FAX, A FEMALE ADULT VOXEL PHANTOM FOR RADIATION PROTECTION DOSIMETRY

Transcription

1 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

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3 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

4 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

5 ADAM and EVA phantoms

6 MAX phantom

7 FAX phantom

8 Exposure conditions Irradiation with a broad beam of photons covering the whole body from the front (AP), from the back (PA) and rotating 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

9 1.4 EXTERNAL EXPOSURE TO PHOTONS Ratio of effective doses MAX-FAX / ADEV (ICRP74) kev Photon Energy (MeV) AP-EGS4 PA-EGS4 AP-MCNP4C PA-MCNPC ROT-EGS4 Replacement of the ADAM-EVA by the MAX-FAX exposure model

10 Exposure conditions Irradiation with a broad beam of electrons covering the whole body from the front (AP), from the back (PA) and rotating 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

11 1.4 EXTERNAL EXPOSURE TO ELECTRONS Ratio of effective doses MAX-FAX / ADEV Electron Energy (MeV) AP-EGS4 PA-EGS4 AP-MCNP4 ROT-EGS4 Replacement of the ADAM-EVA by the MAX-FAX exposure model

12 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

13 1.6 EGS4 INTERNAL EXPOSURE TO PHOTONS Ratio of effective doses MAX-FAX / ADEV Photon Energy (MeV) LIVER LUNGS SKELETON THYROID Replacement of the ADAM-EVA by the MAX-FAX exposure model

14 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

15 1.2 INTERNAL EXPOSURE TO ELECTRONS Ratio of effective doses MAX-FAX / ADEV EGS Photon Energy (MeV) KIDNEYS SKELETON SPLEEN Replacement of the ADAM-EVA by the MAX-FAX exposure model

16 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.

17 Tissue w T Σ w T Bone marrow, Breast, Colon, Lung, Stomach Bladder, Oesophagus, Gonads, Liver, Thyroid Bone surface, Brain,Kidneys, Salivary glands, Skin Remainder tissues* *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 RBM, Colon, Lung, Stomach ICRP Bladder, Breast, Liver, Oesophagus, Thyroid Skin, Bone surface Remainder tissues* *Remainder Tissues (10 in total) Adrenals, Brain, trachea, small intestine, muscle, Pancreas, Kidneys, spleen, thymus, uterus ICRP draft

18 Ratio of effective doses EXTERNAL EXPOSURE TO PHOTONS MAX-FAXdraft / ADEV-ICRP74 MAX-FAX60 / ADEV-ICRP kev 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

19 EXTERNAL EXPOSURE TO ELECTRONS Ratio of effective doses MAX-FAXdraft / ADEV-ICRP74 MAX-FAX60 / ADEV-ICRP 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

20 2 1.8 INTERNAL EXPOSURE TO PHOTONS Ratio of effective doses MAX-FAXdraft / ADEV-ICRP74 MAX-FAX60 / ADEV-ICRP 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

21 1.4 INTERNAL EXPOSURE TO ELECTRONS Ratio of effective doses 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

22 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.

23 MAX FAX

24 Relative number of photons 8.0E E E E E E E E-02 CHEST AP 100 kvcp 2.5 mm Al 17 Deg Tungsten UNSCATTERED SPECTRA BEHIND PHANTOM 0.0E Photon energy (kev) ADAM EVA MAX FAX INCIDENT SPECTRUM

25 Relative number of photons 3.5E E E E E E E-03 CHEST AP 100 kvcp 2.5 mm Al 17 Deg Tungsten SCATTERED SPECTRA BEHIND PHANTOM 0.0E Photon energy (kev) ADAM EVA MAX FAX