ESTRO 2024 - Abstract Book

S3358

Physics - Detectors, dose measurement and phantoms

ESTRO 2024

[6] D. Poppinga, O. Schrenk, K. Renkamp, and S. Kl uter, “Octavius® based plan verification at a mridian® linac,” ptwdosimetry.com.

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[9] G. Heilemann, B. Poppe, and W. Laub, “On the sensitivity of common gamma-index evaluation methods to mlc misalignments in rapidarc quality assurance,” Medical physics, vol. 40, no. 3, p. 031702, 2013.

[10] G. J. Kutcher, L. Coia, M. Gillin, W. F. Hanson, S. Leibel, R. J. Morton, J. R. Palta, J. A. Purdy, L. E. Reinstein, G. K. Svensson, et al., “Comprehensive qa for radiation oncology: report of aapm radiation therapy committee task group 40,” MEDICAL PHYSICS-LANCASTER PA-, vol. 21, pp. 581–581, 1994

2634

Digital Poster

Quality Assurance of respiratory gating with Hexamotion system

Anna Sardo 1 , Nicola Padula 1 , Giorgio Bosticardo 1 , Cristina Pugliatti 1 , Simone Baroni 2 , Luca Frassinelli 2 , Rachele Petrucci 2 , Nicola Franza 3 , Alessia Reali 2 , Francesco Lucio 1 1 ASLCN2, Medical Physics, Verduno, Italy. 2 ASLCN2, Radiotherapy, Verduno, Italy. 3 Dosimetrica, Physics, Nocera Inferiore, Italy

Purpose/Objective:

Respiratory gating is a highly accurate treatment modality. The objective of this study is to validate the respiratory gating procedure performed with the Varian Respiratory Gating Scanners (RGSC) using Hexamotion and Delta4 phantom.

Material/Methods:

Different Delta4 CTs were acquired: a 3DCT with Delta4 phantom not moving (motionless) and several 4DCT with different breath curves. For simplicity it was chosen to use a breathing frequency of 12 bpm, corresponding to the average range of human breath. As for the choice of the breath amplitude, 10 patients 4d scans were analyzed and the average displacement of the center of gravity of the lungs volumes was evaluated (from 0.2 to 0.9 in the antero-posterior (z), from 0.2 to 0.5 in the cranio-caudal (y) and from 0.1 to 0.2 in the lateral axis (x)). Therefore the breath amplitudes chosen were: 10,8,5 and 2 mm z direction and zero in the other two directions, 5mm in z and 2mm and 5mm in y, 5mm in z, 2mm in y and 1