(Sunday, 7/12/2020) [Eastern Time (GMT-4)]
Room: AAPM ePoster Library
Purpose: To develop a method for beam data analysis and the quality assurance of algorithms in the Eclipse Treatment Planning System (Varian Medical Systems).
Methods: A system of tools were developed in ASP.net and C# to analyze measured data for water phantoms, extracted data from calculated plans in Eclipse, and the comparison of both. This platform has been designed in the Cloud for greater accessibility. Metrics were built into the platform to analyze parameters such as beam quality, flatness and symmetry, and effective point of measurement application for measured data. For calculated data, the data was extracted to match to the measured data point by point for ease of comparisons. Comparisons between the datasets included methods to perform dose difference, distance-to-agreement, gamma index (with adjustable thresholds), and absolute dose analysis.
Results: The ability to analyze relative scans from a water phantom and the corresponding extracted data from the treatment planning system greatly increased confidence in the commissioning of new algorithms in the Eclipse TPS. In addition, baselines were able to be set from the analysis for routine annual machine QA. This has allowed for a rapid analysis of measurements, which has made the QA of our treatment planning systems more robust. Tests are sensitive to small errors, and a pass rate of 95% gamma index with a tolerance of 2%/2mm was appropriate in most cases.
Conclusions: The new method for beam data analysis has enabled large scale analysis of measurements and beam models in our network of hospitals. Parameters that used to have to be measured point by point can now be analyzed to the resolution of the scanning data. Routine treatment planning system QA can be performed more often, with little to no impact to the clinic.
Keywords
Commissioning, Quality Assurance, Linear Accelerator
Taxonomy
TH- External Beam- Photons: Quality Assurance - Linear accelerator
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