ESTRO 2023 - Abstract Book

S1570

Digital Posters

ESTRO 2023

Conclusion Fast (6s) CBCT scans produce stable, reproducible target visualization for short (<6s) periods and small (<10mm) amplitudes of motion. Longer periods and larger motion may result in inconsistent target visualization if coupled with fast CBCT scans. For slow breathers and motion >10mm, the tested 60s preset provided better agreement with 4DCT images as it captures several full cycles of respiration. Further parameter optimizations are being conducted for more comprehensive recommendations.

PO-1836 Evaluation of the performance of Brainlab Exactrac Dynamic under different operation conditions

J.A. Blanco Rodriguez 1 , D. Bruzos Lopez 1 , V. Cañon Garcia 1 , U.A. Corro Verde 1 , R. Fabregat Borras 1 , F. Gomez Enriquez 1 , S. Ruiz Arrebola 1 , J.A. Vazquez Rodriguez 1 , M. Garcia Lamela 1 , F. Pinto Guevara 1 , M.T. Pacheco Baldor 1 , J. Alonso Muriedas 1 , G. Camacho de la Vega 2 , A. Reguilon Martin 2 , P.I. Valverde Pascual 3 , M. Martin Veganzones 4 , J. Albendea Roch 5 , J.I. Raba Diez 6 , M. Gutierrez Ruiz 5 , A.L. Rivero Perez 5 1 Hospital Universitario Marqués de Valdecilla , Radiation Oncology Department, Santander, Spain; 2 Hospital Universitario Marqués de Valdecilla , Radiation Protection Department, Santander, Spain; 3 Hospital Universitario de Cruces, Medical Physics and Radiation Protection Department, Barakaldo, Spain; 4 Hospital Universitario de Cruces , Medical Physics and Radiation Protection Department, Barakaldo, Spain; 5 Hospital Universitario Marqués de Valdecilla, Radiation Oncology Department, Santander, Spain; 6 Hospital Universitario Marqués de Valdecilla, Radiation Oncology Department, Santander, Spain Purpose or Objective Brainlab recommends the use of its Brainlab Exactrac Dynamic (ED) surface-guided radiation therapy (SGRT) system under specific conditions of equipment operating status, ambient light in the treatment room and gain of its projected light detection cameras. We evaluate how those conditions influence in the accuracy and precision of patient positioning using SGRT with ED. Materials and Methods The ED installed on a Varian TrueBeam STX lineal accelerator was used as well as the System Calibration Phantom. Exactrac Dynamic uses the structured light projection as SGRT technology and it has three warming-up states, depending on whether the structured light projector has been on for less than 10min or more than 1h. In addition, in clinical mode, the system has 4 gain modes for its projected light detection cameras. Also, Brainlab recommends to use ED without ambient light in the treatment room. The four gain modes (1, 2, 3 and 4), the three operating states (A, B and C) and the presence of ambient light have been evaluated for their influence on positioning, which was repeated 3 times for each of the measurement conditions. The accuracy was evaluated as the difference between the SGRT and the stereoscopic X-ray positioning and a statistics analysis was performed to compare between the difference work conditions.