Towards Safer Radiotherapy

Chapter 6: Learning from errors
Though preventing and detecting errors before harm can occur is important, so is changing practice
to prevent recurrence. At present, many opportunities to improve patient safety are lost because
information is not shared. Learning from incidents, errors and near misses should be local, national
and international.
6.1 Local learning
All UK radiotherapy centres have QART systems, a core function of which is to regularly analyse
errors and other non-conformances for trends and pointers for improving the quality and safety of
treatment. The impetus for QART itself originated from the investigation into the multiple-patient
radiotherapy accident in Exeter. 39 The need for formal, comprehensive quality assurance
programmes in radiotherapy is perhaps the most important lesson that has been learned from a
single radiotherapy accident.
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6.1.1 Analysis of incidents and near misses
When an incident or near miss occurs, it is important to look at the underlying causes to
understand not only what happened, but also why. As discussed in Chapter 3, there are a
multitude of human, procedural and environmental factors, which can be contributory (Table
3.1, page 22). For each radiation incident, there is a chain of events that formed the exact
circumstances in which error occurred and went undetected. It is important that the
investigation is conducted in a timely manner so that important factors are not missed.
A chronological investigative technique used most commonly in the UK is called ‘root cause
analysis’ or, more broadly, ‘systems analysis’. The process is described fully in The London
Protocol 91 but, in essence, involves obtaining information from all possible sources (such as
patient records, planning data, staffing rotas) and conducting semi-structured interviews
with all individuals concerned, including the patient, to understand the sequence of events,
what actually went wrong, and all contributory factors. This information is then compiled to
produce a flowchart, which depicts the sequence of events and contributory factors. The
most commonly used format is the ‘fish-bone’ diagram or ‘cause and effect’ diagram (see
Appendix 6.1 and Patton et al 79 ). Each incident will have factors in most categories.
Root cause analysis is time-consuming, but can provide valuable information on the workings
of a department and may identify other potential problems. Root cause analysis should be
conducted for all level 1 and 2 radiation incidents and other radiation incidents and near
misses identified as potentially important by a systematic analysis of less detailed
investigations. Practical support for using root cause analysis can be found at the NPSA’s
web-based e-learning toolkit at
http://www.npsa.nhs.uk/patientsafety/improvingpatientsafety/rootcauseanalysis/
Once the issues have been established, recommendations and an action plan can be
developed to prevent recurrence. This should be disseminated throughout all staff groups
involved in the relevant part of the patient pathway.
The Princess Margaret Hospital in Toronto, Canada, has demonstrated such an approach can
reduce the error rate in complex radiotherapy by a third. 38
Towards Safer Radiotherapy