TY  - JOUR
UR  - http://dx.doi.org/10.1016/j.phro.2024.100543
TI  - Improving the modelling of a multi-leaf collimator with tilted leaf sides used in radiotherapy
KW  - MLC modelling
KW  -  TPS modelling
KW  -  TPS commissioning
ID  - discovery10196848
N1  - © 2024 The Author(s). Published by Elsevier B.V. on behalf of European Society of Radiotherapy & Oncology Under a Creative Commons license (http://creativecommons.org/licenses/by/4.0/).
EP  - 6
JF  - Physics and Imaging in Radiation Oncology
AV  - public
N2  - BACKGROUND AND PURPOSE: Multi-leaf collimators (MLCs) with tilted leaf sides have a complex transmission behaviour that is not easily matched by radiotherapy treatment planning systems (TPSs). We sought to develop an MLC model that can accurately match test fields and clinically relevant plans at different centres. MATERIALS AND METHODS: Two new MLC models were developed and evaluated within a research version of a commercial TPS. Prototype I used adjusted-constant transmissions and Prototype II used variable transmissions at the tongue-and-groove and leaf-tip regions. Three different centres evaluated these prototypes for a tilted MLC and compared them with their initial MLC model using test fields and patient-specific quality-assurance measurements of clinically relevant plans. For the latter, gamma passing rates (GPR) at 2 %/2mm were recorded. RESULTS: For the prototypes the same set of MLC parameters could be used at all centres, with only a slight adjustment of the offset parameter. For centres A and C, average GPR were >95 % and within 0.5 % GPR difference between the standard, and prototype models. In center B, prototypes I and II improved the agreement in clinically relevant plans, with an increase in GPR of 2.3 % ± 0.8 % and 3.0 ± 0.8 %, respectively. CONCLUSIONS: The prototype MLC models were either similar or superior to the initial MLC model, and simpler to configure because fewer trade-offs were required. Prototype I performed comparably to the more sophisticated Prototype II and its configuration can be easily standardized, which can be useful to reduce variability and improve safety in clinical practice.
Y1  - 2024/01//
PB  - ELSEVIER
VL  - 29
A1  - Hussein, Mohammad
A1  - Angerud, Agnes
A1  - Saez, Jordi
A1  - Bogaert, Evelien
A1  - Lemire, Matthieu
A1  - Barry, Miriam
A1  - Patallo, Ileana Silvestre
A1  - Shipley, David
A1  - Clark, Catharine H
A1  - Hernandez, Victor
ER  -