A taxonomy for Root Cause Analysis of Radiotherapy Incidents

Taxonomies are essential tools in the investigation of incidents. They allow for a clear definition of a cause of the incident or accident, and thus aid in the implementation of adequate measures to prevent future occurrences. The development and use of radiotherapy-specific taxonomies is lagging behind those in other high risk industries. The existing radiotherapy taxonomies often miss information regarding the human influence on the incident. Radiotherapy (HFACS-RT) taxonomy was adapted from HFACS (Human Factors and Classification System), and the International Atomic Energy Agency (IAEA) document on radiation incidents. HFACS-RT incorporates a taxonomy that examines the setting and consequence of the incident, as well as radiotherapy related incident severity ratings. The taxonomy is based on a number of factors, including percentage difference in dose. HFACS-RT also includes a novel approach to classifying near miss incidents. The correct implementation of the taxonomy involves the use of Root Cause Analysis to reduce the user subjectivity involved with this type of analysis. The information obtained from the classification has been developed into a guideline for future quality management protocols. The taxonomy presented here was developed through the application of investigation of incidents using Human Factors and Systems Engineering techniques. The most notable differences between this taxonomy and previously reported taxonomies are the inclusion of different types of communication and patient factors as contributing factors to incidents. As such, HFACS-RT fills in a missing niche in current radiotherapy error and incident classification systems.