Room: AAPM ePoster Library
Purpose: A provincial Community of Practice (CoP) working group was created to investigate patient-specific quality assurance (PSQA) best practice for IMRT/VMAT delivery verification. The main objective was to promote quality and safety of treatment delivery by supporting the coordination and standardization of PSQA practice. This work also served to inform quality metrics specific to PSQA during the development of the new provincial funding model for radiation treatment.
Methods: The working group conducted a provincial wide survey on IMRT/VMAT PSQA in 2019 that illustrated wide variations in many areas of practice. A literature review on existing guidelines and peer-reviewed papers on PSQA was also performed to further inform the best practice recommendations. In the absence of existing literature or evidence, the collective clinical expertise of group members was leveraged. The recommendations apply to IMRT/VMAT delivery on standard linacs, including SBRT, but excluding SRS and “forward-planned” IMRT.
Results: This work resulted in creation of a best practice guidance document on PSQA that included 28 Key Quality Indicators (KQIs) in five categories – Policy and Procedure, Instrumentation, Measurement Setup and Methodology, Evaluation Methodology, and Documentation, Process and Feedback. While the recommendations primarily focused on phantom-based measurements, the use of measurement surrogates such as delivery log calculation were also considered. Moreover, although many KQIs dealt with Gamma analysis, we recommended reconstructed 3D dose distributions in patient anatomy from measured dose or fluence should be used where possible to provide relevant plan comparison.
Conclusion: The CoP successfully created and disseminated a best practice guidance document on PSQA for IMRT/VMAT delivery verification to all participating cancer centres. The document describes recommendations for the current state of PSQA, while providing opportunities for better standardization in PSQA procedures and processes to improve the safety and quality of radiation treatment delivery.
Quality Assurance, Treatment Verification