Exhibit Hall | Forum 7
Purpose: Development and clinical evaluation of a log file based patient-specific quality assurance (PSQA) workflow for an IBA pencil beam scanning (PBS) proton therapy system using open-source software and RayStation scripts.
Methods: A MATLAB-based open-source package, REGGUI, was used to extract delivered PBS spot parameters (i.e., spot positions and MUs) from IBA irradiation log files. An in-house developed python script within the RayStation Treatment Planning System (TPS) was used to import the delivered PBS spot parameters and to re-compute dose on planning patient CT datasets. Clinical evaluation of the log file based PBS QA workflow was carried out through retrospective 3D gamma analysis between planned dose and log file reconstructed dose using 3%/3mm gamma criteria for a patient cohort of 20 patients evenly spread across four disease sites: H&N, prostate, thorax, and brain.
Results: 3D gamma analysis showed 93.49%, 100.00%, and 99.03% for minimum, maximum, and average passing rates across all sites. Average 3D gamma pass rates were 99.87%, 96.87%, 99.57%, and 99.87% for H&N, prostate, thorax, and brain, respectively. An additional benefit of this approach is that the obtained dose differences and dose volume histograms (DVHs) can be evaluated within the RayStation TPS resulting in spatial and organ specific dose delivery information on the patient plan.
Conclusion: A workflow utilizing an open-source software and scripts inside RayStation for log file based PSQA has been developed. The log file based approach allows for fast and comprehensive verification of dose delivered through the use of machine log files.
Protons, Quality Assurance, Treatment Verification
TH- External Beam- Particle/high LET therapy: Proton therapy – quality assurance