Pregled bibliografske jedinice broj: 334372
Geometric models in dosimetry of thyroid remnant mass
Geometric models in dosimetry of thyroid remnant mass // Nuklearmedizin, 47 (2008), 3; 120-126 (međunarodna recenzija, članak, znanstveni)
CROSBI ID: 334372 Za ispravke kontaktirajte CROSBI podršku putem web obrasca
Naslov
Geometric models in dosimetry of thyroid remnant mass
Autori
Grošev, Darko ; Lončarić, Srećko ; Huić, Dražen ; Dodig, Damir
Izvornik
Nuklearmedizin (0029-5566) 47
(2008), 3;
120-126
Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni
Ključne riječi
Internal dosimetry; radioiodine ablation; absorbed fraction; Monte Carlo calculation
Sažetak
Aim: Absorbed dose to thyroid remnant tissue after 131I ablation becomes mass/size-dependent. This is a direct consequence of the small remnant size and radiation escape starts to be relevant. The self-absorbed fraction becomes mass/size-dependent. We have used Monte Carlo simulations to investigate the influence of the thyroid remnant shape upon the absorbed fraction calculation. Methods: Thyroid residue was modeled using spherical, cylindrical and elliptical shapes. Uniform beta activity distribution and unit density medium (water) within a remnant was assumed. For each of the geometrical models beta self-absorbed fraction (φ β ) was calculated using Monte Carlo codes, while the mean absorbed dose per unit cumulated activity (Sβ ) was calculated using MIRD formalism. Results: For spherical objects φ mono for mean beta energy (E = 0.182 MeV) of 131I is always greater than φ β calculated for the complete beta spectrum. For spheres having diameters 2– 6 mm and assumption φ β =1, Sβ is overestimated by 11– 37%. For cylinder and prolate spheroid of the same length and thickness, Sβ for cylinder is 30% smaller because of the greater mass. Similarly, elliptical cylinder and general ellipsoid of the same length and the same perpendicular dimensions (width and breadth), have similar φ β , while Sβ for elliptical cylinder is correspondingly smaller. Conclusion: For accurate dosimetry of thyroid remnants having masses <1 g and chordal lengths <1 cm it is necessary to calculate φ β for the full beta spectrum, or Sβ will be overestimated. The shape of the remnant may also be important since elongated non-spherical objects may also have φ β < 1.
Izvorni jezik
Engleski
Znanstvena područja
Fizika, Kliničke medicinske znanosti
POVEZANOST RADA
Projekti:
108-0362214-0127 - Korekcija gušenje zračenja u emisijskoj tomografiji srca (Dodig, Damir, MZOS ) ( CroRIS)
214-0362214-2055 - Kvantifikacija i parametrizacija akumulacije FDG-a pomoću PET-a (Lončarić, Srećko, MZOS ) ( CroRIS)
Ustanove:
Medicinski fakultet, Zagreb,
Klinički bolnički centar Zagreb
Citiraj ovu publikaciju:
Časopis indeksira:
- Current Contents Connect (CCC)
- Web of Science Core Collection (WoSCC)
- Science Citation Index Expanded (SCI-EXP)
- SCI-EXP, SSCI i/ili A&HCI
- Scopus
- MEDLINE
