1. IAEA E-learning Program
Safety and Quality in Radiotherapy

2. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Sections:
6.1 Principles of Root Cause Analysis
6.2 Rasmussen’s human factors model
6.3 The New York State Incident
6.4 The Epinal Incident
6.5 The Toulouse Incident
In this module, we will be discussing the principles of root cause analysis, Rasmussen’s human factors model, the New York incident, the Epinal incident and the Toulouse incident.

3. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Sections:
6.1 Principles of Root Cause Analysis
6.2 Rasmussen’s human factors model
6.3 The New York State Incident
6.4 The Epinal Incident
6.5 The Toulouse Incident
To get more experience with root cause analysis, we are going to repeat what we just did for the New York State Incident for the one in Epinal.

4. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
Two cautions:
We will reconstruct these example incidents from what we know. However, we don’t have perfect knowledge of any of these incidents. For this reason, our assessment may differ from any formal analyses undertaken by regulatory or professional organizations.
Even with comprehensive, detailed descriptions of incidents, interpretation may depend on the the person(s) reporting and, particularly, investigating the event.
Again, it is important that we remember these cautions. The situation as regards incidents of the type we are discussing is never as black and white as many of our clinical duties.These are the generic section objectives.
Both of these factors can play a role in the analysis of incidents in real life where our knowledge of events is never complete and personal judgment is generally required.

5. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
OBJECTIVES
To develop a graphical description of the events contributing to the incident.
To explore possible basic causes of the incident.
To select appropriate basic causes from the SAFRON taxonomy.
These are the generic section objectives.

6. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
What happened?
In May 2004 at Centre Hospitalier Jean Monnet in Epinal, France
It was decided to change from static (hard) wedges to dynamic (soft) wedges for prostate cancer patients.
In a country of few Medical Physicists (MP), this facility had a single MP who was also on call in another clinic.
In May 2004 at a hospital in Epinal, France, it was decided to change from static wedges to dynamic wedges for prostate cancer patients. In a country of few Medical Physicists (MP), this facility had a single MP who was also on call in another clinic.
The Jean Monnet in Epinal
IAEA Prevention of accidental exposure in radiotherapy

7. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
summary
The clinic decided to implement the use of dynamic (soft) wedges.
Treatment planners were given very limited training on planning with dynamic wedges.
The treatment planning system manual was in a non-native language.
The only medical physicist on staff was also on call for another clinic.
Monitor units were calculated for plans developed using (mistakenly) hard (physical) wedges.
Treatments were delivered with dynamic wedges.
As the monitor units for a hard wedged beam are typically considerably higher than those for a dynamically wedged beam for the same dose, the patients involved received excessive doses.
Here is the summary of the incident. At least 23 patients received an overdose of 20% or more than the intended dose. Please pause the presentation here if you need to refresh your memory of the incident.
At least 23 patients received an overdose (20% or more than the intended dose).

8. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
Root Cause Analysis: the key steps
To establish a group which undertakes the investigation.
Ideally an appropriate group of individuals, as discussed in Section 1 of this module, should perform the root cause analysis.
Sometimes that just isn’t possible. If you have to perform the root cause analysis on your own, go ahead.
While the investigation may be incomplete, any preventive actions you implement have the potential to benefit the clinical program.
We have seen this information already. It’s included again here for completeness.

9. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
Root Cause Analysis: the key steps
A detailed, preferably chronological, description of the events which preceded the incident.
>23 patients
overdosed
Plan made with HW
Planners
trained
Change to SW Tx SW
used
TIME
Here is the detailed, preferably chronological description of the events which preceded the incident. Remember we don’t identify causes at this stage of the investigation. We are just interested in determining exactly what happened.
Key: SW = soft (dynamic) wedge
HW = hard (physical) wedge
Tx = treatment

10. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
Root Cause Analysis: the key steps
An exploration of the basic or root causes of the incident, through review of relevant clinical documents and interviews with involved people.
>23 patients
overdosed
HW MU used for SW Tx
Lack of risk awareness
Incorrect use of TPS
Documentation
No Quality
Control
Training
Lack of
protocol
Staffing shortage
Instructions
not clear
Here is the Cause and Effect diagram. From what we know about the incident, these might be reasonable root causes or contributing factors.

11. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
Basic Causes
Having identified basic causes in our own words we now need to enter them into SAFRON.
And now we have to translate our free text root causes into the language of SAFRON’s taxonomy.

12. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 4: The Epinal Incident
Basic Causes
In order to do this we have to map our “free text” basic causes onto the SAFRON taxonomy.
These items from the taxonomy seem appropriate. It is, of course, always possible to use SAFRON’s taxonomy terms directly in the cause and effect diagram. It’s just a matter of preference.
Documentation = 4.5 Inadequate documentation.
Training = 6.1 Inadequate training/orientation.
Risk awareness = 3.1 Inadequate hazard assessment.
Lack of protocol = 1.1 Not developed.
Staffing shortages = 4.6 Personnel availability.

13. Safety and Quality in Radiotherapy
Section 4: The Epinal Incident
SAFRON entry
We could have added a lot more to the list.
We could have added a lot more basic causes to the list. But in most circumstances, it is worth restricting the list of basic causes just to the main ones. Each basic cause requires at least one preventive action.
A reminder: it’s important to keep the list manageable as it will form the basis of achievable preventive actions.
It’s important to keep the list manageable as it will form the basis of achievable Corrective Actions.

14. Safety and Quality in Radiotherapy
MODULE 6: root cause analysis 1: human factors & basic causes
Section 3: The new york Incident
summary
We have:
Developed a graphical description of the events contributing to the incident.
Explored possible basic causes of the incident.
Selected appropriate basic causes from the SAFRON taxonomy.
In summary, we have developed a graphical description of the events contributing to the incident, we have explored possible basic causes of the incident, and we have selected appropriate basic causes from the SAFRON taxonomy.