scholarly journals The Performance of LiF:Mg-Ti for Proton Dosimetry within the Framework of the MoVe IT Project

2021 ◽  
Vol 11 (17) ◽  
pp. 8263
Author(s):  
Vittoria D’Avino ◽  
Francesco Tommasino ◽  
Stefano Lorentini ◽  
Giuseppe La Verde ◽  
Mariagabriella Pugliese
Keyword(s):  
Proton Beam ◽  
Proton Therapy ◽  
Nuclear Physics ◽  
Ion Beam ◽  
Thermoluminescent Dosimeters ◽  
Depth Dose ◽  
Planning Project ◽  
Depth Dose Curve ◽  
Ion Beam Treatment ◽  
Radiation Treatments

Proton therapy represents a technologically advanced method for delivery of radiation treatments to tumors. The determination of the biological effectiveness is one of the objectives of the MoVe IT (Modeling and Verification for Ion Beam Treatment Planning) project of the National Institute for Nuclear Physics (INFN) CSN5. The aim of the present work, which is part of the project, was to evaluate the performance of the thermoluminescent dosimeters (TLDs-100) for dose verification in the proton beam line. Four irradiation experiments were performed in the experimental room at the Trento Proton Therapy Center, where a 150 MeV monoenergetic proton beam is available. A total of 80 TLDs were used. The TLDs were arranged in one or two rows and accommodated in a specially designed water-equivalent phantom. In the experimental setup, the beam enters orthogonally to the dosimeters and is distributed along the proton beam profile, while the irradiation delivers doses of 0.8 Gy or 1.5 Gy in the Bragg peak. For each irradiation stage, the depth–dose curve was determined by the TLD readings. The results showed the good performance of the TLDs-100, proving their reliability for dose recordings in future radiobiological experiments planned within the MoVe IT context.

scholarly journals Radiosensitization Effect of Gold Nanoparticles in Proton Therapy

2021 ◽  
Vol 9 ◽  
Author(s):  
Charnay Cunningham ◽  
Maryna de Kock ◽  
Monique Engelbrecht ◽  
Xanthene Miles ◽  
Jacobus Slabbert ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Proton Beam ◽  
Proton Therapy ◽  
Metallic Nanoparticles ◽  
Combined Treatment ◽  
Experimental Studies ◽  
High Energy ◽  
Proton Beams ◽  
X Ray ◽  
Depth Dose

The number of proton therapy facilities and the clinical usage of high energy proton beams for cancer treatment has substantially increased over the last decade. This is mainly due to the superior dose distribution of proton beams resulting in a reduction of side effects and a lower integral dose compared to conventional X-ray radiotherapy. More recently, the usage of metallic nanoparticles as radiosensitizers to enhance radiotherapy is receiving growing attention. While this strategy was originally intended for X-ray radiotherapy, there is currently a small number of experimental studies indicating promising results for proton therapy. However, most of these studies used low proton energies, which are less applicable to clinical practice; and very small gold nanoparticles (AuNPs). Therefore, this proof of principle study evaluates the radiosensitization effect of larger AuNPs in combination with a 200 MeV proton beam. CHO-K1 cells were exposed to a concentration of 10 μg/ml of 50 nm AuNPs for 4 hours before irradiation with a clinical proton beam at NRF iThemba LABS. AuNP internalization was confirmed by inductively coupled mass spectrometry and transmission electron microscopy, showing a random distribution of AuNPs throughout the cytoplasm of the cells and even some close localization to the nuclear membrane. The combined exposure to AuNPs and protons resulted in an increase in cell killing, which was 27.1% at 2 Gy and 43.8% at 6 Gy, compared to proton irradiation alone, illustrating the radiosensitizing potential of AuNPs. Additionally, cells were irradiated at different positions along the proton depth-dose curve to investigate the LET-dependence of AuNP radiosensitization. An increase in cytogenetic damage was observed at all depths for the combined treatment compared to protons alone, but no incremental increase with LET could be determined. In conclusion, this study confirms the potential of 50 nm AuNPs to increase the therapeutic efficacy of proton therapy.

scholarly journals Verification of the use of GEANT4 and MCNPX Monte Carlo Codes for Calculations of the Depth-Dose Distributions in Water for the Proton Therapy of Eye Tumours

Nukleonika ◽  
2014 ◽  
Vol 59 (2) ◽  
pp. 61-66 ◽  
Author(s):  
Małgorzata Grządziel ◽  
Adam Konefał ◽  
Wiktor Zipper ◽  
Robert Pietrzak ◽  
Ewelina Bzymek
Keyword(s):  
Monte Carlo ◽  
Proton Beam ◽  
Proton Therapy ◽  
Mean Value ◽  
Energy Spectra ◽  
Primary Proton ◽  
Relative Depth ◽  
Dose Distributions ◽  
Depth Dose

Abstract Verification of calculations of the depth-dose distributions in water, using GEANT4 (version of 4.9.3) and MCNPX (version of 2.7.0) Monte Carlo codes, was performed for the scatterer-phantom system used in the dosimetry measurements in the proton therapy of eye tumours. The simulated primary proton beam had the energy spectra distributed according to the Gauss distribution with the cut at energy greater than that related to the maximum of the spectrum. The energy spectra of the primary protons were chosen to get the possibly best agreement between the measured relative depth-dose distributions along the central-axis of the proton beam in a water phantom and that derived from the Monte Carlo calculations separately for the both tested codes. The local depth-dose differences between results from the calculations and the measurements were mostly less than 5% (the mean value of 2.1% and 3.6% for the MCNPX and GEANT4 calculations). In the case of the MCNPX calculations, the best fit to the experimental data was obtained for the spectrum with maximum at 60.8 MeV (more probable energy), FWHM of the spectrum of 0.4 MeV and the energy cut at 60.85 MeV whereas in the GEANT4 calculations more probable energy was 60.5 MeV, FWHM of 0.5 MeV, the energy cut at 60.7 MeV. Thus, one can say that the results obtained by means of the both considered Monte Carlo codes are similar but they are not the same. Therefore the agreement between the calculations and the measurements has to be verified before each application of the MCNPX and GEANT4 codes for the determination of the depth-dose curves for the therapeutic protons.

scholarly journals Characterization of the proton pulsed beam at CMAM

2021 ◽  
Vol 253 ◽  
pp. 04027
Author(s):  
S. Viñals ◽  
D. Sánchez-Parcerisa ◽  
L.M. Fraile ◽  
S. España ◽  
G. García ◽  
...  
Keyword(s):  
Proton Beam ◽  
Proton Therapy ◽  
Material Science ◽  
Nuclear Physics ◽  
Medical Studies ◽  
Function Generator ◽  
Set Up ◽  
Therapy Studies ◽  
Homogeneous Irradiation

In this paper, the technicalities performed to obtain a pulsed beam at the CMAM facility will be explained. The pulsed beam has been characterized with an 8 MeV proton beam, using an existing equipment at CMAM: two pairs of electrostatic plates (RASTER) that deflect the beam, commonly used for homogeneous irradiation of large areas. A pulsed beam is used in many areas such as nuclear physics, material science and, in particular, for proton-therapy medical studies. Rectangular and pyramidal functions have been used to generate different pulses and characterize the response of the RASTER. The results point out that the pulses obtained are suitable for preclinical proton-therapy studies in the FLASH regime, which consists on fractionating the dose in time with short and intense pulses. The set-up for the characterization has been a function generator and a Si-PM outside the chamber.

scholarly journals Proton therapy for craniopharyngioma in adults: a protocol for systematic review and meta-analysis

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e046043
Author(s):  
Pengtao Li ◽  
Jialing Wang ◽  
Aximujiang Axier ◽  
Kai Zhou ◽  
Jingwei Yun ◽  
...  
Keyword(s):  
Proton Therapy ◽  
Ion Beam ◽  
Grey Literature ◽  
Intervention Group ◽  
Heavy Ion ◽  
Cochrane Library ◽  
Secondary Outcome ◽  
Significant Heterogeneity ◽  
Recurrence Rates ◽  
X Ray

IntroductionCraniopharyngioma is the most challenging to treat brain tumour with high recurrence rates, which can be effectively reduced by adjuvant radiotherapy. In recent years, proton therapy (PT), with its physical properties of heavy ion beam, that is, Prague peak phenomenon, has been more frequently used in patients with craniopharyngioma. Compared with conventional X-ray beam radiotherapy, PT can reduce the damage to normal tissues and enlarge the damage to tumours. Some studies have shown that PT has advantages in the treatment of craniopharyngioma in adults. However, the optimal management of craniopharyngioma remains controversial. The purpose of this study was to evaluate the efficacy and safety of PT for craniopharyngioma in adults.Methods and analysisWe will search six databases (MEDLINE, EMBASE, Web of Science, the Cochrane Library, Amed, Scopus), clinical research registration websites and grey literature, aiming to identify randomised controlled trials (RCTs) on PT for craniopharyngioma in adults between 1 January 1954 and 28 September 2021. In the RCTs, PT will be used as the intervention group, and conventional X-ray beam radiotherapy will be used as the comparator group. Tumour recurrence and survival will be the primary outcome, and treatment-related toxicity will be the secondary outcome. The study selection, data extraction, bias risk and quality evaluation will be operated by two to four researchers independently. We will use Review Manager V.5.2 (RevMan V.5.2) for data analysis. If there is significant heterogeneity, we will identify the source of heterogeneity by subgroup analysis.Ethics and disseminationOur study is based on existing RCTs and does not require ethical approval. The results of the study will be published in a peer-reviewed journal or at a related conference.PROSPERO registration numberCRD42020200909.

Hg1-xCdxTe doping by ion-beam treatment

1993 ◽  
Vol 8 (5) ◽  
pp. 634-637 ◽  
Author(s):  
V I Ivanov-Omskii ◽  
K E Mironov ◽  
K D Mynbaev
Keyword(s):  
Ion Beam ◽  
Ion Beam Treatment

Two-stream and filamentation instabilities for a light ion beam—plasma system

1987 ◽  
Vol 37 (3) ◽  
pp. 373-382 ◽  
Author(s):  
Toshio Okada ◽  
Winfried Schmidt
Keyword(s):  
Proton Beam ◽  
Size Effects ◽  
Ion Beam ◽  
Plasma Heating ◽  
Finite Size ◽  
Stability Conditions ◽  
Plasma System ◽  
Finite Size Effects ◽  
Stability Boundaries ◽  
Gas Discharges

Electrostatic two-stream and electromagnetic filamentation instabilities for a light ion beam penetrating a plasma are investigated. The dispersion relations of these instabilities including the effect of plasma heating by the ion beam are solved analytically and numerically. Stability conditions are derived for propagation through a plasma. Attention is paid to the finite size effects of beams with small diameters of the order 0·1 cm typical for pinched gas discharges. The results are illustrated by plotting stability boundaries for a 100 keV proton beam propagating through a plasma.

ALLOYING THE SURFACE OF STEEL 30KHGSN2A TO INCREASE ITS TRIBOLOGICAL CHARACTERISTICS

2020 ◽  
Vol 4 (2) ◽  
pp. 55-60
Author(s):  
L.I. KUKSENOVA ◽  
D.A. KOZLOV
Keyword(s):  
Wear Resistance ◽  
Steady State ◽  
Alloy Steel ◽  
Dry Friction ◽  
Irradiation Dose ◽  
Copper Ions ◽  
Ion Beam ◽  
Contact Deformation ◽  
Range Effect ◽  
Ion Beam Treatment

The results of evaluating the wear of samples of the model of the same name pair of friction from alloy steel 30KhGSN2A after ion beam treatment and dry friction under conditions of heavy contact are presented. It was shown that in the steady state friction, the wear resistance of steel as a result of implantation of copper ions at an irradiation dose of 1017 ion / cm2 and 5.1017 ion / cm2 increases by 2 and 1.5 times, respectively. The mechanism of the «long-range effect» in ion-doped structural materials under conditions of contact deformation is discussed.

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