ESTRO 2024 - Abstract Book

S4876

Physics - Quality assurance and auditing

ESTRO 2024

[2]: Guckenberger, M., Baus, W.W., Blanck, O. et al. Definition and quality requirements for stereotactic radiotherapy: consensus statement from the DEGRO/DGMP Working Group Stereotactic Radiotherapy and Radiosurgery. Strahlenther Onkol 196, 417–420 (2020). https://doi.org/10.1007/s00066-020-01603-1 [3]: Altundal Y, Cifter F, Mu G, Lee J, Wu EJ, Yeung V, Katz A. Prostate Stereotactic Body Radiation Therapy With Halcyon 2.0: Treatment Plans Comparison Based on RTOG 0938 Protocol. Cureus. 2020 Nov 23;12(11):e11660. doi: 10.7759/cureus.11660. PMID: 33391899; PMCID: PMC7772112. [4]: Pokhrel, D, Webster, A, Mallory, R, et al. Feasibility of using ring-mounted Halcyon Linac for single-isocenter/two lesion lung stereotactic body radiation therapy. J Appl Clin Med Phys. 2022; 23:e13555. https://doi.org/10.1002/acm2.13555

2309

Digital Poster

Automation of the couch sag Quality Control test for Accuray Radixact

Guillermo Camacho de la Vega, Rodrigo Astudillo Olalla, Jorge Alonso Muriedas, Noelia Suárez Álvarez, Marina Gutiérrez Ruiz, Rosa Fabregat Borrás, Ana Reguilón Martín, Paula Delgado Tapia, Fernando Gómez Enríquez, Samuel Ruiz Arrebola, Javier Uzquiza Lopez

Hospital Universitario Marqués de Valdecilla, Radiotherapy, Santander, Spain

Purpose/Objective:

Radixact (Accuray®) is the latest linear accelerator acquired in our institution. As a tomotherapy treatment machine, the pallet support does not completely eliminate couch sag, which can result in errors when delivering the radiation dose. Some tests already exist to evaluate the couch sag and a 2mm Z-axis deviation is set as tolerance by different reports [1] [2]. However, this test is difficult to evaluate manually.

Our objective was to develop a program for automating the analysis of the test results.

Material/Methods:

Two bearing balls and two virtual water slabs are used for this test. These two markers are positioned on the couch, aligned with the sagittal laser 100 cm apart in the Y-axis. In addition, extra weight is loaded at the front part of the couch, to maximize the couch sag (figure 1).