scholarly journals Determination of absorbed dose at different methods of target irradiation with scanning proton beam by means of chemical dosimeter FBX

2020 ◽  
Vol 29 (2) ◽  
pp. 78-88
Author(s):  
E.V. Koryakina ◽  
◽  
M.V. Troshina ◽  
O.Yu. Golovanova ◽  
V.I. Potetnya ◽  
...  
Keyword(s):  
Proton Beam ◽  
Absorbed Dose ◽  
Chemical Dosimeter

The Determination of Absorbed Dose in a Proton Beam for Purposes of Charged-Particle Radiation Therapy

1979 ◽  
Vol 79 (1) ◽  
pp. 34 ◽  
Author(s):  
Lynn J. Verhey ◽  
Andreas M. Koehler ◽  
Joseph C. McDonald ◽  
Michael Goitein ◽  
I-Chang Ma ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Charged Particle ◽  
Proton Beam ◽  
Absorbed Dose ◽  
Particle Radiation

scholarly journals A Monte Carlo Determination of Dose and Range Uncertainties for Preclinical Studies with a Proton Beam

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1889
Author(s):  
Arthur Bongrand ◽  
Charbel Koumeir ◽  
Daphnée Villoing ◽  
Arnaud Guertin ◽  
Ferid Haddad ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Proton Beam ◽  
Dose Response ◽  
Small Animal ◽  
Absorbed Dose ◽  
Normal Tissue Damage ◽  
Dose Homogeneity ◽  
And Control ◽  
The Impact

Proton therapy (PRT) is an irradiation technique that aims at limiting normal tissue damage while maintaining the tumor response. To study its specificities, the ARRONAX cyclotron is currently developing a preclinical structure compatible with biological experiments. A prerequisite is to identify and control uncertainties on the ARRONAX beamline, which can lead to significant biases in the observed biological results and dose–response relationships, as for any facility. This paper summarizes and quantifies the impact of uncertainty on proton range, absorbed dose, and dose homogeneity in a preclinical context of cell or small animal irradiation on the Bragg curve, using Monte Carlo simulations. All possible sources of uncertainty were investigated and discussed independently. Those with a significant impact were identified, and protocols were established to reduce their consequences. Overall, the uncertainties evaluated were similar to those from clinical practice and are considered compatible with the performance of radiobiological experiments, as well as the study of dose–response relationships on this proton beam. Another conclusion of this study is that Monte Carlo simulations can be used to help build preclinical lines in other setups.

Compartmental transfer of mercury released from amalgam

1997 ◽  
Vol 16 (11) ◽  
pp. 667-672 ◽  
Author(s):  
S. Halbach ◽  
L. Kremers ◽  
H. Willruth ◽  
A. Mehl ◽  
G. Welzl ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Urinary Excretion ◽  
Total Mercury ◽  
Excretion Rate ◽  
Absorbed Dose ◽  
Correlation Coefficients ◽  
Urinary Excretion Rate ◽  
Amalgam Fillings

The number of amalgam-covered surfaces and the occlusal area of the fillings, the concentrations of total mercury in plasma, erythrocytes and urine, the urinary excretion rate, and the absorbed daily doses estimated by two separate methods from intra-oral Hg emission were determined in 29 volunteers with a low amalgam load. The transfer ofHg from the fillings via the oral cavity and blood to urinary excretion was evaluated by multiple correla tions between these variables. In addition, the combina tion of variables most representative of the entire compartmental transfer of amalgam Hg was determined. Urinary excretion (1), Hg concentration in plasma (2) and absorbed dose (3) were most closely correlated to each other, followed by correlations with the variables of the fillings (4). Correlation coefficients were 0.75 for variables 1 vs 2 and 2 vs 3, and 0.49 for variables 3 vs 4. It was concluded that variables 1-3 best reflected the transfer of mercury from amalgam fillings throughout the organism and that they were relatively insensitive to dietary mercury. The determination of total mercury in plasma and of its urinary excretion rate appears, under practical aspects, most suitable for the investigation of Hg uptake from amalgam.

scholarly journals Analysis of the 40K levels in soil using gamma spectrometry

2005 ◽  
Vol 48 (spe2) ◽  
pp. 221-228 ◽  
Author(s):  
José Araújo dos Santos Júnior ◽  
Jorge João Ricardo Ferreira Cardoso ◽  
Cleomacio Miguel da Silva ◽  
Suêldo Vita Silveira ◽  
Romilton dos Santos Amaral
Keyword(s):  
Gamma Spectrometry ◽  
Absorbed Dose ◽  
Soil Samples ◽  
Spectrometry Method ◽  
Dose Rates ◽  
Elemental Concentrations ◽  
High Purity Germanium ◽  
Specific Activities ◽  
Potassium 40

Potassium-40 was determined in soil in an area with 40,000 m² situated in the western State of Pernambuco, Brazil. For radiometric measurements, the gamma spectrometry method with a high purity germanium (HPGe) detector was used. Sampling of 78 soil samples has been performed at intervals of 25 m. The specific activities of 40K were calculated based on the photopeak of 1.46 MeV. Values from 541 to 3,572 Bq kg-1 were obtained (mean of 1,827 Bq kg-1). These values allowed the determination of the elemental concentrations as well as the absorbed dose rates in air, 1 m above the ground. The values varied from 1.7 to 11.5% (mean of 6%) and from 23.4 to 154.3 nGy h-1 (mean of 79 nGy h-1), respectively.

Determination of Image Quality in Relation to Absorbed Dose in Mammography

1993 ◽  
Vol 49 (1-3) ◽  
pp. 157-161 ◽  
Author(s):  
J. Zoetelief ◽  
J.Th.M. Jansen ◽  
N.J.P. de Wit
Keyword(s):  
Image Quality ◽  
Absorbed Dose
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