scholarly journals Clinical Implementation of a 6D Treatment Chair for Fixed Ion Beam Lines

2021 ◽  
Vol 11 ◽  
Author(s):  
Jiayao Sun ◽  
Lin Kong ◽  
Zhi Chen ◽  
Dan You ◽  
Jingfang Mao ◽  
...  
Keyword(s):  
Clinical Study ◽  
Imaging System ◽  
Ion Beam ◽  
Clinical Treatment ◽  
Patient Treatment ◽  
Positional Error ◽  
Clinical Implementation ◽  
Beam Position ◽  
Technical Data ◽  
Patient Movement

PurposeTo verify the practicality and safety of a treatment chair with six degrees of freedom (6DTC) through demonstrating the efficacy of the workflow in clinical settings and analyzing the obtained technical data, including intra-fraction patient movement during the use of the 6DTC.Materials and MethodsA clinical study was designed and conducted to test the clinical treatment workflow and the safety of the 6DTC. Based on the demonstrated dosimetric advantages, fifteen patients with head and neck tumors were selected and treated with the 6DTC. The positional error at the first beam position (PE-B1) and the second beam position (PE-B2) were analyzed and compared with the results from daily quality assurance (QA) procedures of the 6DTC and imaging system performed each day before clinical treatment. The intra-fraction patient movement was derived from the total patient alignment positional error and the QA data based on a Gaussian distribution formulism.ResultsThe QA results showed sub-millimeter mechanical accuracy of the 6DTC over the course of the clinical study. For 150 patient treatment fractions, the mean deviations between PE-B1 and PE-B2 were 0.13mm (SD 0.88mm), 0.25mm (SD 1.17mm), -0.57mm (SD 0.85mm), 0.02° (SD 0.35°), 0.00° (SD 0.37°), and -0.02° (SD 0.37°) in the x, y, z (translational), and u, v, w (rotational) directions, respectively. The calculated intra-fraction patient movement was -0.08mm (SD 0.56mm), 0.71mm (SD 1.12mm), -0.52mm (SD 0.84mm), 0.10° (SD 0.32°), 0.09° (SD 0.36°), and -0.04° (SD 0.36°) in the x, y, z, u, v, w directions, respectively.ConclusionsThe performance stability of the 6DTC was satisfactory. The position accuracy and intra-fraction patient movement in an upright posture with the 6DTC were verified and found adequate for clinical implementation.

An Study of Influence of Imperfections on the Delamination of Diamond-Like Carbon Films

2002 ◽  
Vol 719 ◽  
Author(s):  
Myoung-Woon Moon ◽  
Kyang-Ryel Lee ◽  
Jin-Won Chung ◽  
Kyu Hwan Oh
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Imaging System ◽  
Ion Beam ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Glass Substrates ◽  
Atomic Force ◽  
Initiation And Propagation

AbstractThe role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.

scholarly journals Quantitative Assessment of 3D Dose Rate for Proton Pencil Beam Scanning FLASH Radiotherapy and Its Application for Lung Hypofractionation Treatment Planning

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3549
Author(s):  
Minglei Kang ◽  
Shouyi Wei ◽  
J. Isabelle Choi ◽  
Charles B. Simone ◽  
Haibo Lin
Keyword(s):  
Dose Rate ◽  
Treatment Planning ◽  
Organs At Risk ◽  
Patient Treatment ◽  
Average Dose ◽  
Clinical Implementation ◽  
Flash Intensity ◽  
Dose Threshold ◽  
Rate Calculation ◽  
The Impact

To quantitatively assess target and organs-at-risk (OAR) dose rate based on three proposed proton PBS dose rate metrics and study FLASH intensity-modulated proton therapy (IMPT) treatment planning using transmission beams. An in-house FLASH planning platform was developed to optimize transmission (shoot-through) plans for nine consecutive lung cancer patients previously planned with proton SBRT. Dose and dose rate calculation codes were developed to quantify three types of dose rate calculation methods (dose-averaged dose rate (DADR), average dose rate (ADR), and dose-threshold dose rate (DTDR)) based on both phantom and patient treatment plans. Two different minimum MU/spot settings were used to optimize two different dose regimes, 34-Gy in one fraction and 45-Gy in three fractions. The OAR sparing and target coverage can be optimized with good uniformity (hotspot < 110% of prescription dose). ADR, accounting for the spot dwelling and scanning time, gives the lowest dose rate; DTDR, not considering this time but a dose-threshold, gives an intermediate dose rate, whereas DADR gives the highest dose rate without considering any time or dose-threshold. All three dose rates attenuate along the beam direction, and the highest dose rate regions often occur on the field edge for ADR and DTDR, whereas DADR has a better dose rate uniformity. The differences in dose rate metrics have led a large variation for OARs dose rate assessment, posing challenges to FLASH clinical implementation. This is the first attempt to study the impact of the dose rate models, and more investigations and evidence for the details of proton PBS FLASH parameters are needed to explore the correlation between FLASH efficacy and the dose rate metrics.

scholarly journals Magnetic Imaging of Superconducting Tapes to Determine Current Flow

2000 ◽  
Vol 659 ◽  
Author(s):  
G.W. Brown ◽  
M.E. Hawley ◽  
S.R. Foltyn ◽  
F.M. Mueller
Keyword(s):  
Magnetic Field ◽  
Current Flow ◽  
Imaging System ◽  
Ion Beam ◽  
Hard Disk Drives ◽  
Liquid Nitrogen Temperature ◽  
Transport Current ◽  
Superconducting Tapes ◽  
Magnetic Imaging ◽  
Density Maps

ABSTRACTWe have developed a magnetic imaging system that uses magnetoresistive read heads from computer hard disk drives to map the transport-current-induced magnetic field at the surface of superconducting tapes at liquid nitrogen temperature. Transport current pathways are determined from the 2-dimensional magnetic field maps using established inversion schemes. We examined the current flow in pulsed-laser-deposited YBa2Cu3O7-σ films patterned on single crystal SrTiO3 substrates and on a textured yttria-stabilized-zirconia layer deposited on an Inconel ribbon by ion beam assisted deposition. The transport current densities in all cases were consistent with the Critical State Model. For the Inconel-based sample, the transport current density maps have allowed us to observe defects and determine the region that limits the current carrying capacity of the structure.

scholarly journals Scanning transmission imaging in the helium ion microscope using a microchannel plate with a delay line detector

2020 ◽  
Vol 11 ◽  
pp. 1854-1864
Author(s):  
Eduardo Serralta ◽  
Nico Klingner ◽  
Olivier De Castro ◽  
Michael Mousley ◽  
Santhana Eswara ◽  
...  
Keyword(s):  
Delay Line ◽  
Ion Beam ◽  
Microchannel Plate ◽  
Wide Energy Range ◽  
High Angle ◽  
Data Set ◽  
Beam Position ◽  
Angle Scattering ◽  
Helium Ion ◽  
Scanning Transmission

A detection system based on a microchannel plate with a delay line readout structure has been developed to perform scanning transmission ion microscopy (STIM) in the helium ion microscope (HIM). This system is an improvement over other existing approaches since it combines the information of the scanning beam position on the sample with the position (scattering angle) and time of the transmission events. Various imaging modes, such as bright field and dark field or the direct image of the transmitted signal, can be created by post-processing the collected STIM data. Furthermore, the detector has high spatial and temporal resolution, is sensitive to both ions and neutral particles over a wide energy range, and shows robustness against ion beam-induced damage. A special in-vacuum movable support gives the possibility of moving the detector vertically, placing the detector closer to the sample for the detection of high-angle scattering events, or moving it down to increase the angular resolution and distance for time-of-flight measurements. With this new system, we show composition-dependent contrast for amorphous materials and the contrast difference between small-angle and high-angle scattering signals. We also detect channeling-related contrast on polycrystalline silicon, thallium chloride nanocrystals, and single-crystalline silicon by comparing the signal transmitted at different directions for the same data set.

Spatio-temporal measurement of beam properties in the PLS diagnostic beamline

1998 ◽  
Vol 5 (3) ◽  
pp. 642-644 ◽  
Author(s):  
J. Y. Huang ◽  
I. S. Ko
Keyword(s):  
Visible Light ◽  
Imaging System ◽  
Ccd Camera ◽  
Photon Beam ◽  
Transverse Beam ◽  
Beam Position ◽  
X Ray ◽  
X Ray Imaging ◽  
Visible Light Imaging ◽  
Temporal Measurement

A diagnostic beamline is being constructed in the PLS storage ring for measurement of electron- and photon-beam properties. It consists of two 1:1 imaging systems: a visible-light imaging system and a soft X-ray imaging system. In the visible-light imaging system, the transverse beam size and beam position are measured with various detectors: a CCD camera, two photodiode arrays and a photon-beam position monitor. Longitudinal bunch structure is also investigated with a fast photodiode detector and a picosecond streak camera. On the other hand, the soft X-ray imaging system is under construction to measure beam sizes with negligible diffraction-limited error. The X-ray image optics consist of a flat cooled mirror and two spherical focusing mirrors.

scholarly journals Clinical Study of Surgical Combination Chemotherapy in the Treatment of Borderline Ovarian Tumors

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
Chen Ming
Keyword(s):  
Clinical Study ◽  
Surgical Treatment ◽  
Combination Chemotherapy ◽  
Clinical Manifestations ◽  
Research Process ◽  
Clinical Treatment ◽  
Ovarian Tumors ◽  
Borderline Ovarian Tumors

Borderline ovarian tumors belong to a kind of epithelial ovarian tumors, nature between benign and malignant, the incidence of ovarian tumors accounted for 4.0% to 14.0%, clinical manifestations and malignant have a greater similarity,will be transferred, and can recurrence[1]. For the disease,most of the clinical treatment will be given, in recent years,after the completion of surgical treatment, our hospital also on such patients with chemotherapy[2]. In this study, 32 patients were divided into two groups, one group received surgery,chemotherapy, a group of patients undergoing surgery alone,the research process and the results reported in the study of the results of the combination of surgery and chemotherapy in the treatment of borderline ovarian tumors as follows.

Amorphous and Microcrystalline SiC as New Synthetic Wide Gap Semiconductors

1992 ◽  
Vol 242 ◽  
Author(s):  
Y. Hamakawa ◽  
H. Okamoto
Keyword(s):  
Energy Gap ◽  
Ion Beam ◽  
Technological Evolution ◽  
Microcrystalline Silicon ◽  
Technical Data ◽  
Preparation Conditions ◽  
Current State ◽  
Valency Electron ◽  
Impurity Doping ◽  
P Type

ABSTRACTA review is given on recent progress in amorphous and microcrystalline silicon-carbide (a-SiC, nc-SiC) semiconductors and their technological applications to optoelectronic functional devices. Firstly, some significant properties in this alloy as a new synthetic material are pointed out with recent advances of thin film technologies, such as plasma CVD, ECR-CVD and ion-beam CVD etc. There exists an energy gap controllability from 1.7eV to 3.6 eV with retaining the valency electron control from n-type through i- to p-type semiconductors. While its conductivity can also be controlled more than ten order of magnitudes, e.g., from 10-9to 102 Scm-1 by controlling the impurity doping and preparation conditions.Secondly, a series of technical data on the electronic and optoelectronic properties of a-Si, C1−x C1−x and μ-SiC are demonstrated from recent achievements. In the final part of the paper, current state of the art in the field of optoelectronic applications from live technologies on amorphous silicon solar cells. a-SiC visible light LED and EL devices are reviewed. A technological evolution from “microelectronics” to “macroelectronlcs” will be discussed.

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