Application of the Risk Matrix Approach in Radiotherapy: an Ibero-american Experience

The "Risk Matrix" method has been used extensively for safety assessments in the risk industry. The method is characterized by being systematic and simple, features that allow considering its application in hospitals. The practice of radiotherapy, where fatal accidents have occurred, needs to apply methodologies to anticipate and prevent potential accidents. The Ibero-American Forum of Radiological and Nuclear Regulators (FORO) has adapted and applied this methodology of risk matrices in teletherapy (Co-60 equipment and linear accelerators) and brachytherapy (high and low dose rate). A large list of possible human error and equipment failure that could trigger accidents was analyzed. The main defenses (interlocks, alarms and procedures) that could prevent, detect, monitor and mitigate potential accidents were identified; finally, the accident sequences with highest risk were established and the measures to reduce risk in such sequences have been proposed. This work confirmed the importance of radiation protection of patients in the practice of radiotherapy and showed that the risk matrix approach is a useful tool to reduce the risk of accidental exposure.