{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,2]],"date-time":"2026-11-02T18:03:07Z","timestamp":1793642587607,"version":"4.5.1"},"reference-count":63,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,5,25]],"date-time":"2022-05-25T00:00:00Z","timestamp":1653436800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Brigitte und Dr. Konstanze Wegener-Stiftung","award":["53"],"award-info":[{"award-number":["53"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancers"],"abstract":"<jats:p>Background and Purpose: Interfractional anatomical changes might affect the outcome of proton therapy (PT). We aimed to prospectively evaluate the role of Magnetic Resonance Imaging (MRI) based adaptive PT for children with tumors of the head and neck and base of skull. Methods: MRI verification images were acquired at half of the treatment course. A synthetic computed tomography (CT) image was created using this MRI and a deformable image registration (DIR) to the reference MRI. The methodology was verified with in-silico phantoms and validated using a clinical case with a shrinking cystic hygroma on the basis of dosimetric quantities of contoured structures. The dose distributions on the verification X-ray CT and on the synthetic CT were compared with a gamma-index test using global 2 mm\/2% criteria. Results: Regarding the clinical validation case, the gamma-index pass rate was 98.3%. Eleven patients were included in the clinical study. The most common diagnosis was rhabdomyosarcoma (73%). Craniofacial tumor site was predominant in 64% of patients, followed by base of skull (18%). For one individual case the synthetic CT showed an increase in the median D2 and Dmax dose on the spinal cord from 20.5 GyRBE to 24.8 GyRBE and 14.7 GyRBE to 25.1 GyRBE, respectively. Otherwise, doses received by OARs remained relatively stable. Similarly, the target volume coverage seen by D95% and V95% remained unchanged. Conclusions: The method of transferring anatomical changes from MRIs to a synthetic CTs was successfully implemented and validated with simple, commonly available tools. In the frame of our early results on a small cohort, no clinical relevant deterioration for neither PTV coverage nor an increased dose burden to OARs occurred. However, the study will be continued to identify a pediatric patient cohort, which benefits from adaptive treatment planning.<\/jats:p>","DOI":"10.3390\/cancers14112616","type":"journal-article","created":{"date-parts":[[2022,5,25]],"date-time":"2022-05-25T08:41:33Z","timestamp":1653468093000},"page":"2616","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Adaptive Proton Therapy of Pediatric Head and Neck Cases Using MRI-Based Synthetic CTs: Initial Experience of the Prospective KiAPT Study"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0512-1146","authenticated-orcid":false,"given":"Christian","family":"B\u00e4umer","sequence":"first","affiliation":[{"name":"West German Proton Therapy Centre Essen, 45147 Essen, Germany"},{"name":"University Hospital Essen, 45147 Essen, Germany"},{"name":"West German Cancer Center (WTZ), 45147 Essen, Germany"},{"name":"German Cancer Consortium (DKTK), 69120 Heidelberg, Germany"},{"name":"Department of Physics, Technische Universit\u00e4t Dortmund, 44227 Dortmund, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rezarta","family":"Frakulli","sequence":"additional","affiliation":[{"name":"West German Proton Therapy Centre Essen, 45147 Essen, Germany"},{"name":"University Hospital Essen, 45147 Essen, Germany"},{"name":"West German Cancer Center (WTZ), 45147 Essen, Germany"},{"name":"Department of Particle Therapy, 45147 Essen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jessica","family":"Kohl","sequence":"additional","affiliation":[{"name":"West German Proton Therapy Centre Essen, 45147 Essen, Germany"},{"name":"University Hospital Essen, 45147 Essen, Germany"},{"name":"West German Cancer Center (WTZ), 45147 Essen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sindhu","family":"Nagaraja","sequence":"additional","affiliation":[{"name":"West German Proton Therapy Centre Essen, 45147 Essen, Germany"},{"name":"University Hospital Essen, 45147 Essen, Germany"},{"name":"West German Cancer Center (WTZ), 45147 Essen, Germany"},{"name":"Department of Particle Therapy, 45147 Essen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Theresa","family":"Steinmeier","sequence":"additional","affiliation":[{"name":"West German Proton Therapy Centre Essen, 45147 Essen, Germany"},{"name":"University Hospital Essen, 45147 Essen, Germany"},{"name":"West German Cancer Center (WTZ), 45147 Essen, Germany"},{"name":"Department of Particle Therapy, 45147 Essen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3442-6929","authenticated-orcid":false,"given":"Rasin","family":"Worawongsakul","sequence":"additional","affiliation":[{"name":"West German Proton Therapy Centre Essen, 45147 Essen, Germany"},{"name":"University Hospital Essen, 45147 Essen, Germany"},{"name":"West German Cancer Center (WTZ), 45147 Essen, Germany"},{"name":"Department of Particle Therapy, 45147 Essen, Germany"},{"name":"Radiation Oncology Unit, Department of Diagnostic and Therapeutic Radiology, Ramathibodi Hospital, Mahidol University, Nakhon 73170, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Beate","family":"Timmermann","sequence":"additional","affiliation":[{"name":"West German Proton Therapy Centre Essen, 45147 Essen, Germany"},{"name":"University Hospital Essen, 45147 Essen, Germany"},{"name":"West German Cancer Center (WTZ), 45147 Essen, Germany"},{"name":"German Cancer Consortium (DKTK), 69120 Heidelberg, Germany"},{"name":"Department of Particle Therapy, 45147 Essen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"706","DOI":"10.3390\/cancers7020706","article-title":"Dosimetric Comparison and Potential for Improved Clinical Outcomes of Paediatric CNS Patients Treated with Protons or IMRT","volume":"7","author":"Armoogum","year":"2015","journal-title":"Cancers"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/j.radonc.2016.05.013","article-title":"Tumour control and Quality of Life in children with rhabdomyosarcoma treated with pencil beam scanning proton therapy","volume":"120","author":"Leiser","year":"2016","journal-title":"Radiother. Oncol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1001\/archotol.128.6.655","article-title":"Pediatric Head and Neck Malignancies: US Incidence and Trends Over 2 Decades","volume":"128","author":"Albright","year":"2002","journal-title":"Arch. Otolaryngol.\u2013Head Neck Surg."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"367","DOI":"10.14338\/IJPT-14-00026.1","article-title":"Comparative Proton and Photon Treatment Planning in Pediatric Patients with Various Diagnoses","volume":"2","author":"Nilsson","year":"2015","journal-title":"Int. J. Part. Ther."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"561","DOI":"10.3109\/0284186X.2012.692885","article-title":"The potential of intensity-modulated proton radiotherapy to reduce swallowing dysfunction in the treatment of head and neck cancer: A planning comparative study","volume":"52","author":"Christianen","year":"2013","journal-title":"Acta Oncol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"881","DOI":"10.1093\/neuonc\/nov302","article-title":"Endocrine outcomes with proton and photon radiotherapy for standard risk medulloblastoma","volume":"18","author":"Eaton","year":"2015","journal-title":"Neuro-Oncology"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/j.radonc.2012.03.004","article-title":"NTCP models for patient-rated xerostomia and sticky saliva after treatment with intensity modulated radiotherapy for head and neck cancer: The role of dosimetric and clinical factors","volume":"105","author":"Beetz","year":"2012","journal-title":"Radiother. Oncol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.radonc.2011.08.009","article-title":"Predictive modelling for swallowing dysfunction after primary (chemo)radiation: Results of a prospective observational study","volume":"105","author":"Christianen","year":"2012","journal-title":"Radiother. Oncol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.clon.2019.01.002","article-title":"Pediatric Normal Tissue Effects in the Clinic (PENTEC): An International Collaboration to Analyse Normal Tissue Radiation Dose\u2013Volume Response Relationships for Paediatric Cancer Patients","volume":"31","author":"Constine","year":"2019","journal-title":"Clin. Oncol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"986","DOI":"10.1016\/j.ijrobp.2011.08.017","article-title":"Adaptive Radiotherapy for Head-and-Neck Cancer: Initial Clinical Outcomes From a Prospective Trial","volume":"83","author":"Schwartz","year":"2012","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"22TR01","DOI":"10.1088\/1361-6560\/ac344f","article-title":"Adaptive proton therapy","volume":"66","author":"Paganetti","year":"2021","journal-title":"Phys. Med. Biol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1541","DOI":"10.1002\/hed.23477","article-title":"Clinical outcomes among patients with head and neck cancer treated by intensity-modulated radiotherapy with and without adaptive replanning","volume":"36","author":"Chen","year":"2014","journal-title":"Head Neck"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1177\/1533034616662165","article-title":"Adaptive radiotherapy for head and neck cancer: Implications for clinical and dosimetry outcomes","volume":"16","author":"Surucu","year":"2017","journal-title":"Technol. Cancer Res. Treat."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s41199-019-0046-z","article-title":"Adaptive radiotherapy for head and neck cancer","volume":"5","author":"Morgan","year":"2020","journal-title":"Cancers Head Neck"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.ctrv.2010.08.004","article-title":"Systematic review and meta-analysis of radiotherapy in various head and neck cancers: Comparing photons, carbon-ions and protons","volume":"37","author":"Ramaekers","year":"2011","journal-title":"Cancer Treat. Rev."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1107","DOI":"10.1016\/j.ijrobp.2016.02.044","article-title":"Intensity modulated proton therapy versus intensity modulated photon radiation therapy for oropharyngeal cancer: First comparative results of patient-reported outcomes","volume":"95","author":"Sio","year":"2016","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"616","DOI":"10.1016\/j.ijrobp.2016.11.013","article-title":"Effect of Anatomic Changes on Pencil Beam Scanned Proton Dose Distributions for Cranial and Extracranial Tumors","volume":"97","author":"Placidi","year":"2017","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1002\/acm2.13128","article-title":"Potential benefits of adaptive intensity-modulated proton therapy in nasopharyngeal carcinomas","volume":"22","author":"Minatogawa","year":"2021","journal-title":"J. Appl. Clin. Med. Phys."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e87","DOI":"10.1016\/j.prro.2014.07.005","article-title":"Adaptive radiation therapy for pediatric head and neck malignancies: Dosimetric implications","volume":"5","author":"Laskar","year":"2015","journal-title":"Pract. Radiat. Oncol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1111\/1754-9485.12968","article-title":"Magnetic resonance-guided radiation therapy: A review","volume":"64","author":"Chin","year":"2020","journal-title":"J. Med. Imaging Radiat. Oncol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1358","DOI":"10.1088\/1361-6560\/aa5200","article-title":"Generation of synthetic CT data using patient specific daily MR image data and image registration","volume":"62","author":"Kraus","year":"2017","journal-title":"Phys. Med. Biol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.ejmp.2017.09.136","article-title":"Comprehensive clinical commissioning and validation of the RayStation treatment planning system for proton therapy with active scanning and passive treatment techniques","volume":"43","author":"Geismar","year":"2017","journal-title":"Phys. Medica"},{"key":"ref_23","unstructured":"Wambersie, A. (ICRU News, 1999). ICRU report 62, prescribing, recording and reporting photon beam therapy (supplement to ICRU Report 50), ICRU News."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s13063-019-4026-8","article-title":"International randomised controlled trial for the treatment of newly diagnosed EWING sarcoma family of tumours\u2013EURO EWING 2012 Protocol","volume":"21","author":"Anderton","year":"2020","journal-title":"Trials"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1016\/j.zemedi.2020.09.003","article-title":"Model-based comparison of organ at risk protection between VMAT and robustly optimised IMPT plans","volume":"31","author":"Behrends","year":"2021","journal-title":"Z. F\u00fcr Med. Phys."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1016\/j.ijrobp.2020.08.036","article-title":"Adaptive Proton Therapy for Pediatric Patients: Improving the Quality of the Delivered Plan With On-Treatment MRI","volume":"109","author":"Acharya","year":"2021","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/j.semradonc.2019.02.008","article-title":"Head and Neck Cancer Adaptive Radiation Therapy (ART): Conceptual Considerations for the Informed Clinician","volume":"29","author":"Heukelom","year":"2019","journal-title":"Semin. Radiat. Oncol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1118\/1.4894702","article-title":"The ANACONDA algorithm for deformable image registration in radiotherapy","volume":"42","author":"Weistrand","year":"2015","journal-title":"Med. Phys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"5153","DOI":"10.1002\/mp.12406","article-title":"Accuracy of deformable image registration on magnetic resonance images in digital and physical phantoms","volume":"44","author":"Ger","year":"2017","journal-title":"Med. Phys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1002\/mp.12256","article-title":"Use of image registration and fusion algorithms and techniques in radiotherapy: Report of the AAPM Radiation Therapy Committee Task Group No. 132","volume":"44","author":"Brock","year":"2017","journal-title":"Med. Phys."},{"key":"ref_31","unstructured":"Bolan, P. (2020, August 30). 3D Shepp\u2013Logan Phantom. Available online: https:\/\/www.mathworks.com\/matlabcentral\/fileexchange\/9416-3d-shepp-logan-phantom."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"499","DOI":"10.1016\/S0140-6736(12)60815-0","article-title":"Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: A retrospective cohort study","volume":"380","author":"Pearce","year":"2012","journal-title":"Lancet"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1016\/j.radonc.2019.08.005","article-title":"Practical robustness evaluation in radiotherapy \u2013 A photon and proton-proof alternative to PTV-based plan evaluation","volume":"141","author":"Korevaar","year":"2019","journal-title":"Radiother. Oncol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1016\/j.radonc.2011.05.028","article-title":"Comparison of intensity-modulated radiotherapy, adaptive radiotherapy, proton radiotherapy, and adaptive proton radiotherapy for treatment of locally advanced head and neck cancer","volume":"101","author":"Simone","year":"2011","journal-title":"Radiother. Oncol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1113","DOI":"10.1007\/s00066-021-01828-8","article-title":"Postsurgical geometrical variations of tumor bed and brainstem during photon and proton therapy for pediatric tumors of the posterior fossa: Dosimetric impact and predictive factors","volume":"197","author":"Volpe","year":"2021","journal-title":"Strahlenther. Und Onkol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"20190638","DOI":"10.1259\/bjr.20190638","article-title":"Inter-fraction robustness of intensity-modulated proton therapy in the post-operative treatment of oropharyngeal and oral cavity squamous cell carcinomas","volume":"93","author":"Hague","year":"2020","journal-title":"Br. J. Radiol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"554","DOI":"10.1016\/j.canrad.2021.06.017","article-title":"Future technological developments in proton therapy\u2014A predicted technological breakthrough","volume":"25","author":"Vidal","year":"2021","journal-title":"Cancer\/Radioth\u00e9rapie"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/j.clon.2019.09.052","article-title":"TORPEdO\u2014A Phase III Trial of Intensity-modulated Proton Beam Therapy Versus Intensity-modulated Radiotherapy for Multi-toxicity Reduction in Oropharyngeal Cancer","volume":"32","author":"Price","year":"2020","journal-title":"Clin. Oncol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1007\/s13246-018-0707-y","article-title":"A prospective study of weekly intensity modulated radiation therapy plan adaptation for head and neck cancer: Improved target coverage and organ at risk sparing","volume":"42","author":"Aly","year":"2019","journal-title":"Australas. Phys. Eng. Sci. Med."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"439","DOI":"10.18535\/jmscr\/v8i11.75","article-title":"Adaptive Radiotherapy in Orbital Rhabdomyosarcoma: A Case Report","volume":"08","author":"Rathod","year":"2020","journal-title":"J. Med. Sci. Clin. Res."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"S803","DOI":"10.1016\/j.ijrobp.2012.07.2149","article-title":"Adaptive Proton Radiation Therapy for Base of Skull Tumors","volume":"84","author":"Shusharina","year":"2012","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"E15","DOI":"10.3171\/2016.9.FOCUS16298","article-title":"A quantitative analysis of craniopharyngioma cyst expansion during and after radiation therapy and surgical implications","volume":"41","author":"Lamiman","year":"2016","journal-title":"Neurosurg. Focus FOC"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1016\/j.clon.2018.01.012","article-title":"Proton Therapy for Craniopharyngioma\u2014An Early Report from a Single European Centre","volume":"30","author":"Ajithkumar","year":"2018","journal-title":"Clin. Oncol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"225003","DOI":"10.1088\/1361-6560\/ab4d8e","article-title":"End-to-end test of an online adaptive treatment procedure in MR-guided radiotherapy using a phantom with anthropomorphic structures","volume":"64","author":"Elter","year":"2019","journal-title":"Phys. Med. Biol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"909","DOI":"10.1002\/mp.13992","article-title":"Virtual 4DCT from 4DMRI for the management of respiratory motion in carbon ion therapy of abdominal tumors","volume":"47","author":"Meschini","year":"2020","journal-title":"Med. Phys."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1186\/s12968-014-0063-3","article-title":"MRXCAT: Realistic numerical phantoms for cardiovascular magnetic resonance","volume":"16","author":"Wissmann","year":"2014","journal-title":"J. Cardiovasc. Magn. Reson."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"444","DOI":"10.1007\/s00066-020-01604-0","article-title":"Magnetic resonance imaging for brain stereotactic radiotherapy","volume":"196","author":"Putz","year":"2020","journal-title":"Strahlenther. Und Onkol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1007\/s00066-020-01703-y","article-title":"Implementation of a dedicated 1.5 T MR scanner for radiotherapy treatment planning featuring a novel high-channel coil setup for brain imaging in treatment position","volume":"197","author":"Mengling","year":"2021","journal-title":"Strahlenther. Und Onkol."},{"key":"ref_49","first-page":"125","article-title":"3T MR-based treatment planning for radiotherapy of brain lesions","volume":"40","author":"Stanescu","year":"2006","journal-title":"Radiol. Oncol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"e547","DOI":"10.1016\/j.ijrobp.2018.07.1527","article-title":"Quantification of Geometric Distortion in Magnetic Resonance Imaging for Radiation Therapy Treatment Planning","volume":"102","author":"Slagowski","year":"2018","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1120","DOI":"10.1177\/1533034617735454","article-title":"MRI-Related Geometric Distortions in Stereotactic Radiotherapy Treatment Planning: Evaluation and Dosimetric Impact","volume":"16","author":"Pappas","year":"2017","journal-title":"Technol. Cancer Res. Treat."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1584","DOI":"10.1016\/j.ijrobp.2009.10.017","article-title":"Results of a Multi-Institutional Benchmark Test for Cranial CT\/MR Image Registration","volume":"77","author":"Ulin","year":"2010","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1002\/acm2.12090","article-title":"Optimization of a novel large field of view distortion phantom for MR-only treatment planning","volume":"18","author":"Price","year":"2017","journal-title":"J. Appl. Clin. Med. Phys."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1080\/0284186X.2019.1684558","article-title":"Towards a generalised development of synthetic CT images and assessment of their dosimetric accuracy","volume":"59","author":"Handrack","year":"2020","journal-title":"Acta Oncol."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"4634","DOI":"10.1118\/1.4958677","article-title":"Feasibility of MRI-only treatment planning for proton therapy in brain and prostate cancers: Dose calculation accuracy in substitute CT images","volume":"43","author":"Koivula","year":"2016","journal-title":"Med. Phys."},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Boye, D., Lomax, T., and Knopf, A. (2013). Mapping motion from 4D-MRI to 3D-CT for use in 4D dose calculations: A technical feasibility study. Med. Phys., 40.","DOI":"10.1118\/1.4801914"},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Dolde, K., Naumann, P., D\u00e1vid, C., Gnirs, R., Kachelrie\u00df, M., Lomax, A.J., Saito, N., Weber, D.C., Pfaffenberger, A., and Zhang, Y. (2018). 4D dose calculation for pencil beam scanning proton therapy of pancreatic cancer using repeated 4DMRI datasets. Phys. Med. Biol., 63.","DOI":"10.1088\/1361-6560\/aad43f"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"1429","DOI":"10.1080\/0284186X.2019.1630754","article-title":"Evaluation of proton and photon dose distributions recalculated on 2D and 3D Unet-generated pseudoCTs from T1-weighted MR head scans","volume":"58","author":"Neppl","year":"2019","journal-title":"Acta Oncol."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1016\/j.ijrobp.2019.06.2535","article-title":"Deep Convolution Neural Network (DCNN) Multiplane Approach to Synthetic CT Generation From MR images\u2014Application in Brain Proton Therapy","volume":"105","author":"Spadea","year":"2019","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s13014-020-01571-x","article-title":"MR-guided proton therapy: A review and a preview","volume":"15","author":"Hoffmann","year":"2020","journal-title":"Radiat. Oncol."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"11","DOI":"10.14338\/IJPT-20-00099.1","article-title":"Facilitating MR-Guided Adaptive Proton Therapy in Children Using Deep Learning-Based Synthetic CT","volume":"8","author":"Wang","year":"2021","journal-title":"Int. J. Part. Ther."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"6537","DOI":"10.1002\/mp.15150","article-title":"Deep learning based synthetic-CT generation in radiotherapy and PET: A review","volume":"48","author":"Spadea","year":"2021","journal-title":"Med. Phys."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"215010","DOI":"10.1088\/1361-6560\/ac27b5","article-title":"Can a ToF-PET photon attenuation reconstruction test stopping power estimations in proton therapy? A phantom study","volume":"66","author":"Conti","year":"2021","journal-title":"Phys. Med. Biol."}],"container-title":["Cancers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6694\/14\/11\/2616\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:18:32Z","timestamp":1760138312000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6694\/14\/11\/2616"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,5,25]]},"references-count":63,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2022,6]]}},"alternative-id":["cancers14112616"],"URL":"https:\/\/doi.org\/10.3390\/cancers14112616","relation":{},"ISSN":["2072-6694"],"issn-type":[{"value":"2072-6694","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,5,25]]}}}