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Improving Patient Safety by Reducing Unnecessary Potential Collisions Between the Linac and Patient

C Breeze1*, Y Vinogradskiy2 , K Stuhr3 , D Westerly2 , J Aldridge3 , P Kneeland2 , C Fisher2 , A Liu2 , L Schubert2 , (1) Colorado School of Mines, Golden, CO, (2) University of Colorado School of Medicine, Aurora, CO, (3) University of Colorado Hospital, Aurora, CO


(Tuesday, 7/31/2018) 9:30 AM - 10:00 AM

Room: Exhibit Hall | Forum 7

Purpose: Physical collisions between humans and treatment equipment are considered critical safety risks having potentially catastrophic impacts. The increased use of automatic gantry motion poses new risks of collision. The purpose of this study is to improve the physical safety of patients by implementing new standards for treatment planning and collision awareness.

Methods: Treatment planning standards were implemented to reduce the potential for collisions during treatment. These included 1) avoiding unnecessary contralateral gantry rotation (3DCRT treatments), 2) contralateral posterior mini-arcs (VMAT treatments) for peripheral extracranial treatments, and 3) adding collision alerts in charts. The efficacy of the implemented interventions was assessed in two ways: 1) evaluating the number of plans with unnecessary potential collisions as defined as contralateral posterior mini-arcs or contralateral gantry rotation before and after implementation of treatment planning standards, and 2) comparing the frequency of collision alerts before and after implementation.

Results: Just over a quarter of the 1095 patient plans assessed were associated with peripheral extracranial targets using automated machine motion. Before planning standards were implemented, 17% (22 of 133 plans) possessed unnecessary potential collisions. Only 2 of those plans had alerts communicating the potential for collision. After implementation, unnecessary collisions were eliminated (0 of 141 plans), while the number of collision alerts in other patient charts actually increased to 22. These alerts were associated with plans that used beams that were unavoidably close to the patient in order to achieve acceptable plan quality.

Conclusion: New standards for treatment planning were developed to reduce potential collisions and the presented data quantitatively demonstrate the effectiveness of the implemented interventions. These guidelines can be easily implemented using minimal resources.


Treatment Planning


TH- External beam- photons: treatment planning/virtual clinical studies

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