SU‐E‐T‐233: Application of Failure Modes and Effects Analysis to COMS Eye Plaque Brachytherapy

Abstract

Purpose: Failure mode and effects analysis (FMEA) is a systematic technique performed to identify possible failures in the process and help in developing corresponding quality assurance (QA) procedure to avoid such failures. This project was designed to study the process, develop QA procedures, and evaluate safety and reliability of the COMS eye plaque brachytherapy procedure in our department. Methods: The eye plaque implantation procedure was divided into three sub‐processes: pre‐implant preparation, implant, and removal. The possible failure modes were identified by staff members involved in the treatment process. Each mode was quantified using an RPN (Risk Priority Number) score based on the multiplication of three factors: severity (S), frequency of occurrence (O), and detection failure (D). All factors are on a scale of 1 (low) to 10 (high) and determined by the consensus of the staff members. Larger RPN values represent more critical failure modes. Results: A process map was developed for the COMS eye plaque implantation. Twenty‐one failure modes were identified and the potential effects were analyzed by staff members and the RPN scores were averaged. The averaged RPN scores range from 35 to 281.25. Of the top four RPN values (>260), three were related to errors occurring in the pre‐treatment localization step which would cause incorrect dose estimation to the target and organ at risk. Incorrect seed activity ordered/received can also cause a critical error leading to incorrect dose delivery. Potential causes of these failures included human errors, failure in the communication between ophthalmologist, physicists, and the seeds manufactures, and imaging equipment malfunction. Conclusion: FMEA can be a useful tool within the Radiation Oncology department to prospectively examine specific treatment policies and procedures. The results would be useful in developing QA procedure to decrease the possibility of high RPN failure modes.