Dosimetric analysis and verification measurement of VMAT treatment in twins linacs
DOI:
https://doi.org/10.37004/sefm/2021.22.1.002Keywords:
Beam matching, dosimetric verification, VMAT treatments, gamma analysisAbstract
The management of radiotherapy treatments is improved if there is the possibility of treating a patient indistinctly in different linacs without having to make changes to treatment plan. To make this possible, the dosimetric and mechanical characteristics of the linacs must be the same. The purpose of this work was to verify that the Elekta Synergy and Infinity linacs, both with 6 MV photon beam, flattening filter and Agility treatment head, can be considered twins. For this purpose, different dosimetric parameters were measured in the Infinity which were compared later with the Synergy linac acceptance tests. Finally, the quality of the VMAT (Volumetric Modulated Arc Therapy) treatments was evaluated through gamma analysis (3 %/ 2 mm). A good concordance has been observed regarding the dosimetric parameters analyzed and the gamma analysis of the VMAT treatments. Specifically, the difference obtained was < 2 % in all the beam quality parameters and < 3 % in all the VMAT treatments. The possibility of using the same modeling for both linacs is confirmed, which allows to treat in one or the other interchangeably.
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