scholarly journals Automatic feathering algorithm for VMAT craniospinal irradiation: A comprehensive comparison with other VMAT planning strategies

2020 ◽  
Author(s):  
Michele Maddalo ◽  
Giovanna Benecchi ◽  
Luisa Altabella ◽  
Caterina Ghetti ◽  
Nunziata D'Abbiero
Keyword(s):  
Craniospinal Irradiation ◽  
Comprehensive Comparison ◽  
Planning Strategies

Path planning strategies for laser line forming

2003 ◽  
Author(s):  
Edward Reutzel ◽  
Kevin Gombotz ◽  
Richard Martukanitz ◽  
Panagiotis Michaleris
Keyword(s):  
Path Planning ◽  
Laser Line ◽  
Planning Strategies

scholarly journals Scoliosis in Children Treated With Photon Craniospinal Irradiation for Medulloblastoma

2021 ◽  
Vol 109 (3) ◽  
pp. 712-717
Author(s):  
Arnold C. Paulino ◽  
Hilary S. Suzawa ◽  
ZoAnn E. Dreyer ◽  
Alexander N. Hanania ◽  
Murali Chintagumpala ◽  
...  
Keyword(s):  
Craniospinal Irradiation

scholarly journals A potential subsurface cavity in the continuous ejecta deposits of the Ziwei crater discovered by the Chang’E-3 mission

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Chunyu Ding ◽  
Zhiyong Xiao ◽  
Yan Su
Keyword(s):  
Lunar Regolith ◽  
Lava Tubes ◽  
Impact Ejecta ◽  
Comprehensive Comparison ◽  
Ground Penetrating ◽  
Shallow Crust ◽  
Low Permittivity ◽  
Mare Basalts ◽  
Subsurface Cavities ◽  
High Bulk

AbstractIn the radargram obtained by the high-frequency lunar penetrating radar onboard the Chang’E-3 mission, we notice a potential subsurface cavity that has a smaller permittivity compared to the surrounding materials. The two-way travel time between the top and bottom boundaries of the potential cavity is ~ 21 ns, and the entire zone is located within the continuous ejecta deposits of the Ziwei crater, which generally have similar physical properties to typical lunar regolith. We carried out numerical simulations for electromagnetic wave propagation to investigate the nature of this low-permittivity zone. Assuming different shapes for this zone, a comprehensive comparison between our model results and the observed radargram suggests that the roof of this zone is convex and slightly inclined to the south. Modeling subsurface materials with different relative permittivities suggests that the low-permittivity zone is most likely formed due to a subsurface cavity. The maximum vertical dimension of this potential cavity is ~ 3.1 m. While the continuous ejecta deposits of Ziwei crater are largely composed of pre-impact regolith, competent mare basalts were also excavated, which is evident by the abundant meter-scale boulders on the wall and rim of Ziwei crater. We infer that the subsurface cavity is supported by excavated large boulders, which were stacked during the energetic emplacement of the continuous ejecta deposits. However, the exact geometry of this cavity (e.g., the width) cannot be constrained using the single two-dimensional radar profile. This discovery indicates that large voids formed during the emplacement of impact ejecta should be abundant on the Moon, which contributes to the high bulk porosity of the lunar shallow crust, as discovered by the GRAIL mission. Our results further suggest that ground penetrating radar is capable of detecting and deciphering subsurface cavities such as lava tubes, which can be applied in future lunar and deep space explorations.

scholarly journals Improved dynamics of sharing research findings in the COVID-19 epidemic compared with the SARS and Ebola epidemics

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Javad Khanali ◽  
Mohammad-Reza Malekpour ◽  
Ali-Asghar Kolahi
Keyword(s):  
Numerical Data ◽  
Public Health Emergency ◽  
Value Of Time ◽  
Time Period ◽  
Pubmed Database ◽  
Before And After ◽  
Major Outbreak ◽  
Research Findings ◽  
Emergent Pathogen ◽  
Planning Strategies

Abstract Background When a new or re-emergent pathogen, such as SARS-CoV-2, causes a major outbreak, rapid access to pertinent research findings is crucial for planning strategies and decision making. We researched whether the speed of sharing research results in the COVID-19 epidemic was higher than the SARS and Ebola epidemics. We also researched whether there is any difference in the most frequent topics investigated before and after the COVID-19, SARS, and Ebola epidemics started. Methods We used PubMed database search tools to determine the time-period it took for the number of articles to rise after the epidemics started and the most frequent topics assigned to the articles. Results The main results were, first, the rise in the number of articles occurred 6 weeks after the COVID-19 epidemic started whereas, this rise occurred 4 months after the SARS and 7 months after the Ebola epidemics started. Second, etiology, statistics & numerical data, and epidemiology were the three most frequent topics investigated in the COVID-19 epidemic. However, etiology, microbiology, and genetics in the SARS epidemic, and statistics & numerical data, epidemiology, and prevention & control in the Ebola epidemic were more frequently studied compared with other topics. Third, some topics were studied more frequently after the epidemics started. Conclusions The speed of sharing results in the COVID-19 epidemic was much higher than the SARS and Ebola epidemics, and that there is a difference in the most frequent articles’ topics investigated in these three epidemics. Due to the value of time in controlling epidemics spread, the study highlights the necessity of defining more solutions for rapidly providing pertinent research findings in fighting against the next public health emergency.

scholarly journals MPC-08 Molecular risk stratification using genome-wide DNA methylation data of standard-risk medulloblastomas treated with 18-Gy craniospinal irradiation

2020 ◽  
Vol 2 (Supplement_3) ◽  
pp. ii12-ii12
Author(s):  
Tomoya Irikura ◽  
Kohei Fukuoka ◽  
Makiko Mori ◽  
Koichi Oshima ◽  
Yuki Arakawa ◽  
...  
Keyword(s):  
Risk Stratification ◽  
Disease Onset ◽  
Low Risk ◽  
Craniospinal Irradiation ◽  
Diagnostic Tools ◽  
Late Relapse ◽  
Mycn Amplification ◽  
Group 4 ◽  
Radiation Induced ◽  
Standard Risk

Abstract A novel risk stratification of medulloblastoma has been proposed based on retrospective data from patients undergoing standard treatment. However, it remains unclear whether the classification is applicable to patients receiving reduced-dose craniospinal irradiation (CSI). We performed molecular diagnosis and copy number analysis using methylation array on patients with standard-risk medulloblastoma treated with 18 Gy CSI at our institution. Nine tumor samples were available for analysis from seven patients who had a median age of 7.4 years at disease onset and a median observation period of 73 months. Three patients had recurrence, and another patient developed radiation-induced glioblastoma. From the three recurrent cases, one was molecularly diagnosed as SHH subtype with MYCN amplification; another case was a Group 4 tumor without favorable prognostic chromosomal aberrations, and the remaining patient experienced a very late relapse despite low-risk stratification. Of the recurrence-free cases, one was classified as WNT subtype, and another was a Group 4 tumor with chromosome 7 gain, and loss of chromosomes 8 and 11, both of which were associated with good prognosis. Methylation analysis also unveiled the fact that the recurrent tumor diagnosed as relapsing medulloblastoma by conventional diagnostic tools was in fact a radiation-induced glioblastoma. Our data suggested that the new risk stratification may be useful for cases treated with CSI reduced to 18 Gy. However, due to the presence of the late-relapsed case stratified to low risk, further investigations with a larger cohort should be required to confirm the data.

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