. 1996;37:19–23. 10.1111/j.1528-1157.1996.tb00506.x. - PubMed
    1. Kwan P, Arzimanoglou A, Berg AT, Brodie MJ, Allen Hauser W, Mathern G, et al. Definition of drug resistant epilepsy: consensus proposal by the ad hoc Task Force of the ILAE Commission on Therapeutic Strategies. Epilepsia. 2010;51:1069–77. 10.1111/j.1528-1167.2009.02397.x. - PubMed
    1. Kwan P, Schachter SC, Brodie MJ. Drug-resistant epilepsy. N Engl J Med. 2011;365:919–26. 10.1056/NEJMra1004418. - PubMed
    1. Cross JH, Reilly C, Gutierrez Delicado E, Smith ML, Malmgren K. Epilepsy surgery for children and adolescents: evidence-based but underused. Lancet Child Adolesc Health. 2022;6:484–94. 10.1016/S2352-4642(22)00098-0. - PubMed

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