{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T17:19:02Z","timestamp":1778779142945,"version":"3.51.4"},"reference-count":61,"publisher":"IOP Publishing","issue":"17","license":[{"start":{"date-parts":[[2023,8,28]],"date-time":"2023-08-28T00:00:00Z","timestamp":1693180800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/publishingsupport.iopscience.iop.org\/iop-standard\/v1"},{"start":{"date-parts":[[2023,8,28]],"date-time":"2023-08-28T00:00:00Z","timestamp":1693180800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/iopscience.iop.org\/info\/page\/text-and-data-mining"}],"funder":[{"DOI":"10.13039\/100005294","name":"Massachusetts General Hospital","doi-asserted-by":"crossref","award":["C06-CA059267"],"award-info":[{"award-number":["C06-CA059267"]}],"id":[{"id":"10.13039\/100005294","id-type":"DOI","asserted-by":"crossref"}]},{"name":"National Cancer Institute","award":["R01-CA229178"],"award-info":[{"award-number":["R01-CA229178"]}]},{"DOI":"10.13039\/100000070","name":"National Institute of Biomedical Imaging and Bioengineering","doi-asserted-by":"crossref","award":["R21-EB026086"],"award-info":[{"award-number":["R21-EB026086"]}],"id":[{"id":"10.13039\/100000070","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"crossref","award":["299102935"],"award-info":[{"award-number":["299102935"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["iopscience.iop.org"],"crossmark-restriction":false},"short-container-title":["Phys. Med. Biol."],"published-print":{"date-parts":[[2023,9,7]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    <jats:italic>Objective<\/jats:italic>\n                    . Range uncertainty in proton therapy is an important factor limiting clinical effectiveness. Magnetic resonance imaging (MRI) can measure voxel-wise molecular composition and, when combined with kilovoltage CT (kVCT), accurately determine mean ionization potential (\n                    <jats:italic>I<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>m<\/jats:italic>\n                    <\/jats:sub>\n                    ), electron density, and stopping power ratio (SPR). We aimed to develop a novel MR-based multimodal method to accurately determine SPR and molecular compositions. This method was evaluated in tissue-mimicking and\n                    <jats:italic>ex vivo<\/jats:italic>\n                    porcine phantoms, and in a brain radiotherapy patient.\n                    <jats:italic>Approach<\/jats:italic>\n                    . Four tissue-mimicking phantoms with known compositions, two porcine tissue phantoms, and a brain cancer patient were imaged with kVCT and MRI. Three imaging-based values were determined: SPR\n                    <jats:sub>CM<\/jats:sub>\n                    (CT-based Multimodal), SPR\n                    <jats:sub>MM<\/jats:sub>\n                    (MR-based Multimodal), and SPR\n                    <jats:sub>stoich<\/jats:sub>\n                    (stoichiometric calibration). MRI was used to determine two tissue-specific quantities of the Bethe Bloch equation (\n                    <jats:italic>I<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>m<\/jats:italic>\n                    <\/jats:sub>\n                    , electron density) to compute SPR\n                    <jats:sub>CM<\/jats:sub>\n                    and SPR\n                    <jats:sub>MM<\/jats:sub>\n                    . Imaging-based SPRs were compared to measurements for phantoms in a proton beam using a multilayer ionization chamber (SPR\n                    <jats:sub>MLIC<\/jats:sub>\n                    ).\n                    <jats:italic>Main results<\/jats:italic>\n                    . Root mean square errors relative to SPR\n                    <jats:sub>MLIC<\/jats:sub>\n                    were 0.0104(0.86%), 0.0046(0.45%), and 0.0142(1.31%) for SPR\n                    <jats:sub>CM<\/jats:sub>\n                    , SPR\n                    <jats:sub>MM<\/jats:sub>\n                    , and SPR\n                    <jats:sub>stoich<\/jats:sub>\n                    , respectively. The largest errors were in bony phantoms, while soft tissue and porcine tissue phantoms had &lt;1% errors across all SPR values. Relative to known physical molecular compositions, imaging-determined compositions differed by approximately \u226410%. In the brain case, the largest differences between SPR\n                    <jats:sub>stoich<\/jats:sub>\n                    and SPR\n                    <jats:sub>MM<\/jats:sub>\n                    were in bone and high lipids\/fat tissue. The magnitudes and trends of these differences matched phantom results.\n                    <jats:italic>Significance<\/jats:italic>\n                    . Our MR-based multimodal method determined molecular compositions and SPR in various tissue-mimicking phantoms with high accuracy, as confirmed with proton beam measurements. This method also revealed significant SPR differences compared to stoichiometric kVCT-only calculation in a clinical case, with the largest differences in bone. These findings support that including MRI in proton therapy treatment planning can improve the accuracy of calculated SPR values and reduce range uncertainties.\n                  <\/jats:p>","DOI":"10.1088\/1361-6560\/ace876","type":"journal-article","created":{"date-parts":[[2023,7,18]],"date-time":"2023-07-18T18:40:56Z","timestamp":1689705656000},"page":"175033","update-policy":"https:\/\/doi.org\/10.1088\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Validation of an MR-based multimodal method for molecular composition and proton stopping power ratio determination using\n                    <i>ex vivo<\/i>\n                    animal tissues and tissue-mimicking phantoms"],"prefix":"10.1088","volume":"68","author":[{"given":"Raanan","family":"Marants","sequence":"first","affiliation":[{"name":"Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women\u2019s Hospital, and Harvard Medical School, Boston, Massachusetts,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sebastian","family":"Tattenberg","sequence":"additional","affiliation":[{"name":"Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen"},{"name":"Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jessica","family":"Scholey","sequence":"additional","affiliation":[{"name":"University of California"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Evangelia","family":"Kaza","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women\u2019s Hospital, and Harvard Medical School, Boston, Massachusetts,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xin","family":"Miao","sequence":"additional","affiliation":[{"name":"Siemens Medical Solutions USA Inc., Boston, Massachusetts,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas","family":"Benkert","sequence":"additional","affiliation":[{"name":"Siemens Healthcare GmbH, Erlangen,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Olivia","family":"Magneson","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women\u2019s Hospital, and Harvard Medical School, Boston, Massachusetts,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jade","family":"Fischer","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women\u2019s Hospital, and Harvard Medical School, Boston, Massachusetts,"},{"name":"University of Calgary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luciano","family":"Vinas","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women\u2019s Hospital, and Harvard Medical School, Boston, Massachusetts,"},{"name":"University of California"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katharina","family":"Niepel","sequence":"additional","affiliation":[{"name":"Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas","family":"Bortfeld","sequence":"additional","affiliation":[{"name":"Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1707-4068","authenticated-orcid":true,"given":"Guillaume","family":"Landry","sequence":"additional","affiliation":[{"name":"University Hospital"},{"name":"German Cancer Consortium (DKTK), Partner Site Munich, Munich,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7779-6690","authenticated-orcid":true,"given":"Katia","family":"Parodi","sequence":"additional","affiliation":[{"name":"Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen"},{"name":"German Cancer Consortium (DKTK), Partner Site Munich, Munich,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joost","family":"Verburg","sequence":"additional","affiliation":[{"name":"Division of Radiation Biophysics, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts,"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0397-0884","authenticated-orcid":true,"given":"Atchar","family":"Sudhyadhom","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women\u2019s Hospital, and Harvard Medical School, Boston, Massachusetts,"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"266","published-online":{"date-parts":[[2023,8,28]]},"reference":[{"key":"pmbace876bib1","doi-asserted-by":"publisher","first-page":"264","DOI":"10.1016\/j.meddos.2020.01.005","type":"journal-article","article-title":"Dosimetric evaluation of MR-derived synthetic-CTs for MR-only proton treatment planning","volume":"45","author":"Aramburu Nunez","year":"2020","journal-title":"Med. Dosim."},{"key":"pmbace876bib2","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/aad312","type":"journal-article","article-title":"Optimized I-values for use with the Bragg additivity rule and their impact on proton stopping power and range uncertainty","volume":"63","author":"B\u00e4r","year":"2018","journal-title":"Phys Med. Biol."},{"key":"pmbace876bib3","doi-asserted-by":"publisher","first-page":"2332","DOI":"10.1002\/mp.12215","type":"journal-article","article-title":"The potential of dual-energy CT to reduce proton beam range uncertainties","volume":"44","author":"B\u00e4r","year":"2017","journal-title":"Med. Phys."},{"key":"pmbace876bib4","doi-asserted-by":"publisher","first-page":"2059","DOI":"10.1088\/0031-9155\/59\/8\/2059","type":"journal-article","article-title":"A stoichiometric calibration method for dual energy computed tomography","volume":"59","author":"Bourque","year":"2014","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib5","doi-asserted-by":"publisher","first-page":"99","DOI":"10.1016\/j.brainresrev.2010.08.002","type":"journal-article","article-title":"Recent insights into a new hydrodynamics of the cerebrospinal fluid","volume":"65","author":"Bulat","year":"2011","journal-title":"Brain. Res. Rev."},{"key":"pmbace876bib6","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/ab436a","type":"journal-article","article-title":"MRI-guided proton therapy planning: accounting for an inline MRI fringe field","volume":"64","author":"Burigo","year":"2019","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib7","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/aca315","type":"journal-article","article-title":"Improvement of proton beam range uncertainty in breast treatment using tissue samples","volume":"67","author":"Cui","year":"2022","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib8","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/ab2b72","type":"journal-article","article-title":"Experimental comparison of proton CT and dual energy x-ray CT for relative stopping power estimation in proton therapy","volume":"64","author":"Dedes","year":"2019","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib9","doi-asserted-by":"publisher","first-page":"7998","DOI":"10.1002\/mp.15334","type":"journal-article","article-title":"A comparison of proton stopping power measured with proton CT and x-ray CT in fresh postmortem porcine structures","volume":"48","author":"DeJongh","year":"2021","journal-title":"Med. Phys."},{"key":"pmbace876bib10","doi-asserted-by":"publisher","first-page":"1739","DOI":"10.1002\/mrm.27531","type":"journal-article","article-title":"On the sensitivity of quantitative susceptibility mapping for measuring trabecular bone density","volume":"81","author":"Diefenbach","year":"2019","journal-title":"Magn. Reson. Med."},{"key":"pmbace876bib11","doi-asserted-by":"publisher","first-page":"151","DOI":"10.1016\/j.semradonc.2014.02.003","type":"journal-article","article-title":"The value of magnetic resonance imaging for radiotherapy planning","volume":"24","author":"Dirix","year":"2014","journal-title":"Semin. Radiat. Oncol."},{"key":"pmbace876bib12","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/aaede5","type":"journal-article","article-title":"Revisiting the single-energy CT calibration for proton therapy treatment planning: a critical look at the stoichiometric method","volume":"63","author":"Goma","year":"2018","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib13","doi-asserted-by":"publisher","first-page":"600","DOI":"10.1118\/1.4939082","type":"journal-article","article-title":"A linear, separable two-parameter model for dual energy CT imaging of proton stopping power computation","volume":"43","author":"Han","year":"2016","journal-title":"Med. Phys."},{"key":"pmbace876bib14","doi-asserted-by":"publisher","first-page":"129","DOI":"10.1186\/s13014-020-01571-x","type":"journal-article","article-title":"MR-guided proton therapy: a review and a preview","volume":"15","author":"Hoffmann","year":"2020","journal-title":"Radiat. Oncol."},{"key":"pmbace876bib15","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1186\/s13045-018-0683-4","type":"journal-article","article-title":"Proton beam therapy for cancer in the era of precision medicine","volume":"11","author":"Hu","year":"2018","journal-title":"J. Hematol. Oncol."},{"key":"pmbace876bib16","doi-asserted-by":"publisher","first-page":"300","DOI":"10.1016\/j.zemedi.2013.03.001","type":"journal-article","article-title":"Ion range estimation by using dual energy computed tomography","volume":"23","author":"Hunemohr","year":"2013","journal-title":"Z. Med. Phys."},{"key":"pmbace876bib17","doi-asserted-by":"publisher","first-page":"83","DOI":"10.1088\/0031-9155\/59\/1\/83","type":"journal-article","article-title":"Experimental verification of ion stopping power prediction from dual energy CT data in tissue surrogates","volume":"59","author":"Hunemohr","year":"2014a","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib18","doi-asserted-by":"publisher","DOI":"10.1118\/1.4875976","type":"journal-article","article-title":"Tissue decomposition from dual energy CT data for MC based dose calculation in particle therapy","volume":"41","author":"Hunemohr","year":"2014b","journal-title":"Med. Phys."},{"key":"pmbace876bib19","doi-asserted-by":"publisher","first-page":"104","DOI":"10.1016\/j.mri.2019.06.016","type":"journal-article","article-title":"Significant correlations between human cortical bone mineral density and quantitative susceptibility mapping (QSM) obtained with 3D Cones ultrashort echo time magnetic resonance imaging (UTE-MRI)","volume":"62","author":"Jerban","year":"2019","journal-title":"Magn. Reson. Imaging"},{"key":"pmbace876bib20","doi-asserted-by":"publisher","first-page":"1439","DOI":"10.1118\/1.2715481","type":"journal-article","article-title":"Effects of hounsfield number conversion on CT based proton Monte Carlo dose calculations","volume":"34","author":"Jiang","year":"2007","journal-title":"Med. Phys."},{"key":"pmbace876bib21","doi-asserted-by":"publisher","first-page":"1158","DOI":"10.1002\/mrm.24775","type":"journal-article","article-title":"Bone marrow fat quantification in the presence of trabecular bone: initial comparison between water-fat imaging and single-voxel MRS","volume":"71","author":"Karampinos","year":"2014","journal-title":"Magn. Reson. Med."},{"key":"pmbace876bib22","doi-asserted-by":"publisher","first-page":"458","DOI":"10.1038\/s41571-022-00631-3","type":"journal-article","article-title":"Integrated MRI-guided radiotherapy - opportunities and challenges","volume":"19","author":"Keall","year":"2022","journal-title":"Nat. Rev. Clin. Oncol."},{"key":"pmbace876bib23","doi-asserted-by":"publisher","first-page":"14","DOI":"10.4103\/bc.BC_3_18","type":"journal-article","article-title":"Cerebrospinal fluid circulation: what do we know and how do we know it?","volume":"4","author":"Khasawneh","year":"2018","journal-title":"Brain. Circ."},{"key":"pmbace876bib24","doi-asserted-by":"publisher","first-page":"R131","DOI":"10.1088\/0031-9155\/58\/15\/R131","type":"journal-article","article-title":"In vivo proton range verification: a review","volume":"58","author":"Knopf","year":"2013","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib25","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1186\/s13014-020-01524-4","type":"journal-article","article-title":"Medical physics challenges in clinical MR-guided radiotherapy","volume":"15","author":"Kurz","year":"2020","journal-title":"Radiat. Oncol."},{"key":"pmbace876bib26","doi-asserted-by":"publisher","first-page":"375","DOI":"10.1016\/j.radonc.2011.08.029","type":"journal-article","article-title":"Extracting atomic numbers and electron densities from a dual source dual energy CT scanner: experiments and a simulation model","volume":"100","author":"Landry","year":"2011","journal-title":"Radiother. Oncol."},{"key":"pmbace876bib27","doi-asserted-by":"publisher","first-page":"4259","DOI":"10.1088\/0031-9155\/50\/18\/002","type":"journal-article","article-title":"The use of megavoltage CT (MVCT) images for dose recomputations","volume":"50","author":"Langen","year":"2005","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib28","doi-asserted-by":"publisher","first-page":"849","DOI":"10.1038\/sj.bjc.6602754","type":"journal-article","article-title":"Proton beam therapy","volume":"93","author":"Levin","year":"2005","journal-title":"Br. J. Cancer"},{"key":"pmbace876bib29","doi-asserted-by":"publisher","first-page":"7056","DOI":"10.1088\/1361-6560\/aa7dc9","type":"journal-article","article-title":"Comprehensive analysis of proton range uncertainties related to stopping-power-ratio estimation using dual-energy CT imaging","volume":"62","author":"Li","year":"2017","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib30","doi-asserted-by":"publisher","first-page":"297","DOI":"10.1007\/BF03012018","type":"journal-article","article-title":"Densities of cerebrospinal fluid and spinal anaesthetic solutions in surgical patients at body temperature","volume":"45","author":"Lui","year":"1998","journal-title":"Can. J. Anaesth"},{"key":"pmbace876bib31","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1016\/j.radonc.2020.09.029","type":"journal-article","article-title":"Deep learning-based synthetic CT generation for paediatric brain MR-only photon and proton radiotherapy","volume":"153","author":"Maspero","year":"2020","journal-title":"Radiother. Oncol."},{"key":"pmbace876bib32","doi-asserted-by":"publisher","first-page":"9159","DOI":"10.1088\/1361-6560\/aa9677","type":"journal-article","article-title":"Feasibility of MR-only proton dose calculations for prostate cancer radiotherapy using a commercial pseudo-CT generation method","volume":"62","author":"Maspero","year":"2017","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib33","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/abbd14","type":"journal-article","article-title":"Animal tissue-based quantitative comparison of dual-energy CT to SPR conversion methods using high-resolution gel dosimetry","volume":"66","author":"Niepel","year":"2021","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib34","doi-asserted-by":"publisher","first-page":"R99","DOI":"10.1088\/0031-9155\/57\/11\/R99","type":"journal-article","article-title":"Range uncertainties in proton therapy and the role of Monte Carlo simulation","volume":"57","author":"Paganetti","year":"2012","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib35","doi-asserted-by":"publisher","first-page":"71","DOI":"10.1016\/j.radonc.2021.11.002","type":"journal-article","article-title":"Reduction of clinical safety margins in proton therapy enabled by the clinical implementation of dual-energy CT for direct stopping-power prediction","volume":"166","author":"Peters","year":"2022","journal-title":"Radiother. Oncol."},{"key":"pmbace876bib36","doi-asserted-by":"publisher","first-page":"326","DOI":"10.1097\/00000542-199608000-00014","type":"journal-article","article-title":"Density of lumbar cerebrospinal fluid in pregnant and nonpregnant humans","volume":"85","author":"Richardson","year":"1996","journal-title":"Anesthesiology"},{"key":"pmbace876bib37","doi-asserted-by":"publisher","DOI":"10.1002\/mp.16353","type":"journal-article","article-title":"MRI-based quantification of carbon and oxygen concentrations in human soft tissues for range verification in proton therapy","author":"Saito","year":"2023","journal-title":"Med. Phys."},{"key":"pmbace876bib38","doi-asserted-by":"publisher","first-page":"822","DOI":"10.1002\/mp.13309","type":"journal-article","article-title":"Proton beam behavior in a parallel configured MRI-proton therapy hybrid: effects of time-varying gradient magnetic fields","volume":"46","author":"Santos","year":"2019","journal-title":"Med. Phys."},{"key":"pmbace876bib39","doi-asserted-by":"publisher","first-page":"1579","DOI":"10.1088\/0031-9155\/43\/6\/016","type":"journal-article","article-title":"The precision of proton range calculations in proton radiotherapy treatment planning: experimental verification of the relation between CT-HU and proton stopping power","volume":"43","author":"Schaffner","year":"1998","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib40","doi-asserted-by":"publisher","first-page":"3429","DOI":"10.1002\/mp.12961","type":"journal-article","article-title":"Technical note: experimental verification of magnetic field-induced beam deflection and bragg peak displacement for MR-integrated proton therapy","volume":"45","author":"Schellhammer","year":"2018a","journal-title":"Med. Phys."},{"key":"pmbace876bib41","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/aaece8","type":"journal-article","article-title":"Integrating a low-field open MR scanner with a static proton research beam line: proof of concept","volume":"63","author":"Schellhammer","year":"2018b","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib42","doi-asserted-by":"publisher","first-page":"342","DOI":"10.1002\/mp.14555","type":"journal-article","article-title":"Technical note: a methodology for improved accuracy in stopping power estimation using MRI and CT","volume":"48","author":"Scholey","year":"2021","journal-title":"Med. Phys."},{"key":"pmbace876bib43","first-page":"55","type":"journal-article","article-title":"Proton CT for improved stopping power determination in proton therapy, invited","volume":"106","author":"Schulte","year":"2012","journal-title":"Trans. Am. Nucl. Soc."},{"key":"pmbace876bib44","doi-asserted-by":"publisher","first-page":"8521","DOI":"10.1088\/1361-6560\/aa8d9e","type":"journal-article","article-title":"Determination of mean ionization potential using magnetic resonance imaging for the reduction of proton beam range uncertainties: theory and application","volume":"62","author":"Sudhyadhom","year":"2017","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib45","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0244861","type":"journal-article","article-title":"On the molecular relationship between Hounsfield Unit (HU), mass density, and electron density in computed tomography (CT)","volume":"15","author":"Sudhyadhom","year":"2020","journal-title":"PLoS One"},{"key":"pmbace876bib46","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/aa952f","type":"journal-article","article-title":"Validation of proton stopping power ratio estimation based on dual energy CT using fresh tissue samples","volume":"63","author":"Taasti","year":"2017","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib47","doi-asserted-by":"publisher","first-page":"5547","DOI":"10.1118\/1.4962934","type":"journal-article","article-title":"A robust empirical parametrization of proton stopping power using dual energy CT","volume":"43","author":"Taasti","year":"2016","journal-title":"Med. Phys."},{"key":"pmbace876bib48","doi-asserted-by":"publisher","first-page":"4693","DOI":"10.1002\/mp.15644","type":"journal-article","article-title":"Range uncertainty reductions in proton therapy may lead to the feasibility of novel beam arrangements which improve organ-at-risk sparing","volume":"49","author":"Tattenberg","year":"2022a","journal-title":"Med. Phys."},{"key":"pmbace876bib49","doi-asserted-by":"publisher","first-page":"5356","DOI":"10.1002\/mp.15097","type":"journal-article","article-title":"Proton range uncertainty reduction benefits for skull base tumors in terms of normal tissue complication probability (NTCP) and healthy tissue doses","volume":"48","author":"Tattenberg","year":"2021","journal-title":"Med. Phys."},{"key":"pmbace876bib50","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/ac950f","type":"journal-article","article-title":"Validation of prompt gamma-ray spectroscopy for proton range verification in tissue-mimicking and porcine samples","volume":"67","author":"Tattenberg","year":"2022b","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib51","doi-asserted-by":"publisher","first-page":"1310","DOI":"10.1109\/TMI.2010.2046908","type":"journal-article","article-title":"N4ITK: improved N3 bias correction","volume":"29","author":"Tustison","year":"2010","journal-title":"IEEE Trans. Med. Imaging"},{"key":"pmbace876bib52","doi-asserted-by":"publisher","first-page":"L37","DOI":"10.1088\/0031-9155\/58\/20\/L37","type":"journal-article","article-title":"Energy- and time-resolved detection of prompt gamma-rays for proton range verification","volume":"58","author":"Verburg","year":"2013","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib53","doi-asserted-by":"publisher","first-page":"1559","DOI":"10.1002\/mp.15479","type":"journal-article","article-title":"Toward MR-only proton therapy planning for pediatric brain tumors: synthesis of relative proton stopping power images with multiple sequence MRI and development of an online quality assurance tool","volume":"49","author":"Wang","year":"2022","journal-title":"Med. Phys."},{"key":"pmbace876bib54","doi-asserted-by":"publisher","first-page":"149","DOI":"10.1259\/0007-1285-64-758-149","type":"journal-article","article-title":"The composition of body tissues (II). Fetus to young adult","volume":"64","author":"White","year":"1991","journal-title":"Br J. Radiol."},{"key":"pmbace876bib55","doi-asserted-by":"publisher","first-page":"907","DOI":"10.1259\/0007-1285-60-717-907","type":"journal-article","article-title":"Average soft-tissue and bone models for use in radiation dosimetry","volume":"60","author":"White","year":"1987","journal-title":"Br J. Radiol."},{"key":"pmbace876bib56","doi-asserted-by":"publisher","first-page":"277","DOI":"10.1259\/0007-1285-55-652-277","type":"journal-article","article-title":"Bone models for use in radiotherapy dosimetry","volume":"55","author":"Woodard","year":"1982","journal-title":"Br J. Radiol."},{"key":"pmbace876bib57","doi-asserted-by":"publisher","first-page":"1209","DOI":"10.1259\/0007-1285-59-708-1209","type":"journal-article","article-title":"The composition of body tissues","volume":"59","author":"Woodard","year":"1986","journal-title":"Br J. Radiol."},{"key":"pmbace876bib58","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/aaae91","type":"journal-article","article-title":"Ex vivo validation of a stoichiometric dual energy CT proton stopping power ratio calibration","volume":"63","author":"Xie","year":"2018","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib59","doi-asserted-by":"publisher","first-page":"4095","DOI":"10.1088\/0031-9155\/57\/13\/4095","type":"journal-article","article-title":"Comprehensive analysis of proton range uncertainties related to patient stopping-power-ratio estimation using the stoichiometric calibration","volume":"57","author":"Yang","year":"2012","journal-title":"Phys. Med. Biol."},{"key":"pmbace876bib60","doi-asserted-by":"publisher","first-page":"1008","DOI":"10.1118\/1.3077129","type":"journal-article","article-title":"A bone composition model for Monte Carlo x-ray transport simulations","volume":"36","author":"Zhou","year":"2009","journal-title":"Med Phys"},{"key":"pmbace876bib61","doi-asserted-by":"publisher","first-page":"78","DOI":"10.1016\/j.zemedi.2020.10.004","type":"journal-article","article-title":"An MR-only acquisition and artificial intelligence based image-processing protocol for photon and proton therapy using a low field MR","volume":"31","author":"Zimmermann","year":"2021","journal-title":"Z. Med. Phys."}],"container-title":["Physics in Medicine &amp; Biology"],"original-title":[],"link":[{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876","content-type":"text\/html","content-version":"am","intended-application":"text-mining"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876\/pdf","content-type":"application\/pdf","content-version":"am","intended-application":"text-mining"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876\/pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876\/pdf","content-type":"application\/pdf","content-version":"am","intended-application":"similarity-checking"},{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T17:04:16Z","timestamp":1778778256000},"score":1,"resource":{"primary":{"URL":"https:\/\/iopscience.iop.org\/article\/10.1088\/1361-6560\/ace876"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,8,28]]},"references-count":61,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2023,8,28]]},"published-print":{"date-parts":[[2023,9,7]]}},"URL":"https:\/\/doi.org\/10.1088\/1361-6560\/ace876","relation":{},"ISSN":["0031-9155","1361-6560"],"issn-type":[{"value":"0031-9155","type":"print"},{"value":"1361-6560","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,8,28]]},"assertion":[{"value":"Validation of an MR-based multimodal method for molecular composition and proton stopping power ratio determination using\n                      ex vivo\n                      animal tissues and tissue-mimicking phantoms","name":"article_title","label":"Article Title"},{"value":"Physics in Medicine & Biology","name":"journal_title","label":"Journal Title"},{"value":"paper","name":"article_type","label":"Article Type"},{"value":"\u00a9 2023 Institute of Physics and Engineering in Medicine. All rights, including for text and data mining, AI training, and similar technologies, are reserved.","name":"copyright_information","label":"Copyright Information"},{"value":"2023-04-23","name":"date_received","label":"Date Received","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2023-07-18","name":"date_accepted","label":"Date Accepted","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2023-08-28","name":"date_epub","label":"Online publication date","group":{"name":"publication_dates","label":"Publication dates"}}]}}