EFFECTIVE DOSE RATIOS FOR THE TOMOGRAPHIC MAX AND FAX PHANTOMS ******************************************************** EFFECTIVE DOSE RATIOS FOR TOMOGRAPHIC AND STYLIZED MODELS FROM > EXTERNAL EXPOSURE TO PHOTONS > EXTERNAL EXPOSURE TO ELECTRONS > INTERNAL EXPOSURE TO PHOTONS > INTERNAL EXPOSURE TO ELECTRONS ************************************************************************ FAX, A FEMALE ADULT VOXEL PHANTOM FOR RADIATION PROTECTION DOSIMETRY
The main protection quantity (ICRP 60) : Effective Dose E = Σ w T H T H T = Equivalent Dose to Tissue T W T = Tissue Weighting Factor for Tissue T
Remainder equivalent dose: External exposure: Arithmetic average equivalent dose of the 10 organs and tissues Internal exposures: Mass-weighted average equivalent dose of the 10 organs and tissues Footnote 3 of table 2 from ICRP60
ADAM and EVA phantoms
MAX phantom
FAX phantom
Exposure conditions Irradiation with a broad beam of photons covering the whole body from the front (AP), from the back (PA) and rotating 360 0 around the vertical axis of the body Incident energies from 10 kev to 10 MeV Cut-off energies: photons = 2 kev, electrons = 10 MeV and 200 kev Effective dose calculated according to ICRP74
1.4 EXTERNAL EXPOSURE TO PHOTONS Ratio of effective doses 1.2 1 0.8 0.6 MAX-FAX / ADEV (ICRP74) 0.4 30 kev 0.01 0.1 1 10 Photon Energy (MeV) AP-EGS4 PA-EGS4 AP-MCNP4C PA-MCNPC ROT-EGS4 Replacement of the ADAM-EVA by the MAX-FAX exposure model
Exposure conditions Irradiation with a broad beam of electrons covering the whole body from the front (AP), from the back (PA) and rotating 360 0 around the vertical axis of the body Incident energies from 0.1 MeV to 10 MeV Cut-off energies: photons = 2 kev, electrons = 8 kev for E< 1 MeV and 200 kev for E> 1MeV Effective dose calculated according to ICRP74
1.4 EXTERNAL EXPOSURE TO ELECTRONS Ratio of effective doses 1.2 1 0.8 0.6 MAX-FAX / ADEV 0.4 0.1 1 10 Electron Energy (MeV) AP-EGS4 PA-EGS4 AP-MCNP4 ROT-EGS4 Replacement of the ADAM-EVA by the MAX-FAX exposure model
Exposure conditions Irradiation from photon emitters homogeneously distributed in the liver, the lungs, the skeleton and the thyroid. Incident energies from 10 kev to 4 MeV Cut-off energies: photons = 2 kev, electrons = 4 MeV Effective dose calculated according to ICRP68 and footnote 3 of table 2 from ICRP60
1.6 EGS4 INTERNAL EXPOSURE TO PHOTONS Ratio of effective doses 1.4 1.2 1 MAX-FAX / ADEV 0.8 0.01 0.1 1 10 Photon Energy (MeV) LIVER LUNGS SKELETON THYROID Replacement of the ADAM-EVA by the MAX-FAX exposure model
Exposure conditions Irradiation from electron emitters homogeneously distributed in the kidneys, the spleen and the skeleton. Incident energies from 0.1 MeV to 4 MeV Cut-off energies: photons = 2 kev, electrons 8 kev for E<1 MeV and 200 kev for E>1 MeV Effective dose calculated according to ICRP68 and footnote 3 of table 2 from ICRP60
1.2 INTERNAL EXPOSURE TO ELECTRONS Ratio of effective doses 1.1 1 0.9 0.8 0.7 MAX-FAX / ADEV EGS4 0.6 0.1 1 10 Photon Energy (MeV) KIDNEYS SKELETON SPLEEN Replacement of the ADAM-EVA by the MAX-FAX exposure model
Conclusions Regardless of exposure conditions beyond those considered in this study, one can observe that the effective dose would change between +60% and 50% because of the replacement of the ADAM- EVA exposure model by the MAX-FAX exposure model. This margin does not include additional changes from replacing a Monte Carlo code.
Tissue w T Σ w T Bone marrow, Breast, Colon, Lung, Stomach 0.12 0.60 Bladder, Oesophagus, Gonads, Liver, Thyroid 0.05 0.25 Bone surface, Brain,Kidneys, Salivary glands, Skin 0.01 0.05 Remainder tissues* 0.10 0.10 *Remainder Tissues (14 in total) Adipose tissue, Adrenals, Connective tissue, Extrathorarcic Airways Gallbladder, Heart wall, Lymphatic nodes, Muscle, Pancreas, Prostate SI wall, Spleen, Thymus, and Uterus/Cervix *********************************************************************** Tissue w T Σ w T Gonads 0.20 0.20 RBM, Colon, Lung, Stomach 0.12 0.48 ICRP Bladder, Breast, Liver, Oesophagus, Thyroid 0.05 0.25 60 Skin, Bone surface 0.01 0.02 Remainder tissues* 0.05 0.05 *Remainder Tissues (10 in total) Adrenals, Brain, trachea, small intestine, muscle, Pancreas, Kidneys, spleen, thymus, uterus ICRP draft
Ratio of effective doses 1.6 1.4 1.2 1 0.8 0.6 EXTERNAL EXPOSURE TO PHOTONS MAX-FAXdraft / ADEV-ICRP74 MAX-FAX60 / ADEV-ICRP74 0.4 30 kev 0.01 0.1 1 10 Photon Energy (MeV) AP-draft PA-draft ROT-draft AP-60 PA-60 ROT-60 Replacement of the ADAM/EVA exposure model by the MAX/FAX exposure model for ICRP60 and ICRPdraft tissue weighting factors
2.4 2.2 EXTERNAL EXPOSURE TO ELECTRONS Ratio of effective doses 2 1.8 1.6 1.4 1.2 1 0.8 0.6 MAX-FAXdraft / ADEV-ICRP74 MAX-FAX60 / ADEV-ICRP74 0.4 0.1 1 10 Electron Energy (MeV) AP-draft PA-draft ROT-draft PA-60 AP-60 ROT-60 Replacement of the ADAM/EVA exposure model by the MAX/FAX exposure model for ICRP60 and ICRPdraft tissue weighting factors
2 1.8 INTERNAL EXPOSURE TO PHOTONS Ratio of effective doses 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 MAX-FAXdraft / ADEV-ICRP74 MAX-FAX60 / ADEV-ICRP74 0.01 0.1 1 10 Photon Energy (MeV) LIV-draft LUN-draft KID-draft LIV-60 LUN-60 KID-60 Replacemnt of the ADAM/EVA exposure model by the MAX/FAX exposure model for ICRP60 and ICRPdraft tissue weighting factors
1.4 INTERNAL EXPOSURE TO ELECTRONS Ratio of effective doses 1.2 1 0.8 0.6 0.4 0.2 0.1 1 10 Electron Energy (MeV) KID-draft KID-60 MAX-FAXdraft / ADEV-ICRP74 MAX-FAX60 / ADEV-ICRP74 SKEL-draft SKEL-60 Replacemant of the ADAM/EVA exposure model by the MAX/FAX exposure model for ICRP60 and ICRPdraft tissue weighting factors
Conclusions As was shown earlier, for the ICRP60 definition the effective dose would change between +60% and 50% because of the replacement of the ADAM-EVA exposure model by the MAX-FAX exposure model. If the new ICRPdraft definition is used changes of the effective dose between +140% and 50% can occur. This margin does not include additional changes from replacing a Monte Carlo code.
MAX FAX
Relative number of photons 8.0E-02 7.0E-02 6.0E-02 5.0E-02 4.0E-02 3.0E-02 2.0E-02 1.0E-02 CHEST AP 100 kvcp 2.5 mm Al 17 Deg Tungsten UNSCATTERED SPECTRA BEHIND PHANTOM 0.0E+00 0 20 40 60 80 100 120 Photon energy (kev) ADAM EVA MAX FAX INCIDENT SPECTRUM
Relative number of photons 3.5E-02 3.0E-02 2.5E-02 2.0E-02 1.5E-02 1.0E-02 5.0E-03 CHEST AP 100 kvcp 2.5 mm Al 17 Deg Tungsten SCATTERED SPECTRA BEHIND PHANTOM 0.0E+00 0 20 40 60 80 100 120 Photon energy (kev) ADAM EVA MAX FAX