Utilizing simulated errors in radiotherapy plans to quantify the effectiveness of the physics plan review

Area of Science:

• Medical Physics
• Radiation Oncology
• Quality Assurance

Background:

• Physics plan review is crucial for radiation therapy quality.
• Current understanding of the effectiveness of physics plan review in practice is limited.

Purpose of the Study:

• To develop and apply a novel method for measuring the effectiveness of physics plan review.
• To quantify the performance of physicists in detecting errors in simulated radiation therapy plans.

Main Methods:

• Generated six simulated treatment charts with 17 high-frequency, high-severity errors based on incident learning systems.
• Eight physicists reviewed the mock charts; each chart was reviewed by at least six physicists.
• Used a hidden error approach to minimize bias and calculated the Wilson score interval for error detection rates.

Main Results:

• Physicists detected 67% of simulated errors (95% CI [58-75%]).
• High detection rates were observed for incorrect isocenter in DRR (93%), dose discrepancies (92%), and invalid QA (85%).
• Low detection rates were found for incorrect CT dataset (0%) and incorrect isocenter localization (38%).

Conclusions:

• Quantifying error and safety performance in oncology is challenging.
• Simulated errors reveal that physics plan review effectively detects some errors but struggles with others.
• This methodology can guide standardization, automation, and training in radiation oncology quality assurance.