{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T16:10:46Z","timestamp":1753891846187,"version":"3.41.2"},"reference-count":21,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,11,3]],"date-time":"2022-11-03T00:00:00Z","timestamp":1667433600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2019YFB1311300"],"award-info":[{"award-number":["2019YFB1311300"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2019YFB1311301"],"award-info":[{"award-number":["2019YFB1311301"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:sec><jats:title>Purpose<\/jats:title><jats:p>Modern Linacs are equipped with multiple photon energies for radiation therapy, and proper energy is chosen for each case based on tumor characteristics and patient anatomy. The aim of this study is to investigate whether it is necessary to have more than two photons energies.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>The principle of photon energy synthesis is presented. It is shown that a photon beam of any intermediate energy (E<jats:sub>syn<\/jats:sub>) can be synthesized from a linear combination of a low energy (E<jats:sub>low<\/jats:sub>) and a high energy (E<jats:sub>high<\/jats:sub>). The principle is validated on a wide range of scenarios: different intermediate photon energies on the same Linac; between Linacs from the same manufacturer or different manufacturers; open and wedge beams; and extensive photon energies available from published reference data. In addition, 3D dose distributions in water phantom are compared using Gamma analysis. The method is further demonstrated in clinical cases of various tumor sites and multiple treatment modalities. Experimental measurements are performed for IMRT plans and they are analyzed using the standard clinical protocol.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The synthesis coefficients vary with energy and field size. The root mean square error (<jats:italic>RMSE<\/jats:italic>) is within 1.1% for open and wedge fields. Excellent agreement was observed for British Journal of Radiology (BJR) data with an average RMSE of 0.11%. The 3D Gamma analysis shows a good match for all field sizes in the water phantom and all treatment modalities for the five clinical cases. The minimum gamma passing rate of 95.7% was achieved at 1%\/1mm criteria for two measured dose distributions of IMRT plans.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>A Linac with two photon energies is capable of producing dosimetrically equivalent plans of any energy in-between through the photon energy synthesis, supporting the notion that there is no need to equip more than two photon energies on each Linac. This can significantly reduce the cost of equipment for radiation therapy.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fonc.2022.1009553","type":"journal-article","created":{"date-parts":[[2022,11,3]],"date-time":"2022-11-03T06:18:07Z","timestamp":1667456287000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Does radiation therapy need more than two photon energies from Linac?"],"prefix":"10.3389","volume":"12","author":[{"given":"Xile","family":"Zhang","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fugen","family":"Zhou","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bo","family":"Liu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tianyu","family":"Xiong","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiangzhi","family":"Bai","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qiuwen","family":"Wu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2022,11,3]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/0360-3016(86)90277-4","article-title":"Choice of optimum megavoltage for accelerators for photon beam treatment","volume":"12","author":"Laughlin","year":"1986","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"B2","article-title":"An analysis of depth dose characteristics of photon in water","volume":"21","author":"Buzdar","year":"2009","journal-title":"J Ayub Med Coll Abbottabad"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v10i4.3012","article-title":"Optimization of photon beam energy in aperture-based inverse planning","volume":"10","author":"St-Hilaire","year":"2009","journal-title":"J Appl Clin Med Phys"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v12i4.3563","article-title":"The dosimetric effect of mixed-energy IMRT plans for prostate cancer","volume":"12","author":"Park","year":"2011","journal-title":"J Appl Clin Med Phys"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.7314\/apjcp.2015.16.17.7785","article-title":"Breast radiotherapy with mixed energy photons; a model for optimal beam weighting","volume":"16","author":"Birgani","year":"2015","journal-title":"Asian Pac J Cancer Prev"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/61\/4\/1476","article-title":"Modulated photon radiotherapy (XMRT): An algorithm for the simultaneous optimization of photon beamlet energy and intensity in external beam radiotherapy (EBRT) planning","volume":"61","author":"McGeachy","year":"2016","journal-title":"Phys Med Biol"},{"key":"B7","doi-asserted-by":"publisher","first-page":"51","DOI":"10.1002\/acm2.12561","article-title":"Evaluation of mixed energy partial arcs for volumetric modulated arc therapy for prostate cancer","volume":"20","author":"Momin","year":"2019","journal-title":"J Appl Clin Med Phys"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1002\/mp.13700","article-title":"Simultaneous optimization of mixed photon energy beams in volumetric modulated arc therapy","volume":"46","author":"Momin","year":"2019","journal-title":"Med Phys"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejmp.2021.02.004","article-title":"Photon beam energy dependent single-arc volumetric modulated arc optimization","volume":"82","author":"Momin","year":"2021","journal-title":"Phys Med"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1016\/j.canrad.2005.09.011","article-title":"[Cost of quality assurance in radiotherapy: Human and material requirements]","volume":"9","author":"Caudrelier","year":"2005","journal-title":"Cancer Radiother"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1118\/1.3682172","article-title":"Photon energy-modulated radiotherapy: Monte Carlo simulation and treatment planning study","volume":"39","author":"Park","year":"2012","journal-title":"Med Phys"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1118\/1.598248","article-title":"A technique for the quantitative evaluation of dose distributions","volume":"25","author":"Low","year":"1998","journal-title":"Med Phys"},{"key":"B13","first-page":"62","article-title":"Megavoltage X-ray beams: 2-50 MV","volume":"25","author":"Jordan","year":"1996","journal-title":"BJR Suppl"},{"key":"B14","doi-asserted-by":"publisher","first-page":"6981","DOI":"10.1118\/1.4762682","article-title":"Commissioning and dosimetric characteristics of TrueBeam system: Composite data of three TrueBeam machines","volume":"39","author":"Chang","year":"2012","journal-title":"Med Phys"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1118\/1.2969070","article-title":"Accelerator beam data commissioning equipment and procedures: Report of the TG-106 of the therapy physics committee of the AAPM","volume":"35","author":"Das","year":"2008","journal-title":"Med Phys"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v14i1.4077","article-title":"Commissioning measurements for photon beam data on three TrueBeam linear accelerators, and comparison with trilogy and clinac 2100 linear accelerators","volume":"14","author":"Beyer","year":"2013","journal-title":"J Appl Clin Med Phys"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v17i3.6059","article-title":"Small field detector correction factors: Effects of the flattening filter for elekta and Varian linear accelerators","volume":"17","author":"Tyler","year":"2016","journal-title":"J Appl Clin Med Phys"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-12-407741-6.00006-2","article-title":"Plastimatch\u2014An Open-Source Software for Radiotherapy Imaging. In: High Performance Deformable Image Registration Algorithms for Manycore Processors","author":"Shackleford","year":"2013"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1118\/1.594774","article-title":"Estimate of the risk in radiation therapy due to unwanted neutrons","volume":"7","author":"Swanson","year":"1980","journal-title":"Med Phys"},{"key":"B20","doi-asserted-by":"publisher","first-page":"58","DOI":"10.1016\/j.canrad.2018.04.003","article-title":"[Which photon energy for intensity-modulated radiotherapy and volumetric-modulated arctherapy in 2019]","volume":"23","author":"Cosset","year":"2019","journal-title":"Cancer Radiother"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1002\/mp.12462","article-title":"AAPM TG 158: Measurement and calculation of doses outside the treated volume from external-beam radiation therapy","volume":"44","author":"Kry","year":"2017","journal-title":"Med Phys"}],"container-title":["Frontiers in Oncology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2022.1009553\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,11,3]],"date-time":"2022-11-03T06:18:14Z","timestamp":1667456294000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2022.1009553\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,3]]},"references-count":21,"alternative-id":["10.3389\/fonc.2022.1009553"],"URL":"https:\/\/doi.org\/10.3389\/fonc.2022.1009553","relation":{},"ISSN":["2234-943X"],"issn-type":[{"type":"electronic","value":"2234-943X"}],"subject":[],"published":{"date-parts":[[2022,11,3]]},"article-number":"1009553"}}