arXiv: Medical Physics最新文献

{"title":"arXiv : Future Trends in Linacs","authors":"A. Degiovanni","doi":"10.23730/CYRSP-2017-001.151","DOIUrl":"https://doi.org/10.23730/CYRSP-2017-001.151","url":null,"abstract":"High-frequency hadron-therapy linacs have been studied for the last 20 years and are now being built for dedicated proton-therapy centres. The main reason for using high-frequency linacs, in spite of the small apertures and low-duty cycle, is the fact that, for such applications, beam currents of the order of a few nA and energies of about 200 MeV are sufficient. One of the main advantages of linacs, pulsing at 200–400Hz, is that the output energy can be continuously varied, pulse-by-pulse, and a moving tumour target can be covered about ten times in 2–3 minutes by deposing the dose in many thousands of ‘spots’. Starting from the first proposal and the on-going projects related to linacs for medical applications, a discussion of the trend of this field is presented focussing, in particular, on the main challenges for the future, such as the reduction of the footprint of compact ‘single-room’ proton machines and the power efficiency of dual proton and carbon-ion ‘multi-room’ facilities.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77151077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiobiological Characterization of Clinical Proton and Carbon-Ion Beams","authors":"P. Scalliet, J. Gueulette","doi":"10.23730/CYRSP-2017-001.1","DOIUrl":"https://doi.org/10.23730/CYRSP-2017-001.1","url":null,"abstract":"Electromagnetic radiation (photons) or particle beam (protons or heavy ions) have similar biological effects, i.e. damage to human cell DNA that eventually leads to cell death if not correctly repaired. The biological effects at the level of organs or organisms are explained by a progressive depletion of constitutive cells; below a given threshold, cell division is no longer sufficient to compensate for cell loss, up to a point where the entire organism (or organ) breaks down. The quantitative aspects of the biological effects are modulated by the microscopic distribution of energy deposits along the beam or particle tracks. In particular, the ionization density, i.e. the amount of energy deposited by unit path length (measured in keV/μm), has an influence on the biological effectiveness, i.e. the amount of damage per energy unit deposited (measured in gray or Gy, equivalent to 1 joule/kg). The ionization density is usually represented by the Linear Energy Transfer or LET, also expressed in keV/μm. Photon beams (X-rays, g-rays) are low-LET radiation, with a sparsely ionising characteristic. Particle beams have a higher LET, with a more dense distribution of energy deposits along the particle tracks. Protons are intermediary, with a LET larger than the photon one, but still belong to the ‘radiobiological’ group of low LET. The higher the ionization density, the higher the biological effectiveness per unit of dose. When comparing various radiation qualities, it appears that the ionization density is relatively homogeneous along photon tracks, whereas it strongly varies along particular tracks (protons, heavy ions). In the first instance, the biological effectiveness is proportional to the TEL, itself dependant on the particle beam energy. So, when the LET of a particle beam is increased, its biological effectiveness increases in proportion. Secondly, a low-energy beam (f.i. 4 MeV a rays) has a higher LET than a high-energy beam (f.i. 200 MeV a rays). As particle beams continuously loose their energy through their successive interactions with the irradiated medium, it ensues that the LET slowly increases along the beam path, down to a point where all energy has been imparted and the beam stops. Therefore, the biological effectiveness is not homogeneous along the beam path (like with low-LET radiation), with a strong reinforcement at the end of the particle tracks (in the Bragg peak). The modelization of the clinical effects of particle beams is therefore very challenging, as a variable biological weighting function needs to be incorporated in the planning process to account for the increase in biological effectiveness with the progressive loss of beam energy.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74054119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Future (of) Synchrotrons for Particle Therapy","authors":"J. Flanz","doi":"10.23730/CYRSP-2017-001.293","DOIUrl":"https://doi.org/10.23730/CYRSP-2017-001.293","url":null,"abstract":"The field of particle therapy is quickly growing and yet it's more widespread adoption is limited by size, cost and adaptation to the more conformal treatment techniques. In order to realize the benefits of this modality the equipment used to generate and deliver the beam is evolving. The accelerator is one of the key components and its future is dictated by the ability to accommodate the clinical requirements. This lecture is intended to provide an introduction to these requirements and identify how synchrotrons are designed to deliver the desired beams as well as what limitations exist and expectations for the future of synchrotrons.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88433994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prior Variances and Depth Un-Biased Estimators in EEG Focal Source Imaging","authors":"Alexandra Koulouri, V. Rimpilainen, M. Brookes, J. Kaipio","doi":"10.1007/978-981-10-5122-7_9","DOIUrl":"https://doi.org/10.1007/978-981-10-5122-7_9","url":null,"abstract":"","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89751419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bayesian Modelling of Skull Conductivity Uncertainties in EEG Source Imaging","authors":"V. Rimpilainen, Alexandra Koulouri, F. Lucka, J. Kaipio, C. Wolters","doi":"10.1007/978-981-10-5122-7_223","DOIUrl":"https://doi.org/10.1007/978-981-10-5122-7_223","url":null,"abstract":"","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78586422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Derivative Model for Tissue Radiation Response","authors":"J. Weberszpil, O. Sotolongo-Costa","doi":"10.24297/JAP.V13I4.5980","DOIUrl":"https://doi.org/10.24297/JAP.V13I4.5980","url":null,"abstract":"By means of a recently-proposed metric or structural derivative, called scale-q-derivative approach, we formulate differential equation that models the cell death by a radiation exposure in tumor treatments. The considered independent variable here is the absorbed radiation dose D instead of usual time. The survival factor, Fs, for radiation damaged cell obtained here is in agreement with the literature on the maximum entropy principle, as it was recently shown and also exhibits an excellent agreement with the experimental data. Moreover, the well-known linear and quadratic models are obtained. With this approach, we give a step forward and suggest other expressions for survival factors that are dependent on the complex tumor structure.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91346639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microcontroller based automated life savior -- Medisûr","authors":"S. Chatterjee, Pramod George Jose, Priyanka Basak, Ambreen Athar, B. Aravind, Romit S. Beed, R. Biswas","doi":"10.1201/9781315375021","DOIUrl":"https://doi.org/10.1201/9781315375021","url":null,"abstract":"With the course of progress in the field of medicine, most of the patients lives can be saved. The only thing required is the proper attention at the proper time. Our wearable solution tries to solve this issue by taking the patients vitals and transmitting them to the server for live monitoring using the mobile app along with the patients current location. In case of an emergency, that is if any vitals show any abnormalities, an SMS is sent to the caregiver of the patient with the patients location so that he can reach there on time.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88848252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of specific nuclear reaction channels by deconvolution in the energy space of the total nuclear cross-section of protons - applications to proton therapy and technical problems (transmutations)","authors":"W. Ulmer","doi":"10.14319/JPT.21.2","DOIUrl":"https://doi.org/10.14319/JPT.21.2","url":null,"abstract":"The total nuclear cross-section Qtot(E) resulting from the interaction of protons with nuclei is decomposed in 3 different contributions: 1. elastic scatter at the complete nucleus, which adopts a part of the proton kinetic energy; 2. inelastic scatter at a nucleus, which changes its quantum numbers by vibrations, rotations, transition to highly excited states; 3. proper nuclear reactions with change of the mass and/or charge number. Then different particles leave the hit nucleus (neutrons, protons, etc.), which is now referred to as 'heavy recoil' nucleus. The scatter parts of Qtot(E) according to points 1 and 2 can be removed by a deconvolution acting at Qtot(E) in the energy space. The typical nuclear reaction channels are mainly characterized by resonances of a reduced cross-section function Qred(E). The procedure is applied to cross-sections of therapeutic protons and also to Cs55137 as an example with technical relevance (transmutations with the goal to drastically reduce its half-time).","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86084496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative analysis of jugular venous pulse obtained by using a general-purpose ultrasound scanner","authors":"F. Sisini","doi":"10.13140/RG.2.1.2574.6328","DOIUrl":"https://doi.org/10.13140/RG.2.1.2574.6328","url":null,"abstract":"This is a self-published methodological note distributed under the Creative Commons Attribution License (this http URL), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The note contains an original reasoning of mine and the goal to share thoughts and methodologies, not results. Therefore before using the contents of these notes, everyone is invited to verify the accuracy of the assumptions and conclusions.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88898832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical description of the blood flow from the internal jugular vein to the right atrium of the heart: new ultrasound application perspectives","authors":"F. Sisini","doi":"10.13140/RG.2.1.2399.5289","DOIUrl":"https://doi.org/10.13140/RG.2.1.2399.5289","url":null,"abstract":"This is a self-published methodological note distributed under the Creative Commons Attribution License (this http URL), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The note contains an original reasoning of mine and the goal to share thoughts and methodologies, not results. Therefore before using the contents of these notes, everyone is invited to verify the accuracy of the assumptions and conclusions.","PeriodicalId":8462,"journal":{"name":"arXiv: Medical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83695880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}