scholarly journals Verification of Acuros XB dose algorithm using 3D printed low-density phantoms for clinical photon beams

2018 ◽  
Vol 19 (3) ◽  
pp. 32-43 ◽  
Author(s):  
Rodolfo Zavan ◽  
Philip McGeachy ◽  
Joseph Madamesila ◽  
Jose-Eduardo Villarreal-Barajas ◽  
Rao Khan
Keyword(s):  
Low Density ◽  
Photon Beams ◽  
Dose Algorithm ◽  
Acuros Xb ◽  
3D Printed

Additive technology applied to the realization of K-band microwave terminations: reproducibility improvement

2018 ◽  
Vol 10 (1) ◽  
pp. 3-8
Author(s):  
Azar Maalouf ◽  
Ronan Gingat ◽  
Vincent Laur
Keyword(s):  
3D Printing ◽  
Frequency Band ◽  
Rectangular Waveguide ◽  
Three Dimensional ◽  
Low Density ◽  
Support Material ◽  
Additive Technology ◽  
3D Printed ◽  
K Band

This study examines K-band rectangular waveguide terminations with three-dimensional (3D)-printed loads, and proposes an Asymmetrical Tapered Wedge topology. This geometry shows a good tradeoff between microwave performance and 3D-printing issues (printing directions and support material requirements), thus improving noticeably the reproducibility of the devices. The effect of the density of the 3D-printed load on the reflection parameter of the termination was investigated. Even for a low density, reflection level remained below −27.5 dB between 18 and 26.5 GHz. Reproducibility was demonstrated by the characterization of six loads that were 3D printed under the same conditions. Measurements demonstrate that a maximum reflection parameter level of −33.5 dB can be ensured over the whole frequency band without any post-machining of the 3D-printed devices.

Monte Carlo dosimetric evaluation of high energy vs low energy photon beams in low density tissues

2006 ◽  
Vol 79 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Miltiadis F. Tsiakalos ◽  
Sotirios Stathakis ◽  
George A. Plataniotis ◽  
Constantin Kappas ◽  
Kiki Theodorou
Keyword(s):  
Monte Carlo ◽  
High Energy ◽  
Low Energy ◽  
Low Density ◽  
Photon Beams ◽  
Energy Photon

Radiological properties of 3D printed materials in kilovoltage and megavoltage photon beams

2017 ◽  
Vol 38 ◽  
pp. 111-118 ◽  
Author(s):  
O.L. Dancewicz ◽  
S.R. Sylvander ◽  
T.S. Markwell ◽  
S.B. Crowe ◽  
J.V. Trapp
Keyword(s):  
Photon Beams ◽  
3D Printed ◽  
Printed Materials ◽  
Radiological Properties

scholarly journals Application of OSL dosimetry and 3D printed phantom for comparison of calculation algorithms for VMAT treatment planning

2019 ◽  
Vol 1 (1) ◽  
pp. 30-39
Author(s):  
Daniel Villani ◽  
Carolina Dos Santos Moreno ◽  
Roberto Kenji Sakuraba ◽  
Letícia Lucente Campos
Keyword(s):  
Quality Control ◽  
Treatment Planning ◽  
Medical Physics ◽  
Dose Calculation ◽  
Treatment Techniques ◽  
Acuros Xb ◽  
Target Volumes ◽  
Calculation Algorithms ◽  
Dose Calculation Algorithms ◽  
3D Printed

The application of new commercial and industrial technologies in the fields of dosimetry and medical physics is of great interest to the scientific community, both to validate existing protocols and to develop new methodologies. The popularization of 3D printing techniques has been analyzed as a great advantage in quality control in complex treatment techniques, such as radiotherapy and the development of patient simulators. Portable dosimetry systems such as Landauer MicroStar OSL system are versatile and their use in quality control is of great importance. The aim of this paper is to compare two of the most used dose calculation algorithms used in Varian Eclipse TPS – AAA and Acuros XB – for treatment planning of multiple brain metastases using a 3D printed anthropomorphic phantom and the OSL InLight system for experimental dosimetry validation. A 3D printed anthropomorphic skull phantom was submitted to a CT scan and planed five target volumes. In order of comparison, two dose calculations were performed in the Varian Eclipse 13.6 TPS with "Alabama technique", using the Varian’s AAA and AXB algorithms, and treatment delivered with 6 MV photon beam of a Varian TrueBeam linear accelerator. Landauer nanoDot dosimeters were positioned inside each of the five target volumes planned and the experimental dosimetric results were compared with the algorithms’ calculated doses. The findings of this work indicate that ACUROS XB calculates more accurate doses compared with AAA, with all the experimental agreements better than 96.0 %, probably because of the heterogeneity corrections. The uncertainty analysis of the InLight system device is enough to sustain the dosimetric uncertainties below 3.0 %, validating the results.  

scholarly journals A phantom study on the behavior of Acuros XB algorithm in flattening filter free photon beams

2015 ◽  
Vol 40 (3) ◽  
pp. 144 ◽  
Author(s):  
KR Muralidhar ◽  
Suresh Pangam ◽  
P Srinivas ◽  
MirzaAthar Ali ◽  
VSujana Priya ◽  
...  
Keyword(s):  
Phantom Study ◽  
Photon Beams ◽  
Acuros Xb ◽  
Flattening Filter Free ◽  
Flattening Filter

scholarly journals Rebuild-up Effect on Superficial Cardiac Lesion Surrounded by Low-density Lungs: Volumetric Modulated Arc Therapy (VMAT) Planning Study Using 3-D Printed Phantom for Ventricular Tachycardia (VT)

2021 ◽  
Author(s):  
Si-Won No ◽  
Jun-Bong Shin ◽  
Yong-Ki Bae ◽  
Jungmin Kim ◽  
Semie Hong ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Volumetric Modulated Arc Therapy ◽  
Low Density ◽  
Film Dosimetry ◽  
Palo Alto ◽  
Photon Beams ◽  
Dose Distributions ◽  
Cardiac Lesion ◽  
Cardiac Phantom ◽  
Arc Therapy

Abstract The study aimed to evaluate dose distributions on the superficial cardiac lesion surrounded by low-density lungs. We fabricated the 3-D printed cardiac phantom to insert in a multipurpose lungman phantom (KYOTO KAGAKU, Japan) for simulating a stereotactic body radiation therapy (SBRT) in ventricular tachycardia (VT) treatment. The cardiac phantom consists of 11 slabs with 1-cm intervals and is designed to insert radiochromic film (Gafchromic EBT3, Ashland Advanced Materials, Bridgewater, NJ) for film dosimetry. We used film dosimetry scanners (DosimetryPRO Advantage Red, Vidar Systems Corporation, Herndon, VA) with dedicated film dosimetry software (OP-IMRT, ver.1.6, IBA dosimetry, Germany). Volumetric modulated arc therapy (VMAT) technique was applied to optimize the dose distribution using the anisotropic analytic algorithm (AAA) in a radiation treatment planning (RTP) system (Eclipse v. 13.6, Varian, Palo Alto, CA). We used the 6-MV and 15-MV photon energies from a LINAC (Clinac iX, Varian, Palo Alto, CA) to investigate the planning target volume (PTV) under-dose effects due to the inner dose rebuild-up by energy dependence. The dose distributions in the VMAT plans with 6-MV and 15-MV showed good competitive coverages of the cardiac lesion without any severe underdose pattern. On the other side, the film dosimetry results showed significant dose variations near the interface of the cardiac lesion surrounded by low-density lung. The differences between the planning and the film dosimetry results revealed pretty well in both photon energies. The maximum dose differences in the cardiac PTV were ranged from 4.1–7.7% and 4.1–8.1% for 6-MV photon beams and 15-MV photon beams. Furthermore, EBT3 film measurements showed that the widths of 50% of profiles were reduced by 1.3 cm and 2.3 cm on 6-MV photon beams and 15-MV photon beams, respectively. In addition, 3-D printing techniques enabled quite challengeable dose measurements to reveal this kind of dose discrepancies in humanoid structures. This study showed that clinical cases like VT SBRT surrounded by severe inhomogeneous matter could induce wrongly to estimate appropriate dose delivery and to evaluate reasonable clinical outcomes.

scholarly journals Tensile Characteristics of Low Density Infill Patterns for Mass Reduction of 3D Printed Polylactic Parts

2020 ◽  
Vol 17 (2) ◽  
pp. 7927-7934
Author(s):  
M. N. F. Saniman ◽  
M. H. M Hashim ◽  
K. A. Mohammad ◽  
K. A. Abd Wahid ◽  
W. M. Wan Muhamad ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Tensile Strain ◽  
3D Printer ◽  
Low Density ◽  
Mass Reduction ◽  
Hilbert Curve ◽  
High Tensile Strength ◽  
Specific Strain ◽  
3D Printed ◽  
Selection For

Various infill patterns are introduced in 3D printing to generate low density objects that leads to reduced cost and fabrication time through mass reduction. However, as a trade-off, the strength of the 3D printed component is uncertain. Confusions arise in determining the infill pattern with highest value of tensile strength since most studies limited only to rectilinear, honeycomb, and concentric infill patterns. As consequences, there are very little information on rarely used infill patterns such as Hilbert curve, Archimedean cord and octagram spiral. Therefore, the purpose of this research is to investigate and compare the tensile strength and strain of all infill patterns in mass reduction of 3D printed components experimentally. Following ASTM D638 type III standard, ten tensile test specimens of each infill patterns with 20% density were printed with an FFF 3D printer and were then tested. It was found that Archimedean cords infill pattern had the highest specific tensile strength of 33.23×103 MPa∙mm3/g which made it as the optimum infill pattern for the mass reduction of 3D printed parts with a high tensile strength. On the other hand, having the highest specific tensile strain of 18.21×103 %∙mm3/g, concentric infill pattern was found to be more suitable for producing lightweight parts with a higher elongation before break. Additionally, Hilbert curve infill was the worst selection for mass reduction since it had the lowest values of specific tensile strength and specific strain of 19.80×103 MPa∙mm3/g and 8.34 %∙mm3/g, respectively. Nevertheless, the trends of tensile strength and strain of all six infill patterns had been obtained, especially for rarely investigated infill patterns of Archimedean cords, octagram spiral, and Hilbert curve. Specifically, the trend from the strongest to the weakest (in % compared to solid) for specific tensile strength is rectilinear (38.57%), Archimedean chords (37.29%), concentric (36.57%), octagram spiral (34.79%), honeycomb (27.84%), and Hilbert curve (22.25%), while for specific strain is concentric (102.6%), octagram spiral (83.94%), rectilinear (78.22%), Archimedean cords (77.99%), honeycomb (54.84%), and Hilbert curve (45.14%).

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