Comparison of Dose Distribution of Ionizing Radiation in a Water Phantom with Frequency of Cytogenetic Damage in a Human Bronchial Cells

2009 ◽  
pp. 379-382
Author(s):  
M. Konopacka ◽  
J. Rogoliński ◽  
K. Ślosarek
Keyword(s):  
Ionizing Radiation ◽  
Dose Distribution ◽  
Cytogenetic Damage ◽  
Water Phantom ◽  
Bronchial Cells

scholarly journals Investigation on Medical Exposure Analysis, Dose Distribution Outside the Useful Beam in Water Phantom by Means of the Monte Carlo Calculation.

1993 ◽  
Vol 28 (3) ◽  
pp. 311-316 ◽  
Author(s):  
Hideki KATO ◽  
Masatoshi TSUZAKA ◽  
Shuji KOYAMA ◽  
Shoichi SUZUKI ◽  
Takeo ORITO ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Dose Distribution ◽  
Monte Carlo Calculation ◽  
Exposure Analysis ◽  
Water Phantom ◽  
Medical Exposure

Reconstruction of Bremsstrahlung Spectrum of Medical Electron Linear Accelerators from Deep Dose Distributions in Water Phantom

2017 ◽  
Vol 62 (5) ◽  
pp. 47-51
Author(s):  
В. Климанов ◽  
V. Klimanov ◽  
Ж. Галяутдинова ◽  
Zh. Galyautdinova ◽  
Н. Могиленец ◽  
...  
Keyword(s):  
Dose Distribution ◽  
Average Energy ◽  
Field Size ◽  
Bremsstrahlung Spectrum ◽  
Reconstruction Method ◽  
Electron Linear Accelerator ◽  
Linear Accelerators ◽  
Dose Distributions ◽  
Water Phantom ◽  
Dose Kernels

Purpose: Development of the bremsstrahlung spectrum reconstruction method of medical electron linear accelerators (ELA) with different field sizes on the base of the deep dose distributions in a water phantom and determination of photon spectra for Varian Trilogy accelerator 6 MV. Material and methods: The proposed methodology is based on the use of dose kernels algorithm of point monoenergetic monodirectional source (pencil beam (PB)) for the deep dose distribution calculation, created different cross-section beams of in a water phantom, and experimental measurements of these distributions. For solving the inverse problem is applied Toolbox routines 'ptimtool knowing mathematical package MATLAB to solve. Results: Bremsstrahlung energy spectrum generated medical accelerator Varian Triology with different sizes of square fields from 3×3 up to 40×40 cm and average energy photons, depending on the size of the fields were received. Dose kernels for a set of defined energies PB were calculated. Depth dose distribution in a water phantom, calculated using the obtained spectra and dose kernels agree well with measurement dose distributions. Conclusion: The proposed technique reconstruction of bremsstrahlung spectrum of electron linear accelerator is adequate. Average energy spectra of bremsstrahlung photons for Varian Trilogy Accelerator in regime 6 MV varies from 1.71 to 1.43 MeV depending on the field size.

scholarly journals Ionizing Radiation Dose Distribution Produced inside a Canonical Cavity by Direct e-Beam Excitation

1987 ◽  
Vol 34 (6) ◽  
pp. 1521-1527 ◽  
Author(s):  
R. Fleetwood ◽  
K. Kerris ◽  
G. Merkel ◽  
H. Roberts ◽  
M. Smith
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Dose Distribution ◽  
Beam Excitation

scholarly journals Study of Analysis the Sensitivity of the Computational Environment for Radiological Research Field Size Based on Two Dimensional Dose Distribution for Water Phantom Cases

2020 ◽  
Vol 4 (2) ◽  
pp. 39-45
Author(s):  
Yati Hardiyanti ◽  
◽  
Thareq Barasabha ◽  
Choirul Anam ◽  
Novitrian Novitrian ◽  
...  
Keyword(s):  
Dose Distribution ◽  
Dose Calculation ◽  
Target Volume ◽  
Sensitivity Study ◽  
Research Field ◽  
Field Size ◽  
Radiation Beam ◽  
Water Phantom ◽  
Computational Environment ◽  
Beam Parameters

Purpose This study analysed the sensitivity of the field size from variations in the target volume dimensions, depth, and position. The variations in the target volume analysis were used to determine the width of the field size. Thus, the quality control of the radiation beam can be obtained. Materials and Methods The computed tomography (CT) image of the IBA Dose 1 type of water phantom consists of 350 slices. Variations in the dimension of the target volume were modelled in 10×10×10 cm3, 10×12×10 cm3 , 10.2×10×10.2 cm3, and 15×15×15 cm3. Beam parameters use one beam of irradiation on the central axis 0°, 6 MV energy, 100 cm source-skin distance (SSD), beamlet delta x, and y set to 0.1 cm. Dose distribution in the form of the XZ isodose curve and dose profile was used to observe the field size. Results In this study, the isodose curve was successfully displayed in the XZ isodose curve. The field size’s sensitivity has been successfully reviewed from variations of the target volume, depth, and position. The target X and Z direction analysis is used in determining the width and length of the field size. Conclusion The analysis related to the field size sensitivity study was obtained from a relatively valid calculation. The field size was evaluated with variations in depth of 1.5 cm, 5 cm, 10 cm, and variations in positions of 10 cm, 12 cm, 14 cm, 18 cm, and 20 cm. This study will be used as a reference to validate the distribution of computational environment for radiotherapy research (CERR) dose in the future. Thus, the accuracy of the dose calculation can be obtained.

scholarly journals Sensitivity enhancement of DHR123 radio-fluorogenic nanoclay gel dosimeter by incorporating surfactants and halogenides

RSC Advances ◽  
2020 ◽  
Vol 10 (48) ◽  
pp. 28798-28806
Author(s):  
Anri Mochizuki ◽  
Takuya Maeyama ◽  
Yusuke Watanabe ◽  
Shinya Mizukami
Keyword(s):  
Radiation Therapy ◽  
Ionizing Radiation ◽  
Dose Distribution ◽  
Sensitivity Enhancement ◽  
Therapy Planning ◽  
Medical Systems ◽  
Gel Dosimeter ◽  
Radiation Therapy Planning ◽  
Tissue Equivalent ◽  
Image Courtesy

Dosimetry of spatial dose distribution of ionizing radiation in tissue equivalent materials using high sensitive radio-fluorogenic gel dosimeter using DHR123 with sensitizer. (Radiation therapy planning image courtesy of Varian Medical Systems, Inc. All rights reserved.)

into account. Therefore, every time a new batch of food is to be irradiated, the operator must establish the dose and dose distribution by strategically placing dose meters into and between the food packages and evaluating the dose meter reading. Once the process is running smoothly, it is usually not necessary to carry out dosimetry on all the product. Monitoring the process parameters and making occasional dosimetric checks is now sufficient (23). In most countries government regulations require that food irradiation proces­ sors maintain records that describe for each food lot the radiation source, source calibration, dosimetry, dose distribution in the product, and certain other process parameters (see Chapter 11). A short introduction to the interaction of ionizing radiation with matter is appro­ priate at this point, although the effects of ionizing radiation on food components will be described in more detail in Chapter 3. When high-energy electrons are absorbed by a medium they lose their kinetic energy by interacting with electrons of the medium. (At very high energy, far above that allowed for food irradiation, accelerated electrons can also interact with nuclei of the medium.) The interaction with orbital electrons of the atoms of the medium (the absorber) causes ionizations and excitations. Ionization means that orbital electrons are ejected from atoms of the medium; excitation means that orbital electrons move to an orbit of higher energy. Ejected electrons (secondary electrons), carrying a large portion of the energy of the incident electron, also lose energy through interaction with orbital electrons of the absorber. Electrons at low velocities (subexcitation energy level) can cause molecular vibrations on their way to becoming thermalized. As a result of the collisions with atoms of the absorber material the incident electrons can change direction. Repeated collisions cause multiple changes of direction. The result is a scattering of electrons in all directions. This is shown schematically in Figure 12a. When gamma or x-ray photons interact with the absorber, three types of interaction can occur: The photoelectric effect The Compton effect, and Pair production (i.e., formation of pairs of electrons and positrons) Photoelectric absorption occurs largely with photons of energies below 0.1 MeV and pair production primarily with photons of energies above 10 MeV. Both are of minor importance in food irradiation, where the Compton effect predominates. As portrayed in Figure 13, in the Compton effect an incident photon interacts with an absorber atom in such a way that an orbital electron is ejected. The incident photon continues after the collision in a changed direction and with less

1995 ◽  
pp. 47-48
Keyword(s):  
Ionizing Radiation ◽  
Pair Production ◽  
Process Parameters ◽  
Dose Distribution ◽  
High Energy ◽  
Compton Effect ◽  
Food Irradiation ◽  
Minor Importance ◽  
Incident Photon ◽  
Very High Energy
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