{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:50:42Z","timestamp":1760147442301,"version":"build-2065373602"},"reference-count":26,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,2,6]],"date-time":"2023-02-06T00:00:00Z","timestamp":1675641600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"STFC and EPSRC through the IAA route"},{"name":"EPSRC DTA"},{"name":"Chinese Scholarship Council"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Intensity-modulated radiotherapy is a widely used technique for accurately targeting cancerous tumours in difficult locations using dynamically shaped beams. This is ideally accompanied by real-time independent verification. Monolithic active pixel sensors are a viable candidate for providing upstream beam monitoring during treatment. We have already demonstrated that a Monolithic Active Pixel Sensor (MAPS)-based system can fulfill all clinical requirements except for the minimum required size. Here, we report the performance of a large-scale demonstrator system consisting of a matrix of 2 \u00d7 2 sensors, which is large enough to cover almost all radiotherapy treatment fields when affixed to the shadow tray of the LINAC head. When building a matrix structure, a small dead area is inevitable. Here, we report that with a newly developed position algorithm, leaf positions can be reconstructed over the entire range with a position resolution of below \u223c200 \u03bcm in the centre of the sensor, which worsens to just below 300 \u03bcm in the middle of the gap between two sensors. A leaf position resolution below 300 \u03bcm results in a dose error below 2%, which is good enough for clinical deployment.<\/jats:p>","DOI":"10.3390\/s23041799","type":"journal-article","created":{"date-parts":[[2023,2,6]],"date-time":"2023-02-06T02:06:43Z","timestamp":1675649203000},"page":"1799","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Performance of a Full-Scale Upstream MAPS-Based Verification Device for Radiotherapy"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4649-3221","authenticated-orcid":false,"given":"Jaap","family":"Velthuis","sequence":"first","affiliation":[{"name":"School of Physics, University of Bristol, Bristol BS7 1TL, UK"},{"name":"Swansea University Medical School, Faculty of Medicine, Health and Life Science, Swansea University, Swansea SA2 8PP, UK"},{"name":"School of Nuclear Science and Technology, University of South China, Hengyang 421001, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2221-7983","authenticated-orcid":false,"given":"Yutong","family":"Li","sequence":"additional","affiliation":[{"name":"School of Physics, University of Bristol, Bristol BS7 1TL, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2842-6615","authenticated-orcid":false,"given":"Jordan","family":"Pritchard","sequence":"additional","affiliation":[{"name":"School of Physics, University of Bristol, Bristol BS7 1TL, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9112-425X","authenticated-orcid":false,"given":"Chiara","family":"De Sio","sequence":"additional","affiliation":[{"name":"School of Physics, University of Bristol, Bristol BS7 1TL, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4369-7648","authenticated-orcid":false,"given":"Lana","family":"Beck","sequence":"additional","affiliation":[{"name":"School of Physics, University of Bristol, Bristol BS7 1TL, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0352-9607","authenticated-orcid":false,"given":"Richard","family":"Hugtenburg","sequence":"additional","affiliation":[{"name":"School of Physics, University of Bristol, Bristol BS7 1TL, UK"},{"name":"Swansea University Medical School, Faculty of Medicine, Health and Life Science, Swansea University, Swansea SA2 8PP, UK"},{"name":"Department of Medical Physics and Clinical Engineering, Swansea Bay University Health Board, Swansea SA2 4QA, UK"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1016\/j.clon.2010.06.013","article-title":"A Review of the Clinical Evidence for Intensity-modulated Radiotherapy","volume":"22","author":"Staffurth","year":"2010","journal-title":"Clin. 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