A Novel 3D-Printed Device for Linear Accelerator Quality Assurance: Comparison to Purchasable Vendor Solutions
J Winiecki*, S Roles, A Rapchak, J Peng, D McDonald, G Owen, M Maynard, W Godwin, Medical University of South Carolina, Charleston, SC
Presentations
PO-GePV-M-272 (Sunday, 7/10/2022) [Eastern Time (GMT-4)]
ePoster Forums
Purpose: To develop a novel 3D-printable device for routine linear accelerator QA as an accessible alternative to commercially available solutions.
Methods: A 3D-printable QA phantom was designed to perform a subset of linear accelerator mechanical and imaging tests. The device is composed of a 25.2 cm x 26.8 cm x 1 cm base with removable columns and a “step” attachment for geometric imaging. The components were modeled in a free computer-aided design (CAD) software (TinkerCAD). They were printed using a clinical 3D printer (AXIOM 20, Airwolf3D). The device can test laser alignment, collimator walkout, ODI verification, jaw symmetry, couch position, and image geometry. The design was verified by comparing measured results to those of commercially available phantoms – IsoAlign, CIVCO.
Results: The largest absolute difference for the ODI indicator was 0.5 mm for three clinical SSDs. Maximum deviation between devices for laser alignment and collimator walkout was 0.25 mm and 0.0 mm, respectively. The difference in maximum measured couch rotation walkout was 0.5 mm at 90 degrees. Couch position indicators differed by 0.5 mm longitudinally, -0.04 mm laterally, and 0.02 mm vertically. Jaw symmetry deviated by 0.5 mm and 1.0 mm while operating with symmetric field size setting. The largest difference for asymmetric were 1.0 mm for X1 and 1.0 mm for X2 jaws. The largest discrepancies for planar and volumetric image alignment were 0.09 mm and 0.13 mm, respectively. Finally, the automatic table movement deviation was -0.11 mm for vertical -0.02 mm for longitudinal, and -0.11 mm for lateral between devices.
Conclusion: Preliminary results show agreement within 1 mm of current commercial phantoms while allowing for an accessible alternative to expensive vendor products. Improvements to the design could include a radiographic marker insert for easier image alignment or splitting the base into quadrants to decrease print time and size.
Keywords
3D, Quality Assurance, Linear Accelerator
Taxonomy
Not Applicable / None Entered.
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