Risk management in a community Gamma Knife unit

Objective: The records of the San Diego Gamma Knife Center were retrospectively reviewed for unprogrammed events as part of a risk management assessment. Materials and Methods: Review was made of the physicist notes of the first 1,000 patients successfully treated at the center. This encompassed 1,020 stereotactic frame placement procedures, accompanied by Gamma Knife radiosurgery in 98.0% of intended cases. A total of 7,145 Gamma Knife shots were delivered to 1,509 lesions. Results: Of the 43 unprogrammed events documented, 8 were patient related and 14 were related to lesion growth or location; these were considered unavoidable. Further, one event was related to dose administration, 5 to diagnosis, 15 to technique; these were considered potentially avoidable. This yielded an avoidable error rate of 2.1% per patient, 1.4% per lesion treated, and 0.29% per shot. It was clear that more avoidable errors occurred early in the center’s operation, consistent with a learning curve. Review of individual physician’s cases revealed none appeared more likely to have an avoidable event. Conclusions: Consistently high quality may be achieved at a community-based Gamma Knife center if sufficient multidisciplinary involvement is achieved.