The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided.

Al Sabah Hospital Kuwait City Kuwait

Atomic Energy Commission of Syria Damascus Syria

Centro de Investigación en Ciencias Atómicas Nucleares y Moleculares Universidad de Costa Rica San José Costa Rica

Children Clinical University Hospital Riga Latvia

Clinical Radiology Institute University Medical Center Ljubljana Slovenia

Département de Physique Médicale Centre de Recherche Nucléaire D'Alger Algiers Algiers

Department of Radiology The National Hospital of Sri Lanka Colombo Sri Lanka

Faculty of Medicine Department of Radiology Chiang Mai University Chiang Mai Thailand

Hamad Medical Corp Doha Qatar

Harvard Medical School and Massachusetts General Hospital Boston USA

Hospital of Lithuanian University of Health Science Kauno Klinikos Kaunas Lithuania

Institute of Nuclear Medicine and Oncology PAEC Lahore Pakistan

Institute of Physics Ss Cyril and Methodius University Skopje The former Yugoslav Republic of Macedonia

International Atomic Energy Agency Vienna Austria

Lebanese Atomic Eneregy Commission Beirut Lebanon

Mater Dei Hospital TalQroqq Msida Malta

Medical Education Department Dubai Health Authority Dubai UAE

Ministry of Health Malaysia Putrajaya Wilayah Persekutuan Malaysia

Ministry of Health Medical Technology and Infrastructure Administration Jerusalem Israel

National Centre of Public Health Chisinau Republic of Moldova

National Centre of Radiobiology and Radiation Protection Sofia Bulgaria

National Institute for Nuclear Research Carretera Mexico Toluca La Marquesa Ocoyoacac Mexico

National Nuclear Energy Commission Rio de Janeiro Brazil

National Radiation Protection Department Iranian Nuclear Regulatory Authority Tehran Iran

National Radiation Protection Institute Prague Czech Republic

North Estonia Medical Centre Tallinn Estonia

Pusat Kajian Radiografi dan Imajing Depok Indonesia

Radiation Protection Department Vinca Institute of Nuclear Sciences Belgrade Serbia

Radiologist Ministry of Health Yangon Myanmar

Research Center of Radiation Medicine and Burns Yerevan Armenia

Slovak Medical University Limbova Bratislava Slovakia

State Office for Radiological and Nuclear Safety Zagreb Croatia

Sudan Atomic Energy Commission Khartoum Sudan

Tanzania Atomic Energy Commission Arusha Tanzania

Universidade Federal de Pernambuco Cidade Universitaria Recife PE Brazil

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