{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T15:24:39Z","timestamp":1777562679989,"version":"3.51.4"},"reference-count":38,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,3,19]],"date-time":"2021-03-19T00:00:00Z","timestamp":1616112000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:sec><jats:title>Purpose<\/jats:title><jats:p>Enhance rectum and bladder sparing in prostate SBRT with minimum increase in treatment time by complementing dual-arc coplanar VMAT with a two-beam non-coplanar IMRT class solution (CS).<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>For twenty patients, an optimizer for automated multi-criterial planning with integrated beam angle optimization (BAO) was used to generate dual-arc VMAT plans, supplemented with five non-coplanar IMRT beams with individually optimized orientations (VMAT+5). In all plan generations, reduction of high rectum dose had the highest priority after obtaining adequate PTV coverage. A CS with two most preferred directions in VMAT+5 and largest rectum dose reductions compared to dual-arc VMAT was then selected to define VMAT+CS. VMAT+CS was compared with automatically generated <jats:italic>i)<\/jats:italic> dual-arc coplanar VMAT plans (VMAT), <jats:italic>ii)<\/jats:italic> VMAT+5 plans, and <jats:italic>iii)<\/jats:italic> IMRT plans with 30 patient-specific non-coplanar beam orientations (30-NCP). Plans were generated for a 4 x 9.5 Gy fractionation scheme. Differences in PTV doses, healthy tissue sparing, and computation and treatment delivery times were quantified.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>For equal PTV coverage, VMAT+CS, consisting of dual-arc VMAT supplemented with two fixed, non-coplanar IMRT beams with fixed Gantry\/Couch angles of 65\u00b0\/30\u00b0 and 295\u00b0\/-30\u00b0, significantly reduced OAR doses and the dose bath, compared to dual-arc VMAT. Mean relative differences in rectum D<jats:sub>mean<\/jats:sub>, D<jats:sub>1cc<\/jats:sub>, V<jats:sub>40GyEq<\/jats:sub> and V<jats:sub>60GyEq<\/jats:sub> were 19.4 \u00b1 10.6%, 4.2 \u00b1 2.7%, 34.9 \u00b1 20.3%, and 39.7 \u00b1 23.2%, respectively (all <jats:italic>p<\/jats:italic>&amp;lt;0.001). There was no difference in bladder D<jats:sub>1cc<\/jats:sub>, while bladder D<jats:sub>mean<\/jats:sub> reduced by 17.9 \u00b1 11.0% (<jats:italic>p<\/jats:italic>&amp;lt;0.001). Also, the clinically evaluated urethra D<jats:sub>5%<\/jats:sub>, D<jats:sub>10%<\/jats:sub>, and D<jats:sub>50%<\/jats:sub> showed small, but statistically significant improvements. All patient V<jats:sub>X<\/jats:sub> with X = 2, 5, 10, 20, and 30 Gy were reduced with VMAT+CS, with a maximum relative reduction for V<jats:sub>10Gy<\/jats:sub> of 19.0 \u00b1 7.3% (<jats:italic>p<\/jats:italic>&amp;lt;0.001). Total delivery times with VMAT+CS only increased by 1.9 \u00b1 0.7\u00a0min compared to VMAT (9.1 \u00b1 0.7\u00a0min). The dosimetric quality of VMAT+CS plans was equivalent to VMAT+5, while optimization times were reduced by a factor of 25 due to avoidance of individualized BAO. Compared to VMAT+CS, the 30-NCP plans were only favorable in terms of dose bath, at the cost of much enhanced optimization and delivery times.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>The proposed two-beam non-coplanar class solution to complement coplanar dual-arc VMAT resulted in substantial plan quality improvements for OARs (especially rectum) and reduced irradiated patient volumes with minor increases in treatment delivery times.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fonc.2021.620978","type":"journal-article","created":{"date-parts":[[2021,3,19]],"date-time":"2021-03-19T15:15:52Z","timestamp":1616166952000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":8,"title":["Complementing Prostate SBRT VMAT With a Two-Beam Non-Coplanar IMRT Class Solution to Enhance Rectum and Bladder Sparing With Minimum Increase in Treatment Time"],"prefix":"10.3389","volume":"11","author":[{"given":"Abdul Wahab M.","family":"Sharfo","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Linda","family":"Rossi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maarten L. 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