keyword
MENU ▼
Read by QxMD icon Read
search

Proton Beam

keyword
https://www.readbyqxmd.com/read/29351653/calibration-of-gafchromic-ebt3-film-for-dosimetry-of-scanning-proton-pencil-beam-pbs
#1
D Krzempek, G Mianowska, N Bassler, L Stolarczyk, R Kopec, B Sas-Korczynska, P Olko
Gafchromic EBT3 films are applied in proton radiotherapy for 2D dose mapping because they demonstrate spatial resolution well below 1 mm. However, the film response must be corrected in order to reach the accuracy of dose measurements required for the clinical use. The in-house developed AnalyseGafchromic software allows to analyze and correct the measured response using triple channel dose calibration, statistical scan-to-scan fluctuations as well as experimentally determined dose and LET dependence. Finally, the optimized protocol for evaluation of response of Gafchromic EBT3 films was applied to determine 30 × 40 cm2 dose profiles of the scanning therapy unit at the Cyclotron Centre Bronowice, CCB in Krakow, Poland...
January 17, 2018: Radiation Protection Dosimetry
https://www.readbyqxmd.com/read/29351651/radiotherapy-proton-beam-profilometry-with-sccvd-diamond-detector-in-single-particle-mode
#2
Marzena Rydygier, Marcin Jastrzab, Dawid Krzempek, Tomasz Nowak, Leszek Grzanka, Piotr Bednarczyk, Liliana Stolarczyk
Proton radiotherapy requires precise knowledge of the volumetric dose distribution. In proton beam delivery systems, based on narrow pencil beams, a contribution from small doses in low-intensity regions, consisting mainly of scattered protons, may have not negligible influence on total dose delivered to patient. Insufficient information about dose profile can cause underestimation of dose and potential delivery of inflated dose during hadrontherapy treatment. Presented work aims to verify applicability of diamond detectors, produced by Chemical Vapor Deposition method, for therapeutic proton beam profilometry at large fields...
January 17, 2018: Radiation Protection Dosimetry
https://www.readbyqxmd.com/read/29350196/estimation-and-correction-of-produced-light-from-prompt-gamma-photons-on-luminescence-imaging-of-water-for-proton-therapy-dosimetry
#3
Takuya Yabe, Masataka Komori, Toshiyuki Toshito, Mitsutaka Yamaguchi, Naoki Kawachi, Seiichi Yamamoto
Although the luminescence images of water during proton-beam irradiation using a cooled charge-coupled device (CCD) camera showed almost the same ranges of proton beams as those measured by an ionization chamber, the depth profiles showed lower Bragg peak intensities than those measured by an ionization chamber. In addition, a broad optical baseline signal was observed in depths that exceed the depth of Bragg peak. We hypothesize that this broad baseline signal originates from interaction of proton-induced prompt gamma photons with water...
January 19, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29349358/95gtc-and-96gtc-as-alternatives-to-medical-radioisotope-99mtc
#4
Takehito Hayakawa, Yuichi Hatsukawa, Toru Tanimori
We studied 95gTc and 96gTc as alternatives to the medical radioisotope 99mTc. 96gTc (95gTc) can be produced by (p, n) reactions on an enriched 96Mo (95Mo) target with a proton beam provided by a compact accelerator such as a medical cyclotron that generate radioisotopes for positron emission tomography (PET). The γ-rays are measured with an electron-tracking Compton camera (ETCC). We calculated the relative intensities of the γ-rays from 95gTc and 96gTc. The calculated γ-ray intensity of a 96gTc (95gTc) nucleus is as high as 63% (70%) of that of a 99mTc nucleus...
January 2018: Heliyon
https://www.readbyqxmd.com/read/29348437/first-experimental-proof-of-proton-boron-capture-therapy-pbct-to-enhance-protontherapy-effectiveness
#5
G A P Cirrone, L Manti, D Margarone, G Petringa, L Giuffrida, A Minopoli, A Picciotto, G Russo, F Cammarata, P Pisciotta, F M Perozziello, F Romano, V Marchese, G Milluzzo, V Scuderi, G Cuttone, G Korn
Protontherapy is hadrontherapy's fastest-growing modality and a pillar in the battle against cancer. Hadrontherapy's superiority lies in its inverted depth-dose profile, hence tumour-confined irradiation. Protons, however, lack distinct radiobiological advantages over photons or electrons. Higher LET (Linear Energy Transfer) 12C-ions can overcome cancer radioresistance: DNA lesion complexity increases with LET, resulting in efficient cell killing, i.e. higher Relative Biological Effectiveness (RBE). However, economic and radiobiological issues hamper 12C-ion clinical amenability...
January 18, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29348402/self-generated-surface-magnetic-fields-inhibit-laser-driven-sheath-acceleration-of-high-energy-protons
#6
M Nakatsutsumi, Y Sentoku, A Korzhimanov, S N Chen, S Buffechoux, A Kon, B Atherton, P Audebert, M Geissel, L Hurd, M Kimmel, P Rambo, M Schollmeier, J Schwarz, M Starodubtsev, L Gremillet, R Kodama, J Fuchs
High-intensity lasers interacting with solid foils produce copious numbers of relativistic electrons, which in turn create strong sheath electric fields around the target. The proton beams accelerated in such fields have remarkable properties, enabling ultrafast radiography of plasma phenomena or isochoric heating of dense materials. In view of longer-term multidisciplinary purposes (e.g., spallation neutron sources or cancer therapy), the current challenge is to achieve proton energies well in excess of 100 MeV, which is commonly thought to be possible by raising the on-target laser intensity...
January 18, 2018: Nature Communications
https://www.readbyqxmd.com/read/29344499/unilateral-multifocal-choroidal-melanoma
#7
Debarshi Mustafi, Bertil Damato, Jesse L Berry
We report a case of multifocal choroidal melanoma in the same eye, separated in presentation by 20 years. A 57-year-old Caucasian male initially presented with a choroidal melanoma of the right eye that was treated with transpupillary thermotherapy. Due to recurrence, the patient underwent proton beam therapy with subsequent tumor regression. A second small choroidal lesion was noted in the right eye during his surveillance examinations that was closely monitored and demonstrated stable dimensions and features suggestive of a choroidal nevus...
December 2017: Ocular Oncology and Pathology
https://www.readbyqxmd.com/read/29342982/detection-of-zro%C3%A2-nanoparticles-in-lung-tissue-sections-by-time-of-flight-secondary-ion-mass-spectrometry-and-ion-beam-microscopy
#8
Lothar Veith, Julia Böttner, Antje Vennemann, Daniel Breitenstein, Carsten Engelhard, Jan Meijer, Irina Estrela-Lopis, Martin Wiemann, Birgit Hagenhoff
The increasing use of nanoparticles (NP) in commercial products requires elaborated techniques to detect NP in the tissue of exposed organisms. However, due to the low amount of material, the detection and exact localization of NP within tissue sections is demanding. In this respect, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Ion Beam Microscopy (IBM) are promising techniques, because they both offer sub-micron lateral resolutions along with high sensitivities. Here, we compare the performance of the non-material-consumptive IBM and material-consumptive ToF-SIMS for the detection of ZrO₂ NP (primary size 9-10 nm) in rat lung tissue...
January 15, 2018: Nanomaterials
https://www.readbyqxmd.com/read/29342941/development-of-optical-fiber-based-measurement-system-for-the-verification-of-entrance-dose-map-in-pencil-beam-scanning-proton-beam
#9
Jaeman Son, Se Byeong Lee, Youngkyung Lim, Sung Yong Park, Kwanho Cho, Myonggeun Yoon, Dongho Shin
This study describes the development of a beam monitoring system for the verification of entrance dose map in pencil beam scanning (PBS) proton therapy based on fiber optic radiation sensors (FORS) and the validation of this system through a feasibility study. The beam monitoring system consisted of 128 optical fibers optically coupled to photo-multiplier tubes. The performance of the beam monitoring system based on FORS was verified by comparing 2D dose maps of square-shaped fields of various sizes, which were obtained using conventional dosimeters such as MatriXX and EBT3 film, with those measured using FORS...
January 15, 2018: Sensors
https://www.readbyqxmd.com/read/29342035/systematic-review-of-hearing-preservation-after-radiotherapy-for-vestibular-schwannoma
#10
Adam R Coughlin, Tyler J Willman, Samuel P Gubbels
OBJECTIVE: To determine the long-term hearing preservation rate for spontaneous vestibular schwannoma treated by primary radiotherapy. DATA SOURCES: The MEDLINE/PubMed, Web of Science, Cochrane Reviews, and EMBASE databases were searched using a comprehensive Boolean keyword search developed in conjunction with a scientific librarian. English language papers published from 2000 to 2016 were evaluated. STUDY SELECTION: Inclusion criteria: full articles, pretreatment and posttreatment audiograms or audiogram based scoring system, vestibular schwannoma only tumor type, reported time to follow-up, published after 1999, use of either Gamma Knife or linear accelerator radiotherapy...
January 16, 2018: Otology & Neurotology
https://www.readbyqxmd.com/read/29341629/mirror-charge-radii-and-the-neutron-equation-of-state
#11
B Alex Brown
The differences in the charge radii of mirror nuclei are shown to be proportional to the derivative of the neutron equation of state and the symmetry energy at nuclear matter saturation density. This derivative is important for constraining the neutron equation of state for use in astrophysics. The charge radii of several neutron-rich nuclei are already measured to the accuracy of about 0.005 fm. Experiments at isotope-separator and radioactive-beam facilities are needed to measure the charge radii of the corresponding proton-rich mirror nuclei to a similar accuracy...
September 22, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/29324441/a-study-of-lateral-fall-off-penumbra-optimisation-for-pencil-beam-scanning-pbs-proton-therapy
#12
C Winterhalter, A Lomax, D Oxley, D C Weber, S Safai
The lateral fall-off is crucial for sparing organs at risk in proton therapy. It is therefore of high importance to minimize the penumbra for pencil beam scanning (PBS). Three optimisation approaches are investigated: edge-collimated uniformly weighted spots (collimation), pencil beam optimisation of uncollimated pencil beams (edge-enhancement) and the optimisation of edge collimated pencil beams (collimated edge-enhancement). To deliver energies below 70 MeV, these strategies are evaluated in combination with the following pre-absorber methods: field specific fixed thickness pre-absorption (fixed), range specific, fixed thickness pre-absorption (automatic) and range specific, variable thickness pre-absorption (variable)...
January 11, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29319640/orbital-extranodal-marginal-zone-lymphoma-following-radiotherapy-a-report-of-2-cases
#13
Zujaja Tauqeer, Frederick A Jakobiec, Suzanne K Freitag, Michael K Yoon, Natalie Wolkow
PURPOSE: To present 2 patients in whom orbital radiation preceded the development of periorbital extranodal marginal zone lymphoma by more than a decade and to investigate the likelihood of this representing irradiation-induced malignancy. METHODS: Retrospective chart review and histopathologic study with immunohistochemistry of 2 cases. RESULTS: The first patient was a 58-year-old woman who developed an orbital mass within the vicinity of the lateral rectus muscle 17 years after external beam proton radiation therapy for an inferotemporal choroidal melanoma...
January 9, 2018: Ophthalmic Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/29316969/proton-and-helium-ion-radiotherapy-for-meningioma-tumors-a-monte-carlo-based-treatment-planning-comparison
#14
Thomas Tessonnier, Andrea Mairani, Wenjing Chen, Paola Sala, Francesco Cerutti, Alfredo Ferrari, Thomas Haberer, Jürgen Debus, Katia Parodi
BACKGROUND: Due to their favorable physical and biological properties, helium ion beams are increasingly considered a promising alternative to proton beams for radiation therapy. Hence, this work aims at comparing in-silico the treatment of brain and ocular meningiomas with protons and helium ions, using for the first time a dedicated Monte Carlo (MC) based treatment planning engine (MCTP) thoroughly validated both in terms of physical and biological models. METHODS: Starting from clinical treatment plans of four patients undergoing proton therapy with a fixed relative biological effectiveness (RBE) of 1...
January 9, 2018: Radiation Oncology
https://www.readbyqxmd.com/read/29311417/theoretical-and-experimental-comparison-of-proton-and-helium-beam-radiography-using-silicon-pixel-detectors
#15
Tim Gehrke, Carlo Amato, Simon Berke, Maria Martisikova
Ion-beam radiography (iRAD) could potentially improve the quality control of ion-beam therapy. The main advantage of iRAD is the possibility to directly measure the integrated stopping power. Until now there is no clinical implementation of iRAD. Topics of ongoing research include developing dedicated detection systems to achieve the desired spatial resolution (SR) and investigating different ion types as imaging radiation. This work focuses on the theoretical and experimental comparison of proton (pRAD) and helium-beam radiography (αRAD)...
January 9, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29310903/proton-beam-therapy-for-skull-base-chordomas-in-106-patients-a-dose-adaptive-radiation-protocol
#16
Vivien Fung, Valentin Calugaru, Stéphanie Bolle, Hamid Mammar, Claire Alapetite, Philippe Maingon, Ludovic De Marzi, Sébastien Froelich, Jean-Louis Habrand, Rémi Dendale, Georges Noël, Loïc Feuvret
BACKGROUND AND PURPOSE: To evaluate clinical results and safety of a dose adaptive protocol based on tumor volume coverage and critical structure constraints, for the treatment of skull base chordomas. MATERIAL AND METHODS: Between May 2006 and October 2012, 106 patients with skull base chordoma were treated by combined photon and proton irradiation. Prescribed dose levels were 68.4, 70.2, 72 and 73.8 Gy(RBE) in once daily fractionation of 1.8 Gy(RBE). Dose level and dosimetric constraints to organs at risk depended on postoperative residual Gross Tumor Volume (GTV) coverage...
January 6, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29306585/radiation-safety-for-pregnant-workers-at-a-proton-facility
#17
Genevieve Maquilan, Marc R Bussière, Joseph McCormack, Tara Medich, Andrzej Niemierko, Helen A Shih
PURPOSE: To quantify radiation exposure of radiation therapy technologists (RTTs) in a proton treatment facility in comparison with a photon therapy facility, to inform and establish these specialized occupational safety guidelines. METHODS AND MATERIALS: Two groups of RTTs, consisting of 12 full-time passive scattering proton RTTs and 18 full-time conventional photon RTTs, wore an additional dosimetry badge at the waist for a period of 14 weeks. The 2 groups of RTTs were given identical instructions on the proper use of the badges...
November 16, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/29303547/hydrogel-nanosensors-for-colorimetric-detection-and-dosimetry-in-proton-beam-radiotherapy
#18
Sahil Inamdar, Karthik Pushpavanam, Jarrod Lentz, Martin Bues, Aman Anand, Kaushal Rege
Proton beam therapy (PBT) is a state-of-the-art radiotherapy treatment approach that uses focused proton beams for tumor ablation.[1] A key advantage of this approach over conventional photon radiotherapy (XRT) is the unique dose deposition characteristics of protons, resulting in superior healthy tissue sparing. This results in fewer unwanted side effects and improved outcomes for patients. Current available dosimeters are intrinsic, complex and expensive; hence cannot be used to determine the dose delivered to the tumor routinely...
January 5, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29303019/first-report-of-proton-beam-therapy-for-breast-angiosarcoma-from-the-prospective-pcg-registry
#19
Cameron S Thorpe, Joshua R Niska, Daniel C Brunnhoelzl, Lisa A McGee, Christy M Kesslering, William F Hartsell, Carlos E Vargas
No abstract text is available yet for this article.
January 5, 2018: Acta Oncologica
https://www.readbyqxmd.com/read/29300183/improved-proton-ct-imaging-using-a-bismuth-germanium-oxide-scintillator
#20
Sodai Tanaka, Teiji Nishio, Masato Tsuneda, Keiichiro Matsushita, Shigeto Kabuki, Mitsuru Uesaka
Range uncertainty is among the most formidable challenges associated with the treatment planning of proton therapy. Proton imaging, which includes proton radiography (pRG) and proton computed tomography (pCT), is a useful verification tool. We have developed a pCT detection system that uses a thick bismuth germanium oxide (BGO) scintillator and a CCD camera. The current method is based on a previous detection system that used a plastic scintillator, and implements improved image processing techniques. In the new system, the scintillation light intensity is integrated along the proton beam path by the BGO scintillator, and acquired as a two-dimensional distribution with the CCD camera...
January 4, 2018: Physics in Medicine and Biology
keyword
keyword
38412
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"