Estimation of monitor unit through analytical method for dynamic IMRT using control points as an effective parameter

2021 ◽  
pp. 1-8
Author(s):  
M. Athiyaman ◽  
A. Hemalatha ◽  
Arun Chougule ◽  
Mary Joan ◽  
HS Kumar
Keyword(s):  
Analytical Method ◽  
Control Point ◽  
Intensity Modulated Radiation Therapy ◽  
Field Size ◽  
Analytical Relationship ◽  
Dynamic Mode ◽  
Control Points ◽  
Significant Difference ◽  
Step And Shoot ◽  
Number Of Segments

Abstract Introduction: The control points (CP) play a significant role in the delivery of segmented based Intensity-Modulated Radiation Therapy (IMRT) delivery, particularly in dynamic mode. The number of segments is determined by control points and these segments will transfer from one to the other either during beam ON called dynamic delivery or during beam OFF called static delivery or step and shoot. This study was aimed at indirect estimation of the total monitor units (MU) to be delivered per field by exploiting the control points and also to find the MUs at any nth segment. Materials and methods: This study was performed in the Eclipse treatment planning software version 13.8.0. The details of control points, metre set weight per segment, leaf positions for each segment, field size, etc. were taken into consideration. Results: TPS calculated MU value and analytically estimated MU value were compared and the percentage of difference was estimated. The overall mean percentage of deviation was 1·03% between the TPS calculated method and the analytical method. The paired sample t-test was performed and, p-value <0·05, no significant difference was found. The analytical relationship determined to estimate the total number of MU delivered for any nth control point was also evaluated. Conclusion: The control points are a potential parameter in the conventional IMRT delivery. Through this study, we have addressed the indirect method to estimate the monitor units delivered per segment.

scholarly journals PRODUCT ACCURACY EFFECT OF OBLIQUE AND VERTICAL NON-METRIC DIGITAL CAMERA UTILIZATION IN UAV-PHOTOGRAMMETRY TO DETERMINE FAULT PLANE

2016 ◽  
Vol III-6 ◽  
pp. 41-48 ◽  
Author(s):  
C. Amrullah ◽  
D. Suwardhi ◽  
I. Meilano
Keyword(s):  
Fault Plane ◽  
Control Point ◽  
Digital Camera ◽  
Aerial Photographs ◽  
Ground Control ◽  
Control Points ◽  
Point Configuration ◽  
Ground Control Points ◽  
Significant Difference ◽  
Precision And Accuracy

This study aims to see the effect of non-metric oblique and vertical camera combination along with the configuration of the ground control points to improve the precision and accuracy in UAV-Photogrammetry project. The field observation method is used for data acquisition with aerial photographs and ground control points. All data are processed by digital photogrammetric process with some scenarios in camera combination and ground control point configuration. The model indicates that the value of precision and accuracy increases with the combination of oblique and vertical camera at all control point configuration. The best products of the UAV-Photogrammetry model are produced in the form of Digital Elevation Model (DEM) compared to the LiDAR DEM. Furthermore, DEM from UAV-Photogrammetry and LiDAR are used to define the fault plane by using cross-section on the model and interpretation to determine the point at the extreme height of terrain changes. The result of the defined fault planes indicate that two models do not show any significant difference.

scholarly journals PRODUCT ACCURACY EFFECT OF OBLIQUE AND VERTICAL NON-METRIC DIGITAL CAMERA UTILIZATION IN UAV-PHOTOGRAMMETRY TO DETERMINE FAULT PLANE

2016 ◽  
Vol III-6 ◽  
pp. 41-48 ◽  
Author(s):  
C. Amrullah ◽  
D. Suwardhi ◽  
I. Meilano
Keyword(s):  
Fault Plane ◽  
Control Point ◽  
Digital Camera ◽  
Aerial Photographs ◽  
Ground Control ◽  
Control Points ◽  
Point Configuration ◽  
Ground Control Points ◽  
Significant Difference ◽  
Precision And Accuracy

This study aims to see the effect of non-metric oblique and vertical camera combination along with the configuration of the ground control points to improve the precision and accuracy in UAV-Photogrammetry project. The field observation method is used for data acquisition with aerial photographs and ground control points. All data are processed by digital photogrammetric process with some scenarios in camera combination and ground control point configuration. The model indicates that the value of precision and accuracy increases with the combination of oblique and vertical camera at all control point configuration. The best products of the UAV-Photogrammetry model are produced in the form of Digital Elevation Model (DEM) compared to the LiDAR DEM. Furthermore, DEM from UAV-Photogrammetry and LiDAR are used to define the fault plane by using cross-section on the model and interpretation to determine the point at the extreme height of terrain changes. The result of the defined fault planes indicate that two models do not show any significant difference.

scholarly journals Mutual inductance instability of the tip vortices behind a wind turbine

2014 ◽  
Vol 755 ◽  
pp. 705-731 ◽  
Author(s):  
Sasan Sarmast ◽  
Reza Dadfar ◽  
Robert F. Mikkelsen ◽  
Philipp Schlatter ◽  
Stefan Ivanell ◽  
...  
Keyword(s):  
Growth Rate ◽  
Wind Turbine ◽  
Numerical Study ◽  
Operating Conditions ◽  
Analytical Relationship ◽  
Dynamic Mode ◽  
Spatial Structures ◽  
Tip Vortices ◽  
Positive Growth ◽  
The Stability

AbstractTwo modal decomposition techniques are employed to analyse the stability of wind turbine wakes. A numerical study on a single wind turbine wake is carried out focusing on the instability onset of the trailing tip vortices shed from the turbine blades. The numerical model is based on large-eddy simulations (LES) of the Navier–Stokes equations using the actuator line (ACL) method to simulate the wake behind the Tjæreborg wind turbine. The wake is perturbed by low-amplitude excitation sources located in the neighbourhood of the tip spirals. The amplification of the waves travelling along the spiral triggers instabilities, leading to breakdown of the wake. Based on the grid configurations and the type of excitations, two basic flow cases, symmetric and asymmetric, are identified. In the symmetric setup, we impose a 120° symmetry condition in the dynamics of the flow and in the asymmetric setup we calculate the full 360° wake. Different cases are subsequently analysed using dynamic mode decomposition (DMD) and proper orthogonal decomposition (POD). The results reveal that the main instability mechanism is dispersive and that the modal growth in the symmetric setup arises only for some specific frequencies and spatial structures, e.g. two dominant groups of modes with positive growth (spatial structures) are identified, while breaking the symmetry reveals that almost all the modes have positive growth rate. In both setups, the most unstable modes have a non-dimensional spatial growth rate close to $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\pi /2$ and they are characterized by an out-of-phase displacement of successive helix turns leading to local vortex pairing. The present results indicate that the asymmetric case is crucial to study, as the stability characteristics of the flow change significantly compared to the symmetric configurations. Based on the constant non-dimensional growth rate of disturbances, we derive a new analytical relationship between the length of the wake up to the turbulent breakdown and the operating conditions of a wind turbine.

scholarly journals Evaluation of The Effectiveness and Side Effects of Radiotherapy in Patients With Primary Nervous System Lymphoma. A Single Center Experience

2020 ◽  
Vol 7 ◽  
Author(s):  
Timur Koca ◽  
Aylin Fidan Korcum ◽  
Yasemin Şengün ◽  
Melek Gamze Aksu ◽  
Mine Genç
Keyword(s):  
Central Nervous System ◽  
Overall Survival ◽  
Nervous System ◽  
Side Effects ◽  
Disease Free Survival ◽  
Central Nervous System Lymphoma ◽  
Field Size ◽  
High Dose ◽  
Free Survival ◽  
Significant Difference

Aim: In this study, we aimed to evaluate the overall and progression-free survival, the radiotherapy process and the early and late adverse effects in patients who underwent radiotherapy (RT) for primary nervous system lymphoma in our clinic.Method: Between January 2010 and September 2019, 16 patients who received radiotherapy due to primary central nervous system lymphoma in our clinic were examined according to their statistically significant differences in terms of survival and side effects.Results: The median disease-free survival of the patients was 6 months, and the median overall survival was 12.5 months. 18.75% of the patients could not receive chemotherapy but only radiotherapy. Radiotherapy doses were range from 2600 to 5000 cGy. When patients were evaluated in terms of radiotherapy dose, field size and chemotherapy, no statistically significant difference in overall survival was detected. Cognitive disorders were observed as the most common late side effects while the most common acute side effects in patients were headaches.Conclusion: In the treatment of primary central nervous system lymphoma, changes in radiotherapy portals and radiotherapy doses can be predicted in patients who received high-dose methotrexate chemotherapy or not. Furthermore, it has been considered that more comprehensive studies are needed to increase the success of treatment and provide standardization in treatment, especially in patients with elderly and comorbid diseases.

scholarly journals Analysis of the Effect of Different Combinations of Observation Satellites on the Resolving Accuracy of GNSS Observation Data

2020 ◽  
Vol 206 ◽  
pp. 03025
Author(s):  
Junze Wang ◽  
Maohua Yao ◽  
Wenting Zhou ◽  
Xiangping Chen
Keyword(s):  
Measurement Accuracy ◽  
Control Point ◽  
Satellite System ◽  
Base Stations ◽  
Observation Data ◽  
Control Points ◽  
Level Control ◽  
Satellite Systems ◽  
Beidou Navigation Satellite System ◽  
Stable Measurement

In this paper, 24 C-level control points under different terrain conditions were selected to be the testing points. The binary-satellite system (GPS+GLONASS) and the triple-satellite system with BeiDou Navigation Satellite System (BDS) (BDS+GPS+GLONASS) were adopted for static measurement; and the observation data from BeiDou Ground-based Augumentation System (GBAS) base stations in Guangxi were collected for solution. By comparing the residuals of GPS tri-dimensional baseline vectors and the internal accord accuracy of each control point under the binary and triple-satellite systems, the effect of data collected by different satellite systems under different terrain conditions on measurement accuracy was studied. According to the results, (1) the triple-satellite system with BDS showed more stable measurement accuracy; (2) in plane, the two systems were of equivalent measurement accuracy in mountainous and flat areas; in elevation, the triple-satellite system showed higher and more stable measurement accuracy.

scholarly journals MULTIRESOLUTION CONTROL OF CURVES AND SURFACES WITH A SELF-SIMILAR MODEL

Fractals ◽  
2010 ◽  
Vol 18 (03) ◽  
pp. 271-286 ◽  
Author(s):  
HOUSSAM HNAIDI ◽  
ERIC GUÉRIN ◽  
SAMIR AKKOUCHE
Keyword(s):  
Wavelet Transform ◽  
Control Point ◽  
Iterated Function Systems ◽  
Control Points ◽  
Similar Model ◽  
Surface Theory ◽  
Curves And Surfaces ◽  
Iterated Function ◽  
Resolution Level ◽  
Self Similar

This paper presents two self-similar models that allow the control of curves and surfaces. The first model is based on IFS (Iterated Function Systems) theory and the second on subdivision curve and surface theory. Both of these methods employ the detail concept as in the wavelet transform, and allow the multiresolution control of objects with control points at any resolution level.In the first model, the detail is inserted independently of control points, requiring it to be rotated when applying deformations. In contrast, the second method describes details relative to control points, allowing free control point deformations.Modeling examples of curves and surfaces are presented, showing manipulation facilities of the models.

Out-of-field photon and neutron dose equivalents from step-and-shoot intensity-modulated radiation therapy

2005 ◽  
Vol 62 (4) ◽  
pp. 1204-1216 ◽  
Author(s):  
Stephen F. Kry ◽  
Mohammad Salehpour ◽  
David S. Followill ◽  
Marilyn Stovall ◽  
Deborah A. Kuban ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Neutron Dose ◽  
Intensity Modulated ◽  
Step And Shoot

scholarly journals Optimization of tillage and sowing operations using discrete event simulation 

2018 ◽  
Vol 64 (No. 4) ◽  
pp. 187-194 ◽  
Author(s):  
Armaghan Kosari Moghaddam ◽  
Hassan Sadrnia ◽  
Hassan Aghel ◽  
Mohammad Bannayan
Keyword(s):  
Discrete Event Simulation ◽  
Discrete Event ◽  
Daily Basis ◽  
Simulation Software ◽  
Field Size ◽  
Daily Work ◽  
Event Simulation ◽  
Significant Difference ◽  
Average Work ◽  
Work Method

A simulation model was developed for secondary tillage and sowing operations in autumn, using discrete event simulation technique in Arena<sup>®</sup> simulation software (Version 14). Eight machinery sets were evaluated on a 50-hectare farm. Total costs including fixed-costs, variable costs and timeliness costs were calculated for each machinery set. Timeliness costs were estimated for 21-years period on daily basis (Daily Work method) and compared with another method (Average Work method) based on the equation proposed by ASAE Standards, EP 496.3FEB2006. The Inputs of the model were machinery sets, field size, machines performances and daily soil workability state. The optimization criteria were the lowest costs and lowest standard deviation in daily work method plus the lowest costs based on average work method. The validity of the model was evaluated by comparing the output of the model with field observed data collected from various farms. Results revealed that there was no significant difference (P &gt; 0.01) between the observed and predicted finish day. 

scholarly journals Dosimetric Comparison of Three Radiotherapy Techniques in Irradiation of Left-Sided Breast Cancer Patients after Radical Mastectomy

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jian Hu ◽  
Guang Han ◽  
Yu Lei ◽  
Ximing Xu ◽  
Wei Ge ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Radical Mastectomy ◽  
Target Volume ◽  
Conformity Index ◽  
Breast Cancer Patients ◽  
Ipsilateral Lung ◽  
Significant Difference

Introduction. This study is aimed at evaluating the dosimetric differences among target segmented planning (TSP), conventional 9-field intensity modulated radiation therapy (9FIMRT) planning, and volumetric modulated arc therapy (VMAT) planning for postmastectomy radiotherapy of left-sided breast cancer patients. Material and Methods. Fifteen left-sided breast cancer patients who underwent radical mastectomy were enrolled. In TSP, the planning target volume (PTV) was divided into four regions (supra/infraclavicular, chest wall, external mammary region, and internal mammary region), and each individual PTV region was treated with respective fixed fields. Results. The VMAT plans showed superior to PTV dose conformity index (CI), homogeneity index (HI), protection of the ipsilateral lung, monitor units (MUs), and maximum dose (Dmax) to the contralateral breast compared with TSP and 9FIMRT plans. The TSP provided better protection for Dmean of the heart and left ventricle (p<0.05). A dose for left anterior descending artery from the three techniques had no significant difference. Compared with the 9FIMRT plans, the V5Gy (%) and V10Gy (%) for the ipsilateral lung were significantly reduced with TSP and VMAT (p<0.05). The V5Gy (%) and V10Gy (%) for the ipsilateral lung turned out to be similar between VMAT and TSP techniques. Conclusions. Our study indicates that VMAT should be a better choice of radiotherapy for left-sided breast cancer patients after radical mastectomy. If VMAT is unavailable, 9FIMRT can achieve better CI and HI values and be more MU-efficient compared with TSP; however, TSP can effectively reduce the low dose volume of the ipsilateral lungs and heart.

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