Dose calculations in heterogeneous volumes with the GATE Monte Carlo software for radiological protection

2019 ◽  
Vol 54 (2) ◽  
pp. 125-132
Author(s):  
T. Deschler ◽  
N. Arbor ◽  
F. Carbillet ◽  
A. Nourreddine

Monte Carlo methods have become widespread in the field of radiation protection and in particular in medical physics where the use of voxelized volumes for the reconstruction of dosimetric quantities is increasing. Changing the resolution of a dose map can be useful to compare dosimetric results coming from voxelized volumes with different resolutions, or to reduce computation time. This can be done by superimposing a dosel grid with a different resolution than that of the voxelized volume. In this case, each dosel will cover several voxels, leading the Monte Carlo code to calculate the dose in heterogeneous volumes. Two algorithms are available in GATE to perform these calculations, the Volume-Weighting (V-W) and the Mass-Weighting (M-W) algorithms, the latter being the subject of this work. In a general way, the M-W algorithm tends to reconstruct a higher dose than that the V-W one. In dosels involving heavy and lightweight materials (air-skin, bone-tissue), the M-W reconstructed dose is better estimated than the V-W one (up to 10% better at the air-skin interface). Moreover, the statistical uncertainty of the M-W dose can be up to 80% lower than the V-W one at air-skin interfaces. These results show that the M-W algorithm is more suitable for radiological protection applications and must be preferentially used in GATE for dose calculations in heterogeneous volumes.

2009 ◽  
Vol 55 (5(2)) ◽  
pp. 2242-2247
Author(s):  
Oyeon Kum ◽  
Oyeon Kum ◽  
Kil-Houm Park ◽  
Youngyih Han

2020 ◽  
Vol 76 ◽  
pp. 166-172
Author(s):  
Tordis Johnsen Dahle ◽  
Espen Rusten ◽  
Camilla Hanquist Stokkevåg ◽  
Antti Silvoniemi ◽  
Andrea Mairani ◽  
...  

Author(s):  
Ю. Кураченко ◽  
Yu. Kurachenko ◽  
Н. Санжарова ◽  
N. Sanzharova ◽  
Г. Козьмин ◽  
...  

Purpose: This work aims first to improve the reliability of absorbed dose calculation in critical organs of cattle during internal irradiation immediately after radiation accidents by a) improving the compartmental model of radionuclide metabolism in animal body; b) the use of precision computing technologies for modeling as the domain, and the actual radiation transport. In addition, the aim of the work is to determine the agreed values of the 131I critical dose in the cattle thyroid, leading to serious gland dysfunction and its follow-up destruction. Material and methods: To achieve aforecited goals, comprehensive studies were carried out to specify the parameters of the compartmental model, based on reliable experimental and theoretical data. Voxel technologies were applied for modeling the subject domain (thyroid gland and its environment). Finally, to solve the 131I radiation transport equation, the Monte Carlo code was applied, which takes into account the contribution of gamma and beta radiation source, and the contribution of the entire chain of secondary radiations in the dose calculation, up to the total energy dissipation. Results: As the main theoretical result, it is necessary to emphasize the conversion factor from the 131I activity, distributed uniformly in volume of the thyroid gland, to the average dose rate in the gland (Bq × Gy/s). This factor was calculated for both cows and calves in the selected domain configuration and thyroid morphology. The main practical result is a reliable estimation the lower bound of the absorbed dose in the thyroid, which in a short time leads to its destruction under internal 131I irradiation: ~300 Gy. Conclusion: Usage a compartmental model of the 131I metabolism with biokinetic parameters, received on the basis of reliable experimental data, and precise models of both the subject area and radiation transport for evaluation the dose in the cattle thyroid after the radiation accident allowed to obtain reliable values of the thyroid dose, adducting to its destruction at short notice.


2017 ◽  
Vol 42 ◽  
pp. 50
Author(s):  
Giuseppe Battistoni ◽  
Francesca Ballarini ◽  
Julia Bauer ◽  
Till Böhlen ◽  
Mario Pietro Carante ◽  
...  

2017 ◽  
Vol 17 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Huseyin Ozan Tekin ◽  
Asghar Mesbahi ◽  
Viswanath P. Singh ◽  
Umit Kara ◽  
Tugba Manici ◽  
...  

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