{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T14:01:49Z","timestamp":1789740109730,"version":"4.0.1"},"reference-count":27,"publisher":"Wiley","issue":"8","license":[{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["aapm.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["J Applied Clin Med Phys"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Flattening filter\u2010free (FFF) beams are increasingly deployed for stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS). The Elekta Versa HD (VHD) and Varian TrueBeam (TB) are the two most widely used FFF\u2010capable platforms; however, no prior study has compared their 6 MV FFF commissioning parameters under fully equipment\u2010equivalent conditions.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>To quantify the dosimetric differences between the Elekta VHD and Varian TB 6 MV FFF platforms under equipment\u2010equivalent conditions and to assess their translation into patient treatment plan parameters.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Percentage depth doses (PDDs), lateral beam profiles, and output factors (OFs) were acquired using an identical\u2010model IBA SMARTSCAN three\u2010dimensional water tank, a unified detector set (IBA RAZOR for small fields; CC13 for standard fields), and a fixed source\u2010to\u2010surface distance of 90\u00a0cm for both platforms, in conformance with AAPM TG\u201045, AAPM TG\u2010106, and IAEA TRS\u2010483. A treatment planning translation study was performed in the Monaco TPS using the IBA IMRT phantom, with 3D\u2010CRT plans generated for four spherical targets (1, 3, 6, and 12\u00a0cm diameter) on both beam models.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      VHD demonstrated consistently deeper beam penetration, with R50 exceeding TB by a mean of 1.753\u00a0\u00b1\u00a00.048\u00a0cm across all field sizes (\n                      <jats:italic>t<\/jats:italic>\n                      (9)\u00a0=\u00a036.34,\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0&lt;\u00a00.001, Cohen's\n                      <jats:italic>d<\/jats:italic>\n                      \u00a0=\u00a011.49, 95% CI [1.643, 1.862] cm). TB delivered significantly higher surface doses than VHD (mean Ds: 63.64\u00a0\u00b1\u00a05.77%\u00a0vs. 48.78\u00a0\u00b1\u00a07.72%;\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0=\u00a00.002, |\n                      <jats:italic>r<\/jats:italic>\n                      |\u00a0=\u00a01.000). At 10\u00a0cm depth, VHD showed a higher percentage depth dose (mean difference\u00a0=\u00a05.005\u00a0\u00b1\u00a00.352%;\n                      <jats:italic>t<\/jats:italic>\n                      (9)\u00a0=\u00a014.22,\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0&lt;\u00a00.001,\n                      <jats:italic>d<\/jats:italic>\n                      \u00a0=\u00a04.498). The Unflatness conversion index (UCI) was strongly correlated with field size (\n                      <jats:italic>r<\/jats:italic>\n                      \u00a0=\u00a00.916,\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0=\u00a00.001) and statistically independent of measurement depth (\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0=\u00a00.292). At the plan level, TB required 5.9\u201317.6% more monitor units (MU) than VHD across all target sizes, with the differential diminishing as target diameter increased. Surface dose differences were preserved across all four targets (TB \u2212 VHD: 15.9\u201331.1%). Both the homogeneity index and gradient index reversed direction between the 1\u00a0cm target (VHD superior) and targets of 3\u00a0cm and larger (TB superior), consistent with the field\u2010size dependence of UCI.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      A harmonized, equipment\u2010equivalent measurement approach demonstrated systematic differences between VHD and TB FFF beams in penetration, surface dose, and field\u2010size\u2010dependent unflatness. Treatment planning study across four target sizes (1\u201312\u00a0cm) showed these differences propagate to plan\u2010level parameters in a target\u2010size\u2010dependent manner, with VHD advantageous for small targets and TB for larger ones. The UCI, depth\u2010independent and strongly correlated with field size (\n                      <jats:italic>r<\/jats:italic>\n                      \u00a0=\u00a00.916), provides a simple cross\u2010platform unflatness comparison tool supporting machine\u2010specific planning strategies in multi\u2010platform clinical settings.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/acm2.70723","type":"journal-article","created":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T16:30:50Z","timestamp":1785342650000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Assessment of 6MV flattening filter free (FFF) beam commissioning parameters for Versa HD and TrueBeam: A comparison study"],"prefix":"10.1002","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2873-583X","authenticated-orcid":false,"given":"Mustafa K.","family":"Al\u2010Aseebee","sequence":"first","affiliation":[{"name":"Department of Physics Faculty of Science University of Kufa  Al\u2010Najaf Iraq"},{"name":"Middle Euphrates Cancer Center  Al\u2010Najaf Iraq"},{"name":"Amal Al\u2010Hayat Hospital  Al\u2010Najaf Iraq"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4011-4099","authenticated-orcid":false,"given":"Hussien","family":"Mraity","sequence":"additional","affiliation":[{"name":"Department of Physics Faculty of Science University of Kufa  Al\u2010Najaf Iraq"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9332-5351","authenticated-orcid":false,"given":"Marco","family":"Esposito","sequence":"additional","affiliation":[{"name":"S.O.C. Fisica Sanitaria Firenze\u2010Empoli Azienda USL Toscana Centro  Bagno a Ripoli Italy"},{"name":"Medical Physics The Abdus Salam International Center for Theoretical Physics  Trieste Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,7,29]]},"reference":[{"key":"e_1_2_10_2_1","doi-asserted-by":"publisher","DOI":"10.1038\/nrclinonc.2012.203"},{"key":"e_1_2_10_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12829"},{"key":"e_1_2_10_4_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12878"},{"key":"e_1_2_10_5_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v16i3.5219"},{"key":"e_1_2_10_6_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031\u20109155\/55\/8\/003"},{"key":"e_1_2_10_7_1","first-page":"473","volume-title":"Special Techniques: II SRS, SRT, and SBRT","author":"Munshi A","year":"2025"},{"key":"e_1_2_10_8_1","doi-asserted-by":"publisher","DOI":"10.1111\/1754\u20109485.12583"},{"key":"e_1_2_10_9_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.2198327"},{"key":"e_1_2_10_10_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.4754799"},{"key":"e_1_2_10_11_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.4938060"},{"key":"e_1_2_10_12_1","doi-asserted-by":"publisher","DOI":"10.31557\/APJCB.2026.11.1.31"},{"key":"e_1_2_10_13_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.14757"},{"key":"e_1_2_10_14_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361\u20106560\/ad154c"},{"key":"e_1_2_10_15_1","doi-asserted-by":"publisher","DOI":"10.15406\/ijrrt.2024.11.00394"},{"key":"e_1_2_10_16_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.597398"},{"key":"e_1_2_10_17_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.2969070"},{"key":"e_1_2_10_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.apradiso.2021.110054"},{"key":"e_1_2_10_19_1","doi-asserted-by":"publisher","DOI":"10.1007\/s13246\u2010018\u20100716\u2010x"},{"key":"e_1_2_10_20_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.15030"},{"key":"e_1_2_10_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radphyschem.2025.112819"},{"key":"e_1_2_10_22_1","unstructured":"AgencyIAE.Dosimetry of Small Static Fields Used in External Beam Radiotherapy.2017. 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