Comparison of three different phantoms used for Winston-Lutz test with Artiscan software

Hubert Szweda; Kinga Graczyk; Dawid Radomiak; Krzysztof Matuszewski; Bartosz Pawałowski

doi:10.1016/j.rpor.2020.03.003

Comparison of three different phantoms used for Winston-Lutz test with Artiscan software

Rep Pract Oncol Radiother. 2020 May-Jun;25(3):351-354. doi: 10.1016/j.rpor.2020.03.003. Epub 2020 Mar 4.

Authors

Hubert Szweda¹, Kinga Graczyk², Dawid Radomiak¹, Krzysztof Matuszewski¹, Bartosz Pawałowski¹

Affiliations

¹ Dosimetry Department of Medical Equipment, The Maria Skłodowska-Curie Greater Poland Cancer Centre, Poznań, Poland.
² Wydział Fizyki, Uniwersytet im. Adama Mickiewicza w Poznaniu, Poznań, Poland.

Abstract

Background: One of the most important test in every quality assurances process of medical linear accelerators is the Winston-Lutz test, allowing an evaluation of the treatment isocentre in the light of uncertainty of the position of the collimator, the gantry and the couch.

Aim: The purpose of this work was analysis of the results of the Winston-Lutz test performed with three different phantoms for two different accelerators.

Materials and methods: Measurements were performed on two Varian machines: TrueBeam equipped with aS1200 EPID and TrueBeam equipped with aS1000 EPID. During the study three different phantoms dedicated for verification of the radiation isocentre were used: PTW Isoball, AQUILAB Isocentre Phantom and Varian Isocentre Cube. Analysis of the DICOM images was performed in Artiscan software.

Results: For TrueBeam with as1200 EPID, gantry MV isocentre was about 0.18 mm larger for Varian Isocentre Cube than for two other phantoms used in this study. The largest variability of this parameter was observed for the couch. The results differed to 1.16 mm. For TrueBeam with as1000 EPID, results for collimator isocentre with PTW Isoball phantom were about 0.10 mm larger than for two other phantoms. For the gantry, results obtained with Varian Isocentre Cube were 0.21 mm larger.

Conclusion: The obtained results for all three phantoms are within the accepted tolerance range. The largest differences were observed for treatment couch, which may be related to the phantom mobility during couch movement.

Keywords: Artiscan; IGRT; QA; Winston-Lutz test.