eprintid: 10196848 rev_number: 6 eprint_status: archive userid: 699 dir: disk0/10/19/68/48 datestamp: 2024-09-12 09:29:07 lastmod: 2024-09-12 09:29:07 status_changed: 2024-09-12 09:29:07 type: article metadata_visibility: show sword_depositor: 699 creators_name: Hussein, Mohammad creators_name: Angerud, Agnes creators_name: Saez, Jordi creators_name: Bogaert, Evelien creators_name: Lemire, Matthieu creators_name: Barry, Miriam creators_name: Patallo, Ileana Silvestre creators_name: Shipley, David creators_name: Clark, Catharine H creators_name: Hernandez, Victor title: Improving the modelling of a multi-leaf collimator with tilted leaf sides used in radiotherapy ispublished: pub divisions: UCL divisions: B04 divisions: F42 keywords: MLC modelling, TPS modelling, TPS commissioning note: © 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/). abstract: 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. date: 2024-01 date_type: published publisher: ELSEVIER official_url: http://dx.doi.org/10.1016/j.phro.2024.100543 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2276825 doi: 10.1016/j.phro.2024.100543 medium: Electronic-eCollection pii: S2405-6316(24)00013-7 lyricists_name: Clark, Catharine lyricists_name: Silvestre Patallo, Ileana lyricists_id: CCLAR52 lyricists_id: ISILV85 actors_name: Silvestre Patallo, Ileana actors_id: ISILV85 actors_role: owner funding_acknowledgements: [National Measurement System of the UK's Department for Science, Innovation and Technology] full_text_status: public publication: Physics and Imaging in Radiation Oncology volume: 29 article_number: 100543 pages: 6 event_location: Netherlands citation: Hussein, Mohammad; Angerud, Agnes; Saez, Jordi; Bogaert, Evelien; Lemire, Matthieu; Barry, Miriam; Patallo, Ileana Silvestre; ... Hernandez, Victor; + view all <#> Hussein, Mohammad; Angerud, Agnes; Saez, Jordi; Bogaert, Evelien; Lemire, Matthieu; Barry, Miriam; Patallo, Ileana Silvestre; Shipley, David; Clark, Catharine H; Hernandez, Victor; - view fewer <#> (2024) Improving the modelling of a multi-leaf collimator with tilted leaf sides used in radiotherapy. Physics and Imaging in Radiation Oncology , 29 , Article 100543. 10.1016/j.phro.2024.100543 <https://doi.org/10.1016/j.phro.2024.100543>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10196848/1/Improving%20the%20modelling%20of%20a%20multi-leaf%20collimator%20with%20tilted%20leaf%20sides%20used%20in%20radiotherapy.pdf