title: Monte Carlo simulation of skull and knee voxel phantoms for the assessment of skeletal burden of low-energy photon emitters.
abstract: In case of internal contamination due to long-lived actinides by inhalation or injection pathway, a major portion of activity will be deposited in the skeleton and liver over a period of time. In this study, calibration factors (CFs) of Phoswich and an array of HPGe detectors are estimated using skull and knee voxel phantoms. These phantoms are generated from International Commission of Radiation Protection reference male voxel phantom. The phantoms as well as 20 cm diameter phoswich, having 1.2 cm thick NaI (Tl) primary and 5cm thick CsI (Tl) secondary detector and an array of three HPGe detectors (each of diameter of 7 cm and thickness of 2.5 cm) are incorporated in Monte Carlo code 'FLUKA'. Biokinetic models of Pu, Am, U and Th are solved using default parameters to identify different parts of the skeleton where activity will accumulate after an inhalation intake of 1 Bq. Accordingly, CFs are evaluated for the uniform source distribution in trabecular bone and bone marrow (TBBM), cortical bone (CB) as well as in both TBBM and CB regions for photon energies of 18, 60, 63, 74, 93, 185 and 238 keV describing sources of (239)Pu, (241)Am, (238)U, (235)U and (232)Th. The CFs are also evaluated for non-uniform distribution of activity in TBBM and CB regions. The variation in the CFs for source distributed in different regions of the bones is studied. The assessment of skeletal activity of actinides from skull and knee activity measurements is discussed along with the errors.
authors.affiliation: Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India minalyn@barc.gov.in.
authors.forename: M Y
authors.initials: MY
authors.lastname: Nadar
authors.affiliation: Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: D K
authors.initials: DK
authors.lastname: Akar
authors.affiliation: Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: H K
authors.initials: HK
authors.lastname: Patni
authors.affiliation: Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: I S
authors.initials: IS
authors.lastname: Singh
authors.affiliation: Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: L
authors.initials: L
authors.lastname: Mishra
authors.affiliation: Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: D D
authors.initials: DD
authors.lastname: Rao
authors.affiliation: Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: K S
authors.initials: KS
authors.lastname: Pradeepkumar
mesh_terms: D008671:Actinoid Series Elements / Q000009:adverse effects / Q000493:pharmacokinetics; D001822:Body Burden; D003198:Computer Simulation; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology / Q000528:radiation effects; D057230:Limit of Detection; D008297:Male; D008954:Models, Biological; D009010:Monte Carlo Method; D016273:Occupational Exposure; D019047:Phantoms, Imaging; D017785:Photons / Q000009:adverse effects*; D011834:Radiation Monitoring / Q000706:statistics & numerical data*; D011874:Radiometry; D012886:Skull / Q000033:anatomy & histology / Q000528:radiation effects
chemical_list: D008671:Actinoid Series Elements