An updated system for categorising and reporting unintended incidents in radiotherapy at a national level

Authors

  • Kirsten L Jakobsen Department of Oncology and Palliative Care, University Hospital Region Zeeland, Næstved, Denmark
  • Annette R Jakobsen Department of Medical Physics, Department of Oncology, Aalborg University Hospital, Aalborg, Denmark https://orcid.org/0009-0002-2668-3017
  • Karina L Gottlieb Laboratory of Radiation Physics, Department of Oncology, Odense University Hospital, Odense, Denmark https://orcid.org/0009-0008-2121-4469
  • Martin Berg Department of Medical Physics, Department of Oncology, Vejle Hospital, Lillebaelt Hospital - University Hospital of Southern Denmark, Vejle, Denmark https://orcid.org/0000-0001-6943-3267
  • Harald Spejlborg Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
  • Susan B N Biancardo Department of Oncology, Copenhagen University Hospital - Herlev and Gentofte, Denmark. https://orcid.org/0009-0008-1355-4009
  • Bob Smulders Department of Oncology, Copenhagen University Hospital, Rigshospitalet, Copenhagen
  • Heidi S. Rønde Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark https://orcid.org/0000-0002-2736-8433

DOI:

https://doi.org/10.2340/1651-226X.2026.45699

Keywords:

Radiotherapy, Unintended events, Patient safety, risk management

Abstract

Background and purpose: Radiotherapy is a complex, multistage process that involves collaboration across professional disciplines (radiographers working in pre-treatment preparation, physicians, physicists, radiation therapists during planning and treatment. While severe errors are uncommon, they can have profound consequences for patients. The Danish Society for Medical Physics supports a Special Interest Group dedicated to improving patient safety by analysing unintended events (UEs) and near misses in radiotherapy. Here we report on the work conducted with an updated system for categorising UEs in radiotherapy in Denmark.

Material and methods: An updated reporting system based on the English Radiotherapy Pathway Coding (RPC) system has been taken into use in 2025. This system, including the use of a Danish system that ranks the UEs from the patients perspective, called Patient Centred Coding, is outlined and UEs reported in 2025 are summarised.

Results: Radiotherapy is generally a safe treatment modality, a conclusion further supported by our results from 2025. In 2025 only 339 UEs were reported, 315 of these with low risk and 24 with medium risks. The lesson learned is that the main focus in order to prevent the most harmful UEs should be on the delineation and the planning process.

Interpretation: Based on our experience from this work, we recommend the development of a national system for categorising and ranking UEs. We further recommend establishing a national working group that meets regularly and focuses on UEs at a national level.

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References

dccg.dk. DCCC radiotherapy – the Danish National Research Center [Internet]. c2020–2026 [cited 2026 Mar 3]. Available from: https://www.dccc.dk/english/national-research-centres/dccc-radiotherapy

Shafic J, Barton M, Noble D, Lemer C, Donaldson LJ. An international review of patient safety measures in radiotherapy practice. Radiother Oncol. 2009;92:15–21. DOI: https://doi.org/10.1016/j.radonc.2009.03.007

Malicki J, Bly R, Bulot M, Godet J-L, Jahnen A, Krengli M, et al. Patient safety in external beam radiotherapy, results of the ACCIRAD project: current status of proactive risk assessment, reactive analysis of events, and reporting and learning systems in Europe. Radiother Oncol. 2017;123:29–36. DOI: https://doi.org/10.1016/j.radonc.2017.02.016

Consolidation Act of the Health Act, Consolidation Act No. 210 of 27 January 2022 [Internet]. Danish. (Bekendtgørelse af sundhedsloven, LBK nr 210 af 27/01/2022.). [cited 2026 Mars 11]. Available from: https://www.retsinformation.dk/eli/lta/2022/210

Towards Safer Radiotherapy | The Royal College of Radiologists [Internet]. [cited 2026 Mars 11]. Available from: https://www.rcr.ac.uk/our-services/all-our-publications/clinical-oncology-publications/towards-safer-radiotherapy/

Crouch K, Adamson L, Beldham-Collins R, Sykes J, Thwaites D. Learning in radiation oncology: 12-month experience with a new incident learning system. J Med Radiat Sci. 2025;72(1):63–73. DOI: https://doi.org/10.1002/jmrs.823

Milosevic M, Angers C, Liszewski B, Drudge CS, Marchand E-L, Bissonnette JP, et al The Canadian National System for Incident Reporting in Radiation Treatment (NSIR-RT) taxonomy. Pract Radiat Oncol. 2016;6(5):334–341. DOI: https://doi.org/10.1016/j.prro.2016.01.013

Arnold A, Ward I, Gandhidasan S. Incident review in radiation oncology. J Med Imaging Radiat Oncol. 2022;66(2):291–8. DOI: https://doi.org/10.1111/1754-9485.13358

Baehr A, Hummel D, Gauer T, Oertel M, Kittel C, Löser A, et al. Risk management patterns in radiation oncology – result of a national survey within the framework of the Patient Safety in German Radioation Oncology (PaSaGeRO) project. Strahlenther Onkol. 2023;199(4):350–9. DOI: https://doi.org/10.1007/s00066-022-01984-5

Smith S, Wallis A, King O, Moretti D, Vial P, Shafiq J, et al. Quality management in radiation therapy: a 15 year review of incident reporting in two integrated cancer centres. Tech Innov Patient Support Radiat Oncol. 2020;14:15–20. DOI: https://doi.org/10.1016/j.tipsro.2020.02.001

The Danish Act on Patient Safety in the Health Care System, Act No. 429 of 10 June 2003 [Internet]. Danish. (Lov om patientsikkerhed i sundhedsvæsenet, LOV nr 429 af 10/06/2003). [cited 2026 Mars 11]. Available from: https://www.retsinformation.dk/eli/lta/2003/429

Kumah A. Adverse event reporting and patient safety: the role of a just culture. Front Health Sev. 2025;5:15811516. DOI: https://doi.org/10.3389/frhs.2025.1581516

Wiegmann D, Wood L, Cohen TN, Shappell SA. Understanding the ‘Swiss Cheese Model’ and its application to patient safety. J Patient Saf. 2022;18(2):119–23. DOI: https://doi.org/10.1097/PTS.0000000000000810

International Atomic Energy Agency (IAEA). Lessons learned from accidental exposures in radiotherapy. Safety Report Series No. 17. Vienna; 2000.

Eaton DJ, Byrne JP, Cosgrove VP, Thomas SJ. Unintended doses in radiotherapy – over, under and outside? Br J Radiol. 2018;91:20170863. DOI: https://doi.org/10.1259/bjr.20170863

Cunningham J, Coffey M, Knöös T, Holmberg O. Radiation Oncology Safety Information System (ROSIS) – profiles of participants and the first 1074 incidents reports. Radiother Oncol. 2010;97(3):601–7. DOI: https://doi.org/10.1016/j.radonc.2010.10.023

Prieto Martin C, Kelly C, Paulo G, Akata D, Mille E, Pourel N, et al. Recommandations for reporting and learning from patient-related incidents and near misses in radiotherapy, interventional cardiology, nuclear medicine and interventional and diagnostic radiology [Internet]. Final report of the MARLIN study. Publications Office of the European Union; 2026. [cited 2026 Mars 11]. Available from: https://data.europa.eu/doi/10.2833/7103627

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Published

2026-05-11

How to Cite

Jakobsen, K. L., Jakobsen, A. R., Gottlieb, K. L., Berg, M., Spejlborg, H., Biancardo, S. B. N., … Rønde, H. S. (2026). An updated system for categorising and reporting unintended incidents in radiotherapy at a national level. Acta Oncologica, 65, 416–421. https://doi.org/10.2340/1651-226X.2026.45699

Issue

Vol. 65 (2026): Acta Oncologica

Section

Original article

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Copyright (c) 2026 Kirsten L Jakobsen, Annette R Jakobsen, Karina L Gottlieb, Martin Berg, Harald Spejlborg, Susan B N Biancardo, Bob Smulders, Heidi S. Rønde

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This work is licensed under a Creative Commons Attribution 4.0 International License.