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Collection efficiency of a monitor parallel plate ionization chamber for pencil beam scanning proton therapy

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Nuclear Science and Techniques 2020年第2期31卷 1-10页

作者： Rong-Cheng Han Yong-Jiang Li yue-hu pu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai APACTRON Particle Equipment Co.Ltd Shanghai 201800China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China

The collection efficiency of monitor parallel plate ionization chambers is the main uncertainty in the beam control of pencil beam scanning *** calculation methods for collection efficiency in photon or passive scattering proton systems have not considered the characteristics of non-uniform charge density in pencil beam scanning *** this study,Boag’s theory was applied to a proton pencil beam scanning *** transverse distribution of charge density in the ionization chamber was considered to be a Gaussian function and an analytical solution was derived to calculate collection efficiency in the beam spot *** calculation method is called the integral method and it was used to investigate the effects of beam parameters on collection *** was determined that collection efficiency is positively correlated with applied voltage,beam size,and beam energy,but negatively correlated with beam current ***,it was confirmed that collection efficiency is improved when the air filling the monitor parallel plate ionization chamber is replaced with nitrogen.

关键词： Collection efficiency Monitor ionization chamber Pencil beam scanning Proton therapy

Physical design and multi-particle simulations of a compact IH-DTL with KONUS beam dynamics for proton therapy

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Nuclear Science and Techniques 2020年第7期31卷 12-24页

作者： Jian Qiao Xiu-Cui Xie De-Ming Li yue-hu pu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of the Chinese Academy of Sciences Beijing 100049China Shanghai APACTRON Particle Equipment Company Ltd. Shanghai 210800China

A compact room-temperature inter-digital H-mode(IH)drift tube linac(DTL)with Kombinierte Null Grad Struktur beam dynamics is proposed in this *** proposed IH-DTL,which operates at 325 MHz,accelerates 18 mA proton particles from 3.0 to 7.0 MeV as part of a proton synchrotron-based therapy *** is composed of two main sections,namely a bunching section(-30°)and accelerating section(0°).There is no transverse focusing element inside the cavity,which increases the acceleration gradient and reduces the cavity length and power *** our physical designs,LORASR code is utilized for beam dynamics design and multi-particle *** synchronous particle energy,injection phase,and acceleration voltage of each gap are optimized carefully to increase transmission efficiency while minimizing beam emittance growth and beam *** total length of the cavity is 0.82 m and the acceleration gradient reaches 4.88 MV/m,resulting in a transmission efficiency of 100%and beam emittance growth less than10%.The details of the specific work undertaken in this study are presented in this paper.

关键词： bunch beam particle

Shortening the delivery time of proton therapy by real-time compensation method with raster scanning

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Nuclear Science and Techniques 2022年第6期33卷 62-74页

作者： Xiang-Shang Sun Yong-Jiang Li Jun-Ya Liu Wen-Tao Liao Chao Wu yue-hu pu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai APACTRON Particle Equipment Co. LtdShanghai 201800China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Medical Equipment Innovation Research Center West China HospitalSichuan UniversityChengdu 610041China

Among the various scanning techniques, spot and raster scanning are the most frequently adopted. Raster scanning turns off the beam only when each isoenergy slice irradiation is completed. This feature intrinsically solves the leakage dose and frequent beam-switching problems encountered during spot scanning. However, to shorten the delivery time of raster scanning, a sophisticated dose control strategy is required to guarantee dose *** this study, a real-time compensation method with raster scanning for synchrotron systems was designed. It is characterized by a small spot-spacing planning strategy and real-time subtraction of the transient number of particles delivered between two planning-spot positions from the planned number of particles of the subsequent raster *** efficacy of the compensation method was demonstrated by performing accurate raster scanning simulations with an in-house simulation code and accurate final dose evaluations with a commercial treatment planning *** the similar dose evaluation criteria under a practical high scanning speed, compared with the spot scanning method, the total delivery time of the compensated raster scanning method was significantly shortened by 53.3% in the case of irradiating a cubical target and by 28.8% in a pelvic case. Therefore, it can be concluded that real-time compensated raster scanning with a fast scanning configuration can significantly shorten the delivery time compared to that of spot scanning. It is important to reduce the pressure on patients caused by prolonged immobilization and to improve patient throughput capacity at particle therapy centers.

关键词： Proton therapy Raster scanning Delivery time Scanning simulation

RF design and study of a 325 MHz 7 Me V APF IH-DTL for an injector of a proton medical accelerator

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Nuclear Science and Techniques 2019年第9期30卷 34-46页

作者： Xuan Li yue-hu pu Fan Yang Xiu-Cui Xie Qiang Gu Jian Qiao Ming-hua Zhao Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201210 China Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049 China Shanghai APACTRON Particle Equipment Co. Ltd Shanghai 201800 China

A compact interdigital H-mode drift-tube linac (IH-DTL) with the alternating-phase-focusing (APF) method, working at 325 MHz was designed for an injector of a proton medical accelerator. When fed in with a proper RF (radio frequency) power, the DTL cavity could establish the corresponding electromagnetic field to accelerate the ‘‘proton bunches’’ from an input energy of 3 MeV to an output energy of 7 MeV successfully, without any additional radial focusing elements. The gap-voltage distribution which was obtained from the CST■ Microwave Studio software simulations of the axial electric field was compared with that from the beam dynamics, and the errors met the requirements within ± 5%. In this paper, the RF design procedure and key results of the APF IH-DTL, which include the main RF characteristics of the cavity, frequency sensitivities of the tuners, and coupling factor of the RF power input coupler are presented.

关键词： Proton therapy Proton medical accelerator Injector Drift-tube linac (DTL) Interdigital H-mode (IH) Alternating-phase-focusing (APF)

Reformatted method for two-dimensional detector arrays measurement data in proton pencil beam scanning

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Nuclear Science and Techniques 2021年第6期32卷 83-93页

作者： Meng-Ya Guo Xiu-Fang Li Jie Wang Qi Liu Xiu-Zhen Deng Man-Zhou Zhang Li-Ren Shen yue-hu pu Zhi-Ling Chen Shanghai Institute of Applied Physics Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Shanghai APACTRON Particle Equipment Co.Ltd Shanghai 201800China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China

The spatial resolution of a commercial two-dimensional(2D)ionization chamber(IC)array is limited by the size of the individual detector and the center-to-center distance between *** dose distributions with areas of steep dose gradients,inter-detector dose values are derived by the interpolation of nearby detector readings in the conventional mathematical interpolation of 2D IC array *** may introduce significant errors,particularly in proton spot scanning *** this study,by combining logfile-based reconstructed dose values and detector measurements with the Laplacian pyramid image blending method,a novel method is proposed to obtain a reformatted dose distribution that provides an improved estimation of the delivered dose distribution with high spatial ***,the similarity between the measured original data and the downsampled logfilebased reconstructed dose is regarded as the confidence of the reformatted dose ***,we quantify the performance benefits of this new approach by directly comparing the reformatted dose distributions with 2D IC array detector mathematically interpolated measurements and original low-resolution *** result shows that this new method is better than the mathematical interpolation and achieves gamma pass rates similar to those of the original low-resolution *** reformatted dose distributions generally yield a confidence exceeding 95%.

关键词： 2D ion chamber array detectors Laplacian pyramid image blending High-resolution reformatted methods Pencil beam scanning Proton therapy

Correction to: Gpu-accelerated scanning path optimization in particle cancer therapy

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Nuclear Science and Techniques 2019年第5期30卷 147-147页

作者： Chao Wu yue-hu pu Xiao Zhang Shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

Correction to:NUCL SCI TECH (2019) 30:56https://***/10.1007/s41365-019-0582-6In the original article the authors affiliations are incorrectly *** authors correct affiliations are provided in this correction article.

关键词： Correction to Gpu-accelerated scanning path optimization in particle cancer therapy

Correction to:Shortening the delivery time of proton therapy by real-time compensation method with raster scanning

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Nuclear Science and Techniques 2022年第8期33卷 33-33页

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License,which permits use,sharing,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s)and the source,provide a link to the Creative Commons licence,and indicate if changes were *** images or other third party material in this article are included in the article’s Creative Commons licence,unless indicated otherwise in a credit line to the *** material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use,you will need to obtain permission directly from the copyright *** view a copy of this licence,visit http://***/licenses/by/4.0/.

关键词： otherwise method compensation

Repetitive transcranial magnetic stimulation in Alzheimer’s disease:effects on neural and synaptic rehabilitation

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Neural Regeneration Research 2025年第2期20卷 326-342页

作者： Yi Ji Chaoyi Yang Xuerui Pang Yibing Yan yue Wu Zhi Geng Wenjie hu Panpan hu Xingqi Wu Kai Wang Department of Neurology The First Affiliated Hospital of Anhui Medical UniversityHefeiAnhui ProvinceChina Anhui Province Key Laboratory of Cognition and Neuropsychiatric Disorders HefeiAnhui ProvinceChina Collaborative Innovation Center of Neuropsychiatric Disorders and Mental Health HefeiAnhui ProvinceChina Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefeiAnhui ProvinceChina Department of Psychology and Sleep Medicine The Second Affiliated Hospital of Anhui Medical UniversityHefeiAnhui ProvinceChina

Alzheimer’s disease is a neurodegenerative disease resulting from deficits in synaptic transmission and *** Alzheimer’s disease brain tends to be hyperexcitable and hypersynchronized,thereby causing neurodegeneration and ultimately disrupting the operational abilities in daily life,leaving patients *** transcranial magnetic stimulation is a cost-effective,neuro-modulatory technique used for multiple neurological *** the past two decades,it has been widely used to predict cognitive decline;identify pathophysiological markers;promote neuroplasticity;and assess brain excitability,plasticity,and *** has also been applied to patients with dementia,because it can yield facilitatory effects on cognition and promote brain recovery after a neurological ***,its therapeutic effectiveness at the molecular and synaptic levels has not been elucidated because of a limited number of *** study aimed to characterize the neurobiological changes following repetitive transcranial magnetic stimulation treatment,evaluate its effects on synaptic plasticity,and identify the associated *** review essentially focuses on changes in the pathology,amyloidogenesis,and clearance pathways,given that amyloid deposition is a major hypothesis in the pathogenesis of Alzheimer’s *** mechanisms associated with repetitive transcranial magnetic stimulation procedures and different pathways mediating gene transcription,which are closely related to the neural regeneration process,are also ***,we discuss the outcomes of animal studies in which neuroplasticity is modulated and assessed at the structural and functional levels by using repetitive transcranial magnetic stimulation,with the aim to highlight future directions for better clinical translations.

关键词： Alzheimer’s disease amyloid deposition apoptotic mechanisms biomarker neural regeneration neurodegeneration repetitive transcranial magnetic stimulation synaptic plasticity

Return to work in young and middle-aged colorectal cancer survivors:Factors influencing self-efficacy,fear,resilience,and financial toxicity

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World Journal of Gastroenterology 2025年第1期31卷 79-92页

作者： Dan hu yue Li hua Zhang Lian-Lian Wang Wen-Wen Liu Xin Yang Ming-Zhao Xiao Hao-Ling Zhang Juan Li Department of Nursing The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Nursing National Clinical Research Center for Child Health and DisordersMinistry of Education Key Laboratory of Child Development and DisordersChildren’s Hospital of Chongqing Medical UniversityChongqing 400014China Department of Gastrointestinal Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Biomedical Science Advanced Medical and Dental InstituteUniversity Sains MalaysiaPenang 13200Malaysia Academic Affairs Office The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China

BACKGROUND Return to work(RTW)serves as an indication for young and middle-aged colorectal cancer(CRC)survivors to resume their normal social ***,these survivors encounter significant challenges during their RTW ***,scientific research is necessary to explore the barriers and facilitating factors of returning to work for young and middle-aged CRC *** To examine the current RTW status among young and middle-aged CRC survivors and to analyze the impact of RTW self-efficacy(RTW-SE),fear of progression(FoP),eHealth literacy(eHL),family resilience(FR),and financial toxicity(FT)on their RTW *** A cross-sectional investigation was adopted in this *** September 2022 to February 2023,a total of 209 participants were recruited through a convenience sampling method from the gastrointestinal surgery department of a class A tertiary hospital in *** investigation utilized a general information questionnaire alongside scales assessing RTW-SE,FoP,eHL,FR,and *** analyze the factors that influence RTW outcomes among young and middle-aged CRC survivors,Cox regression modeling and Kaplan-Meier survival analysis were *** A total of 43.54%of the participants successfully returned to work,with an average RTW time of 100 *** regression univariate analysis revealed that RTW-SE,FoP,eHL,FR,and FT were significantly different between the non-RTW and RTW groups(P<0.05).Furthermore,Cox regression multivariate analysis identified per capita family monthly income,job type,RTW-SE,and FR as independent influencing factors for RTW(P<0.05).CONCLUSION The RTW rate requires further *** levels of RTW-SE and FR were found to significantly increase RTW among young and middle-aged CRC *** professionals should focus on modifiable factors,such as RTW-SE and FR,to design targeted RTW support programs,thereby facilitating their timely reintegration into mainstream society.

关键词： Return to work Colorectal neoplasms Return-to-work self-efficacy Fear of progression Family resilience Financial toxicity