Cardiac catheterization of children with congenital heart defects

The project aims to establish a European cohort of children and adolescents who have undergone one or more cardiac catheterizations due to congenital heart defects, in order to analyze trends in radiation doses and estimate the risk of leukemia and other cancer diseases in these individuals.
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Oslo University Hospital (Department of Paediatric Cardiology and Cancer Registry) and the University of Southern Norway are participating in a European study on medical radiation and childhood cancer: HARMONIC, and

Background and purpose

Children born with heart defects often undergo a series of examinations and treatments that involve the use of ionizing radiation (X-ray). We know that children are particularly vulnerable to the side effects of radiation. Examination and treatment using X-ray fluoroscopy by cardiac catheterisation are of invaluable importance for survival in this young patient group. Although the benefits of treatment far outweigh the risks, it is important to increase understanding of possible long-term health effects in order to optimise treatment and reduce the risk of negative health outcomes in the long term.

In this study, we will calculate radiation doses associated with cardiac catheterisations of children and adolescents from birth up to eighteen years of age performed at Rikshospitalet between 1985 and 2022 and analyse whether the risk of cancer is linked to the radiation dose.

The Norwegian cohort will consist of 5-8000 patients with associated anthropometric and clinical data as well as technical data from surveys. These data will be compared with similar data from other European countries in a cohort of about 100 000 individuals. Results from the analyses will be published in international scientific articles. All data processing and publication is subject to ethical and legal requirements. That is, none of the researchers will have access to directly identifiable data while the data is being analyzed. Measures are also being taken to limit the possibility of backward identification, e.g. by using the number of days between the date of birth and the procedures instead of specific dates. Published results will include aggregate radiation doses and group-based risk estimates, and will in any case be generalised so that no individuals can be identified.

Data sources

We will collect data from patient records at the Department of Paediatric Cardiology at Rikshospitalet and radiation data from the hospital's radiological information system in order to calculate radiation doses during examinations and treatment. In addition, we will link to relevant data from other registers; from the Medical Birth Registry of Norway about any congenital conditions or diagnoses associated with a higher risk of cancer; from the Norwegian Patient Registry if applicable. organ transplantation as procedures around this can lead to an increased risk of cancer; and from the Cancer Registry of Norway about any cancer diagnoses in the period after assessment and treatment for heart defects. The patients are followed up until a censorship date, and we obtain information from the National Registry about any death or move out of the country and from the Cause of Death Registry about the cause of death.

Patient rights

According to the EU's General Data Protection Regulation and the Personal Data Act, patients have the right to access, correct and delete their own data. In this project, the research group will receive de-identified data from various registries. This means that we cannot meet the requirement for access, correction or deletion of data. Such a requirement may be imposed on registers that process the source material. However, several of the relevant registers will not be able to meet all requirements due to their own regulations.

Until 31.03.2023, the patient or the patient's next of kin may choose to withdraw from the study.

Norwegian partners

Oslo University Hospital HF

  • The Cancer Registry of Norway is the administrator of the patient cohort, database and linkage of data (national PI)
  • Rikshospitalet contributes with clinical patient data and technical parameters from the interventions

University of South Norway

  • Participates in data collection at Rikshospitalet, establishes database
  • Participates in the work package to determine radiation dose to the children in the cohort based on technical data (dosimetry)

Main responsible for the HARMONIC project

Isabelle Thierry-Chef, IS Global, Barcelona, Spain


Barcelona Institute for Global Health (ISGlobal)


French National Institute of Health and Medical Research (INSERM)


University Hospital Essen (UK Essen)


University of Newcastle upon Tyne (UNEW)


Institut de Radioprotection et de Sûreté Nucléaire (IRSN)


Belgian Nuclear Research Centre (SCK.CEN)


Stockholm University (SU)


KU Leuven (KUL)


Aarhus University hospital (AUH)


Aarhus University (AU)


Commissariat à l’énergie atomique & aux énergies alternatives (CEA)


Centre Régional François Baclesse (CRFB)


Institute Gustave Roussy (GR)


Leibniz-Institute for Prevention Research & Epidemiology (BIPS)


The West German Proton Therapy Centre Essen (WPE)


Institute of Clinical Physiology (IFC-CNR)


Luxembourg Institute of Science and Technology (LIST)


Princess Maxima Center (PMC)


University Medical Center Groningen (UMCG)


University of Zurich (UZH)


National Research Center for Radiation Medicine (NRCRM)



1. Harbron RW, Thierry-Chef I, Pearce MS, Bernier MO, Dreuil S, Rage E, Andreassi MG, Picano E, Dreger S, Zeeb H, Olerud H, Thevathas U, Kjaerheim K, Døhlen G, Jahnen A, Hermen J, Chumak V, Bakhanova E, Voloskyi V, Borrego D, Lee C, Dabin J. The HARMONIC project: study design for the assessment of radiation doses and associated cancer risks following cardiac fluoroscopy in childhood. J Radiol Prot. 2020 Sep 24;40(4). doi: 10.1088/1361-6498/aba66d. PMID: 32668420.


Utheya Salini Thevathas, Gaute Døhlen, Kristina Kjærheim, Hilde M. Olerud. Trends in doses for two common pediatric interventional cardiology procedures in Norway (2008 – 2019) ISRRT World Congress 2021; 2021-08-20 - 2021-08-22

Olerud HM, Thevethas US, Kjærheim K, Døhlen G. Dose reconstruction for pediatric cardiac catheterizations in Norway, before and after PACS. Methods and preliminary results. Medfys dagene; Hurdalsjøen, Norway 2022-05-23 – 2022-05-25

Olerud HM, Thevethas US, Kjærheim K, Døhlen G. Dose reconstruction for pediatric cardiac catheterizations in the 1980s – an input to the epidemiological study HARMONIC. EPOS Scientific exhibit #15236. European congress of radiology; Vienna 2022-03-02 - 2022-03-06