Experimental study on monitoring system of clinical beam purity in multiple-ion beam operation for heavy-ion radiotherapy

2020 ◽  
Vol 91 (2) ◽  
pp. 023309
Author(s):  
K. Mizushima ◽  
Y. Iwata ◽  
M. Muramatsu ◽  
S. H. Lee ◽  
T. Shirai
Keyword(s):  
Experimental Study ◽  
Monitoring System ◽  
Ion Beam ◽  
Heavy Ion ◽  
Heavy Ion Radiotherapy

scholarly journals Analysis of the Dose Drop at the Edge of the Target Area in Heavy Ion Radiotherapy

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Xiaoyun Ma ◽  
Mengling Zhang ◽  
Wanbin Meng ◽  
Xiaoli Lu ◽  
Ziheng Wang ◽  
...  
Keyword(s):  
Data Analysis ◽  
Ion Beam ◽  
Heavy Ion ◽  
Beam Irradiation ◽  
Posterior Edge ◽  
Target Region ◽  
Decay Data ◽  
Back Edge ◽  
Heavy Ion Beam ◽  
Heavy Ion Radiotherapy

Background. The dose distribution of heavy ions at the edge of the target region will have a steep decay during radiotherapy, which can better protect the surrounding organs at risk. Objective. To analyze the dose decay gradient at the back edge of the target region during heavy ion radiotherapy. Methods. Treatment planning system (TPS) was employed to analyze the dose decay at the edge of the beam under different incident modes and multiple dose segmentation conditions during fixed beam irradiation. The dose decay data of each plan was collected based on the position where the rear edge of the beam began to fall rapidly. Uniform scanning mode was selected in heavy ion TPS. Dose decay curves under different beam setup modes were drawn and compared. Results. The dose decay data analysis showed that in the case of single beam irradiation, the posterior edge of the beam was 5 mm away, and the posterior dose could drop to about 20%. While irradiation in opposite direction, the posterior edge of the beam was 5 mm away, and the dose could drop to about 50%. In orthogonal irradiation of two beams, the posterior edge of the beam could drop to about 30-38% in a distance of 5 mm. Through the data analysis in the TPS, the sharpness of the dose at the back edge of the heavy ion beam is better than that at the lateral edge, but the generated X-ray contamination cannot be ignored. Conclusions. The effect of uneven CT value on the dose decay of heavy ion beam should also be considered in clinical treatment.

Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

1989 ◽  
Vol 47 ◽  
pp. 652-653
Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher
Keyword(s):  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
Mechanical Twinning ◽  
In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

HEAVY ION RADIOTHERAPY

1989 ◽  
Vol 50 (C1) ◽  
pp. C1-629-C1-641
Author(s):  
Y. JONGEN
Keyword(s):  
Heavy Ion ◽  
Heavy Ion Radiotherapy

Ballooning structure in density fluctuations observed with the 2 MeV heavy ion beam probe on the TEXT-U tokamak

1995 ◽  
Author(s):  
A. Fujisawa ◽  
A. Ouroua ◽  
J.W. Heard ◽  
T.P. Crowley ◽  
P.M. Schoch ◽  
...  
Keyword(s):  
Ion Beam ◽  
Heavy Ion ◽  
Density Fluctuations ◽  
Heavy Ion Beam ◽  
Heavy Ion Beam Probe

scholarly journals Direct observation of potential profiles with a 200 keV heavy ion beam probe on the Compact Helical System

1997 ◽  
Vol 4 (5) ◽  
pp. 1357-1361 ◽  
Author(s):  
A. Fujisawa ◽  
H. Iguchi ◽  
S. Lee ◽  
T. P. Crowley ◽  
Y. Hamada ◽  
...  
Keyword(s):  
Direct Observation ◽  
Ion Beam ◽  
Heavy Ion ◽  
Heavy Ion Beam ◽  
Heavy Ion Beam Probe

A Heavy-ion Beam Monitor Based on 3D NAND Flash Memories

2021 ◽  
pp. 1-1
Author(s):  
S. Gerardin ◽  
M. Bagatin ◽  
A. Paccagnella ◽  
S. Beltrami ◽  
A. Costantino ◽  
...  
Keyword(s):  
Ion Beam ◽  
Heavy Ion ◽  
Nand Flash ◽  
Flash Memories ◽  
Beam Monitor ◽  
Heavy Ion Beam

scholarly journals Comparison of short-range order in irradiated dysprosium titanates

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Roman Sherrod ◽  
Eric C. O’Quinn ◽  
Igor M. Gussev ◽  
Cale Overstreet ◽  
Joerg Neuefeind ◽  
...  
Keyword(s):  
Long Range ◽  
Short Range ◽  
Structural Model ◽  
Ion Irradiation ◽  
Function Analysis ◽  
Ion Beam ◽  
Structural Response ◽  
Heavy Ion ◽  
Range Order ◽  
Radiation Resistant

AbstractThe structural response of Dy2TiO5 oxide under swift heavy ion irradiation (2.2 GeV Au ions) was studied over a range of structural length scales utilizing neutron total scattering experiments. Refinement of diffraction data confirms that the long-range orthorhombic structure is susceptible to ion beam-induced amorphization with limited crystalline fraction remaining after irradiation to 8 × 1012 ions/cm2. In contrast, the local atomic arrangement, examined through pair distribution function analysis, shows only subtle changes after irradiation and is still described best by the original orthorhombic structural model. A comparison to Dy2Ti2O7 pyrochlore oxide under the same irradiation conditions reveals a different behavior: while the dysprosium titanate pyrochlore is more radiation resistant over the long-range with smaller degree of amorphization as compared to Dy2TiO5, the former involves more local atomic rearrangements, best described by a pyrochlore-to-weberite-type transformation. These results highlight the importance of short-range and medium-range order analysis for a comprehensive description of radiation behavior.

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.

Sign in / Sign up

Export Citation Format

Share Document