Winston-Lutz tests gained popularity as a stereotactic radiosurgery (SRS) QA test, but they can also be used as a fast and quantitative method to determine IGRT setup accuracy. After using your IGRT system to position a phantom with an embedded metal sphere, take two orthogonal images using film or EPID. Load the images in DoseLab Pro, and within 20 seconds you can have a PDF document detailing the alignment accuracy. It’s a simple but powerful test that can be performed on each day of SRS/SBRT treatments, and as part of your monthly QA.
Winston-Lutz tests have full tolerance support. Their results can be added to DoseLab’s database and/or exported to Sun Nuclear’s ATLAS database. The Pass/Warn/Fail status is shown in the PDF and all databases. DoseLab’s internal database allows physicists to view trends immediately after saving a result.
DoseLab Pro features a batch Winston-Lutz mode for multiple images that contain a single exposure each (such as a series of EPID images). In this mode, multiple images are selected and DoseLab Pro automatically determines the optimal ROI placement. ROIs can be manually selected for films that have multiple exposures.
Download the IGRT isocenter testing procedure, which uses a phantom that can be purchased from Sun Nuclear Corporation.
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