Risk analysis of electronic intraoperative radiation therapy for breast cancer.

PURPOSE: To evaluate the process and improve safety of intraoperative radiation therapy (IORT) for early-stage breast cancers treated with electronic brachytherapy. METHODS AND MATERIALS: A multidisciplinary team conducted a failure mode and effects analysis (FMEA) for IORT breast cancer treatments by first developing a process map. This map was then used to identify failure modes for all steps in the treatment workflow. Risk priority numbers (RPNs) were assigned to each failure mode and were calculated as the product of the failure mode's probability of occurrence (O), severity (S), and lack of detectability (D). Corrective steps were implemented to address failure modes with the highest risk, and a revised process was generated. RESULTS: The steps with the highest risk failure modes were related to source calibration, use of correct plan and dwell times, and the correct site and intent. The introduction of a physician calibration check and an extended time-out checklist reduced the risk of these failure modes. The highest risk steps in the Xoft breast IORT treatment process are associated with source calibration and manual entry of dwell positions for each balloon size and volume combination. High-risk failure modes that could be mitigated with improved hardware and software interlocks were identified. CONCLUSION: High-risk failure modes are identified with FMEA and addressed with corrective steps. This application of FMEA can be used in principle for clinical processes throughout breast cancer care. This analysis demonstrates the importance of well-designed QC policies, procedures, and oversight in a Xoft electronic brachytherapy program for breast cancer IORT.