title: Inclusion of thin target and source regions in alimentary and respiratory tract systems of mesh-type ICRP adult reference phantoms.
abstract: It is not feasible to define very small or complex organs and tissues in the current voxel-type adult reference computational phantoms of the International Commission on Radiological Protection (ICRP), which limit dose coefficients for weakly penetrating radiations. To address the problem, the ICRP is converting the voxel-type reference phantoms into mesh-type phantoms. In the present study, as a part of the conversion project, the micrometer-thick target and source regions in the alimentary and respiratory tract systems as described in ICRP Publications 100 and 66 were included in the mesh-type ICRP reference adult male and female phantoms. In addition, realistic lung airway models were simulated to represent the bronchial (BB) and bronchiolar (bb) regions. The electron specific absorbed fraction (SAF) values for the alimentary and respiratory tract systems were then calculated and compared with the values calculated with the stylized models of ICRP Publications 100 and 66. The comparisons show generally good agreement for the oral cavity, oesophagus, and BB, whereas for the stomach, small intestine, large intestine, extrathoracic region, and bb, there are some differences (e.g. up to ~9 times in the large intestine). The difference is mainly due to anatomical difference in these organs between the realistic mesh-type phantoms and the simplified stylized models. The new alimentary and respiratory tract models in the mesh-type ICRP reference phantoms preserve the topology and dimensions of the voxel-type ICRP phantoms and provide more reliable SAF values than the simplified models adopted in previous ICRP Publications.
authors.affiliation: Department of Nuclear Engineering, Hanyang University, Seoul, Korea.
authors.forename: Han Sung
authors.initials: HS
authors.lastname: Kim
authors.forename: Yeon Soo
authors.initials: YS
authors.lastname: Yeom
authors.forename: Thang Tat
authors.initials: TT
authors.lastname: Nguyen
authors.forename: Chansoo
authors.initials: C
authors.lastname: Choi
authors.forename: Min Cheol
authors.initials: MC
authors.lastname: Han
authors.forename: Jai Ki
authors.initials: JK
authors.lastname: Lee
authors.forename: Chan Hyeong
authors.initials: CH
authors.lastname: Kim
authors.forename: Maria
authors.initials: M
authors.lastname: Zankl
authors.forename: Nina
authors.initials: N
authors.lastname: Petoussi-Henss
authors.forename: Wesley E
authors.initials: WE
authors.lastname: Bolch
authors.forename: Choonsik
authors.initials: C
authors.lastname: Lee
authors.forename: Rui
authors.initials: R
authors.lastname: Qiu
authors.forename: Keith
authors.initials: K
authors.lastname: Eckerman
authors.forename: Beom Sun
authors.initials: BS
authors.lastname: Chung
mesh_terms: D000328:Adult; D003198:Computer Simulation; D004064:Digestive System / Q000528:radiation effects*; D005260:Female; D006801:Humans; D008297:Male; D009010:Monte Carlo Method; D019047:Phantoms, Imaging / Q000592:standards*; D011829:Radiation Dosage; D011835:Radiation Protection; D012137:Respiratory System / Q000528:radiation effects*; D014057:Tomography, X-Ray Computed / Q000379:methods*