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To ensure the correct delivery of increasingly complex radiotherapy (RT) treatments avoiding undue exposures to patients, it is essential to use proactive methods of risk management. This study describes the application of the Failure Mode and Effect Analysis (FMEA) in order to enhance the safety and quality of the RT treatment delivery process.

Following the FMEA multidisciplinary approach, a mono-institutional group of 4 RTTs, 1 RTT student, 1 radiation oncologist and 2 medical physicists was set up and met on a weekly basis from May to October 2022. FMEA was applied to the treatment delivery proceeding as follows: 1) identification of the single steps (phases and activities), based on previously performed process analysis and existing documents as part of ISO 9001 Quality System; 2) for each activity, identification of the potential failure modes (FM), together with their causes and effects; 3) for each FM, severity (S), occurrence (O) and detectability (D) were discussed and rated using the AAPM TG-100 radiotherapy specific scales; 4) Risk priority number (RPN) was calculated as the product of S, O, and D (range 1-1000). Additional safety measures, improvements, or mitigations were proposed and considered for FM with a RPN higher than 180.

Six phases were identified with seventeen activities. A total of 56 FM was recognized with RPN ranging from 27 to 576, 23 of them (41%) characterized by an RPN score higher than 180. The highest RPN (576) was associated to wrong IGRT parameters definition. The solutions proposed to mitigate the O of this FM were the adoption of strict IGRT protocols and an accurate training of the involved users. Other critical RPNs were related to wrong or missing bolus application (450), incorrect assessment of patient’s clinical conditions before starting the treatment (400), wrong evaluation of EPID images (360) and undetected patient’s movements during treatment (320). Effective strategies identified for risk mitigation included: organizational changes, improved communication modes, and new technologies, such as Surface Guided Radiation Therapy systems and EPID in vivo dosimetry.

The FMEA method proved to be a reliable and effective approach of risk management for the RT treatment delivery process. The presented results were generated by consensus of a multidisciplinary group of professionals following RT specific ranking scales, guaranteeing a critical and shared scoring. A continuous review and update of activities, FM and ratings is mandatory to ensure safety and quality to a process in such rapid and constant evolution. The results could be a useful tool to suggest and support the introduction of novel technologies.