{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T14:47:03Z","timestamp":1785941223785,"version":"3.56.0"},"reference-count":26,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:00:00Z","timestamp":1785888000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004504","name":"Lithuanian Research Council","doi-asserted-by":"publisher","award":["S-MIP-24-66"],"award-info":[{"award-number":["S-MIP-24-66"]}],"id":[{"id":"10.13039\/501100004504","id-type":"DOI","asserted-by":"publisher"}]},{"award":["S-MIP-24-66"],"award-info":[{"award-number":["S-MIP-24-66"]}],"id":[{"id":"https:\/\/ror.org\/02gs16m83","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Early-stage glottic cancer requires highly precise radiotherapy due to laryngeal motion and the proximity of critical structures. Magnetic resonance-guided radiotherapy (MRgRT) enables real-time visualization and motion management, potentially improving dose conformity while reducing treatment margins. This pilot comparative planning study compared the dosimetric characteristics of MR-guided intensity-modulated radiotherapy (IMRT) delivered on the Unity MR-linac with volumetric modulated arc therapy (VMAT) plans generated for the TrueBeam STx and Halcyon systems. Materials and Methods: Ten patients with T1\u2013T2N0 glottic squamous cell carcinoma were included. For each patient, treatment plans prescribing 42.5 Gy in five fractions were generated using all three systems. Planning target volume (PTV) coverage, conformity index (CI), homogeneity index (HI), organ-at-risk (OAR) doses, monitor units, and beam-on times were compared using Friedman and post hoc Wilcoxon signed-rank tests. Results: Unity achieved superior dose conformity (CI 0.97 \u00b1 0.01 vs. 0.78 \u00b1 0.15 for TrueBeam STx and 0.58 \u00b1 0.19 for Halcyon; p &lt; 0.001) and the highest mean dose, while PTV coverage (D95% and D98%) was comparable to TrueBeam STx and higher than Halcyon. Reduced treatment margins resulted in significantly smaller PTV volumes (11.09 \u00b1 3.87 cm3 vs. 17.43 \u00b1 4.75 cm3; p = 0.0001). Halcyon demonstrated the most homogeneous dose distribution (HI 7.88 \u00b1 3.14), whereas TrueBeam STx showed intermediate homogeneity (HI 12.81 \u00b1 3.90). Most OAR dose metrics were comparable among techniques, although selected laryngeal structures and the esophagus differed significantly. Beam-on time was longest for Unity. Conclusions: MR-guided IMRT provided superior dose conformity while maintaining target coverage comparable to TrueBeam STx with clinically acceptable OAR sparing. Prospective clinical studies are required to determine whether these dosimetric advantages translate into improved patient outcomes.<\/jats:p>","DOI":"10.3390\/medicina62081507","type":"journal-article","created":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T13:16:29Z","timestamp":1785935789000},"page":"1507","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Dosimetric Evaluation of MR-Guided IMRT and VMAT Techniques for Early-Stage Glottic Cancer: A Pilot Comparative Planning Study"],"prefix":"10.3390","volume":"62","author":[{"given":"Viktoras","family":"Rud\u017eianskas","sequence":"first","affiliation":[{"name":"Oncology Institute, Lithuanian University of Health Sciences, Eiveniu str. 2, LT-50161 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8895-1833","authenticated-orcid":false,"given":"Evelina","family":"Jaselsk\u0117","sequence":"additional","affiliation":[{"name":"Physics Department, Kaunas University of Technology, Studentu str. 50, LT-51368 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4485-381X","authenticated-orcid":false,"given":"Jurgita","family":"Laurikaitien\u0117","sequence":"additional","affiliation":[{"name":"Physics Department, Kaunas University of Technology, Studentu str. 50, LT-51368 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vita","family":"\u0160imonyt\u0117-Verbickien\u0117","sequence":"additional","affiliation":[{"name":"Oncology Institute, Lithuanian University of Health Sciences, Eiveniu str. 2, LT-50161 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8683-8757","authenticated-orcid":false,"given":"Diana","family":"Adlien\u0117","sequence":"additional","affiliation":[{"name":"Physics Department, Kaunas University of Technology, Studentu str. 50, LT-51368 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.ijrobp.2024.09.051","article-title":"Stereotactic Radiation Therapy in 3 Fractions for T1 Glottic Cancer","volume":"121","author":"Sanguineti","year":"2025","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_2","first-page":"e1837","article-title":"Overview of Glottic Laryngeal Cancer Treatment Recommendation Changes in the NCCN Guidelines from 2011 to 2022","volume":"6","author":"Arboleda","year":"2023","journal-title":"Cancer Rep."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"317","DOI":"10.14639\/0392-100X-N0870","article-title":"Organ Preservation and Oncological Outcomes in Early Laryngeal Cancer: A Propensity Score-Based Study","volume":"41","author":"Kohler","year":"2021","journal-title":"Acta Otorhinolaryngol. Ital."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1447","DOI":"10.3389\/fonc.2020.01447","article-title":"Is Single Cord Irradiation Going to Be a New Standard for T1a Glottic Carcinoma?","volume":"10","author":"Figen","year":"2020","journal-title":"Front. Oncol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3345","DOI":"10.1007\/s00405-023-07904-2","article-title":"Oncological Outcome of Vocal Cord-Only Radiotherapy for cT1\u2013T2 Glottic Laryngeal Squamous Cell Carcinoma","volume":"280","author":"Rijken","year":"2023","journal-title":"Eur. Arch. Otorhinolaryngol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"105782","DOI":"10.1016\/j.oraloncology.2022.105782","article-title":"Single Vocal Cord Irradiation for Early-Stage Glottic Cancer: Excellent Local Control and Favorable Toxicity Profile","volume":"127","author":"Tans","year":"2022","journal-title":"Oral Oncol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"854","DOI":"10.1002\/hed.26052","article-title":"Feasibility of Single Vocal Cord Irradiation as a Treatment Strategy for T1a Glottic Cancer","volume":"42","author":"Chung","year":"2020","journal-title":"Head. Neck"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.ijrobp.2024.07.2147","article-title":"Stereotactic Ablative Radiotherapy for T1 to T2 Glottic Larynx Cancer: Mature Results From the Phase 2 GLoTtic Larynx-SABR Trial","volume":"121","author":"Sher","year":"2025","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Gupta, A., Wong, K.H., Newbold, K., Bhide, S., Nutting, C., and Harrington, K.J. (2021). Early-Stage Glottic Squamous Cell Carcinoma in the Era of Image-Guided Radiotherapy. Front. Oncol., 11.","DOI":"10.3389\/fonc.2021.753908"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1186\/s13014-021-01833-2","article-title":"Organ Motion in Linac-Based SBRT for Glottic Cancer","volume":"16","author":"Perillo","year":"2021","journal-title":"Radiat. Oncol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"109790","DOI":"10.1016\/j.radonc.2023.109790","article-title":"Cine MRI-Based Analysis of Intrafractional Motion in Radiation Treatment Planning of Head and Neck Cancer Patients","volume":"184","author":"Weiss","year":"2023","journal-title":"Radiother. Oncol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"603","DOI":"10.2217\/fon-2016-0403","article-title":"Survey of Current Practices from the International Stereotactic Body Radiotherapy Consortium (ISBRTC) for Head and Neck Cancers","volume":"13","author":"Karam","year":"2017","journal-title":"Future Oncol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.ijrobp.2019.09.038","article-title":"Spinal Cord Dose Tolerance to Stereotactic Body Radiation Therapy","volume":"110","author":"Sahgal","year":"2021","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"7021","DOI":"10.3390\/curroncol29100552","article-title":"Dose-Volume Constraints fOr oRganS At Risk In Radiotherapy (CORSAIR): An \u201cAll-in-One\u201d Multicenter-Multidisciplinary Practical Summary","volume":"29","author":"Bisello","year":"2022","journal-title":"Curr. Oncol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1016\/j.ijrobp.2021.09.027","article-title":"A Story of Hypofractionation and the Table on the Wall","volume":"112","author":"Timmerman","year":"2022","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e14566","DOI":"10.1002\/acm2.14566","article-title":"Surrogate Gating Strategies for the Elekta Unity MR-Linac Gating System","volume":"26","author":"Rusu","year":"2025","journal-title":"J. Appl. Clin. Med. Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e70005","DOI":"10.1002\/acm2.70005","article-title":"Commissioning of a Motion Management System for a 1.5T Elekta Unity MR-Linac: A Single Institution Experience","volume":"26","author":"Smith","year":"2025","journal-title":"J. Appl. Clin. Med. Phys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"100628","DOI":"10.1016\/j.adro.2020.11.013","article-title":"Stereotactic Radiation Therapy for De Novo Head and Neck Cancers: A Systematic Review and Meta-Analysis","volume":"6","author":"Malik","year":"2021","journal-title":"Adv. Radiat. Oncol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1016\/S0360-3016(02)04617-5","article-title":"Simultaneous Integrated Boost Intensity-Modulated Radiotherapy for Locally Advanced Head-and-Neck Squamous Cell Carcinomas. I: Dosimetric Results","volume":"56","author":"Wu","year":"2003","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1016\/S0360-3016(96)00601-3","article-title":"A Conformation Number to Quantify the Degree of Conformality in Brachytherapy and External Beam Irradiation: Application to the Prostate","volume":"37","author":"Mak","year":"1997","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1177\/15330338251413154","article-title":"A Unified Planning Platform Comparison of VMAT, Helical Tomotherapy, and IMRT in Nasopharyngeal Carcinoma: Dosimetric Superiority and Organ Sparing Analysis","volume":"25","author":"Hu","year":"2026","journal-title":"Technol. Cancer Res. Treat."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"663","DOI":"10.5603\/rpor.108086","article-title":"A Dosimetric and Treatment Delivery Comparisons of the Halcyon and TrueBeam Stereotactic Plans for One or More Brain Metastases","volume":"30","author":"Sundaram","year":"2025","journal-title":"Rep. Pract. Oncol. Radiother."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Cheung, E.Y.W., Poon, D.M.C., Chan, G.C.K., Ma, R.W.S., Wong, J.S.Y., Nip, Y., Lam, C.N.K., and Fong, K.P. (2026). MR-Linac-Based SBRT for Prostate Cancer: Dosimetric Benefits for Urethral Sparing Compared to VMAT and Tomotherapy. Cancers, 18.","DOI":"10.3390\/cancers18040568"},{"key":"ref_24","first-page":"100760","article-title":"MR-Guided Stereotactic Radiation Therapy for Head and Neck Cancers","volume":"46","author":"Wang","year":"2024","journal-title":"Clin. Transl. Radiat. Oncol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"690","DOI":"10.5603\/rpor.108575","article-title":"Craniospinal Irradiation Planning and Delivery: A Comparison Between Halcyon Ring Gantry and TrueBeam C-Arm LINAC Delivery Systems","volume":"30","author":"Sundaram","year":"2025","journal-title":"Rep. Pract. Oncol. Radiother."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3344","DOI":"10.3390\/curroncol30030254","article-title":"Adaptive Volumetric-Modulated Arc Radiation Therapy for Head and Neck Cancer: Evaluation of Benefit on Target Coverage and Sparing of Organs at Risk","volume":"30","author":"Franzese","year":"2023","journal-title":"Curr. 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