MARRTA: Risk matrix in advanced radiotherapy

Proactive risk analyses identify potential risks before they occur, enabling us to pinpoint the most vulnerable aspects of our treatment process, thus promoting safer treatments. The proactive risk matrix methodology assesses the risk from potential errors and failures (initiating events) by evaluating and integrating their frequency, the severity of their potential consequences and the probability of failure of the barriers designed to prevent these consequences. Based on this methodology, the MARRTA project derived a theoretical risk model of advanced radiotherapy treatments and developed software to implement the model and facilitate the risk analysis.

A multidisciplinary team built the risk model by identifying initiating events in a generic advanced radiotherapy process, along with their preventive and mitigating barriers, categorized by nature and effectiveness. Each initiating event was assigned a frequency, a consequence, and the corresponding failure probability of the barriers in place. By integrating these three parameters, a calculated risk was associated to each given initiating event. This initial risk model was then incorporated into the developed software and distributed to 18 Spanish hospitals for testing. Feedback from these hospitals was used to refine and update the model and software.

The final risk model (reference risk model) identifies 110 potential initiating events, 60 barriers, 54 frequency reducers and 13 consequence reducers.

The MARRTA model and software provide a novel means to easily apply the risk matrix methodology for comprehensive and straightforward risk analysis, as it allows the reference model to be customized to the specific features of each radiotherapy department.