A . Bouzouita et al .: Radioprotection 2024 , 59 ( 4 ), 296 – 305 303
Table 5 . Averaged organ DCFs for male and female ICRP110 phantoms compared to values obtained from published ICRP 144 report data using the same phantom type ( ICRP , 2020 ).
|
ICRP 144 |
This work |
ICRP 144 |
This work |
ICRP 144 |
This work |
Adrenals |
0.346 |
0.372 |
0.426 |
0.453 |
0.032 |
0.036 |
Brain |
0.347 |
0.412 |
0.428 |
0.528 |
0.036 |
0.043 |
Breast |
0.366 |
0.434 |
0.448 |
0.553 |
0.040 |
0.043 |
Colon |
0.401 |
0.384 |
0.503 |
0.501 |
0.039 |
0.040 |
Gonads |
0.368 |
0.430 |
0.449 |
0.580 |
0.038 |
0.043 |
Kidneys |
0.338 |
0.359 |
0.416 |
0.468 |
0.033 |
0.037 |
Liver |
0.342 |
0.375 |
0.420 |
0.487 |
0.036 |
0.039 |
Lungs |
0.364 |
0.425 |
0.444 |
0.546 |
0.039 |
0.045 |
Muscles |
0.423 |
0.461 |
0.516 |
0.594 |
0.040 |
0.048 |
Oesophagus |
0.264 |
0.357 |
0.300 |
0.468 |
0.033 |
0.037 |
Pancreas |
0.324 |
0.359 |
0.401 |
0.465 |
0.031 |
0.037 |
Red bone marrow |
0.238 |
0.244 |
0.300 |
0.303 |
0.029 |
0.024 |
Skin |
0.482 |
0.526 |
0.469 |
0.663 |
0.049 |
0.055 |
Spleen |
0.324 |
0.368 |
0.399 |
0.474 |
0.032 |
0.038 |
Thymus |
0.352 |
0.378 |
0.432 |
0.487 |
0.036 |
0.040 |
Thyroid |
0.359 |
0.362 |
0.451 |
0.467 |
0.033 |
0.038 |
Fig . 3 . Discrepancy between the DCFs values of the present work and those from ( Sanusi et al ., 2021 ).
in a significant computation time gain , eliminating the need for physical approximations such as locally killing the secondary particles , reducing the entire gamma ray spectrum or minimising the soil and air volume dimensions ( Sanusi et al ., 2021 ; Zankl et al ., 1997 ).
Table 6 compares the effective dose derived from organ DCFs in our study with literature values . Although the discrepancy in organ DCFs between the present work and the literature is relatively large , the values of the effective doses are close to each other . This is because the organ tissue factors w T used in equation ( 2 ) for calculating the effective dose are very low weighting factors . This leads to the conclusion that investigation on more detailed dose assessment is necessary .
4 Conclusion
We performed a two-stage Monte Carlo simulation using Geant4 to calculate dose-to-organ conversion factors ( DCFs ) for external gamma radiation exposure from grounddistributed radioactive sources . Voxel-based ICRP110 female and male phantoms and an optimised soil-air geometry were used to realistically transport particles and save computing time without physical approximations . We determined DCFs for the 238 Uand 232 Th series , and the radionuclides 40 Kand 137 Cs , and tabulated results for 55 female and 54 male organs .
Our results are higher than published values using less accurate MIRD phantoms . The results indirectly obtained