Author: Michael Burke, David J. Carlson, Yiu-Hsin Chang, Huixiao Chen, Zhe (Jay) Chen, Emily A. Draeger, Dae Yup Han, Vanessa Hill, Ann-Teresa Jasman, John Kim, Svetlana Kuznetsova, MinYoung Lee, Daniel Longo, Henry S. Park, Adam Shulman, Lauren Tressel, Weili Zhong 👨🔬
Affiliation: Department of Therapeutic Radiology, Yale University School of Medicine 🌍
Purpose:
The complexity of biology-guided radiotherapy (BgRT), particularly with systems like RefleXion X1, necessitates robust pre-treatment quality assurance (QA) to ensure patient safety, treatment accuracy, and delivery efficiency. This study develops and evaluates the effectiveness of a pre-treatment physics plan checklist in detecting and mitigating errors specific to BgRT workflows.
Methods:
An in-house physics checklist was developed to address critical aspects of BgRT planning. Error categories were classified into naming conventions, geometry (contouring, contour role assignment, spacing between target and OAR, and non-PET avid areas in PTV), dosimetry (target coverages and organ-at-risk (OAR) constraints), PET-CT image alignment, and motion pattern designation. 8 clinical BgRT plans and 8 simulated plans with intentionally introduced errors (such as naming convention, contour role misalignments, and PET-CT alignment inaccuracies) were retrospectively evaluated. The developed plan checklist was applied by two medical physics residents to assess its effectiveness in detecting these errors. Individual plan check time was recorded for efficiency review.
Results:
Of the 16 plans evaluated, the checklist detected 90% of the introduced errors including sub-optimal dosimetric coverage, 100% of geometric errors, and 100% of PET-CT alignment issues. In the retrospective analysis, 4 simulated plans required adjustments following checklist review, with the majority of errors related to contour role misassignments, naming conventions and OAR constraint violations. The checklist streamlined the pre-treatment check processes without significant additional time burden, with a plan review time range of 10 to 25 minutes per plan.
Conclusion:
The pre-treatment physics checklist proved highly effective in identifying errors in BgRT treatment plans, enhancing patient safety, treatment quality, and staff cross training. It demonstrated the improved QA workflows and streamlined delivery in addressing the unique treatment settings and parameters of BgRT, including the involvement of PET tracer signals. Further refinement and standardization may improve its utility across diverse clinical settings.