{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,29]],"date-time":"2026-08-29T15:25:47Z","timestamp":1788017147619,"version":"build-2784847793"},"reference-count":28,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,1,26]],"date-time":"2023-01-26T00:00:00Z","timestamp":1674691200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background: Despite the development of iterative reconstruction (IR) in diagnostic imaging, CBCT are generally reconstructed with filtered back projection (FBP) in radiotherapy. Varian medical systems, recently released with their latest Halcyon\u00ae V2.0 accelerator, a new IR algorithm for CBCT reconstruction. Purpose: To assess the image quality of radiotherapy CBCT images reconstructed with FBP and an IR algorithm. Methods: Three CBCT acquisition modes (head, thorax and pelvis large) available on a Halcyon\u00ae were assessed. Five acquisitions were performed for all modes on an image quality phantom and reconstructed with FBP and IR. Task-based image quality assessment was performed with noise power spectrum (NPS), task-based transfer function (TTF) and detectability index (d\u2019). To illustrate the image quality obtained with both reconstruction types, CBCT acquisitions were made on 6 patients. Results: The noise magnitude and the spatial frequency of the NPS peak was lower with IR than with FBP for all modes. For all low and high-contrast inserts, the values for TTF at 50% were higher with IR than with FBP. For all inserts and all modes, the contrast values were similar with FBP and IR. For all low and high-contrast simulated lesions, d\u2019 values were higher with IR than with FBP for all modes. These results were also found on the 6 patients where the images were less noisy but smoother with IR-CBCT. Conclusions: Using the IR algorithm for CBCT images in radiotherapy improve image quality and thus could increase the accuracy of online registration and limit positioning errors during processing.<\/jats:p>","DOI":"10.3390\/diagnostics13030448","type":"journal-article","created":{"date-parts":[[2023,1,27]],"date-time":"2023-01-27T02:30:38Z","timestamp":1674786638000},"page":"448","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Task-Based Image Quality Assessment Comparing Classical and Iterative Cone Beam CT Images on Halcyon\u00ae"],"prefix":"10.3390","volume":"13","author":[{"given":"Marion","family":"Lassot-Buys","sequence":"first","affiliation":[{"name":"Department of Oncology Radiotherapy, N\u00eemes University Hospital, University Federation of Radiation Oncology of Mediterranean Occitanie, Bd Prof Robert Debr\u00e9 CEDEX 9, 30029 N\u00eemes, France"},{"name":"Medical Physics Unit, N\u00eemes University Hospital, Bd Prof Robert Debr\u00e9, CEDEX 9, 30029 N\u00eemes, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rodolfe","family":"Verstraet","sequence":"additional","affiliation":[{"name":"Department of Oncology Radiotherapy, N\u00eemes University Hospital, University Federation of Radiation Oncology of Mediterranean Occitanie, Bd Prof Robert Debr\u00e9 CEDEX 9, 30029 N\u00eemes, France"},{"name":"Medical Physics Unit, N\u00eemes University Hospital, Bd Prof Robert Debr\u00e9, CEDEX 9, 30029 N\u00eemes, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Djamel","family":"Dabli","sequence":"additional","affiliation":[{"name":"Medical Physics Unit, N\u00eemes University Hospital, Bd Prof Robert Debr\u00e9, CEDEX 9, 30029 N\u00eemes, France"},{"name":"Department of Medical Imaging, N\u00eemes University Hospital, IMAGINE UR UM 103, Montpellier University, 30029 N\u00eemes, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gilles","family":"Moliner","sequence":"additional","affiliation":[{"name":"Department of Oncology Radiotherapy, N\u00eemes University Hospital, University Federation of Radiation Oncology of Mediterranean Occitanie, Bd Prof Robert Debr\u00e9 CEDEX 9, 30029 N\u00eemes, France"},{"name":"Medical Physics Unit, N\u00eemes University Hospital, Bd Prof Robert Debr\u00e9, CEDEX 9, 30029 N\u00eemes, France"},{"name":"Cancer Institute of Montpellier, INSERM U1194 IRCM, 34090 Montpellier, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1735-5129","authenticated-orcid":false,"given":"Jo\u00ebl","family":"Greffier","sequence":"additional","affiliation":[{"name":"Medical Physics Unit, N\u00eemes University Hospital, Bd Prof Robert Debr\u00e9, CEDEX 9, 30029 N\u00eemes, France"},{"name":"Department of Medical Imaging, N\u00eemes University Hospital, IMAGINE UR UM 103, Montpellier University, 30029 N\u00eemes, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1191","DOI":"10.1118\/1.2842072","article-title":"Combined kV and MV imaging for real-time tracking of implanted fiducial markers","volume":"35","author":"Wiersma","year":"2008","journal-title":"Med. 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